Book of Abstracts - EMR2017 Conference

Book of Abstracts The Energy and Materials Research Conference - EMR2017 Lisbon (Portugal), 5-7 April 2017

The Energy and Materials Research Conference - EMR2017 Lisbon (Portugal), 5-7 April 2017

Introduction

VII

Plenary Lectures

IX

Session: Energy Production from Biomass – Biofuels

1

Biodiesel properties from okra seed oil using ultra-sonic trans-esterification Bio-oil deoxygenation from catalytic pyrolysis of Posidonia Oceanica Characterization and catalytic activity of calcium silicate based catalysts in methanolysis of sunflower oil Conversion of 5-hydroxymethylfurfural (HMF) to 2,5-Dimethylfuran (DMF) using Co based catalysts Effect of biomass pre-treatment and pyrolysis temperatures on key physicochemical properties of cypress sawdust-derived biochar Improving Microbial Fuel Cell efficiency by using of Modified Cathodes Increase of Energy Output by Rational Use of Sub Products at Ethanol Distilleries from Sugar Cane Issues regarding the use of bio-fuels and other types of renewable fuels for the purpose of reducing environmental pollution in Romania Modeling the need for solid biofuels for local heating in villages Natural antioxidants for biodiesel application New generation redox-active electrode materials for high-performance supercapacitor applications: Poly(3,6-dithienylcarbazole) derivatives Optimization of cellulase production from locally isolated Fusarium sp. and its application on enzymatic saccharification of corn husk Possibility of producing briquettes from cashew shell press cake Production of raw starch degrading amylase by Bacillus subtilis TLO3 and its application in bioethanol production from starch-rich flours Productive technologies of biogas and biodiesel fuel by transformation of energy from wastes of appearing in establishments of the public catering Prospective energy power of corncob husk and its biochars: Kinetic parameters and isoconventional models Pyrolysed lignocellulosic residues - biosyncrude for entrained flow gasification Pyrolysis of olive bone in a fluidized bed reactor: characterization of bio-oil and char Solid base heterogeneous catalysts for the synthesis of diethyl carbonate as an oxygenated fuel additive: synthesis, characterization and applications Sustainable utilization of bi-ecofriendly materials for CO2 capture The effect of ultrasound on the conversion of cellulose to 5-hydroxymethylfurfural The Importance of Bioenergy at Renewable Energies in Turkey The use of agro-industrial waste as antioxidant for biodiesel The use of biodiesel and its emulsions as pilot fuels for compression ignition engines dual-fuelled with NG Thermochemical conversion of a lignocellulosic waste by estimating the pyrolysis yield of its basic compounds

3 4

15

Session: Solar Energy / Wind Power / Geothermal Energy

29

A comparison between PI and SMC pitch angle control for standalone fixed speed wind energy system based on Self- Excited Induction Generator Advances the monitoring of photovoltaic systems - Use of the Internet of Things (IoT) of a photovoltaic installation Alkali polyphosphates as new materials for thermal energy storage An assessment on the impacts of the integration of photovoltaic power generations on the reliability of distribution networks

31

I

5 6 7 8 9 10 11 12 13 14

16 17 18 19 20 21 22 23 24 25 26 27

32 33 34


An energy-stored boost inverter for photovoltaic systems Conduction-Band Positions in Oxide Semiconductors (TiO2, SnO2): Experiments, Theory and Energy-Applications Corrosion of low-alloy steel in molten sodium nitrate at 340°C Czochralski and mono-like silicon solar cells p-type and n-type relationship between strain and stress reduced from the Al back contact and photovoltaic properties Digital charge controller for battery bench in a photovoltaic system Effect of Dust accumulation on the solar cells efficiency at Jazan region Energy, environmental and economic efficiency of solar photovoltaic in the central part of Europe EU resilience to potential supply bottlenecks along the rare earths value chain for the future deployment of wind power in the EU Experimental Study of a Plan Solar Still Region of Béchar, South Algeria Fabrication of Cu2ZnSn(S,Se)4 Thin Film Solar Cell by introducing a Carbon Intermediate Layer at the Absorber/Back Contact Interface Forward bias (EL) and reverse bias luminescence (ReBEL) imaging of silicon solar cells using a consumer grade camera High temperature hyperbolic metamaterial for selective thermal emitters in thermophotovoltaic (TPV) systems Improved performance of bulk-heterojunction solar cell embedding PbS nanoparticles with mixed surface-capping agents Influence of deposition methods on Cu2O thin films for solar cell application Influence of surface etching treatment for the high efficient Cu2ZnSn(S,Se)4 (CZTSSe) thin film solar cell Influence of zinc oxide morphology on hybrid solar cells Luminescent, structural and chemical characterization of defects in polycrystalline thin film solar cells Multi Role of Novel Ru Based Dye in Enhancing the Performance of Hybrid TiO2/P3HT Solar Cells New Geothermal Database for Hungary Optimized sizing of PV Battery standalone system (case study Tunisia) Photoelectrode morphology and kinetic processes in dye-sensitized solar cells with ionic liquid electrolytes Storing heat in hydration transitions: illustrated with K2CO3 Study of interdigitated back contact silicon heterojunctions solar cells by 2D- numerical simulations The formation of SnS thin films by physical vapor transport The outdoor performance of four different PV technologies in Poland TiO2 solar cells using natural extracts

35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Session: Fuel Cells

61

Analysis of the anode diffusion layer properties on a passive direct methanol fuel cell (DMFC) using electrochemical impedance spectroscopy (EIS) Cluster of boron as a liquid anodic fuel Corrosion of nickel-coated stainless steel for OER catalyst in alkaline electrolysis Electrochemical and degradation behaviour study of different SOFC compounds Electrochemical polymerization of polyaniline and polypyrrole modified carbon cloth anode for high performance of microbial fuel cells Imaging the formation of PtCu3/C clectrocatalyst by In-Situ Annealing Transmission Electron Microscopy Implantable glucose fuels cells - molybdenum phthalycayanine complexes as bio inspired oxidation catalysts

63

II

64 65 66 67 68 69


Improved Gas Diffusion in Solid Oxide Fuel Cells through using Cellulose Microfibrils as a Pore Formers in Electroless Co-Deposited Anodes Influence of the carbon support properties on the PdSn/C ethanol oxidation reaction in alkaline medium New electrocatalysts for PEM Fuel cell application based on platinum supported on nanostructured carbon support Pd/biocarbon electrocatalyst for ethanol oxidation reaction in alkaline medium: correlation between physicochemical properties an electrocatalytic performance in EOR by in-situ ATR-FTIRS Study on hydrogen production via diesel-hydrogen peroxide fuel processor for subsea applications The Relationship between Stability and Activity for Pt/C and PtM/C Electrocatalysts: the Role of Morphology and Architecture of Nanoparticles

70 71 72 73 74 75

Session: Hydrogen

77

3-D electrodes for large-scale electrochemical H2 production

79

All that glitters isn´t gold - Plasmonic coinage metal particles in visible-light driven H2 production watched by in situ spectroscopy Ammonia borane confinement in graphene oxide 3D structures for H2 storage Boron- and nitrogen-based compounds for chemical hydrogen storage Characterization of metal/oxide catalyst for methanol steam reforming synthesized by glycine-nitrate process Electric fields as means to improve the hydrogen storage capacity of metal-organic frameworks H+-reduction using SnIV-porphyrinoid molecules as photosensitizers in photocatalytic reaction Hydrogen production by ethanol steam reforming over supported CoNi catalysts Hydrogen Production by Pressurized Methanol Fuel Reformer utilizing Latent Heat Hydrogen production by the methane reforming with carbon dioxide on Mg-promoted Ni/H-Y zeolite catalyst Hydrogen production using ethylenediaminetetraacetic acid Improving dehydrogenation properties of MgH2 by addition of dihydrogen complexes Interesting Hydrogen Storage behaviour of volcanic powders Methods of increasing the production of bio hydrogen by genetically modifying E. coli strands Modeling of hydrogen absorption into magnesium Nanostructuring a means to control H-embrittlement of Pd films Physical and chemical destabilization of ammonia borane for an improved hydrogen storage system Pt and Pd deposition at the surface of nitrogen doped TiO2 - combined XPS and DFT study Recycled ZnO from zamak wastes as support of Ni catalyst. Preparation of highly active catalyst for the sustainable production of hydrogen by steam reforming of bioethanol Solid State hydrogen storage and production for mobility applications Stability and electronic structure of various metal hydrides - DFT insight Storage of hydrogen on modified active carbon The influence of high pressure hydrogen on the non-metallic materials in the hydrogen infrastructure Unexpected behaviour of novel complex hydrides under high static pressure

80 81 82 83 84 85 86 87 88 89 90 91 92 93-94 95 96 97 98 99 100 101 102 103

Session: Nuclear Energy and Materials / Energy Production from Fossil Fuels

105

Behavior of metallic uranium in cement and geopolymer matrices Cr-Ta multilayers as a potential coating material for fuel cladding in Gen III and Gen IV nuclear plants Development of Tritium Permeation Barrier coating for fusion TBM in CIAE Electrochemistry of Coal for Fuel Synthesis and Energy Storage

107

III

108 109 110


Formation of Fe-Al/Al2O3 Tritium Permeation Barrier Coating by a Low Temperature Pack Cementation and Subsequent Oxidation Process Interactions of coolants with hot-dip galvanized materials after loss-of-coolant accidents in pressurized water reactors Microstructure evolution of new nickel alloys in the operation of the test loop HWTI Molten Salt Reactor: Experimental approach and modelling of safety-related properties of the fluoride fuel Study on the fabrication and properties of the lithium orthosilicate pebbles by improved gel-casting method The chemistry of water on Cu(110) - a first principles investigation The problems of structure and properties degradation WWER-type nuclear reactor materials under neutron irradiation The selection of catalytic mixed packing for detritition of heavy water from Cernavoda Nuclear Power Plant Session: Energy Harvesting Materials / Energy Transmission, Distribution and Storage / Advances in Lighting Materials AlGaN-based UV lasers by electron beam pumping Applicability of polymeric materials for heat storages Assessment of a Magnetic Refrigeration, General Perspectives Battery-based DC-linked-type quasi-switched-boost inverter for ESS applications Comparative analysis of shore-to-ship and ship-to-shore synchronization strategy for high voltage shore connection systems Composite materials of conducting polymers and reduced graphene oxide for energy storing Development of a bifunctional manganese oxide-based catalyst for the oxygen electrochemistry in electrically rechargeable zinc-air batteries Electrochemical study of Na insertion into nanocrystalline Li4Ti5O12 Experimental Characterization of Fatigue Crack Initiation of Mineralized AA320 Alloy under CTC & ML during Four Point Rotating and Bending Fatigue Testing Machine Fabrication of GaN-based LEDs by pulsed sputtering Hot water stores in segmental construction: adhesive strength between sealing materials and segment coatings Low temperature Energy harvesting from waste used tires Mg- and Zn-doped GaN nanostructured thick films by HCVD Preparation of a glass based separator for lithium-ion batteries Renewable Energy Based Microgrids for Sustainable Development in The Western Balkans Safe Lithium-ion Battery Electrolytes based on Organic Carbonates Study of Nusselt number evolution in PCM shell-and-tube configuration Synthesis of CdS/CdSe core-shell heterostructure nanowires towards solar cells application The Analysis of the Number of the Resonator about the Air Intake System Thermochemical storage composites: impact of salts and supports Session: Energy-Efficient Buildings Materials / Materials, Processes and Systems for Energy Saving and Sustainability A guide presenting strategies for the application of renewable energy in existing buildings Capitalization of the renewable potential energies of coastal areas in integrated systems Complex system for electricity production based on the cumulative effect of different sources of renewable energy Dry lithiation process for all-solid state electrochromic devices

IV

111 112 113 114 115 116 117 118 119 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 143 144 145 146


Electrochemical synthesis of Cu3(BTC)2 metal organic framework for CO2 and CH4 adsorption Energy characterization and classification of apartment buildings in Algeria Evaluation of a dual system of motive power and refrigeration Global energy sustainability: brief analysis of World Energy Trilemma and prospective scenarios as tools for discussion Innovative evaporator designs enable increased process energy efficiency Investigation of the ionic conductivity mechanism of LiNbO3 thin films by EIS method Materials for energy Mycelium Acoustics (Phase 1) - Exploring the acoustic properties of mycelium based bio-composites Particulate Solid Waste for Dye Removal and Degradation in Effluents: A Doubly Beneficial Strategy for the Environment Photochemical reduction of Cr (IV) in aqueous solution containing Na4W10O32 Surface modification and sulfur-rich functionalization of microporous carbons for elemental mercury adsorption Tetrahedrite-based Materials as a Source of Sustainable Energy The Conservation of the Energy by the Use of Local Materials in Buildings The effect of different aggregate grading on the properties of normal and lightweight pervious concretes Using Osmotic Dehumidification to Enable Evaporative Cooling in Humid Climates Performance of fuel cell integrated system and packed-bed reactor for electric energy generation

V

147 148 149-150 151 152 153 154 155 156 157 158 159 160 161 162 163


INTRODUCTION This book contains a selection of the abstracts that were accepted for presentation at The Energy & Materials Research Conference (EMR2017), which was held at the Rectorate of Nova Lisboa University in Lisbon, Portugal, from April 5th to 7th, 2017. The EMR conference series aims at bringing together researchers and professionals from a broad set of science and engineering disciplines with the aim of sharing the latest developments and advances in materials, processes and systems involved in the energy generation, transmission-distribution and storage. This third edition of the EMR conference gathered around 160 participants, coming from more than 40 countries. And more than 150 works were presented at the conference. The organization called for research papers dealing with the following topics:  Biomass - Biofuels:

Extraction of biomass materials. Development/Improvement/Performance of materials for biomass systems/plants for heat & power and biofuels production (combustion, gasification, pyrolysis, anaerobic digestion, fermentation and composting). Materials/Coatings of biomass combustion chambers. Materials for capturing CO2. Second generation of biofuels. Corrosion resistant materials for biofuel processing. Materials, processes and systems for water filtration and desalination in biofuels production. Materials for biofuels storage…  Solar Energy:

Photovoltaics (PV). Concentrating photovoltaics (CPV) and high concentration photovoltaics (HCPV). Concentrating Solar Power (CSP) and Solar Thermal…  Fuel Cells:

Novel high-performance materials for components and systems in PEM, solid oxide, microbial, alkaline, direct methanol, phosphoric acid, molten carbonate and regenerative fuel cells. Anode, cathode and electrolyte materials. Development of new materials for fuel cell catalyst. Nanotechnology. Nanocomposite catalyst. Degradation of fuel cell components. Identification of fundamental corrosion mechanisms. Recycling of fuel cell materials…  Hydrogen:

Materials for hydrogen production and purification • Characterization and analysis of high capacity materials for hydrogen storage. Carbon nanostructures. Metal hydrides. Low-cost materials resistant to hydrogen embrittlement. Materials for hydrogen vehicles. Materials for hydrogen infrastructure: pipeline transport, tanks, etc. Biohydrogen…  Wind Power:

Development/Improvement of advanced materials for high-speed, high volume processing, increasing gearing efficiency and harsh environments. Materials/Coatings/Methods to reduce fatigue and erosion-corrosion in constituent materials, sub- components and major structures. Rare earth metals in wind turbines. Nanoreinforcements…  Geothermal Energy:

Development/Improvement of materials resistant to hot corrosion, for drilling hard rock. Nanotech materials for geothermal energy…  Hydropower. Wave and Tidal Power:

Development/Improvement of materials resistant to high pressure, abrasion and corrosion for water turbines. Construction materials in dams, hydroelectric power plants. Materials/Coatings/Methods to reduce fatigue and corrosion in constituent materials, sub-components and major structures. New materials and methods for energy-efficient tidal turbines…

VII


 Nuclear Energy and Materials:

Development/Improvement of structural materials capable of operating at high temperatures, resistant to radiation damage, corrosion, environmental degradation, etc. Development of advanced ceramics and coatings for fuels. Development/Improvement of materials to contain nuclear waste. Radioactive elements used in nuclear power plants. Uranium mining and processing. Radiation detector materials. Advanced materials developed by computational modeling tools…  Energy Production from Fossil Fuels:

Materials for fossil fuel extraction. Research into advanced materials and coating techniques to increase the efficiency of power plants. Materials for construction of advanced ultra-supercritical plants. New methods and materials for CO2 storage and sequestration…  Energy Harvesting Materials:

Piezoelectric, thermoelectric and pyroelectric materials (ceramics, single crystals, polymers, composites…)  Energy Transmission, Distribution and Storage:

Materials for energy transmission and distribution. Materials for mechanical storage (compressed air storage, flywheel energy storage, etc.). Materials for electrical storage. Materials for electrochemical storage. Materials for thermal storage. Materials for chemical storage: hydrogen storage, biofuels storage…  Advances in Lighting Materials:

Materials for energy-efficient lighting  Energy-Efficient Buildings Materials:

Integration of renewable energy systems in buildings, phase-change materials for walls, floors and roofs, insulation materials, smart windows, energy-efficient lighting systems, appliances with Energy Star ratings…  Materials for Energy Saving and Sustainability  Other Topics

The regular conference program was complemented with two Plenary Lectures: “Current status on advanced lignocellulose conversion to bioethanol and higher alcohols as biofuels” by Francisco Gírio, from the National Laboratory of Energy and Geology (LNEG), Portugal “Interpretation of kinetic processes governing the operation of perovskite solar cells” by Juan Bisquert, from the Institute of Advanced Materials, Jaume I University, Castellón, Spain

We hope readers will find the content of this second edition of the conference inspiring and stimulating and look forward to seeing another fruitful edition in 2019. A. Méndez-Vilas EMR2017 General Coordinator Formatex Research Center C/Zurbarán 1, Planta 2, Oficina 1 06002 Badajoz Spain

VIII


Current status on advanced lignocellulose conversion to bioethanol and higher alcohols as biofuels Francisco Gírio LNEG – Laboratório Nacional de Energia e Geologia, Estrada do Paço do Lumiar, 22, Ed. F, 1649-038 Lisboa, Portugal

Significant advances have been achieved in the past several years in all aspects of lignocellulose conversion into ethanol. Companies such as Beta-Renewables/Biochemtex (Crescentino, Italy), Inbicon/Dong Energy (Kalundborg, Denmark), Abengoa (Babilafuente, Spain), Clariant (Straubing, Germany) in Europe; Abengoa (Hugoton, Kansas), Dupont (Nevada, Iowa) and POET-DSM (Emmetsburg, Iowa) in USA; Iogen Corporation in Canada; GranBio (Alagoas) and Raízen (Piracicaba) in Brazil, are giving the first steps as major players to commercialize cellulosic ethanol. The existent commercial, demonstration and pilot plants are essencial industrial platforms to overcome bottlenecks and barriers to full commercialization of 2G bioethanol in the near future. This talk shall give an overview of challenges and also some of the recent achievements on improving the lignocellulosic ethanol and higher alcohols production as biofuels for transportation sector.

IX


Interpretation of kinetic processes governing the operation of perovskite solar cells Juan Bisquert Institute of Advanced Materials, Universitat Jaume I, Castelló, Spain * Corresponding author: email: [email protected]

The surge of organic-inorganic lead halide perovskites with very large efficiency has opened up the interest to understand the operation of the solar cell, in terms of physical photovoltaic processes. We have used the measurement of impedance spectroscopy in combination of voltage ramps and we present a series of insights about the physical processes occurring in perovskite solar cells in photovoltaic operation. Apart from the remarkable bulk properties of this class of semiconductors, it has been realized that the contacts are a key aspect of the operation and show dynamic interactions. We start from the distinction between capacitive and noncapacitive hysteresis, we provide an interpretation of capacitances as a function of frequency both in dark and under light, and we discuss the meaning of resistances and how they are primarily related to the operation of contacts. We aim to present a global view of kinetic processes governing the operation of the solar cell, combining electronic and ionic transport, recombination, interfacial barriers, and influence of morphologies and compositions.

X

Energy Production from Biomass – Biofuels


Biodiesel properties from okra seed oil using ultra-sonic trans-esterification S.A. Moosavi1, M. AghaAlikhani1 and B. Ghobadian2 1 2

Department of Agronomy, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran Department of Bio systems Engineering, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran

Concept of renewable and clean energy find a great interest in Iranian energy sector [1]. This is motivated primarily by environmental concerns about greenhouse gas pollution and global climate change. There is also great potential in job making for young people and improving economic condition of society. Okra (Abelmoscus esculentus L.) is an annual warm season crop which recently find interests as a new source for oil and protein [2], [3]. In this study an ultra-sonic reactor was used to perform trans-esterification reaction of oil in presence of methanol and KOH (Fig1). Results revealed that Iranian okra ecotypes with average seed yield as 1800 kg.ha -1 containing 20% of oil content and total oil yield could reach to 360 kg.ha-1. The most dominated fatty acids were linoleic acid (C18:2) (38-40%), Palmitic acid (C16:0) (29-30%) and Oleic acids (C18:1) (19-22%). Biodiesel derived from okra seed oil by trans-esterification reaction using ultrasonic system could meet ASTM D6751 (American Society for Testing Materials- D6751 standard) with satisfactory results in methyl ester content (more than 96%), viscosity (2.3-2.4 mm2.S-1) and flash point (155-158oC). Therefore according to large ecological adaptation window, high seed yield and good oil quality, okra could well be place as a new source of non-edible oil for biodiesel production in bioenergy farms.

Fig 1 Conversion of extracted okra seed oil to biodiesel using Ultra-sonic trans-esterification reactor. Keywords: Abelmoschus esculentus; Biodiesel; Biofuel; Energy References [1] B. Ghobadian, “Liquid biofuels potential and outlook in Iran,” Renew. Sustain. Energy Rev., vol. 16, no. 7, pp. 4379– 4384, 2012. [2] R. Sami, J. Lianzhou, L. Yang, Y. Ma, and J. Jing, “Evaluation of fatty acid and amino acid compositions in okra (Abelmoschus esculentus) grown in different geographical locations,” Biomed Res. Int., vol. 2013, 2013. [3] B. S. Dhankhar and R. Singh, Okra handbook: Global production, processing, and crop improvement. HNB publishing. 2009.

3


Bio-oil deoxygenation from catalytic pyrolysis of Posidonia Oceanica S. Maisano, F. Urbani, N. Mondello and V. Chiodo CNR-ITAE, Institute for Advanced Energy Technologies “N. Giordano”, Via Salita S. Lucia sopra Contesse, 5-98126, Messina, Italy

In the last years, interest on energy alternative sources is increasing. In particular, among renewable fuels, the employment of biomass and biofuels (biogas, ethanol, glycerol, organic waste, etc…) as raw feedstock for energy production, through gasification and pyrolysis technologies are often proposed. Pyrolysis is a promising process for to convert biomass into liquid fuels (bio-oil) mainly due to its low capital and operating cost advantages compared to competing technologies, such as: thermal-acidic, organic solvent extraction, transesterification, fermentation or gasification. The pyrolysis bio-oil can be potentially used for direct combustion in energy generation, or can be upgraded further into liquid transport fuels and bio-chemicals. In particular, the catalytic “in situ” cracking pyrolysis is a promise process that produces directly a pyrolysis upgrated bio-oil. This means that the bio-oil is produced with high acidity, oxygen content and grater low heating value. Hence, the use of different catalytic materials (HZSM-5, CeO2, Ni-based catalyst) were proposed in literature to promote the conversion both biomass and biofuels (i.e. biogas) [1]. Further, Ni catalysts combined with Cerium oxides resulted very active into deoxygenation reactions for production of high-quality bio-oil from algae [2]. In this context, many papers are present in literature on catalytic biomass pyrolysis for bio-oil production however, researches on effect of catalysts on pyrolysis process apply to sea plants are really scarce [3]. Thus, the main objective of this work was to investigate about the feasibility to produce high-quality bio-oil from a Mediterranean Sea plant (Posidonia Oceanica) by pyrolysis process. First, experiments of pyrolysis at 500 °C in a fixed bed reactor were carried out in order to investigate about yields of the reaction in terms of bioproducts (bio-oil, bio-char and syngas) selectivity. Furthermore, the bio-oil obtained was analysed in terms of oxygen and organic compounds content. Successively, effects of different “home-made” Ni, Ce, HZSM-5 based catalysts on bio-oil yield and bio-oil oxygen content were evaluated. Results highlighted that the bio-oil coming from catalytic pyrolysis of Posidonia Oceanica has a lower content of acids and oxygen and high hydrocarbons and HHV values. In particular, using CeO2 catalyst was recorded the highest bio-oil yield (51.15 wt.%) and the lowest bio-oil oxygen content (6.87 wt.%). Though, the best composition in terms of hydrocarbons content (34.18 %), detected by GC-MS, was obtained by Ni/HZSM-5 catalyst. Keywords: Catalytic pyrolysis; Bio-oil; Posidonia Oceanica; Bio-fuels References [1] S. Cheng, L. Wei, X. Zhao, Y. Huang, D. Raynie, C. Qiu, J. Kiratu, Y. Yu, Directly catalytic upgrading bio-oil vapor produced by prairie cordgrass pyrolysis over Ni/HZSM-5 using a two stage reactor, AIMS Energy 3 (2015) 227-240 [2] T. Aysu, A. Sanna, Nannochloropsis algae pyrolysis with ceria-based catalysts for production of high-quality bio-oils, Bioresource Technology 194 (2015) 108–116 [3] V.Chiodo, G. Zafarana, S. Maisano, S. Freni, F. Urbani, Pyrolysis of different biomass: Direct comparison among posidonia Oceanica, Lacustrine Alga and White-Pine, Fuel 164 (2016) 220-227

4


Characterization and catalytic activity of calcium silicate based catalysts in methanolysis of sunflower oil Ž. Kesić1, I. Lukić1, M. Zdujić2 and D. Skala1 1 2

University of Belgrade, Faculty of Technology and Metallurgy, Karnegijeva 4, 11000 Belgrade, Serbia Institute of Technical Sciences of the Serbian Academy of Sciences and Arts, Knez Mihailova 35, 11000 Belgrade, Serbia

The transesterification of sunflower oil with a calcium silicate catalysts was investigated in order to produce fatty acid methyl esters (FAME or biodiesel). Biodiesel represents an alternative to petroleum diesel and contributes to the reduction of the CO2 emissions. Mechanochemical synthesis has a prospective application in catalysis due to its advantages, such as simple process and ecological safety. Catalysts were synthesized from CaO, SiO2 and water by mechanochemical treatment in a planetary ball mill, followed by subsequent calcination at 900ºC in air atmosphere for 48 h. In order to examine the role of the molar ratio of the starting powders, the CaO/SiO2 molar ratio of the samples was varied in the range of 1–3. The prepared catalysts were characterized by X-ray diffraction (XRD), basic strength using Hammett indicator method and Fourier transform infrared (FTIR) spectroscopy. On the basis of the data obtained, it can be concluded that mechanical activation of the mentioned mixtures, followed by calcination leads either to partial interaction (multiphase system) or to total interaction (single phase is obtained). All the catalytic experiments were carried out in a temperature range from 60 to 160ºC, with the molar ratio of methanol to sunflower oil of 10:1 and with 2 wt% of catalyst based on oil weight. Effects of free CaO content on the yield of FAME were also investigated. Keywords: biodiesel; mechanochemistry; heterogeneous catalyst

5


Conversion of 5-hydroxymethylfurfural (HMF) to 2,5-Dimethylfuran (DMF) using Co based catalysts Merve Esen, Esra Sezgin, Solmaz Akmaz, Serkan Naci Koç and M. Ali Gurkaynak Department of Chemical Engineering, Faculty of Engineering, Istanbul University, 34320 Avcılar, Istanbul, Turkey

5-Hydroxymethylfurfural (HMF) is formed by the removal of three water molecules from hexoses in the presence of acid catalyst. HMF is one of the important intermediate products of cellulosic materials to obtain fuels and chemicals. Recently, energy demands have increased with the development of industry and population in the world. Especially, due to the growth of transporting fuel consumption in the last few decades, the development of alternative fuels is required to supply energy demand. 2,5-Dimethylfuran (DMF) has an important potential as a sustainable and renewable liquid fuel. 2,5-Dimethylfuran (DMF), a non-toxic fuel with a high energy density suitable for modern automobile engines, are produced by catalytic hydrogenation of HMF [1].

Fig. 1 The conversion of HMF to DMF.

Since over-all hydrogenation reaction of HMF consists of a number of steps in series, catalytic activity, temperature and hydrogen pressure are important parameters in terms of DMF selectivity. Especially, the type of catalyst is very effective on DMF selectivity. In the recant years, many studies focused on the development of hydrogenation catalyst for converting of HMF to DMF. Ru-based catalysts are commonly known catalysts for synthesis of DMF and researches are going on for alternative catalysts to obtain high DMF yields [2,3]. In this study, Co-based catalysts were prepared by precipitation method for HMF hydrogenation to DMF. Hydrogenation reactions were carried out in a stainless steel reactor at 130-180 oC for 6 hours using THF solvent. Hydrogen pressure effect on the reactions was also investigated. After reactions, HMF and DMF were analysed by GC-MS. Catalysts were also characterized by X-Ray Diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and BET analysis. Co catalyst is efficient on hydrogenation of HMF but DMF yield was increased by using cobalt catalyst with other transition metals. Keywords: 5-hydroxymethylfurfural; 2,5-Dimethylfuran Acknowledgments: This study was supported by The Scientific and Technological Research Council of Turkey (TUBITAK), Project No: 214M149. References [1] Dutta, S., Pal, S. 2014. “Promises in direct conversion of cellulose and lignocellulosic biomass to chemicals and fuels: Combined solventenanocatalysis approach for biorefinary”, Biomass and Bioenergy, 62, 182-197 [2] Zu, Y.H., Yang, P. P., Wang, J. J., Liu, X. H., Ren, J. W., Lu, G. Z., Wang, Y. Q. 2014, “Efficient production of the liquid fuel 2,5-dimethylfuran from 5-hydroxymethylfurfural over Ru/Co3O4 catalyst.”, Appl. Catal., B, 146, 244−248 [3] Hu, L., Tang X., Xu, J., W., Zhen, Lin, L., Liu, S. 2014. “Selective Transformation of 5‑Hydroxymethylfurfural into the Liquid Fuel 2,5-Dimethylfuran over Carbon-Supported Ruthenium”, Ind. Eng. Chem. Res, 53 (8), 3056–3064

6


Effect of biomass pre-treatment and pyrolysis temperatures on key physicochemical properties of cypress sawdust-derived biochar K. Haddad1,2, M. Jeguirim1, S. Jellali2 and L. Limousy1 1 2

Institut de Science des Matériaux de Mulhouse, 15, rue Jean Starcky, BP 2488, 68057 Mulhouse cedex, France Water Research and Technologies Centre (CERTE), Wastewaters and Environment Laboratory, Echo- park of Borj Cédria, B.P. 273, 8020, Soliman, Tunisia

Lignocellulosic biomasses (LB) have great and proven potential as renewable energy sources. LB Pyrolysis operation has been identified as a promising thermochemical conversion technique. It is considered also as an attractive technology for the production of bio-oil fuels, biogases and biochars. The LB often contains variable amounts of alkali and alkaline earth metallic (AAEM) species such as potassium, sodium, calcium and magnesium. These species (Na, K, Mg and Ca) taken up by biomass during its growth can be recycled or returned to soils via the use of the produced biochars for agricultural purposes as amendments. Reports regarding the impact of AAEM species on physical and chemical proprieties of biochar are fairly limited. In this study, the effects of the AAEM species addition to LB and the used pyrolysis temperatures on both the yields and the physicochemical proprieties of biochars were explored. The biochars were produced from the pyrolysis of raw, washed and impregnated cypress sawdust with Na, K, Mg and Ca at five temperatures (400, 500, 600, 700 and 800 °C). The experimental results obtained from the pyrolysis of the different cypress sawdust samples demonstrated that the biochar yield was extremely dependent on the temperature and the added mineral. As an example, for biochar produced from the raw sawdsut (RS-char) this percentage decreased from about 33.5% to 25.3% when the pyrolysis temperature was increased from 400°C to 800°C. The same tendency was observed for wasched and AAEM-impregnated samples. For the washed sample the produced biochars yields decreased regardless of temperature. This difference is attributed to the increase of volatiles compounds emissions for the washed sample. Such behavior may be attributed to the AAEMs effects on the secondary reactions that favor char formation via the catalytic cross-linking reactions [1]. On the other hand, X-Ray fluorescence analyses showed that the majorities of the AAEM species (Ca, Mg, K, and Na) were retained by the biochars while substantial amounts of S and Cl are released during the pyrolysis operation. Under such pyrolysis conditions (high temperature), the interactions between volatiles and pyrolysis biomass particles were minimal; therefore the effect of volatile-biochar interactions was relatively small. The Ca is the dominant inorganic component in all biochars. The surface properties of all the tested biochars showed that the total alkaline content increased with pyrolysis temperature leading to higher, pH and electrical conductivity. It is worth mentioning that the addition of potassium and sodium induced a significant effect on the pH of zero-point charge values since it increased from about 7.1 for RS-char to 8.2 for K-char for a pyrolysis temperature of 600°C. The surface properties of all produced biochars were studied through various analytical procedures. The Raman spectroscopy analysis showed that as the pyrolysis temperature increased, the content of small polyaromatic structures with aliphatic and oxygenated groups decreased significantly and the chars became more aromatic with cross-linked structures. Furthermore, the BET analyses showed that the use of higher pyrolysis temperature generally leads to a significant increase of biochars the surface areas For instance, the surface area of the biochar obtained from raw and washed cypress sawdust gradually increased as the pyrolysis temperature increased from 400 to 800 °C while the surface areas of biochar produced from the impregnated sawdust (K-char, Na-char, Mg-char and Cachar) decreased from 700°C. The former behavior was attributed to the ash content in the biochar, which might partially fill or block the access to micropores, resulting in a relatively lower surface area [2]. Keywords: Cypress sawdust; AAEM species; pyrolysis; biochar; textural properties References [1] Y. Zhao., D .Feng, Y. Zhang, Y. Huang, S. Sun, “Effect of pyrolysis temperature on char structure and chemical speciation of alkali and alkaline earth metallic species in biochar”. Fuel Processing Technology 116 (2015) 149–157. [2] K. Jindo, H. Mizumoto, Y. Sawada, M. A. Sanchez-Monedero, and T. Sonoki,“Physical and chemical characterization of biochars derived from different agricultural residues” Biogeosciences, 11, (2014 )6613–6621.

7


Improving Microbial Fuel Cell efficiency by using of Modified Cathodes Mehrdad Mashkour, Mostafa Rahimnejad* and Ali Ghoreyshi Biofuel and Renewable Energy Research Center, Department of Chemical Engineering, Babol Noshirvani University of Technology, Babol, Iran * Corresponding author: email: [email protected], [email protected]

Finite resources of the world’s fossil fuel give rise to the irresistible urge to explore for renewable energy supplies such as solar, wind and the one produced by microbial activities. Microbial fuel cells (MFCs) are unique bioprocess for the conversion of chemical energy restored in organic compounds to power generation by active microorganism while the microorganism utilizes organic or inorganic substrate for growth. In this study, two chamber MFC was designed and applied. The main focus was on cathode improvement to obtain higher power density. Carbon paste electrode (CPE) was used as bare cathode and it was hence modified by titanium dioxide (TiO2) and nano graphene oxide (NGO). These modifications resulted in a considerable improvement in the MFC performance. The enhanced power density of 80 mW/m2 for CPE- TiO2 and 220 mW/m2 for CPE-GO (80% Pt coated cathode) were observed with respect to that of ~ 30 mW/m2 for CPE. This is due mainly to positive effects of TiO2 and NGO on cathodic chamber electrochemical reaction. Additionally, NGO reached 80% of power produced by Pt coated cathode. And it can be used as an alternative to Pt. Keywords: Active catalyst; Power generation; Microbial fuel cell; Cathode; Titanium dioxide; Nano graphene oxide

8


Increase of Energy Output by Rational Use of Sub Products at Ethanol Distilleries from Sugar Cane Adrianus van Haandel1 and Jules B. van Lier2 1 2

Universidade Federal de Campina Grande, Av. Aprígio Veloso, 882, Bodocongó,58.970-000, Campina Grande-PB, Brazil Department of Water management, Section Sanitary Engineering, Delft University of Technology, P.O. Box 5048, 2600 GA Delft, The Netherlands and Unesco-IHE, P.O. Box 3015, 2601 DA Delft, The Netherlands

Under suitable conditions sugar cane is a fast growing plant with relatively efficient energy accumulation. The chemical energy content in sugar cane is about 6900 KJ per ton of cane and is roughly equally divided in three fractions: (1) juice, the liquid part; (2) bagasse, the fibrous part of stalks; and (3) straw, the leaves and tops of cane. However only the juice has productive use as a raw material for sugar and alcohol production, whereas bagasse has limited utility as an energy source for power generation and straw is left on the fields for the greater part and has no use. In this paper it is shown that there are possibilities of increasing the output of useful products, especially energy, if adequate processes are applied. Fermentation of cane juice leads to the generation of waste water called stillage or vinasse, which is spread on the cane fields, thus recycling its nutrients. However vinasse is very rich in soluble biodegradable material and anaerobic digestion can be applied to generate biogas while concomitantly reducing the environmental impact of distilleries. The stoichiometric potential of producing 9 kg of methane per ton of cane (tc-1) has been shown to be technically feasible and can generate electric energy at a rate of 45 kWh·tc-1 for a conversion efficiency of 40%, which is 50 % more than the energy demand of distilleries. Presently bagasse is burnt at sugar mills and distilleries for the generation of electric energy with boilers and steam turbines The best available equipment can produce 100 kWh·tc-1 at the maximum conversion efficiency of 16%. However, as shown in this paper, alternative routes can yield a much higher energy production. Application of anaerobic digestion after suitable pre-treatment (especially steam explosion) can increase the energy production potential to 150 kWh.tc-1. Another 150 kWh·tc-1 can be added to the distillery’s energy output from cane straw. Thus, with proven technology, the energy output obtained from sub products of ethanol distilleries from can be increased by 45 (vinasse) + 150 (bagasse) + 150 (straw) = 345 kWh per ton of cane. To put this number into perspective, it can be compared with the actual electric energy demand in Brazil, which is about 500 TWh per annum. Currently the production rate of sugar cane in Brazil is about 720 million tc·per annum with an electric energy production potential of 720*345 = 250 TWh·per annum from vinasse and bagasse and straw. Hence, this represents 50% of the national demand. Another very promising source of energy production is the use of photosynthetic ponds to produce algae from the nutrients in the effluent of the anaerobic digesters for vinasse and bagasse and carbon dioxide that is released during juice fermentation and methane combustion. The algae biomass can be converted into biodiesel by separation from the water phase, extracting the fat from the algae and then apply transesteriphication with ethanol to produce biodiesel. The stoichiometric production potential of biodiesel as an automotive fuel is almost equivalent to that of ethanol. While the technical feasibility of these processes has been demonstrated at lab scale, large scale production of biodiesel from sub products of ethanol distilleries has not yet been carried out, so that the economic feasibility has not yet been established. Keywords: Ethanol distilleries; sub products; vinasse; bagasse; straw; anaerobic digestion; electric energy; biodiesel

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Issues regarding the use of bio-fuels and other types of renewable fuels for the purpose of reducing environmental pollution in Romania A.I. Daescu, D. Fronescu, V. Daescu, M. Raischi and G. Deák National Institute for Research and Development in Environmental Protection, 294 Splaiul Independenței, 6th District, 060031, Bucharest, Romania

The use of bio-fuels and other types of renewable fuels is promoted for transport with a view to partly replace gas and gas-oil and facilitate the achievement of certain objectives such as: - meeting the obligations regarding the reduction of greenhouse gas emissions, - ensuring the safety of fuel provisioning in a friendly environmentally manner as well as increasing the degree of energetic independence, - promoting the use of renewable energetic sources.[1] The use of bio-fuels could also generate new opportunities for sustainable rural development that shall allow the opening of new markets for agricultural products. In conformity with the Energetic Policy of Europe, the Commission proposed the consolidation of the legislative framework which stipulates the attaining of 20% bio-fuels share on the market until 2020, by presenting policies to stimulate the production and the use of bio-fuels at European level. In Romania, suppliers of fuels are obliged to introduced on the market only gas and gas-oil containing bio-fuels through the decision no. 935 from 21 September 2011 regarding the promotion of the use of bio-fuels and bioliquids. [2] This paper tries to draw attention to the stage of bio-fuels use at national, European and international level from the legislative as well as from the technical and economic points of views related to the environmental impacts for the purpose of increasing public awareness on bio-fuels use. Keywords: bio-fuels ; renewable fuels ; environmental pollution References [1] Chintoana N., Naghiu AL, Naghiu L, 2009, Sources of biomass to produce bio energy (I), agriculture, science and practice, 1-2 (69-70), 112-116 [2] Decision no. 935 from 21 September 2011 (revised on 6 january2014) regarding the promotion of the use of bio-fuels and bio-liquids.

10


Modeling the need for solid biofuels for local heating in villages K. Vávrová1, J. Weger1, J. Knápek2, M. Valentová2, T. Králík2 and J. Beranovský3 1

Silva Taroucy Reaserch Institute for Landscape and Ornamental Gardening, Průhonice, Czech Republic Czech Technical niversity in Prague, Faculty of Electrical Engineering, Prague, Czech Republic 3 EkoWatt, Prague, Czech Republic 2

The article focuses on the methodology for determining the amount needed for production of solid biofuels from specifically grown biomass, or residual biomass from conventional agriculture and forest harvesting for local heating of residential and municipal buildings in small villages. Solid fuels produced from biomass - pellets / briquettes - serve as a substitute for previously used fossil fuels - especially coal - still massively used in the countries of Central Europe for local heating in rural areas. When designing a system of production of biofuels based on locally available biomass, in addition to mapping biomass potential, a key issue is determining the amount of required biofuels in relation to age, mode of use and the pace of renovation of existing buildings, or construction of new buildings. The methodology developed for simulating future need for solid biofuels divides existing and new housing stock into categories based on thermo-technical characteristics of buildings with regard to their mode of use (permanent housing, recreation, municipal, etc.). The methodology respects the expected development of the refurbishment of buildings in the next 20 years, which is the expected lifetime of pelletizing and combustion plants. The methodology also allows the mapping of need for solid biofuels in the course of the year. The methodology includes quantification of heating costs. Application of the methodology allows dimensioning systems for production of solid biofuels for the particular municipality based on locally available biomass and quantifying the necessary capital and operating costs. The article also presents an application of the methodology in a case study on the Czech Republic. Keywords: Biomass; biofuels References [1] Vávrová K., Knápek J., Weger J. (2017): Short-term boosting of biomass energy sources – Determination of biomass potential for prevention of regional crisis situations. Renewable & Sustainable Energy Reviews 67(2017): 426–436. http://dx.doi. org/10.1016/j.rser.2016.09.015 [2] Vávrová, K., Knápek, J. (2012): Economic Assessment of Miscanthus Cultivation for Energy Purposes in the Czech Republic. Journal of the Japan Institute of Energy, Vol. 91, 6, ISNB 0916-8753. pp. 485. [3] Vávrová K., Knápek J., Weger J. (2014): Modeling of biomass potential from agricultural land for energy utilization using high resolution spatial data with regard to food security scenarios. Renewable & Sustainable Energy Reviews 35(2014): 436–444.

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Natural antioxidants for biodiesel application G.R. Scaburi1, M.G.P. Valenga1, G.P. Pavanello1, G.A.R. Maia2, G.O. Machado1,3 and P.R.P. Rodrigues1,2 1

Programa de Pós-graduação em Bioenergia, Universidade Estadual do Centro-Oeste, Rua Simeão Camargo Varela de Sá, 03, 85040-080, Guarapuava – Brazil 2 Departamento de Química, Universidade Estadual do Centro-Oeste, Rua Simeão Varela de Sá, 03, 85040-080, Guarapuava - Brazil 3 Departamento de Engenharia Florestal, Universidade Estadual do Centro-Oeste, Campus de Irati PR 153 Km 7,84500-000 Irati - Brazil

Biodiesel is originated from renewable sources and have efficiency like diesel, because it comes from unsaturated fatty acids, which accelerate this biofuel oxidation process[1]. The natural intemperisms can alter this biofuel properties [2]. The antioxidants addition in biodiesel aims to increase the storage time and consequent life time. The main natural antioxidants are ascorbic acid, citric acid, retinol and tocopherol, in addition to other compounds [3]. The main objective of this work is to verify the natural antioxidants synergy obtained by acid extraction of Candeia (Eremanthus erythropappus) residues associated with citric acid in pure biodiesel. For this work the methods used was Rancimat Oxidative Acceleration (Metrohm®) EN 14112 (at110 °C), experimental design with simplex-centroid planning for three componentes (with three repetitions at the central point, with 2q-1, where “q”is the number of components), mixtures combinations, specific mass determinations, flash point, electrical conductivity, pH, material characterization through Scanning Electron Microscopy (SEM) and Infrared Spectroscopy. The oxidative acceleration results show that the presence of antioxidants has a better response when 0.5 g L-1of Candeia and 0.05% (m/v) of citric acid (BC05AC005) are added, with 11.83 hours of mean induction time. The samples BC1AC0 (with 1 g L-1of Candeia and without citric acid), BC0AC01 (without Candeia and with 0.1% (m/v) of citric acid) and BC1AC01 (1 g L-1 of candle and 0.1 % (m/v) of citric acid) presented, respectively, results of 7.11 hours, 5.85 hours and 7.27 hours. As required by National Petroleum Agency (ANP), resolution 45/2014 [4], oxidation stability at 110°C should be at least 8 hours, while the European Standard EN 14214 [5] requires a minimum of 6 hours. Thus, sample BC05A005, as shown in Figure 1, accord both legislations, samples BC1AC0 and BC1AC01 accord only the European standard.

Fig. 1 Mean oxidative stability of the samples. Keywords: bionergy; oxidative stability Acknowledgments: To Fundação Araucária, CNPq, CAPES, FAU – UNICENTRO for the financial support. References [1] FOCKE, W. W.; WESTHUIZEN, I. V. der.; GROBLER, A. B. L.; NSHOANE, K. T.; REDDY, J. K.; LUYT, A. S.; The effectofsyntheticantioxidantsontheoxidativestabilityof biodiesel. Fuel. Vol. 94, 227–233, 2012. [2] BORSATO, D., DALL’ANTONIA, L.H., GUEDES, C.L.B., MAIA, E.C.R., DE FREITAS, H.R., MOREIRA, I., E, K.R. Aplicação do delineamento simplex-centroide no estudo da cinética da oxidação de biodiesel B100 em mistura com antioxidantes sintéticos. Quim. Nova, Vol. 33, No. 8, 1726-1731, 2010. [3] BOSCHEN, N.L. Estudo da aplicação de antioxidante natural para Biodiesel e óleo de soja. UNICENTRO, Dissertação de mestrado, 64p, Guarapuava – PR, Brasil, 2016. [4] ANP – Agência Nacional do Petróleo, Gás Natural e Biocombustíveis. Resolução nº 45 de 25 de agosto de 2014. [5] UNE-EN 14214, Liquidpetroleumproducts. Fattyacidmethylesters (FAME) for use in diesel enginesandheatingapplications. Requirementsandtestmethods, 2013.

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New generation redox-active electrode materials for high-performance supercapacitor applications: Poly(3,6-dithienylcarbazole) derivatives Mustafa Güllü and Deniz Yiğit Department of Chemistry, Faculty of Science, Ankara University, Besevler, 06100 Ankara, Turkey

Supercapacitors, also known as ultracapacitors, are promising electrical energy storage systems and they fill the region between traditional dielectric capacitors and primary or secondary batteries in terms of their energy and power densities [1]. π-Conjugated conducting polymers have been attracting a great deal of interest as redoxactive electrode materials due to their excellent electrochemical and mechanical properties as well as carbonbased materials and transition metal oxides. Particularly, polythiophene, polypyrrole and polyaniline derivatives have been extensively used as electrode materials in various supercapacitor devices [2-5]. To fabricate unique redox-active electrode materials and obtain better supercapacitive performances, the design and synthesis of novel π-conjugated conducting polymers is highly demanded in supercapacitor research. In this context, this study presents the supercapacitive performances of novel poly(3,6-dithienylcarbazole) derivatives for high performance electrochemical energy storage applications. Both solid-state and flexible supercapacitor devices have been assembled using these poly(3,6-dithienylcarbazole)-based electrode materials. The hetereostructured composite electrodes have also been fabricated with poly(3,6-dithienylcarbazole)/TiO2 hybrid materials and their capacitive performances have been tested in detail. Electrochemical studies have been carried out by using cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy techniques. The supercapacitor device prototypes fabricated using novel poly(3,6-dithienylcarbazole) derivatives have been delivered superior specific capacitances in the range of Cspec= 462.88- 640 F/g, energy densities in the range of SE= 89.98- 1280 Wh/kg and power densities in the range of SP= 32.7- 266.96 kW/kg [6,7]. O

O O

O S n

S

N O O

Cspec= 640 F/g SE= 1280 Wh/kg SP= 36 kW/kg

Keywords: Supercapacitors; redox-active electrodes; poly(3,6-dithienylcarbazole) derivatives; flexible supercapacitors Acknowledgment: We thank to the Scientific and Technological Research Council of Turkey (T.BİTAK, Grant No. KBAG-114Z167) for financialsupport of this work. D. Yiğit is generously supported byT.BİTAK (KBAG-114Z167) with a postdoctoral scholarship. References [1] T. Chen, L. Dai, J.Mater. Chem. A, 2014, 2, 10756-10775. [2] K.S. Ryu, K.M. Kim, N.G. Park, Y.J. Park, S.H. Chang, J. Power Sources, 2002, 103, 305-309. [3] R.K. Sharma, A.C. Rastogi, S.B. Desu, Electrochem. Commun., 2008, 10, 268-272. [4] K.S. Ryu, Y.G. Lee, Y.S. Hang, Y.J. Park, X. Wu, K.M. Kim, M.G. Kang, N.G. Park, S.H. Chang, Electrochim. Acta, 2004, 50, 843-847. [5] S. Admassie, A. Elfwing, O. Inganas, Adv. Mater. Interfaces, 2016, 3, 1500533-1500538. [6] D. Yiğit, M.Güllü, T. Yumak, A. Sınağ, J. Mater. Chem. A, 2014, 2, 6512-6524. [7] D.Yiğit, M.Güllü, J. Mater. Chem. A, 2017, DOI:10.1039/c6ta08978j.

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Optimization of cellulase production from locally isolated Fusarium sp. and its application on enzymatic saccharification of corn husk Vinay Sharma*, Shivani Sharma and Arindam Kuila Department of Bioscience & Biotechnology, Banasthali University, Rajasthan-304022, India * Corresponding author: email: [email protected]

Lignocelllulosic biofuel production is the area of focus of different researchers (Mishra et al., 2016; Silva et al., 2016). Enzymatic hydrolysis of pretreated lignocellulosic raw material is the rate limiting step in the biofuel production (Revin et al., 2016). Cellulase is the key enzyme for hydrolysis of lignocellulosic biomass (Sharma et al., 2016). Optimization of cellulase production using efficient strain plays a significant role in higher reducing sugar production from lignocellulosic biomass. The present study deals with optimization of cellulase production under submerged fermentation (SmF) using locally isolated strain of Fusarium sp. Further the produced cellulase was used for fed batch enzymatic hydrolysis of dilute sodium hydroxide pretreated corn husk. In the present study, corn husk was pretreated under previously optimized conditions (using 0.5 M sodium hydroxide, 8% substrate concentration, 120 oC temperature and 20 min of incubation time). After pretreatment, the biomass was washed using distilled water and was dried at 70 oC. The dried biomass was subsequently used for enzymatic hydrolysis. Cellulase enzymes was produced under submerged fermentation using locally isolated Fusarium sp. Effect of different parameters (carbon source, nitrogen source, surfactant, substrate concentration, incubation time and temperature) were studied for cellulase production using one variable at a time approach (OVAT). Cellulase production was further optimized using CCD (central composite design) based RSM (response surface methodology). Maximum cellulase production (2.8 FPU/ml) was obtained at 8% waste paper, 0.05% glucose, 003% yeast extract, 30 oC temperature and within 3 days of incubation time. Enzymatic hydrolysis of pretreated biomass was carried under fed batch strategy using cellulase produced from Fusarium sp. Optimization of fed batch enzymatic hydrolysis process parameters (substrate concentration, temperature and incubation time) yielded maximum reducing sugar of 456 mg/g dry substrate within 48 h of incubation at 15% substrate concentration and 50 oC temperature. In addition, biomass hydrolysis will be carried out using blends of Fusarium sp. cellulase and Aspergillus niger cellulase under above optimum conditions to get higher reducing sugar. Aspergillus niger cellulose production will be carried out under our previous optimized conditions (Sharma et al., 2016). The above study can be useful for efficient hydrolysis of lignocellulosic biomass for cost effective biofuel production. Keywords: Lignocellulosic biofuel; Fusarium cellulase; Aspergillus cellulose; Fed batch enzymatic hydrolysis References [1] Sharma S, Sharma V, Kuila A (2016) Cellulase production using natural medium and its application on enzymatic hydrolysis of thermo chemically pretreated biomass. 3 Biotech 6:1-11. [2] Mishra A, Sharma AK, Sharma S, Mathur AS, Gupta RP, Tuli DK (2016) Lignocellulosic bioethanol production employing newly isolated inhibitor and thermotolerant Saccharomyces cerevisiae DBTIOC S24 strain in SSF and SHF. RSC Adv. 6:24381-24390. [3] Revin V, Atykyan N, Zakharkin D (2016) Enzymatic hydrolysis and fermentation of ultradispersed wood particles after ultrasonic pretreatment. Electron J Biotechnol 20:14-19. [4] Silva ADG, Ortega CET, Rong BG (2016) Techno-economic analysis of different pretreatment processes for lignocellulosic-based bioethanol production. Bioresource Technol 218:561-570.

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Possibility of producing briquettes from cashew shell press cake M. Sawadogo1, S. Tchini Tanoh1, E. Zeida2 and I. Tankouano1 1

Laboratoire Biomasse Energie et Biocarburants, Institut International d'Ingénierie de l'Eau et de l'Environnement (2iE), 01 BP 594 Ouagadougou 01, Burkina Faso 2 Université Ouaga I Pr Joseph KI-ZERBO, BP 7021, Ouagadougou, Burkina Faso

The use of biomass for energy production is one of the ways to ensure energy security and solve the environmental problems related to the use of fossil fuels in developing countries. Cashew production is an emerging sector in Africa. In 2011, Africa’s production reached up to 40% of the total world production of raw nuts. Production in Burkina Faso is estimated annually at 10 000 tonnes [1]. The cashew processing units generate large quantities of waste either on a semi-industrial scale or on an artisan scale. The production of 1 kg of almonds generates about 4.5 kg of waste, including 4 kg of shell and 0.5 kg of dandruff. The literature review shows that cashew shells can be recovered directly by thermochemical methods such as combustion. Furthermore, direct combustion of cashew shells is used in small-scale industrial units as well as in semi-industrial units, shells are generally burned in boilers for the production of heat, electricity or process steam. However, this method results in the production of many anacardic acid and smoke which are irritating and estimated to be carcinogenic [2] due to the presence of CNSL (Cashew Nut Shell Liquid). (a)

(b)

(c) Fig. 1 (a) Cashew press cake; (b) Carbonized press cake; (c) Produced briquettes.

In this study, press cake from the CNSL extraction process is used; this press cake is cleared of about 20% of CNSL (figure 1 (a)); which reduce the toxicity of the raw material. The press cake have been carbonized (results in table1) and then powdered. Table 1 Results of immediate analysis and NCV of the obtained charcoal Moisture content 5,47 %

Volatile Materials 33,44 %

Ash content 6,03 %

Fixed Carbon 60,53 %

Net calorific value 26420 (J/g)

The obtained charcoal powder has been mixed to water and a binder. The binder used here is cassava starch because of its availability in the local market, its low cost and its physicochemical characteristics. The mixture obtained is then densified in a screw press to obtain a briquette about 5.5 cm in diameter and 10 cm in length (figure 1- (c)). Many proportions of water and binder have been tested and the best briquettes have been found for a mixture containing about 35% of water and 10% of binder. Table 2 Characteristic of the obtained briquettes Moisture ontent 8,67 %

Compressive strength index 382,89 (kPa)

Ash content 6,65 %

Impact Resistance index 61,11

density 0,91

Net calorific value 24 ,61 MJ /kg

Regarding these results, the ash content obtained is higher than the norm. This is mainly due to the composition of the charcoal obtained after carbonization. However, the net calorific value is closed to the wood charcoal net calorific value (30MJ/kg). Keywords: Cashew nuts; Carbonization; Briquetting; Industrial waste management; Bioenergy References [1] Audouin, Sarah. 2014. Systèmes d’innovation et territoires : un jeu d’interactions. Les exemples de l’anacarde et du jatropha dans le sud-ouest du Burkina Faso. s.l. : Thèse pour l'obtention du grade de docteur en géographie, UNIVERSITE PARIS I - PANTHEON-SORBONNE, 2014. [2] Study of Carbonization for Cashew Nut Shell. Sanger S.H., Mohod A.G., Khandetode Y.P., Shrirame H.Y. and Deshmukh A.S. May (2011) . 43-55, s.l. : Research Journal of Chemical Sciences , May (2011) , Vol. 1(2). 15


Production of raw starch degrading amylase by Bacillus subtilis TLO3 and its application in bioethanol production from starch-rich flours Slimane Choubane 174/1 n5 Hai Essedikia, Oran, Algeria

Since the 20th century, oil became indispensable in fields of energy and chemical industry, leading to a global dependence and causing great damages to environment. Bioethanol is currently the most widely used liquid biofuel in the world. The starch pre-treatment for ethanol production requires the use of amylolytic microorganisms, or starch degrading enzymes, such as α-amylases and glucoamylases, to convert it into fermentable sugars. In this study, an amylase hyperproducer strain Bacillus subtilis TLO3 newly isolated from natural soil, was used for amylase production. The crude enzyme was used thereafter for raw corn and wheat starches pre-treatment. After that, the yeast Saccharomyces cerevisiae was inoculated into the saccharified starch solutions for fermentation. The total reducing sugars released during saccharification were measured, and the amount of ethanol produced, as well as, the reducing sugars were monitored all along the fermentation process. Thus, 70% and 91% reducing sugars were obtained after saccharification of wheat and corn starch, respectively, by B. subtilis TLO3 amylase. The fermentation process monitoring showed a continuous decrease in the total sugars, concurrently with an increase in ethanol production that reached 0.92 g/l (2%) for wheat flour and 1.1 g/l (2.4%) for corn flour after 24 h. Keywords: Bioethanol; amylase; Bacillus subtilis TLO3; wheat; corn

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Productive technologies of biogas and biodiesel fuel by transformation of energy from wastes of appearing in establishments of the public catering A. Elizaryev1, L. Kiiashko1, G. Maniakova1, A. Trusova1 and E. Elizaryeva2 1 2

Department of Protection of Emergency, University of Aviation Technology. Karl-Marx st. 12, 450008 Ufa, Russia Management and Business Security Institute, BSU. Gubkina st. 10B, 450064 Ufa, Russia

One of the most actual economic problems is research of low-waste technologies for the increase purpose of manufacturing enterprises overall performance. The interest is shown in the relation to technologies of development of energy from production wastes and consumption. Such technologies are biofuel production from biomass. It is about a biodiesel fuel and biogas. The purpose of the project is research of actions for introduction of biogas technologies in sphere of the reference with a waste of public catering establishments. Besides, there is study of capability of their use those materials for manufacture of a biodiesel fuel in purpose. Biogas is formed from splitting of organic components – protein, fats and carbohydrates. Most of all biogas it is formed at fermentation fats, least it is formed at fermentation carbohydrates. The maximum quantity of biogas, and the high maintenance in it СН4 turns out at fermentation fats. There are fast food restaurants of Open Company "McDonald's" and «Rostik's KFC», in territory of Moscow. As a result of their activity the fat maximum quantity is formed. It is formed about 8,8 t/day or 264 t/month culinary fat. The given volume of materials from culinary fat it is formed 11440 m3/day or 343200 m3/month biogas at fermentation. The given quantity of biogas is equivalent 22880 kVthour/day or 686400 kVthour/month to the electric power (45988,8 rbl/day or 1379664 rbl/month, accordingly). Average cost of the equipment for a biogas complex is 1200000 rbl. Average installations cost for simultaneous manufacture of heat and the electric power is 10800000 rbl. Thus, taking into account expenditure of energy fermentation and illumination of an industrial premise, a time of recovery of outlay of building of a biogas complex makes reactor heating 11,2 months. Research of the fuel alternative kinds market by the Ministry of Agriculture of the USA and National laboratory of energy renewed kinds has shown that the most competitive kind of alternative fuel is the biodiesel on the basis of raw materials of an animal origin. Such biodiesel fuel is made at oil refining factories and on the same technology, as a ordinary diesel fuel. Almost all food waste is suitable for biodiesel fuel manufacture. The annual quantity of a waste of the Russian food-processing industry makes 14 million tons in the dry rest that on the energy potential is equivalent to 7 million tons of oil. If to count that all quantity of a waste of the Russian food-processing industry will be processed in a biodiesel fuel its quantity will make 1,05109liters. The cost price of a biodiesel fuel of the cost price about 10 rbl/l. Thus, without profit on glycerin sales an annual turnover will make nearby 10 billion rbl. The recoupment of installation productivity of 1000 litre/hour will make 10 days. To determine the optimal conditions in the bioreactor, as well as determining the intensity of biogas experiment was conducted, during which the methane-producing bacteria species used «Methanobacteriales». The scheme of experimental laboratory model of a biogas plant is presented below.

Fig. 1 The experimental laboratory model of a biogas plant; (1) waste collection; (2) bioreactor; (3) thermometer; (4) flowmeter; (5) gas-holder

Increasing the intensity of biogas formation is associated with more rapid growth in the number of methanogenic bacteria in a bioreactor. Consequently, more comfortable conditions created for methanogenic bacteria, can achieve the best results. Keywords: biogas; biofuel References [1] B. Eder, H. Schulz.1996 Biogas plants. A Practical Guide. Zorg Biogas. 2008, 268 pp. [2] O. Dobrynina, Technological aspects of biogas production / О. Dobrynina, Е. Kalinina//Vestnik, PSТU - 2010. 17


Prospective energy power of corncob husk and its biochars: Kinetic parameters and isoconventional models C.C. Bueno, A.A.D. Maia, L.C. Morais and A.H. Rosa Department of Environmental Engineering – Institute of Science and Technology, São Paulo State University (UNESP), Av. Três de Março, 511 – CEP: 18087-180 – Sorocaba- SP – Brazil

The biofuel properties of biomasses play an important role in achieving their utilization on agro-systems and industries. In this context, the biomass waste of maize, corncob husk, and its biochars were taken into account to be investigated by thermogravimetric analysis, thermodynamic parameters for non-isothermal analyses using Ozawa-Flynn-Wall kinetic isoconversional model [1] in order to comprehend its fuels features. It was also investigated compounds generated after pyrolysis under air and nitrogen atmospheres and its relation with oxidation reactions for the safe-handling and storage of these materials. It was found that corncob biochar produced at 300ºC shows the best qualities as a biofuel, since it requires less energy input on pyrolysis to be produced. The formation of crystalline sheets of carbon suggested by the thermogravimetric analysis seems to be an important feature for pore development on biochar. The results obtained by biochars made of corncob husks on the means of material safety, BC250, BC300 and BC550 appeared to be the more harmless materials to handle and store. BC450 appeared to be more sensitive to oxidation reactions which lead this particular material to be more prone to self-heating and auto-ignition [2], not being safe for storage and handling. Finally, analysing the compounds generated and stuck on the biochar’s surface, by FTIR analysis, it was observed that the BC300 combustible components left in the fuel is almost completely consumed in the burn, showing also that this material presents one of the lowest sensibility mark to oxidation reactions, especially under nitrogen atmosphere. Keywords: corncob husk biomass; biochar; Ozawa-Flynn-Wall; kinetic parameters; auto-ignition; safety storage References [1] A.A. Domingos Maia, L.C. de Morais, Kinetic parameters of red pepper waste as biomass to solid biofuel, Bioresource Technology, 204 (2016) 157-163. [2] K. Candeliera, J. Dibdiakovab, G. Vollea, P. Rousseta, Study on chemical oxidation of heat treated lignocellulosic biomassunder oxygen exposure by STA-DSC-FTIR analysis, Thermochimica Acta, 644 (2016) 33–42.

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Pyrolysed lignocellulosic residues - biosyncrude for entrained flow gasification K. Raffelt, T. Nicoleit, N. Dahmen and J. Sauer Institute of Catalysis Research and Technology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany

If renewable fuels from biomass should profit from the economy of scale, they have to be produced in large facilities comparable to conventional refineries for fossil resources. But a high share of agricultural and forestry wastes have only a low density and transportation of large volumes is cost-intensive. Therefore energy densification is an important issue which can be achieved by thermochemical processes like fast pyrolysis, yielding liquid bio-oil and solids consisting of char and ash. Mixing pyrolysis char with pyrolysis condensates leads to biosyncrudes with a density of 1100 – 1300 kg/m3 and higher heating values between 10 – 23 MJ/kg depending on the formulation applied. In the bioliq® process these pumpable biosyncrudes are used as feed for high pressure entrained flow gasification and downstream synthesis of fuels and chemicals. This presentation describes the mixing process of bio-slurries and the most relevant parameters, which have to be taken into consideration. The materials used are mainly derived from the pyrolysis of beech wood, wheat straw and oil palm residues, but also bark, waste wood, rape straw, sunflower straw, corn stover, hay, corn cobs, flotsam, and residues of grain mills have been employed, which show the large diversity of potential feedstocks. Also model mixtures of char with ethylene glycol and water show principal features of the biosyncrude and are used for the experiments. Particle size and deagglomeration are shown to be the most important parameters to obtain a high solid content and nonetheless maintain free flowability. The power consumption of milling and mixing was measured and related to the mechanical quality of the biosyncrude, which is expressed by the viscosity, sedimentation time and sediment stability (inversely related to the power consumption of resuspension). Pyrolysis oil is a complex mixture of medium and highly polar small organics and a significant amount of water and oligomeric fragments of lignin. This alone can imply the possibility of liquid-liquid phase separation, and moreover ageing reactions lower the polarity, increase the water content and promote phase instability. Examples are shown how liquid-liquid phase separation has negative influence to the handling of bio-slurries and how this can be avoided. A successful biosyncrude preparation results in a flowable suspension of at least reasonable stability with an energy content of > 85 % of the energy of the biomass feedstock. The concept of mixing, storing and providing biosyncrude is explained for the bioliq® pilot plant, which is designed for gasifier operation times of up to two weeks. Keywords: lignocellulose; fast pyrolysis; entrained flow gasification; biosyncrude

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Pyrolysis of olive bone in a fluidized bed reactor: characterization of bio-oil and char J.O. Pou Ibar Industrial Engineering Department, IQS School of Engineering, Universitat Ramon Llull, Via Augusta 390, 08017 Barcelona, Spain

Agricultural waste biomass has a wide variety of forms but all of them have the common denominator of being a mixture of lignin, cellulose and hemicellulose. One of the typical ways of using biomass is by burning it alone or mixed with coal establishing some synergies which are not completely understood. Another energetic use of biomass includes the pyrolysis, which is a way to convert it into liquid products suitable to be used in an internal combustion engine. Spain is the world largest producer of olive oil with 1,537,000 ton/year (2013-2014). The olive oil quality ranges from the best, first pressed oil, to the lowest: oil from smashed olive bones. Still, after this last process, there are an important amount of smashed bones which are burnt as a residue. In this study, the characterization of the pyrolysis of this waste is carried on in order to determine its potential in other energetic uses different form combustion. The pyrolysis experiments were performed in N2 atmosphere in a stainless steel tubular reactor (40 x 9 cm) heated by an electric furnace with the temperature being controlled with two thermocouples in the furnace and one inside the reactor. 50g of air dried olive bones in the range of 1 < D < 1.5mm particle size were placed inside the reactor. The experiments were carried out to the final temperature of 450ºC until no further significant release of gas was observed. The bio-oil was characterized using gas chromatographic and spectroscopic techniques. In addition the char was characterized using BET and SEM analysis. Elementary analysis of the original substrate, the char and the bio-oil obtained were also done. According to the experimental results, the liquid products can be used as liquid fuels and the solid product shows a high surface area being useful in adsorption. Keywords: olive bone; thermal degradation; product characterization

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Solid base heterogeneous catalysts for the synthesis of diethyl carbonate as an oxygenated fuel additive: synthesis, characterization and applications Narendra Kumar1, Ewelina Leino1, Päivi Mäki-Arvela1, Atte Aho1, Anne-Riikka Rautio3, Kari Eränen1 and Jyri-Pekka Mikkola1,2 1

Laboratory of Industrial Chemistry and Reaction Engineering, Faculty of Science and Engineering, Johan Gadolin Process Chemistry Centre, Åbo Akademi University, FI-20500 Turku/Åbo, Finland 2 Chemical-Biological Centre, Department of Chemistry, Technical Chemistry, Umeå University, SE-90187 Umeå, Sweden 3 Laboratory of Microelectronics and Material Physics, University of Oulu, FI-4500 Oulu, Finland

Solid base catalytic materials such as CeO2, Ce-H-MCM-41, Cs-MCM-41 and Cs-ZSM-12 are important for synthesis of various types of fuel component additives, speciality and fine chemical synthesis. Production of environmental friendly processes and materials for the energy, fuel components and fine chemicals are significant, taking into consideration the human health, wellbeing, climate change, air purity and long term existence of flora and fauna on the planet earth. The aim of this research work is synthesis and characterization of CeO2, Ce-H-MCM-41, Cs-MCM-41 and Cs-ZSM-12 solid base heterogeneous catalysts. Sold base catalysts have been identified as potential catalysts for the synthesis of oxygenated fuel additive such as diethyl carbonate. Hence, further aim was to evaluate these catalysts containing basic sites in the direct transformation of CO2 to diethyl carbonate for use as oxygenated fuel additive. The influence of synthesis parameters such as synthesis time, pH, mode of synthesis and calcination temperature were studied for the preparation of CeO2 base catalysts. CeO2 modified MCM-41 mesoporous materials with different loadings were synthesized using evaporation impregnation method. Aqueous solution of cerium nitrate was used as a source of ceria modification of MCM41. Cs modified MCM-41 and ZSM-12 catalysts were synthesized by ion-exchange method using aqueous solution of cesium nitrate. The physico-chemical properties of the synthesized catalytic materials were determined using several characterization techniques. X-ray powder diffraction was used to analyse the phase purity and structure of CeO2, Ce-MCM-41, Cs-MCM-41 and Cs-ZSM-12 catalysts. Transmission electron microscopy and scanning electron microscopy were applied to determine the particle size of CeO2, morphology of CeO2 and Ce-MCM-41, respectively. The amount and type of basic sites were measured using temperature programmed desorption of CO2. The surface area and micro-pore volume were measured using Nitrogen physisorption. The presence and amount of Bronsted and Lewis acid sites were determined by FTIR using pyridine as probe molecule. It was observed that methods of catalyst preparation influenced the physico-chemical characterization results of solid base catalytic materials. Furthermore variations in the synthesis parameters of CeO2 were observed to influence the crystal size distribution, structure, morphology, surface area, formation of basic and acid sites. The evaluation of the catalytic properties of the sold base heterogeneous catalysts for the direct transformation of CO2 to diethyl carbonate was carried out in 300 ml stainless steel autoclave. The amount of basic sites, CeO2 crystal size distribution, surface area and structure of catalysts were observed to influence the formation of diethyl carbonate. Keywords: Catalysts; materials; energy; fuels; sustainability References [1] Narendra Kumar, Ewelina Leino, Päivi Mäki-Arvela, Atte Aho, Mats Käldström, Marjukka Tuominen, Pekka Laukkanen, Kari Eränen, Jyri-Pekka Mikkola, Tapio Salmi, Dmitry Yu. Murzin, Microporous and Mesoporous Materials 152 (2012) 71-77. [2] Ewelina Leino, Narendra Kumar, Päivi Mäki-Arvela, Atte Aho, Krisztian Kordas, Anne-Riikka Leino, Andrey Shchukarev, Dmitry Yu. Murzin, Jyri-Pekka Mikkola, Materials Chemistry and Physics 143 (2013) 65-75.

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Sustainable utilization of bi-ecofriendly materials for CO2 capture Paula Teixeira, Carla I.C. Pinheiro, Auguste Fernandes and Maria F. Ribeiro CQE-Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Avenida Rovisco Pais 1, 1049-001 Lisboa, Portugal

Among the technologies developed for CO2 capture, the Ca-looping based on the reversible chemical reaction between the CaO and CO2 to form CaCO3, appears to be one of the most promising. Comparatively with other technologies, the sorbent can be easily regenerated and additionally the initial CO2 capture efficiency is especially high during the initial carbonation cycles (600°C-700°C) and calcination cycles (800°C-900°C). During the calcination step CO2 is selectively separated from CaCO3, and if this step is carried out under a higher CO2 partial pressure, a pure stream of CO2 can be generated suitable for storage or for conversion processes. Furthermore, the Ca-looping concept has unique potential advantages, i.e., it can be integrated in a variety of plants, and the exhausted sorbent (CaO) can be used as raw material in the cement industry. Currently, the CO2 capture challenge through the Ca-looping is related with the decay of the sorbent reactivity with increasing number of capture cycles, especially if limestone is used as a sorbent. To overcome this issue, some synthetic sorbents with high and stable capture capacity along the cycles have been investigated1. However, the main advantage of Ca-looping is that different types of available and inexpensive sorbents can be used, which means that a compromise should be made between improving the sorbent performance and the cost, so a practical, scalable and inexpensive method should be found2. This work presents a bi-ecofriendly materials perspective, i.e., an economic and ecological option. The utilization of waste marble powder (WMP) and dolomite resources as sorbents in the Ca-looping have potential to be a good and attractive option. Preliminary studies indicate that the CO2 carrying capacity and stability performance of WMP, a waste without commercial value, are better than the limestone3. In addition, its use as a sorbent material allows minimizing the adverse environmental impacts associated with the high volume of WMP generated by the marble producers traditionally disposed in landfills. In this work the CO2 carrying capacity of limestone, WMP and dolomite were assessed experimentally in a laboratorial fixed bed reactor unit using a gas mixture with a CO2 concentration similar to industrial flue gas emissions. The limestone and the WMP show a similar initial capture capacity on the first cycles; however, after 20 cycles the limestone and WMP deactivation is 71% and 57 %, respectively. When compared with limestone and WMP, the initial CO2 capture capacity of dolomite is lower; however, after 20 cycles it decreases only 28 %, which means that for long term its capacity capture is higher, probably due the MgO presence. Usually, the CaO based sorbents deactivation or loss of capture capacity is mainly attributed to the sorbent particles sintering and pore blocking, which is related with the loss of microporosity and grain size growing along the cycles. Hence, the experimental tests were stopped after 2, 5, 10 and 20 cycles and the sorbents textural properties were evaluated. The N2 sorption technique was used to estimate the BET surface area and pore size distribution of the fresh calcined and used sorbent samples. When the carbonation-calcination cycles number increased from 2 to 20 a linear correlation between the BET surface area and CO2 capture deactivation was observed for all sorbents. The Scherrer formula for X-Ray particle size determination was also used to evaluate the increase of the CaO particles size along the cycles. The results show that the sorbents deactivation was also followed by an increase of the CaO particles size. The innovative results presented in this study show that the use of WMP as bi-ecofriendly material sorbent for Ca-looping should be encouraged, and the synergies between dolomite and WMP blending should be assessed. Keywords: CO2 capture; Ca-looping; sorbents; waste marble powder; limestone; dolomite References [1] Santos, E., Alfonsin, C., Chambel, A., Fernandes, A., Soares Dias A., Pinheiro C., Ribeiro M. Investigation of a stable synthetic sol-gel CaO sorbent for CO2 capture”. Fuel, 2012, 94: 624-628 [2] Erans, M., Manovic, V., Anthony, E. Calcium looping sorbents for CO2 capture. Applied Energy, 2016, 180: 722–742 [3] Pinheiro, C.I.C., Fernandes, A., Freitas, C., Santos, E.T., Ribeiro, M.F. Waste Marble Powders as Promising Inexpensive Natural CaO-Based Sorbents for Post-Combustion CO2 Capture. Ind. Eng. Chem. Res., 2016, 55 (29) 7860– 787

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The effect of ultrasound on the conversion of cellulose to 5-hydroxymethylfurfural Esra Sezgin, Merve Esen, Solmaz Akmaz, Serkan Naci Koç and M. Ali Gurkaynak Department of Chemical Engineering, Faculty of Engineering, Istanbul University, 34320 Avcılar, Istanbul, Turkey

Renewable biomass resources can be utilized for the production of fuels and chemicals as alternative to fossil fuels. Cellulosic materials, which are the most common and renewable resource on the planet, have an important potential to develop fuel chemicals although some challenges need to be overcome for using cellulosic materials. The conversion of cellulosic biomass to valuable chemicals such as furan derivatives has been a worldwide interest for researchers. Furan derivatives such as 5-hydroxymethylfurfural (HMF) obtained from acid-catalyzed dehydration of carbohydrates are used as precursors in the production of biofuels and bioplastics.

HO O

O OH

OH

OH

HO OH O HO

O OH OH

OH HO O

O

O

O HO

OH

OH

Fig. 1 The conversion of cellulose to HMF.

Treatment with mineral acids such as H2SO4 and HCl is still being applied in the cellulose hydrolysis because of the high crystallinity grade of cellulose. However, the toxically effects of waste acids make it difficult to apply this technology. Solid acid catalysts can be treated under hydrothermal conditions as an environmentally friendly chemical process and products are easily separated by simple filtration [1]. In our previous study, we prepared Cr-USY zeolite catalyst and we studied the effect of Cr in the solid catalyst on the HMF formation from cellulose [2]. The physical and chemical resistance of cellulosic structure to degradation make difficult the conversion of cellulose to HMF using solid catalysts. Nowadays, the interest in studies on the development of cellulose conversion reactions has increased. Few studies tried the ultrasound effect as a pre-treatment method for the cellulose hydrolysis [3]. In this study, the effect of ultrasound on cellulose conversion to HMF was investigated by using Cr-USY zeolite and USY zeolite catalyst without Cr. The reactions were carried out at different temperatures from 155 to 175 oC in the ionic liquids and dimethyl sulfoxide (DMSO) solvent mixture and performed at 130 oC in the presence of ultrasound system. Pretreated cellulose in the presence of ultrasound system was also used for HMF formation reactions. HMF yields were determined by using High-Performance Liquid Chromatography (HPLC) instrument. The results of reactions showed that the ultrasound effect increased the cellulose conversion to HMF. Keywords: cellulose; 5-hydroxymethylfurfural Acknowledgments: This study was supported by The Scientific and Technological Research Council of Turkey (TUBITAK), Project No: 214M149. References [1] Veronque J., Flora C., Frank R., Amandine C., Catherine P., Emmanuelle G., 2009, Non catalyzed and Pt γ-Al2O3 catalyzed hydrothermal cellulose dissolution- conversion: Influence of the reaction parameters and analysis of the unreacted cellulose, Green Chemistry, 11(12), 2052-2060 [2] Esra Sezgin, Merve Esen, Solmaz Akmaz, Serkan Naci Koç, M. Ali Gurkaynak, The Conversıon Of Cellulose To 5Hydroxymethyl Furfural (HMF) With Zeolite Catalysts, NCC6-The 6th Catalysis Conference, Bursa, Turkey, 27-30 Apr. 2016. [3] Bussemaker, M. J. Zhang D. 2013, “Effect of Ultrasound on Lignocellulosic Biomass as a Pretreatment for Biorefinery and Biofuel Applications”, Ind. Eng. Chem. Res., 52, 3563−3580. 23


The Importance of Bioenergy at Renewable Energies in Turkey Nedim Saraçoğlu Bartın University, Faculty of Forestry, 74100 Ağdacı/Bartın Merkez/Bartın, Turkey

According to economists and other observers of the energy scene, there is an impending shortage in the civilized world of petroleum and gas. Exhaustion of these nonrenewable fuels promts consideration of alternative energy sources. Green energy or green power is the generation of electricity from sources such as biomass, wind, solar, geothermal, hydraulic and sea energies that do not place harmful effects to the environment. Green energy sources have sustainable and secure characteristics beneficial to nature and economy. The interests in renewable energy sources increases steadily all over the world, since they are an alternative to fossil fuels. Turkey has rich renewable energy sources. The potentials of the main renewable energy sources of Turkey are 6015 TWh/year solar, 290 TWh/year wind, 216 Twh/year hydro, 197 TWh/year biomass and 35 TWh/year geothermal energy. Turkey aims at further increasing its use of solar, wind, hydro, biomass and geothermal energy resources and Turkey has potential producing 30% of its electricity need from the renewables by 2023. Turkey has different kinds of energy sources which turkish energy sector is becoming more active, competitive and attracting the attention of investors. The turkish electricity market is one of the fastest growing in the world with an average of approximately 9 % annual growth in 2010 and 2011. Turkey has the second highest energy consumption growth after China and is highly dependent on external energy resources. Energy intensity of turkish industry is two times higher than the OECD average and four times than Japan’s average. Turkey is located in a region that holds 72 % of the world’s proven gas reserves and 78 % of proven oil reserves and at crossroads of energy in the middle of five seas. Biomass is the major energy source in rural Turkey. Biomass is used to meet a variety of energy needs, including generating electricity, heating homes, fueling vechiles and providing process heat for industrial facilities. Among the biomass energy sources, fuelwood seems to be the most interesting because its share of the total energy production of Turkey is high at 21%. Turkish forest area occupies about 28,6 % (22,3 million hectares) of entire land area. Annual wood production including private is about 26 million m3, of which 46 % is consumed as fire wood. Biomass energy is one of the most significant renewable energy resources regarding its potential, 117 million ton/year, 32 Mtoe and usable amount is approximately 17 Mtoe and expected to play a crucial role in Turkey. Turkey has huge capacity for biofuels industry which is expected to see rapid expansion over the next years due to agricultural potential, 88 million ton/year, and policies on environmental friendly alternative fuels in Turkey. Forty-eight biomass plants has 227 MW capacity and producing 1,2 billion kWh electricity and heat by using forest and agricultural wastes. The electrical production from useable biomass has a net impact of 4,4 billion USD and represent more than 160.000 jobs. Keywords: Renewable energy; Bioenergy; Turkey

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The use of agro-industrial waste as antioxidant for biodiesel M.G.P. Valenga1, N.L. Boschen1, M.T. da Cunha1, T. Sawczen1, E. D’Elia2 and P.R.P. Rodrigues1 1

Departamento de Química, Universidade Estadual do Centro-Oeste, Rua Simeão Varela de Sá, 03, 85040-080, Vila Carli, Guarapuava, Paraná, Brasil 2 Instituto de Química, Universidade Federal do Rio de Janeiro, Athos da Silveira Ramos, 149, 21941-909, Ilha do Fundão, Rio de Janeiro, Rio de Janeiro, Brasil

For antioxidant of agro-industrial waste (AW) caracterization, infrared spectroscopy and RAMAN were used. The AW extraction was performed by three different solvents: hydrochloric acid, potassium methoxide and methanol. RAMAN spectra presented aromactic-characteristic C-H2 bonding band and C-H bonds at 2974 cm-1. High signal intensity was also observed for AW extracted in acid environment, suggesting a greater amount of dissolved chemicals in this hydrochloric acid solution. RAMAN spectra presented in Figures 1(a) e 1(b) show there is no significant change in characteristics bands for B100 biodiesel samples (100% biodiesel, without addition of other fuel or biofuel) with and without of AW antioxidant extracted in acid medium.

(a) Fig. 1

(b)

RAMAN spectra for biodiesel B100 samples (a) without and (b) with antioxidant extracted from AW in HCl.

Figure 2 shows RAMAN and infrared spectra for AW acid extract. Bands in common are presented in range of 3000 cm-1, aromatic-characteristic C-H bonds. Infrared spectra bands in range of 1000 cm-1 are characteristic signals of alcohol C-O bonds; in 3400 cm-1, O-H bonds; in 3668 cm-1, O-H and N-H bonds; in 1350 cm-1, C-CH3 bonds; in 1645 cm-1, C=C bonds. These signals and a comparison with BEATTIE et al (2007), it is suggested that the molecule present in AW acid extract is tocoferol (C29H50O2).

Fig. 2 Infrared (-) and RAMAN (-) spectra obtained for acid extracts. Keywords: bioenergy; biofuels; environment; biomass Acknowledgements: To Fundação Araucária, CNPq, CAPES, FAU – UNICENTRO for the financial support. References [1] Beattie, J.R.; Maguire, C.; Gilchrist, S.; Barrett, L.J.; Cross, C.E.; Possmayer, F.; Ennis, M.; Elborn, J.S.; Curry, W.J.; McGarvey, J.J.; Schock, B.C. The use of Raman microscopy to determine and localize vitamin E in biological samples. The FASEB Journal. V.21, n.1, p.766-776, Mar. 2007.

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The use of biodiesel and its emulsions as pilot fuels for compression ignition engines dual-fuelled with NG Abdelrahman Hegab1,2 and Paul Shayler1 1 2

Department of Mechanical Engineering, the University of Nottingham, Nottingham NG7 2RD, United Kingdom Department of Mechanical Engineering, Al-Azhar University, Cairo 11371, Egypt

The use of natural gas (NG) as a partial substitute for diesel fuel in compression ignition engines is recognized as a potent approach towards a more sustainable fuel market. In this fuelling strategy, known as dual-fuelling, most of the engine power output is provided by the NG, while a pilot amount of diesel fuel is used as an ignition source to ignite the NG-air mixture. NG-diesel dual-fuel engines could produce power levels comparable to those produced from conventional diesel engines, while they generally produce less harmful exhaust emissions owing to the clean nature of combustion of NG. A higher degree of sustainability could be achieved in these engines by using diesel-like biofuels (referred to as biodiesels), or their emulsions with water, as alternatives to the diesel fuel pilot. This is not only convenient from the perspective of reducing the dependence on the petroleum diesel (aka petrodiesel, or simply diesel fuel) but also beneficial for improving some of the combustions and emissions characteristics of the engine. Biodiesel, obtained from an oil or fat through a transesterification reaction with glycerol as a co-product, has fairly similar properties to the petrodiesel. With a chain length of C14-C22, biodiesel has an elevated cetane number (as high as 63), and also a relatively high LHV (around 40 MJ/kg). It is also easy to handle because of its high boiling point, while it is eco-friendly with low smoke and PM emissions owing to its oxygen content. Above and beyond, the emulsions of biodiesel with varying concentrations of water can be used as replacements to diesel fuel, where these emulsions could be prepared using different techniques (e.g. mechanical mixing; ultrasonic vibration), with the aid of mixing agents surfactants (e.g. Span 80; Tween 80) to stabilize the emulsions. The present work aims at providing an overview of the potential benefits as well as the practical challenges of the use of biodiesel fuels and their emulsions as pilot fuels for NG dual-fuel engines; covering the most promising ones. On top of the list comes the rapeseed methyl ester (RME), which has more than 10% oxygen (mass basis) and hence it yields enhanced combustion. Yet, issues related to the viability of RME as a first-generation biofuel (e.g. competition for land with food crops) and its effects of long-term use in engines (e.g. cylinder deposits and cold weather suitability) remain. A promising second generation biofuel is the dimethyl ether (DME), which has a high cetane number that exceeds 55, and also a significant oxygen content (about 35%) with no direct carbonto-carbon (C-C) bond, and hence it produces considerably lower pollutant emissions. Still, DME suffers from low viscosity and lacks good lubricating characteristics, which may cause fuel leakage throughout the fuel supply system, and could also cause surface wear of moving parts in the injection system. DME also has a low boiling point and fast evaporation, and hence it has to be stored under constant pressure (at least 0.5MPa) in order to remain in the liquid phase, which adds more complexity to the system. Other alternative biodiesel fuels that do not require many modifications include jojoba-(seed) methyl ester (JME), pongamia pinnata methyl ester (PPME), vegetable (edible frying) oil, and eucalyptus oil. With elevated cetane numbers (ranging 63-53), these fuels lower the rate of combustion pressure rise; reducing the engine noise and knock tendency. Smoke and PM emissions are substantially reduced but CO and HC emissions are increased. However, problems such as blocked injectors’ nozzles, filter clogging, and reduced service life are likely to be encountered. As far as biodiesel fuel emulsions with water are considered, it was found that the “micro-explosion” phenomenon associated with these fuels (the phenomenon in which the emulsified fuel droplets explode violently during the combustion process as a result of vaporization of the entrained water) allows more ignition points to be distributed throughout the entire charge. This could speed up the flame propagation and combustion rate, while the cooling effect of the emulsions due to the vaporization of the entrained water droplets decreases the cylinder temperature; reducing the harmful NOx emissions. However, any separation of the water-in-fuel along the fuel system before being introduced to the cylinder may result in some inconsistencies in engine combustion and emissions. Keywords: fuel sustainability; diesel fuel; natural gas; biodiesel; fuel emulsions; engines; combustion; emissions

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Thermochemical conversion of a lignocellulosic waste by estimating the pyrolysis yield of its basic compounds M. Calero, A. Pérez, M.A. Martín-Lara, G. Blázquez, I. Iáñez and A. Ronda Department of Chemical Engineering, University of Granada, Avda. Fuentenueva s/n, 18071 Granada, Spain

Thermochemical conversion of biomass waste is receiving renewed attention to recover materials and energy from them and to reduce the landfill. Besides, lignocellulosic wastes have been considered as a potential feedstock for energy production. The olive tree pruning (OTP) is a biomass waste obtained by pruning of olive trees very abundant in the Mediterranean countries for which no industrial applications were yet consistently envisaged. In this work, the thermochemical conversion of the OTP was analyzed by estimating the yield of pyrolysis on its basic compounds (hemicellulose, cellulose and lignin). For that, it was taken into account that the vegetal biomass is composed mainly by hemicellulose, cellulose and lignin, as well as low moisture, extractives, and mineral matter contents [1]. The OTP samples were provided by a local plantation in Jaén. In the laboratory, the material was milled under 1 mm particle size and it was characterized. Then, thermochemical analysis was performed by TGA under inert conditions (20 mL/min of N2), from 140 to 800 ºC and at a heating rate of 10°C/min, using a weight of sample approximately of 40 mg. From characterization, it was obtained that OTP was composed by 32.43% of hot water soluble compounds, 9.72% of ethanol-benzene soluble compounds. Besides, the free extractive sample was formed mainly by holocellulose (61.84%) and lignin (36.07 %). Hence, it was considered that the pyrolysis of OTP biomass was formed by the pyrolysis of three independent fractions (hemicellulose, cellulose and lignin). Experiments in TGA were performed using each simple obtained fraction in laboratory (holocellulose, lignin and free extractive sample), and also using the raw OTP. In Figure 1 are observed the TG and DTG curves obtained from the pyrolysis of them.

Fig. 1 TG (a) and DTG (b) curves obtained from the pyrolysis of each studied fraction.

It was observed that these materials exhibited great differences that can be related to their chemical structure. Lignin was the component most difficult to decompose and it decomposed slightly over a wide temperature range, with a very low mass loss (a final residue around 41 %, the highest one). It is attributed to the its structure, which consists of a complex network of cross-linked aromatic molecules that are difficult to decompose and therefore have high thermal stability. However, the holocellulose decomposed mainly between 500 to 673 K and it remained a residue around 40 % of the initial mass. Holocellulose was compound by hemicellulose and cellulose. They were complex polymers with a high thermal stability. Its degradation consisted of two steps, the first one, around 534 K, was representative of the hemicellulose decomposition (which occurred at lower temperature range due to its amorphous and random structure), and the second stage, around 598 K, is attributed to cellulose, which is consisted of a long polymer of glucose with a stronger structure. Finally, from Figure 1, it is observed that the shape of TG curve for pyrolysis of OTP extracts free is very similar to OTP one, but slightly move up, indicating the effect of this kind of compounds. Obtained curves agree with obtained by other authors for the pyrolysis of biomass components at the same heating rate [2]. Keywords: Olive tree pruning, Pyrolysis, Thermogravimetric analysis, Valorisation, Yield References [1] Rueda-Ordóñez, Y., Tannous, K., 2016. Thermal decomposition of sugarcane straw, kinetics and heat of reaction in synthetic air. Bioresource Technology 211, 231–239. [2] Quan, C, Gao, N., Song, Q., 2016. Pyrolysis of biomass components in a TGA and a fixed-bed reactor: Thermochemical behaviors, kinetics, and product characterization. Journal of Analytical and Applied Pyrolysis 121, 84–92. 27

Solar Energy / Wind Power / Geothermal Energy


A comparison between PI and SMC pitch angle control for standalone fixed speed wind energy system based on Self- Excited Induction Generator A. Sadek* Laboratory of Materials and Sustainable Development (LM2D), Department of GE, University of Bouira, Algeria * Corresponding author: email: [email protected]

According to the rotation speed and drive train types, the traditional Wind Energy Conversion Systems (WECS) can be classified into the following types: constant speed WECS with multiple-stage gearbox variable speed WECS with multiple a single-stage gearbox. The constant speed WECS has been used with a multiple-stage gearbox [1]. Induction generator systems have been widely used and studies in wind power system because of their advantages over synchronous generators such as smaller size, lower cost, and lower requirement of maintenance [2, 3]. The power conversion technique using squirrel-cage induction generator (SCIG) is widely accepted in fixed- speed applications (Fig.1), the reactive power is required for the operation of this type of machine. In case of a grid-connected mod, the SCIG can draw a reactive power from the grid. For an isolated mode there must be a suitable, capacitor bank connected across the generator terminals (self-excited induction generator). The operating principle of the SCIG is based on maintaining the nominal speed and this through the pitch angle control. The objective of this paper is to compare PI (proportional integral) and SMC (sliding mode control) pitch angle control for standalone fixed speed wind energy system based on self-excited induction generator. β Gearbox L O A D

V R

Ωt

Ωmec

Turbine

SCIG C C C

Fig. 1 Block diagram of a self-excited induction generator. Keywords: constant speed WECS; SCIG; PI pitch angle control; SMC pitch angle control References [1] M. Cheng, Y. Zhu, “The state of the art of wind energy conversion systems and technologies: A review” Energy Conversion and Management 88 (2014) 332–347. [2] M. Orabi, T. Ahmed, and M. Nakaoka, “Efficient performances of induction generator for wind energy utilization,” in Proc. 30th Annu. Conf. IEEE Ind. Elect. Soc., Nov. 2004, pp. 838–843. [3] M. Molinas, J. A. Suul, and T. Undeland, “Low voltage ride through of wind farms with cage generators:STATCOM versus SVC,” IEEE Trans. Power Electron., vol. 23, no. 3, pp. 1104–1117, May 2008.

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Advances the monitoring of photovoltaic systems – Use of the Internet of Things (IoT) of a photovoltaic installation P. Gómez Vidal1, M. Jiménez-Torres2, L. Hontoria2, G. Almonacid2, F. Muñoz- Rodríguez2, J.I. Fernández-Carrasco3 and C. Rus-Casas2 1

Department of Electricity Engineering, University of Jaén, Campus Lagunillas, Jaén. Spain Department of Electronic and Automatic Engineering, University of Jaén, Campus Lagunillas, Spain 3 Centre of Advanced Studies in Energy and Environment CEAEMA, University of Jaen, Spain 2

The use of renewables energies must be stimulated, due to the problems that the actual energetic systems in the world have. Photovoltaic systems have some special characteristics which provide values added as systems of electric energetic production (the modularity of these systems is an example of this value added). Also it is important to point out that photovoltaic solar energy has enough capacity to become an important part of the electric mix due to its high cost decrease. According to a report of the International Renewable Energy Agency (IRENA), the decreasing of total cost of a typical photovoltaic installation between the years 2010 and 2014 has been of 29-65% (depending on the region where the installation is) and the cost of modules has decrease around a 75 % in the year 2014 comparing with the year 2009 [1]. The monitoring of photovoltaic installations has allowed a great development of the photovoltaic industry. Thanks to the monitoring the detection of failures in the installation and the evaluation of its performance can be done. Also, with the results and analysis of the data provide by the monitoring preventing and correcting actions on the installation can be done, and so permits that the photovoltaic installation works more efficiently [2]. Nowadays, in the monitoring field, the electric companies are including the use of smart electric-meters which allows the user to know the energy consumption. This action helps to reduce the energy consumption between 15% and 25% [3]. This awareness in the use of the energy is only possible with the assistance of “Smart Grids”.

Fig. 1 Simplify scheme of the monitoring in this study.

In this work the experience in the monitoring and tracing of photovoltaic systems done by researcher of the University of Jaén (Spain) is shown. All of this study is to guide to the contribution of smart distributed generation of energy using a monitoring system for photovoltaic installations. So the main objective of this work is to develop a method to estimate the energy in real time, using data recorded on Internet of Thigs (Fig. 1). This way the energy self-consumption of the photovoltaic system could be encouraged. Keywords: photovoltaic; smart grid; internet of the things (IoT) References [1] Renewable Power Generation Costs in 2014. IRENA (International Rewable Energy Agency) (Enero 2015). [2] Torres Ramírez M., Muñoz Rodríguez F. J.; Muñoz Díez, J. V., Rus Casas, C. (2012). Online Monitoring System for Stand-Alone Photovoltaic Applications. Analysis of System Performance From Monitored Data. Journal Of Solar Energy Engineering. 134 - 3, pp. 0345021 - 0345028. Universidad de Jaén. [3] Spano E., Niccolini L., Di PascoliS., et ál. (2015). Last Meter “Smart Grid” Embedded in an Internet-of-Things Platform. IEEE Transactions on “Smart Grid”, 6 (1), pp. 468-476. DOI: 10.1109/TSG.2014.2342796.

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Alkali polyphosphates as new materials for thermal energy storage Abdoul Razac Sane, Doan Pham Minh, Patrick Sharrock and Ange Nzihou Université de Toulouse, Mines Albi, CNRS, Centre RAPSODEE, Campus Jarlard, F-81013 Albi Cedex 09, France

During the last decades, energy consumption rapidly increases worldwide, linked with the expansion of world population and the consumption of new emerging countries, while the classical fossil sources such as coal, natural gas, petroleum... are limited. Also, the use of fossil-origin products increases the risk of global climate change. In this context, the renewable energies such as: wind, solar, biomass are of increasing interest. Heat takes important place in the global energy consumption. The valorization of solar energy, the recovery of waste heat from industrial sites and the improvement of energy efficiency for industrial sites appear to be strategic actions for the future [1]. As for other energies, such as electricity, heat storage is one of the key issues and challenges to deal with. Nowadays, the development on thermal energy storage (TES) can be divided in three main groups: sensible heat storage; latent heat storage; and thermochemical heat storage. Currently, large-scale sensible heat storage (SHS) by solid or liquid media is the most attractive option. The availability TES and suitable materials is a key for ensuring continuous power supply from solar thermal power plants (CSP). Up-todate, TES technology that uses molten salts (alkali nitrates and alkali nitrites) is the only major industrial scale realization for exploiting concentrated solar energy [2]. However, these materials have several disadvantages including low thermal conductivity, low operational temperature range (with risk of complete thermal decomposition) and corrosive property. In addition, their use may cause competition with agricultural activity because of their limited sources. Thus, the development of new competitive materials for TES application is highly required. This work was focused on the development of multiple alkali polyphosphates eutectics with low phase change temperature as novel liquid media for sensible heat storage. Different alkali polyphosphates (MPO3, with M = Na, K and Li) were investigated and different binary diagrams were built. Liquid alkali phosphates could be obtained above 440°C which are thermally stable up to around 850°C. Keywords: Thermal energy storage; materials; Alkali polyphosphates; eutectics References [1] IAE, “Technology roadmap-solar thermal electricity”, OECD/IAE, (2014) [2] K. Vignarooban, Xinhai Xu, A. Arvay, K. Hsu, A.M. Kannan, Heat transfert fluids for concentrating solar power systems – A review, Applied Energy 146 (2015) 383-396

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An assessment on the impacts of the integration of photovoltaic power generations on the reliability of distribution networks C. Arias, A. Rasouli and E. Shayesteh School of Electrical Engineering, KTH Royal Institute of Technology, S-100 44 Stockholm, Sweden

The continuous global warming and climate change due to the increasing amount of greenhouse gases in the atmosphere are two of the most important problems humankind is facing in present’s world. One of the main targets of the “Europe 2020” vision states that the emission of greenhouse gases shall be reduced by at least 20% until year 2020 compared to the year 1990. In addition to that, it is expected to have 70% of the total power production mix in Europe by 2030 conformed only by renewable energies. If these targets, amongst many others, are to be met, significant changes need to be made [1]. One way of reducing the emission of greenhouse gases and to get less impact on the environment overall is to abandon nuclear and fossil-fuelled power plants and move on to more renewable power sources, such as photovoltaic (PV) modules. This migration combined with the current smart grid trend and the intermittent nature of the renewable power sources, may produce a negative impact on the reliability of the distribution networks. In this paper, the impact of the migration from centralized conventional power plants to distributed generation renewable energy sources will be analysed from a reliability perspective, considering the current trend of large scale PV system installation on low-voltage distribution networks (PV modules on household’s rooftops spread all over the cities). The purpose of this study is to have an overview of how the reliability of a distribution network will be affected during the migration process and within a 100% renewable scenario. To achieve this goal, a typical low-voltage distribution network is considered in this paper and three different scenarios based on availability of the photovoltaic and power grid generations are defined. These scenarios are then studied and reliability-related indexes are calculated [2] in order to establish advantages and disadvantages of each scenario. The defined scenarios for the electric power supply are as follows: 1. Conventional power grid: no distributed PV systems considered, only centralized generation. 2. Hybrid power grid: both centralized generation and distributed PV generation is considered. 3. 100% renewable power grid: only distributed PV generation is considered, meaning that a full migration from centralized power generation to distributed renewable (PV) generation has been achieved. Simulation of these scenarios and comparing their results will help to answer the following questions: - How does the introduction of renewable power sources affect the reliability of the distribution network? - How would a distribution network perform with only distributed renewable energy sources in terms of reliability indices? - What are the advantages and disadvantages of each scenario? A three-bus distribution system with two photovoltaic generators [3] is used to test the aforementioned scenarios. A general conclusion is that adding the photovoltaic generators to the system can considerably increase the system reliability, while trusting only on these photovoltaic generators may cause a catastrophic result. Keywords: Distribution system; Photovoltaic; Power system reliability References [1] European Commission, (2015, May). “Europe 2020 Targets”. Available: http://ec.europa.eu/europe2020/europe-2020in-a-nutshell/targets/index_en.htm [2] J. Setreus, C. J. Wallnerström, P. Hilber, C. Böös, R. Göransson, “RACalc – a Power Distribution Reliability Tool”. Stockholm, Sweden. [3] H. S. Huang, J. C. Jao, K. L. Yen, C. T. Tsai, “Performance and Availability Analyses of PV Generation Systems in Taiwan”. International Journal of Electrical, Computer, Electronics and Communication Engineering Vol:5, No:6, 2011.

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An energy-stored boost inverter for photovoltaic systems Minh-Khai Nguyen, Chang-Jin Kim, Dong-Jin Lee, Youn-Ok Choi and Geum-Bae Cho Department of Electrical Engineering, Chosun University, 61452 Gwangju, Korea

With using of the renewable energy sources increasingly, the application of the distributed generation (DG) in the distribution system acquired more attention. The DG systems are powered by micro sources such as fuel cell (FC), photovoltaic (PV) and wind energy that generate their power at very low voltage are unsuitable for grid connection directly without transformer. A quasi-switched-boost inverter (qSBI) can replace a quasi-Z-source inverter (qZSI) in low-power applications because it has one less LC pair than the qZSI. In this paper, a power conversion system which is integrated to a microgrid using the embedded-type qSBI is presented. The embedded-type qSBI with battery operation can balance the fluctuations from photovoltaic panel and supply the continuous power to the grid whenever photovoltaic panel cannot generate the power because of some low irradiation. The inverter output power and the battery power can be controlled, simultaneously. The voltage boost, energy storage and inversion are integrated in a single stage inverter. A control method for the energystored embedded-type qSBI when applied to the photovoltaic power system are presented. Operating characteristic of the proposed solution is presented. Simulation results are shown to verify the validity of the energy-stored boost inverter. Keywords: power conversion; boost inverter; energy storage system (ESS); single-phase inverter; PV system Acknowledgments This work was supported by the Human Resource Training Program for Regional Innovation and Creativity through the Ministry of Education and National Research Foundation of Korea (NRF-2014H1C1A1066713). Also, this work was supported by the Korea Institute of Energy Technology Evaluation and Planning (KETEP) and the Ministry of Trade, Industry & Energy (MOTIE) of the Republic of Korea (NO. 20164010201020). References [1] Nguyen M. K., Le T. V., Park S. J., Lim Y. C., "A Class of Quasi-Switched Boost Inverters,“ IEEE Trans. Ind. Electron., vol.62,no. 3, 1526-1536, March 2015. [2] Y. Liu, B. Ge, H. Abu-Rub, and F. Z. Peng, "Control system design of battery-assisted quasi-Z-Source inverter for grid-tie photovoltaic power generation," IEEE Trans. Sustain. Energy, vol. 4, no. 4, pp. 994-1001, Oct. 2013. [3] B. Ge, H. Abu-Rub, F. Z. Peng, Q, Lei, A. T. de Almeida, F. J. T. E. Ferreira, D. Sun, and Y. Liu, "An energystored quasi-Z-source inverter for application to photovoltaic power system " IEEE Trans. lnd. Electron., vol. 60, no. 10, pp. 4468-4481, Oct. 2013. [4] O. Tremblay, L. A. Dessaint, and A. I. Dekkiche, "A generic battery model for the dynamic simulation of hybrid electric vehicles," in Proc. IEEE Vehicle Power Propul. Conf., TX, 2007, pp. 284-289. [5] H. Fakham, D. Lu, B. Francois,‘Power control design of a battery charger in a hybrid active PV generator for loadfollowing applications’, IEEE Trans. Ind. Electron., vol. 58, no. 1, pp. 85–94, 2011. [6] Y. Riffonneau, S. Bacha, F. Barruel, S. Ploix, ‘Optimal power flow management for grid-connected PV systems with batteries’, IEEE Trans. Sustain. Energy, vol.2, no. 3, pp. 309–320,201.

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Conduction-Band Positions in Oxide Semiconductors (TiO2, SnO2): Experiments, Theory and Energy-Applications Ladislav Kavan J. Heyrovský Institute of Physical Chemistry, v.v.i., Academy of Sciences of the Czech Republic, Dolejškova 3, CZ-18223 Prague 8, Czech Republic

The electronic band structure of TiO2 or SnO2 is of fundamental implication for variety of applications in electrochemistry and photocatalysis. The position of conduction band (CB) edge controls the reductive photocatalytic reactions (e.g. hydrogen evolution from water or CO2 reduction), potential of dye-sensitized solar cell (DSC), recombination blocking in perovskite solar cells, etc. However, there is a considerable controversy about the position of CB in TiO2 (anatase, rutile, including the crystals with distinguished facets) [1]. Long-time debate concerns the fact that the CB edge of rutile (in contrast to anatase) is not sufficiently upshifted compared to the energy equivalent to the H+/H2 reduction potential [1]. A standard electrochemical tool monitoring the CB edge is the flatband potential. It is measured by Mott-Schottky plots from electrochemical impedance spectroscopy, onset of anodic photocurrent of water oxidation or dark H+ reduction, cyclic voltammetric mapping of DOS including the electron trap states, spectroelectrochemical determination of optical absorbance of CB electrons, etc. The staggered alignment in mixed phases, such as in anatase/rutile, is assumed to enhance photocatalytic activity of titania, but it is widely disputed whether the conduction band edge of rutile or that of anatase is higher. Photoelectron spectroscopy (PES) and most DFT simulations support the former, but the flatband potential measurements provide just opposite results. The controversy can be explained by taking into account the adsorption of OH– and H+ ions from the electrolyte solution on the electrode surface [2,3]. Furthermore, PES indicates that the CB edge of (001)-anatase is upshifted by 0.1 eV referenced to (101)-anatase in agreement with the DFT calculation [4] and with the electrochemical flatband potentials (upshift of CB by 60 meV) but there are again some conflicting works claiming the opposite (see Ref. [5] for discussion). The lowtemperature ALD-grown SnO2 layers are of particular interest for blocking layers (electron selective contacts) in perovskite solar cells [6]. Amorphous SnO2 films are perfectly pinhole-free for thicknesses down to 2 nm. Their excellent blocking behavior allows photoelectrode designs with even thinner electron selective layers thus potentially minimizing resistance losses. The compact nature and blocking function of thin SnO2 films is not perturbed by annealing at 450 oC, which is a significant benefit compared to other amorphous ALD oxides [6]. Amorphous and crystalline ALD SnO2 films substantially differ in their flatband (and conduction band) positions. This needs to be be taken into account when considering band alignment engineering in solar devices using these high-quality blocking layers. Acknowledgement: This work was supported and by the Czech National Science Foundation (contract No. 13-07724S). Keywords: titanium dioxide; tin dioxide; electrochemistry; photoelectrochemistry; solar cells References [1] L. Kavan, Chem. Rec., 12 (2012) 131. [2] J. Kullgren, B. Aradi, T. Frauenheim, L. Kavan, P. Deak, J. Phys. Chem. C, 119 (2015) 21952. [3] P. Deak, J. Kullgren, B. Aradi, T. Frauenheim, L. Kavan, Electrochim. Acta, 199 (2016) 27. [4] F. De Angelis, G. Vitillaro, L. Kavan, M. K. Nazeeruddin, M. Grätzel, J. Phys. Chem. C, 116 (2012) 18124. [5] B. Laskova, T. Moehl, L. Kavan, M. Zukalova, X. Liu, A. Yella, P. Comte, A. Zukal, M. K. Nazeeruddin, M. Grätzel, Electrochim. Acta, 160 (2015) 296. [6] L. Kavan, L. Steier, M. Grätzel, J. Phys. Chem. C, DOI: 10.1021/acs.jpcc.6b09965 (2016)

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Corrosion of low-alloy steel in molten sodium nitrate at 340°C Sylvie Delpech and Kim LE Institut de Physique Nucléaire - CNRS/IN2P3 Univ. Paris Sud, Université Paris Saclay, 91406 Orsay, France

Concentrating solar power (CSP) systems which use concentrated sunlight to produce electricity by turning steam turbines have been receiving a lot of attention in recent years. However, as we all know, solar energy is a fluctuating resource because of the daily rotation of the earth, seasons and weather conditions. The challenge here is to store this energy and release it at the right time. An innovative thermal storage solution has been developed to apply to CSP plants with direct steam generation. Principle of the storage is using a phase change material (PCM) for storing and releasing thermal energy. During the storage phase, when the sun shines, the heat transfer fluid passes through a heat exchanger and transfers its heat to the PCM, making it to change phase from solid to liquid. The releasing phase is done with the same way, the heat transfer fluid is now heated in the exchanger, and in this case, the PCM passes from the liquid phase to the solid phase. Today, molten salt is an important solvent system for high temperature applications. Nitrates melt are privileged materials to fill the role of material storage due to the high heat capacity, low melting point, and easy availability. However, the corrosion reaction which occurs between the molten salt and the structural material (using to make heat exchanger and tank) is an issue both for mechanical resistance and heat transfer efficiency. Based on good understanding about the corrosion products nature, the kinetics of corrosion of iron in fused salt nitrate, the design, operational conditions, the thickness of heat exchangers required for operation in a given period can be calculated. In this work, the behavior of low alloy steel in pure molten sodium nitrate (NaNO3) was studied. Corrosion tests of steel in NaNO3 at 340°C by weight-loss method were conducted and corrosion rate was found to follow a logarithmic kinetic: In addition, DRX and Tof-Sims analysis performed at the end of corrosion test proved the formation of an oxide layer especially constituted of Fe2O3. Besides, the electrochemical behavior of steel in NaNO3 at 340°C compared to a platinum electrode in the same media is also investigated by electrochemical methods. The similarity of the i-E stationary curves obtained by chronoamperometry showed that corrosion of steel lead to formation of a protective and conductive oxide layer on the steel’s surface. This observation is consistent with the formation of Fe2O3. Impedance spectroscopy measurements were also performed at open circuit potential (corrosion potential) to have additional information on corrosion kinetics and characteristics of the layers (resistance, capacitance…). A corrosion mechanism of steel in NaNO3 at 340°C is also proposed. The kinetic analysis of the mechanism combined with the fit of the impedance diagrams leads to calculate the corrosion rate of steel in nitrate molten salt at 340°C, the results so obtained being in good agreement with those obtained by weight loss/gain method. This study has shown the possibility of using impedance spectroscopy to measure in-situ the corrosion kinetic of steel. The primary advantage of this method is to obtain data at the corrosion potential without applying a potential which could be responsible of a modification of interface and therefore of a modification of the corrosion process. Other experiments will be performed by impedance spectroscopy to evaluate the corrosion of steel in thermal cycling conditions. Keywords: Nitrate storage; Impedance spectroscopy; Corrosion

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Czochralski and mono-like silicon solar cells p-type and n-type relationship between strain and stress reduced from the Al back contact and photovoltaic properties Thu Nhi Tran Thi1, Sébastien Dubois2, Nicolas Enjalbert2, Bruno Fernandez3, Tobias Schülli1, Tamzin lafford4 and José Baruchel1 1

European Synchrotron Radiation Facility, 6 rue Jules Horowitz, BP 220, 38043 Grenoble cedex 9, France CEA-INES, Savoie Technolac, 50 avenue du Lac Léman, 73375 Bourget du Lac, France 3 Institut Néel CNRS/UJF UPR2940, 25 rue des Martyrs, BP 166, 38042 Grenoble cedex 9, France 4 IBEX Innovations Ltd., NETPark, Sedgefield, TS21 3FH, United Kingdom 2

The target for manufacturers of photovoltaic (PV) silicon solar cells is to reach the highest photovoltaic (PV) efficiencies reproducibly. For p-type Si solar cells with screen-printed aluminium-alloyed emitter back contacts which are now in industrial production, cell efficiencies of up to 20% have been reported, while n-type silicon is also of interest since PV efficiencies of up to 22% to 23% in Cz-Si have been obtained. Our focus is on finding an explanation for the differences in those efficiencies, based on the structure of the solar cells, especially the back contact. Optimisation of the back contact has been largely an empirical process until recently. With p-type Si solar cells with screen-printed Al back-planes, the back contacts are created with a p+ doped layer/eutectic AlSi layer structure at the Si surface. The formation of the eutectic layer is a consequence of the screen-printing and annealing process, but it is not part of the device structure as designed. With its inhomogeneity, it causes distortion and strain of the Si at the back surface, which play an important role in the electrical properties of the solar cells, affecting the PV efficiency. X-ray diffraction imaging in section (section topography, which is carried out in transmission geometry) and X-ray nano-diffraction carried out at the European Synchrotron Radiation Facility (ESRF) gave quantitative, spatially-resolved information on these deformations. The Full Width at Half Maximum (FWHM) cross-section maps of full p-type Si solar cell structures (Si 220 reflection) show that the FWHM varies significantly, from 8×10-3 degrees at the interface of the Si at the back side, to 1×10-3 degrees in the Si bulk. The distorted zones (caused by inhomogeneity of the eutectic layer) were found to be 30 μm to 60 μm thick, have a strong influence on the minority carrier life time and the electron mobility. By contrast, in the case of n-type solar cells where the back-plane is made of SiO2 and silicon nitride, the FWHM profile shows much less distortion of the Si at the back interface (~3×10-3 degrees) with the thickness of the distorted zone less than 20 μm only, thanks to the absence of a eutectic layer in this structure. The mechanical stress (bowing) is another parameter that was extracted from white beam X-ray diffraction (in the range of 0.6 mm to 1 mm for wafers 15.6 × 15.6 cm2). This low bowing aids solar cell module manufacture, reducing the frequency of wafer breakage at this stage. The work focuses in detail on the relation between electrical properties (Jcc and Voc, measured by illuminated Current-Voltage (I-V) measurements; and the IQE extracted from Light-Beam Induced Current (LBIC)), the distortion of the Si and the morphology and composition of different Al pastes used for screen-printed Al layer and also bulk carrier lifetime, the electron mobility and the rear surface passivation. Those parameters have important influence on the PV efficiency. We conclude that the size of the Al particles in the Al paste is a potential cause of the differences in PV efficiency, via the inhomogeneity of the eutectic layer and the deformation induced at the Si back surface. On the other hand, the experimental results highlight a clear correlation between the solar cell performances (i.e., the PV conversion efficiency and the electron diffusion length), the overall stress (measured by WB topography) and the local (in the vicinity of the Al-doped Si layer) compressive strain (extracted from nano X ray diffraction): the lower the stress and strain values, the higher the PV performances. Our results clearly demonstrate that advanced synchrotron methodologies are valuable techniques for investigating not only the structure and crystalline perfection of Si but also features associated with electrical efficiency affecting the selection of production parameters.

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Digital charge controller for battery bench in a photovoltaic system S. Ould Amrouche1, S.H. Saidj1,2, S. Boumechta1 and A. Hadj Arab1 1 2

Renewable Energy Development Center, B.P. 62, Route de l’Observatoire, Bouzareah, C.P. 16340, Algiers, Algeria Laboratory of Photovoltaic Communication and Conversion Devices, Ecole Nationale Polytechnique, B.P. 182, ElHarrach, Algiers 16200, Algeria

Currently the most suitable solution to take advantage of all the energy produced by a solar panel is to store some of this energy in the batteries. The storage makes it possible to ensure the supply in all circumstances (day, night, overcast sky). Nevertheless it is risky to connect a battery directly to a solar panel because its level of charge should be neither too low (deep discharge) nor too high (overload). In both cases, the battery worsens and its lifetime decreases significantly. Consequently, this work aims to realize a digital controller based on a microcontroller for a bench of batteries connected to a photovoltaic system. The charge is limited to a maximum potential, and the discharge to a minimum potential threshold. To do this, the microcontroller uses a hysteresis for the charge / discharge cycle. The duty cycle of the control signal is variable, according to the measured voltage. Some experimental results are presented in this paper. Keywords: PV System; Battery; Controller; Charge; Digital; microcontroller References [1] Galib Hashmi, Manjurul Alam Dipon and Md. Habibiur Rahman ‘Design & Development of a Microcontroller Based High-Efficient Smart Solar Charge Controller for Standalone Solar Photovoltaic Systems’ J. Bangladesh Electron. 11 (12); 25-33, 2011. [2] James P.Dunlop ‘Batteries and Charge Control in Stand-Alone Photovoltaic Systems Fundamentals and Application’ Florida Solar Energy Center; FSEC-CR-1292-01. [3] Cheikh, MS Aït, et al. "Simulation et réalisation d’un contrôleur de batterie solaire à base de PIC16F876" Revue des Energies Renouvelables SIENR’12 Ghardaïa (2012) 1 – 9.

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Effect of Dust accumulation on the solar cells efficiency at Jazan region Rachid Karmouhc Physics Department, Science College, Jazan University, PO Box 114, 45142 Jazan, Saudi Arabia

The accumulation of dust on the solar cells panels worsens the situation and lowers the efficiency of the solar cells day by day especially in the regions known by their high rate of dust, low frequency and intensity of rain. The accumulated dust on the solar cells panel blocks the cells from the sun’s rays and act as a screening effect as shown by the calculated spectral transmittance of dust which decreases the performance of the solar cells over time until the cell panels are cleaned manually or by rain. The tilt angle of the solar cell panels affects considerably the amount of accumulated dust on the surface of the panels. This effect is tested in outdoor measurements at Jazan region known by the frequent dust storm. The results show a reduction of the solar cells efficiency by 10% for an exposure time of 16 weeks. Moreover the tilted panel with a 30º shows more efficiency loss compared to the one tilted by 50º.

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Energy, environmental and economic efficiency of solar photovoltaic in the central part of Europe S. Wciślik Department of Environmental Engineering, Kielce University of Technology, Aleja Tysiąclecia Państwa Polskiego 7, 25314, Kielce, Poland

This paper analyses energy, environmental and economic efficiency of solar photovoltaic installation located in the middle of Europe (Poland), where the intensity of the sun radiation is not too high in comparison with other Europe [1] world countries [2]. Currently, one of the basic requirements posed for the buildings subjected to modernization is to reduce carbon dioxide emissions even above 90% in comparison with the original values. In order to fulfil such criteria, it is necessary to apply alternative solutions based on renewable energy sources. The solar PV provide a rational option. For such a case, the emissions of basic pollutants such as CO2, SOx, NOx or particulates is obtained. European law [3] prompts us to the use of renewable energy sources, but often cost-effectiveness analysis of their use demonstrates a lack of profitability. The study also gives the results of calculations of payback time (SPBT, NPV and IRR) for an exemplary investment. Keywords: solar PV; SPBT; NPV; IRR; carbon dioxide emissions; emissions equivalent; Thermal Energy Storage (TES); Electrical Energy Storage (EES); sun radiation; renewable energy economics References [1] J. Hernandez-Moro, J.M.Martinez-Duart, Analytical model for solar PV and CSP electricity costs: Present LCOE values and their future evolution, Renewable and Sustainable Energy Reviews 20 (2013) 119–132 [2] T.A. Deetjen et al., Solar PV integration cost variation due to array orientation and geographic location in the Electric Reliability Council of Texas, Applied Energy 180 (2016) 607–616. [3] Directive 2006/32/EC of the European Parliament and of the Council of 5 April 2006 on energy end-use efficiency and energy services and repealing Council Directive 93/76/EEC.

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EU resilience to potential supply bottlenecks along the rare earths value chain for the future deployment of wind power in the EU D. Blagoeva, P. Alves Dias, A. Marmier and C. Pavel European Commission, Joint Research Centre, PO Box 2, NL-1755 ZG Petten, the Netherlands

Wind energy is one of the most cost-effective technologies that can contribute to climate-change mitigation. Further penetration of wind technology in the EU and global markets is dependent on its techno-economic characteristics alongside regulatory frameworks and the effectiveness of energy policies. Nevertheless, it will also be influenced by the stability of the rare earths supply and prospects of prices. Rare earths, namely neodymium, praseodymium and dysprosium, are key ingredients of permanent magnet synchronous generators (PMSG). Concerns that the supply of rare earths may not be sufficient to meet the expected growing demand emerged through the rare earths crisis in 2011, during which near-monopolistic China imposed export restrictions. As a follow-up of these export restrictions, several studies flagged rare earths as critical, on the basis of their economic importance and high supply risks for the EU economy [1], and also specifically for the energy sector [2]. This work focuses on identifying whether neodymium, praseodymium and dysprosium might holdup the widespread adoption of wind energy in the EU until 2030. The results are presented in terms of the EU resilience to potential supply bottlenecks, with final scores ranging from low, medium and high. The assessment is based on a comprehensive methodology relying on sets of indicators covering both upstream and downstream dimensions of the value chain. The methodology is described in detail in a recently produced report by the authors [3]. In this approach, the EU mine production, recycling and substitution potentials serve as mitigation factors, therefore deriving three resilience scenarios. This study looks at the 2030 time horizon with 5-y. time intervals. The analysis shows that the EU resilience remains low for neodymium, praseodymium and dysprosium until 2030 without mitigation measures in place. The potential to increase mine production in the EU, based on an assessment of current development-stage exploration projects, will have limited impact on the resilience of these rare earth elements. Recycling, on the other hand, if developed as forecasted could have a more tangible effect on improving resilience, although this is not sufficient to reach the medium-resilience level in 2025. It is only thanks to substitution alternatives, applied in addition to an increase in mining production and recycling, that the EU resilience can improve to medium level for the three rare earth elements in 2025. In 2030, increased recycling rates, might just be sufficient to raise EU resilience to the medium level. However, the supply situation can only be substantially improved if substitution is developed to a feasible forecasted rate of around 60%, ultimately moving EU resilience closer to the high level in 2030. Keywords: Rare earths; Supply bottlenecks; EU resilience References [1] European Commission, 2014. Report on critical raw materials for the EU. Report of the Ad hoc Working Group on defining critical raw materials. [2] R. Moss, E. Tzimas, H. Kara, P. Willis, J. Kooroshy, 2011. Critical metals in strategic Energy technologies; EUR 24884; doi: 10.2790/35600. [3] D. T. Blagoeva, P. Alves Dias, A. Marmier, C.C. Pavel, 2016. Assessment of potential bottlenecks along the materials supply chain for the future deployment of low-carbon energy and transport technologies in the EU. Wind power, photovoltaic and electric vehicles technologies, time frame: 2015-2030; EUR 28192 EN; doi:10.2790/198578

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Experimental Study of a Plan Solar Still Region of Béchar, South Algeria M. Abdelkarim1,*, B. Bounegta2 and Y. Touhami2 1

Laboratoire d'ARCHItecture et Patrimoine EnvironnementaL chez ARCHIPEL, University of Bechar, BP 417 Route de Kenadsa, 08000 Bechar, Algeria 2 University of Bechar, BP 417 Route de Kenadsa, 08000 Bechar, Algeria * Corresponding author: email: [email protected]

Algeria as many developing countries has considerable saline water resources (salt content varies between 1500 and 2000 ppm, values that exceed the required standards for drinking water which means that this water is not fit for human consumption), which leads us to think about ways to make the most of this huge water supply by developing desalination techniques. Therefore, the aim of this research work is to take a serious interest in the desalination of saline water through plan solar stills, and the main planned task is to realize a plan solar still which fulfils drinking water requirements. However, classical desalination plants need important amounts of electrical and calorific energy that the areas of study don’t have. Using solar energy for desalination is an adequate solution of many problems. Such an installation is constituted by a recovery pool with a black absorbing layer and a transparent recovery plate made of glass or plastic. Saline water is water that contains a significant concentration of dissolved salts (mainly NaCl) and is commonly known as salt water. The salt concentration is usually expressed in parts per thousand (permille, ‰) or parts per million (ppm). The United States Geological Survey classifies saline water in three salinity categories. Salt concentration in slightly saline water is around 1,000 to 3,000 ppm (0.1-0.3%), in moderately saline water 3,000 to 10,000 ppm (0.3-1%) and in highly saline water 10,000 to 35,000 ppm (1-3.5%). Introduction The need for drinking water is in a steady increase worldwide while underground water supply is quickly taking its way to be exhausted. Demands for drinking water have increase rates of around 4% per year, whereas the third of the mankind still don’t have access to drinking water. Amidst this water supply crisis which is getting worse worldwide, coupled with economic constraints in order to achieve sustainable development, adequate solutions have to be envisaged for the sake to face the new upcoming challenges which make the humankind survival on earth at stake [1, 2]. However, classical desalination plants need important amounts of electrical and calorific energy that the areas of study don’t have. Using solar energy for desalination is an adequate solution of many problems. For example, when demands for water are relatively low (few m3 to some tens of m3), direct solar distillation seems to be a good solution, especially in case of operating with a qualified staff [3, 4, 5]. Sizing and Installing

Fig. 1 Plan Solar Still model Keywords: plan solar stills; water; the multi parameter C861; glass; solar References [1] N.Kerroumi « Modélisation et étude expérimentale d’un capteur solaire à air destiné pour le chauffage domestique ». [2] B. Draoui, N. Fezzioui «Energie solaire & capteur solaire, cours et exercices avec solution, centre universitaire de Bechar, 2001 » [3] J.Bernard «Energie solaire, calculs et optimisation », Ellipses édition Marketing S.A2004, Paris. [4] L.Bellal, A.Maachou « Etude et réalisation d’un distillateur solaire », Oran 1990 [5] A.Harmim, M.Boukar, M.Gahgah «Chauffage solaire » Rapport d’activités 2003 Adrar [6] Bernard, G. Menguy, M.Schwartz «Conversion thermique et applications » Edition Paris technique et documentation 1980. [7] F.Haoula, T.Touati «Le dessalement des eaux salées à l’aide d’un distillateur solaire » Centre universitaire de Bechar. 43


Fabrication of Cu2ZnSn(S,Se)4 Thin Film Solar Cell by introducing a Carbon Intermediate Layer at the Absorber/Back Contact Interface Hyeongho Shin and Jinhyeok Kim Optoelectronic Convergence Research Center, Department of Materials Science and Engineering, Chonnam National University, 300 Yongbong-Dong, Puk-Gu, Gwangju 500-757, South Korea

Cu2ZnSn(S,Se)4(CZTSSe) absorber thin films were sputter coated on Mo-coated soda-lime glass (SLG) substrates followed by sulfo-selenization of stacked Cu/Sn/Zn precursor thin films using rapid thermal annealing (RTA) system. The resulting films were processed into solar cell devices by following the standard procedures that include chemical bath deposition of CdS (~60 nm), radio frequency (RF) sputtering of i-ZnO (~100 nm) and Al-ZnO (AZO) (~600 nm), and direct current (DC) sputtering of a patterned Al grid as the top electrode. Back contact modifications play an important role in improving the solar energy conversion efficiency of CZTSSe thin film solar cells. Therefore, an investigation into carbon thin intermediate layer at CZTSSe/Mo contact has been studied in the present work. Deposition of carbon intermediate layer has been carried out by thermal evaporation system. The effects of carbon intermediate layer on the microstructure, crystallinity, electrical properties, and cell efficiencies of CZTSSe thin film solar cells have been studied by using field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), Raman spectroscopy, I-V measurement, and external quantum efficiency measurement system(EQE). The fabricated CZTSSe thin film solar cell using thin carbon intermediate layer showed a conversion efficiency of 7.62%(Voc:415mV, Jsc:34.84mA/cm2, FF:52.7% and active area is 0.3cm2). Keywords: Cu2ZnSn(S,Se)4(CZTSSe); Thin film solar cells; Intermediate layer; Back contact References [1] Fangzhou Zhou, et all , ACS Appl. Mater. Interfaces 2015, 7, 22868−22873

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Forward bias (EL) and reverse bias luminescence (ReBEL) imaging of silicon solar cells using a consumer grade camera K. Lobato1,*, M. Frazão2, J.A. Silva1 and J.M. Serra2 1

Instituto Dom Luiz, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal * Corresponding author: email: [email protected]

2

An electroluminescence measuring system was developed [1,2] based on a consumer grade Nikon D40 digital camera equipped with a complementary metal oxide semiconductor (CMOS) sensor. The system was used to perform Electroluminescence (EL) and Reverse Bias Electroluminescence (ReBEL) imaging. Validation occurred by comparison with a similar setup employing a specifically developed scientific grade Sensovation HR-320 camera equipped with a charge coupled device (CCD) sensor [3]. The imaging performed permitted the identification of defects such as metal contaminations, shunts, metal contact failures or cracks. Defects such as metal contamination and cracks were also induced for observation. Furthermore, luminescence measurements were performed at different temperatures which permitted the differentiation between intrinsic and extrinsic defects [4]. Thermography imaging using a Xenics GOBI-2833 camera equipped with an amorphous silicon sensor was also undertaken for further comparison and validation. Shown in Fig. 1 is an example of EL, ReBEL images of a mc-Si solar cell using the consumer grade camera. Also shown is a thermography image of the same solar cell. The EL image is a typical image resultant from a mc-Si solar cell - darker areas of lower luminesce indicate high recombination regions. The observed darker lines are due to gran boundary recombination. The significantly brighter top-right area is a result of current collection concentration occurring via a point probe on the busbar. The image also shows that on the left-hand border there is an area with darker spots indicating problems in the either boron diffusion and/or passivation during solar cell manufacturing. These problems are not observed in the thermography image which is fairly homogenous with no hotspots indicating that shunting is not occurring. The three ReBEL images serve the purpose of differentiating between types of defects [5]. In this type of imaging, areas of luminesce are indicative of recombination (unlike EL imaging). At 8 V no luminescence is observed suggesting that type-1 surface defects due to Al contamination are not present. At 12 V emission occurs in the same left-hand side border which has been highlighted as problematic from the EL images. This indicates the presence of type-2 defects induced by metal-containing precipitates lying within recombination-active grain boundaries. Finally, at the 16 V bias, type-3 avalanche breakdown is observed resulting from etch pits. To further analyze the influence of defects and confirm defect type (induced or not), the solar cells were also characterized by Suns-Voc, AM1.5G iV, dark iV and local quantum efficiency. Forward Bias EL

Reverse Bias EL

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EL -0.6 V

8V

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Fig. 1 Forward bias EL image and reverse bias images of a 156×156 cm mc-Si solar cell using a consumer grade CMOS camera. Also shown is a thermography image. On all images whiter indicates more luminescence emission for the EL and ReBEL images and higher temperature for the thermography image. Keywords: luminescence imaging; electroluminescence; ReBEL; thermography; multicrystalline silicon References [1] M Frazão et al., Measurement 99, p.7 (2017), doi: 10.1016/j.measurement.2016.12.017 [2] JA Silva et al., EMRS 2016 Spring Meeting, Lille France [3] J Madeira et al., EMRS 2012 Spring Meeting, Strasbourg France [4] T Fuyuki & A. Kitiyanan, App. Phys. A 96, p189 (2009), doi: 10.1007/s00339-008-4986-0 [5] O Breitenstein et al., J. Appl. Phys. 109, p.071101 (2011); doi: 10.1063/1.3562200 45


High temperature hyperbolic metamaterial for selective thermal emitters in thermophotovoltaic (TPV) systems P.N. Dyachenko1, S. Molesky3, A.Y. Petrov1,2, S. Lang1, M. Störmer4, T. Krekeler5, M. Ritter5, J. Zubin3,6 and M. Eich1,4,* 1

Institute of Optical and Electronic Materials, Hamburg University of Technology (TUHH), Eißendorfer Straße 38, 21073 Hamburg, Germany 2 ITMO University, 49 Kronverskii Ave., 197101, St. Petersburg, Russia 3 University of Alberta, Department of Electrical and Computer Engineering, 9107 - 116 Street, T6G 2V4, Edmonton, Canada 4 Institute of Materials Research, Helmholtz-Zentrum Geesthacht, Max-Planck-Straße 1, 21502 Geesthacht, Germany 5 Electron Microscopy Unit, TUHH, Eissendorfer Strasse 42, 21073 Hamburg, Germany 6 Birck Nanotechnology Center, School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN 47906, United States * Corresponding author: email: [email protected]

In order to tailor emitters for thermophotovoltaic (TPV) systems to match specific photovoltaic receivers a spectrally selective emitter is required that have close to black body emission at short wavelengths and substantially reduced emission at long wavelengths. We propose a hyperbolic metamaterial for this purpose which changes its emission properties close to the topological transition of its isofrequency surface. At short wavelength the metamaterial has permittivity close to one and thus efficiently absorbs and emits radiation. At longer wavelength, beyond the topological transition, the thermally excited hyperbolic modes employ large wave vectors and thus cannot leave the metamaterial due to total internal reflection. In order to emit significant power at the wavelengths usable for photovoltaic conversion (below 2 µm) the TPV-emitter needs to be heated to high temperatures and thus must be thermally stable. We demonstrate selective band-edge emitters based on a W-HfO2 layered metamaterial [1]. The thicknesses of tungsten and hafnium oxide are 20 and 100 nm correspondingly. The metamaterial selectivity comes from the change in effective permittivity and does not rely on the phase matching condition. Thus the metamaterial exhibits almost angle independent selective emission. Stability up to 1000°C is demonstrated in vacuum conditions. At higher temperature residual oxygen in vacuum diffuses through HfO2 cap layer and oxidizes the upper W layer of the metamaterial leading to degradation of the selective emission.

Fig. 1 a) Absorptivity/Emissivity of the tungsten based metamaterial after annealing in vacuum. Schematic inset shows the layered structure of W-HfO2 (20 nm-100 nm) metamaterial. Keywords: hyperbolic; metamaterial; high temperature; thermophotovoltaic; thermal emitter References [1] P.N. Dyachenko, S. Molesky, A. Yu Petrov, M. Störmer, T. Krekeler, S. Lang, M. Ritter, Z. Jacob, and M. Eich, Nat. Commun. 7, 11809 (2016)

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Improved performance of bulk-heterojunction solar cell embedding PbS nanoparticles with mixed surface-capping agents S. Fernández de Ávila, J.C. Ferrer, J.L. Alonso and F. Rodriguez-Mas POLI-NANO Research Group, Miguel Hernandez University, Avda Universidad s/n, Ed. Innova, 03202 Elche, Spain

In the last decades, photovoltaic cells based on bulk heterojunctions (BHJ) of semiconducting polymers are focusing the attention of researchers due to several potential advantages over their inorganic counterparts [1]. Among the different candidates to be used as active material for these cells, the mixture of poly(3hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) has been probably the most extensively studied system. However, hybrid nanocomposites consisting of semiconducting organic polymers hosting inorganic nanoparticles (NPs) combine the ease of processing of semiconducting polymers, and the properties of NPs, like size dependent optical absorption and multiple exciton generation. The optimal integration of these NPs in the hosting polymer and the electrical properties of the resulting nanocomposite strongly depend on the surface-capping agent which stabilizes the nanoparticles. Decanethiol is an organic radical which solubilizes NPs in the same polar solvents as P3HT:PCBM blend. Nevertheless, its isolating nature and length prevent the charge transfer from the nanoparticles to the surrounding material. Thiophenol is a shorter molecule with delocalized electrons which is more suitable when charge transport is required. Unfortunately, thiophenol stabilized NPs are insoluble in P3HT:PCBM compatible solvents. In order to combine the best properties of the two ligands, novel PbS nanoparticles have been synthesized following a modified chemical route based on the method of Herron et al. [2] which results in nanoparticles capped with a combination of both organic radicals. These colloidal nanoparticles have been easily incorporated into a blend of P3HT:PCBM in chlorobenzene solution. Two solar cells with an area of 4 cm2 were fabricated by spin coating: a reference bulk-heterojunction sample (BHJ) containing a P3HT:PCBM active layer, and a sample (PbS) with an active layer consisting in a blend of P3HT:PCBM with these PbS NPs. The incorporation of the nanoparticles into the P3HT:PCBM active layer of a photovoltaic cell results in the improvement of the short-circuit current, open-circuit voltage and maximum output power as shown in figure below [3]. Keywords: PbS nanoparticles; bulk heterojunction; photovoltaics; I-V characteristics References [1] M. T. Dang, L. Hirsch, G. Wantz, Adv. Mater. 23, 3597 (2011). [2] N. Herron, Y. Wang, H. Eckert.. J. Am. Chem. Soc. 112, 1322 (1990). [3] J.L. Alonso, J.C. Ferrer, F. Rodriguez-Mas, S. Fernandez de Avila, Opt. & Adv. Mat.- Rapid Commun. 10, 634 (2016). 0.5

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Influence of deposition methods on Cu2O thin films for solar cell application Jae Yu Cho and Jaeyeong Heo Department of Materials Science and Engineering, and Optoelectronics Convergence Research Center, Chonnam National University, Gwangju 500-757 Korea

Photovoltaic power generation as an infinite clean energy source is still below the widespread use because of power generation unit cost. Cu2O has large band gap of 2.17 eV. But, there are many reports on solar cells based on Cu2O as active layer because it shows many interesting characteristics such as earth-abundant, low cost, nontoxic, good mobility, and direct energy gap. The theoretical limit of the energy conversion efficiency of a Cu2O solar cell is 20%. [1] In this work, we have investigated changes in the properties of materials by two different deposition methods which contains sputtering and electrodeposition. In the sputtering method, the films were deposited using both Cu and Cu2O targets according to substrate temperature, rf-power, and annealing condition. Also, in the electrodeposition, the samples are prepared to study dependence of film properties on pH, temperature of solution, and potential. Finally, we confirmed the structural properties of thin films by XRD and SEM. Figure 1 is Result of optimized conditions for each deposition method. Si

1000

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Fig. 1 Result of optimized conditions for each deposition method. Keywords: Cu2O; Sputtering; Electrodeposition; Solar Cell; absorber layer References [1] T. Minami, Y. Nishi, and T. Miyata, Appl. Phys. Express. 8, 022301-4 (2015)

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Influence of surface etching treatment for the high efficient Cu2ZnSn(S,Se)4 (CZTSSe) thin film solar cell Hongjae Shim and Jinhyeok Kim Optoelectronics Convergence Research, Department of Materials Science & Engineering, Chonnam National University, Gwangju, South Korea

Cu2ZnSn(S,Se)4 (CZTSSe) absorber thin films were prepared on soda lime glass substrates by sulfo-selenization of sputtering deposited stacked Zn-Sn-Cu precursor thin films. The CZT precursor thin films were sulfoselenized in the S+Se vapor atmosphere. And after annealing try to surface etching. effect of different etching solution such as KCN, Ammonia, HCl on the structural, optical and electrical properties of the CZTSSe thin films were studied using FE-SEM (field-emission scanning electron microscopy), XRD (X-ray diffraction), XRF (energy dispersive spectroscopy), Dark current, SIMS (secondary ion mass spectrometry), Cell efficiency. The XRD, XRF, FE-SEM, Dark current, SIMS and Cell efficiency results indicated that the properties of sulfoselenized CZTSSe thin films were strongly related to the etching solution. In particular, the cell efficiency of the sulfo-selenized CZTSSe thin films indicated highest Jsc and FF using KCN etching as compared to that another etching process. The fabricated Cu2ZnSn(S,Se)4 thin film solar cell shows the best conversion efficiency of 7.93% (Voc : 453 mV, Jsc : 33.33 mA/cm2, FF : 52%, and active area : 0.3 cm2). Further detailed analysis and discussion for effect of etching solution on the properties CZTSSe thin films will be discussed. Keywords: CZTSSe; etching; KCN; Ammonia; HCl; thin film solar cells

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Influence of zinc oxide morphology on hybrid solar cells G.A.R. Maia1, L.F.G. Larsson1, A. Viomar1, S.R.M. Antunes2, E.C.R. Maia, H. de Santana and P.R.P. Rodrigues1,* 1

GPEL, Laboratório do Grupo de Pesquisas em Eletroquímica, Departamento de Química, Universidade Estadual do Centro-Oeste - UNICENTRO, Rua Simeão Varela de Sá , n. 03, CEP: 85040-080, Guarapuava, Paraná, Brazil 2 Universidade Estadual de Ponta Grossa, Departamento de Química, CEP: 87020- 900, Ponta Grossa- PR, Brazil 3 Universidade Estadual de Londrina, Departamento de Química, Rodovia Celso Garcia Cid, Km 380, s/n – Campus Universitário, Londrina - PR, 86057-970, Brazil * Corresponding author: e-mail: [email protected]

The technological advances require a clean and renewable energy sources development and replace the largest current source of energy, the fossil fuels. Inorganic/organic hybrid solar cells appear as an alternative to obtain photovoltaic energy. Poly(3-octylthiophene), P3OT, is an organic polymer formed by conjugated structures with conductive properties. ZnO presents physico-chemical characteristics with promising application in solar cells [1]. The film morphology has an important role for solar cells, so the standardization and regularity of the nanometric particles is dependent of variables such as: nature of precursor salt anion and reaction temperature [2]. This work aims to study the influence of the different ZnO nanoparticle morphologies applied in generation of photosensitive hybrid films with poly(3-octylthiophene) (P3OT) polymer. The co-precipitation method was used to generate ZnO particles, with 20 hours of time reaction and 80°C of temperature, varying the [Zn(NO3)2] in 5x10-2, 1x10-1 and 1,5x10-1 mol L-1. For particles characterization were used: light scattering measurements, scanning electron microscopy (SEM) and photoelectrochemical characterization by j x V curve. Light scattering analysis results showed that the particle size of ZnO was 500 ± 100 nm for different [Zn(NO3)2]. SEM images showed three different structures types due to [Zn(NO3)2] concentration variation (figure 1). The j x V curves showed different efficiency values (η / %) due to the different ZnO nanoparticles morphologies (Figure 2), and this result shows the direct ZnO morphology influence on the P3OT-hybrid solar cells efficiency.

(A)

(B)

(C)

Fig. 1 ZnO SEM images (A) spheres, (B) mosaic and (C) prism-hexagonal (10 m scale).

Fig. 2 Solar cells j-V curves for three ZnO morphologies.

Keywords: semiconductor; poly(3-octylthiophene); poly(3-hexylthiophene); solar energy Acknowledgments: To Fundação Araucária, CNPq, CAPES, FINEP, FAU - Unicentro for research financial support. References [1] MAIA, G. A. R.; LARSSON, L. F.; VIOMAR, A.; MATOS, L. A. C.; ANTUNES, S. R. M.; MAIA, E. C. R.; OLIVEIRA, M. F.; CUNHA, M. T.; RODRIGUES, P. R. P; Influence of zinc oxide morphology in hybrid solar cells of poly(3-octylthiophene), Journal of Materials Science, v. 27, p. 8271–8278, 2016. [2] MAIA, G. A. R.; VIOMAR, A.; LARSSON, L. F.; DE SANTANA, H.; MAIA, E. C. R.; ANTUNES, A. C., RODRIGUES, P. R. P; Aperfeiçoamento da produção de partículas de óxido de zinco para aplicação em células solares, Cerâmica, v. 62, p. 91-97, 2016.

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Luminescent, structural and chemical characterization of defects in polycrystalline thin film solar cells Mowafak Al-Jassim, Harvey Guthrey, Chun-sheng Jiang, John Moseley, Helio Moutinho and Adam Stokes National Renewable Energy Laboratory, Golden, Colorado 80401, USA

Polycrystalline thin film technologies are rapidly evolving to be an important part of the solar energy portfolio and currently have about 10% of the photovoltaics market share. Cell efficiencies exceeding 23% have been reported, which makes thin film solar cells competitive with wafer Si cells. However, this is still considerably lower than the theoretical efficiency limit. In this work, we report on the luminescent, chemical and structural properties of CIGS and CdTe cells. The purpose of the study is to investigate loss mechanisms in both CIGS and CdTe cells and devise a path forward for efficiency improvement. We combined scanning electron microscopy (SEM)-based cryogenic cathodoluminescence (CL) spectrum imaging and electron backscatter diffraction (EBSD) in order to map the spatial distribution of various atomic-level defects as a function of deposition and film processing. Two different deposition techniques were used. Lattice-matched, epitaxial CdTe films were deposited on single crystal as well as polycrystalline CdTe substrates by molecular beam epitaxy (MBE). For comparison purposes, polycrystalline CdTe films were deposited using our standard close-spaced sublimation (CSS) method on glass-based substrates. Correlations between the CSL relationship, defect structure, and radiative recombination intensity at grain boundaries and intra-grain regions are then made and discussed in the context of film deposition conditions and post-deposition processing history. Further, the effect of passivating treatments was investigated. The distribution of impurities on grain boundaries and intra-grain dislocations was studied by time of flight SIMS (TOF-SIMS) imaging, high resolution STEM-EELS and atom probe tomography. These results were correlated with the recombination behavior of these defects as revealed by CL. The results of this detailed characterization study are correlated with device performance. Keywords: thin films; solar cells; characterization

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Multi Role of Novel Ru Based Dye in Enhancing the Performance of Hybrid TiO2/P3HT Solar Cells K. Prashanthan1, T. Thivakarasarma1, P. Sumanthiran1, S. Rasalingam2, K. Mariappan3 and P. Ravirajan1,* 1

Department of Physics, University of Jaffna, Jaffna, Sri Lanka Department of Chemistry, University of Jaffna, Jaffna, Sri Lanka 3 Department of Chemistry, University of South Dakota, United States * Corresponding author: email: [email protected] or [email protected] 2

Hybrid polymer solar cells using colloidal Titanium dioxide (TiO2) nanoparticles as acceptors and poly(3hexylthiophenee) (P3HT) as donor material represent one of the most promising routes towards low-cost, renewable, carbon-neutral production of electrical power. However the poor power conversion efficiency found in such devices is mainly attributed to the poor compatibility between the metal oxide and polymer. This causes a higher degree of inefficient exciton dissociation at the heterojunction and interfacial charge recombination. Interface modification is a well-known and powerful technique to address this issue and the field has made impressive progress in recent years1-4. In this work, a thin layer of commercially available and widely used ruthenium (Ru) based dye, N719, and a newly synthesized [Ru(bpy)2(dcbpy)][PF6]2 (bpy = 2,2’-bipyridine; dcbpy = 4,4’-dicarboxy-2,2’-bipyridine) dye (RuC2) were introduced separately at the TiO2 / P3HT interface, and their effect in photovoltaic parameters were examined. UV-VIS spectroscopic measurement of the dye coated TiO2/P3HT nanocomposite and its control show that dye has a very weak contribution of the optical absorption of the nanocomposite. The results indicate that these two dyes only facilitate the electron transfer from P3HT to TiO2 than contributing charge carriers for device current. In addition, the RuC2 treated devices showed about a factor two enhancement in the power conversion efficiency compared to the devices treated with N719 dye. The reason for this observation may be due to the better adsorption of RuC2 dye on the surface of TiO2 than N719 dye as the dyes used in this study mainly differ in their chemical structures; the N719 dye consist NCS functional group along with substituted two biphenyl rings, whereas the newly synthesized dye contains three biphenyl rings with two COOH groups. Keywords: hybrid solar cell; P3HT; metal oxide; Ru dye References [1] R Ravirajan, P.; Peiró, A. M.; Nazeeruddin, M. K.; Graetzel, M.; Bradley, D. D.; Durrant, J. R.; Nelson, J., The Journal of Physical Chemistry B 2006, 110, 7635-7639. [2] Loheeswaran, S.; Balashangar, K.; Jevirshan, J.; Ravirajan, P.. Journal of Nanoelectronics and Optoelectronics 2013, 8, 484-488. [3] Planells, M.; Abate, A.; Snaith, H. J.; Robertson, N., ACS applied materials & interfaces 2014, 6, 17226-17235. [4] Thanihaichelvan, M.; Sockiah, K.; Balashangar, K.; Ravirajan, P., Journal of Materials Science: Materials in Electronics 2015, 26, 3558-3563.

52


New Geothermal Database for Hungary Aniko N. Toth* and Janos Zsuga University of Miskolc, Miskolc-Egyetemváros, 3515, Hungary * Corresponding author: email: [email protected]

Hungary’s excellent geothermal potential is well-known. Traditionally, most of the country’s thermal water has been used for spas. Of the geothermal energy production, most is used as a direct heat supply, to heat housing projects and businesses. As yet, there is no operational geothermal power-plant in Hungary, neither is the market for ground-source heat-pumps very strong, perhaps because of a depressed economy that has still not recovered from the global recession. Despite the weak economy, however, a few large-scale projects are being prepared. These are hindered by the absence of a strong, reliable and official government authority which can absolutely and unequivocally vouch for Hungary’s geothermal data. For this reason, the Hungarian Energy and Public Utility Regulatory Authority requested in 2016 that a study be made to analyze and summarize the geothermal potential of every one of the country’s 19 counties. The resulting study used information from the Hungarian Geological and Geophysical Institute, and consulted the geothermal databases of the Hungarian Office for Mining and Geology. These two sources yielded data for 1622 thermal wells. In addition, more than 70 abandoned hydrocarbon wells were also analysed, as the Hungarian Mine Utilization Company judged those wells to be suitable for geothermal use. In the course of assembling the necessary data into a national geothermal atlas, numerous smaller-scale charts and graphs and maps were also created. In addition to creating a solid informational basis where none had existed before, the study was valuable as a means of showing all 19 Hungarian county governments how they might profit from their geothermal potential. Keywords: Geothermal potential; thermal well; abandoned hydrocarbon well; national geothermal atlas

53


Optimized sizing of PV Battery standalone system (case study Tunisia) Aissaoui Abir1,*, Tlijani Hatem2 and Ben Younes Rached1 1

Electrical Department, National Engineering school of Gabes- Faculty of Science Gafsa, Ecole Nationale d’Ingénieurs de Gabes (ENIG), Unité de Recherche de physique informatique et mathématiques, Avenue Omar Ibn El Khattab, Zrig Eddakhlania ,6072, Gabes,Tunisia 2 Electrical Department, National Engineering School of Tunis, Ecole Nationale d’Ingénieurs de Tunis (ENIT), Laboratoire de Recherche en Automatique, (LA.R.A), BP.37, le Belvédère, 1002, Tunis, Tunisia * Corresponding author: email: [email protected]

Given that the Photovoltaic energy is clean free and inexhaustible it’s acquire a global importance but its intermittency and dependence on the weather condition is a problem to treat. The main objective of this paper is to characterize optimize and simulate a photovoltaic generator battery storage and boost converter MATLAB/SIMULINK model adopted combinary with annual measured meteorological data of Tunisia. Keywords: MATLAB_Simulink, PV generator, Battery Optimization, Tunisia

54


Photoelectrode morphology and kinetic processes in dye-sensitized solar cells with ionic liquid electrolytes F. Olmo-Sánchez, E. González-Galindo, M.J. Ariza and M.J. García-Salinas Applied Physics, CITE II-A, University of Almería, E-04120 Almería, Spain

After the initial development of dye sensitised solar cells (DSSCs) at the end of the nineties, different strategies aimed to improve their performance and stability modifying the original materials and setup [1]. One of the earliest attempts was to raise the stability of DSSCs using electrolytes based on ionic liquids (ILs) [2], but the reported energy efficiencies were always lower than that for liquid electrolytes, mainly due to kinetic limitation of the ion transport processes. Moreover, the main goal of DSSCs was to fabricate low-cost solar cells based on nontoxic materials [1-3], and ILs are more expensive and less environmentally friendly than conventional liquid electrolytes. Another strategy was to replace the electrolyte directly by a solid one, which led to develop perovskite solar cells (PSCs) [4]. Nowadays it is well know that PSCs are a different and emergent photovoltaic technology, but these two types of devices still share many features since both of them are hybrid solar cells based on big organic cations and inorganic anions and currently PSCs also have serious stability problems [5]. Despite all the disadvantages of DSSCs with ILs electrolytes technology, these photovoltaic devices are still very interesting from a fundamental point of view, since the photoelectrode TiO2 nanostructure provides an opportunity to study the kinetic of the IL ions confined in nanochannels or nanopores, which has not only photovoltaic energy production but many other applications [6]. In this work we fabricate and characterize the morphology of two mesoporous TiO2 nanostructures with two different surfactants (EC and T) following the procedure described in the bibliography [7-8]. After absorbing a commercial dye, they are tested as photoelectrodes of DSSCs using two ionic liquids of the same family but with different cation size (PMMI and BMII). The kinetics of the charge transfer and transport processes is studied by cyclic voltammetry and impedance spectroscopy. Current-voltage curves are measured in environmental conditions under direct sun radiation. The EC nanostructure is more porous but has a smaller average pore size than the T nanostructure. The best energy conversion efficiency is obtained for the EC nanostructure with the PMMI electrolyte, which provides a slightly higher ion diffusion coefficient and higher resistance but lower capacitance in the impedance spectroscopy feature associated with the ion transport processes. Keywords: Dye-sensitized solar cells; mesoporous titanium dioxide structures, diffusion coefficients; confined ionic liquids References [1] M. Grätzel, Photoelectrochemical cells, Nature 414 (2001) 338-344. [2] Y. Bai, Y. Cao, J. Zhang, M. Wang, R. Li, P. Wang, S. M. Zakeeruddin, M. Grätzel, High-performance dye-sensitized solar cells based on solvent-free electrolytes produced from eutectic melts. Nature Materials. 7 (2008) 626–630. [3] N.A. Ludin, A.M. Al-Alwani Mahmoud, Mohamad, Abu Bakar; Kadhum, Abd. Amir H.; Sopian, K.; Nor Shazlinah, A. K. Review on the development of natural dye photosensitizer for dye-sensitized solar cells. Renewable and Sustainable Energy Reviews. 31 (2014) 386–396. [4] H.S. Kim, C.R. Lee, J. H. Im, K.B. Lee, T. Moehl, A. Marchioro, S.J. Moon, R. Humphry-Baker, J.H. Yum, J.E. Moser, M. Grätzel, N.G. Park, Lead iodide perovskite sensitized all-solid-state submicron thin film mesoscopic solar cell with efficiency exceeding 9%. Scientific Reports. 2 (2012) 591. [5] A. Fakharuddin, F. de Rossi, T. M. Watson, L. Schmidt-Mende, R. Jose, Research update: Behind the high efficiency of hybrid perovskite solar cells. Applied Materials. 4 (2016) 091505. [6] T. S. Kim and R. H. Dauskardt, Molecular Mobility under Nanometer Scale Confinement. Nano Letters. 10 (2010) 1955–1959. [7] A.I. Maldonado-Valdivia, E.G. Galindo, M.J. Ariza, M.J. Garcia-Salinas, Surfactant influence in the performance of titanium dioxide photoelectrodes for dye-sensitized solar cells. Solar Energy 91 (2013) 263–272. [8] E.G. Galindo, M.J. Ariza, F.J. de las Nieves, M.J. Garcia-Salinas, Effects of multilayer coating and calcination procedures on the morphology of dye-sensitized solar cell semiconductor photoelectrodes. Thin Solid Films 590 (2015) 230–240.

55


Storing heat in hydration transitions: illustrated with K2CO3 H.P. Huinink1, L. Sogütoglü1, P.A.J. Donkers1, O.C.G. Adan1,2 and H.R. Fischer2 1 2

Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands TNO, De Rondom 1, 5612 AP Eindhoven, The Netherlands

Energy storage plays a key role in the use of renewable energy resources in order to bridge time and space that separates production and consumption. In contrast to the storage of electric, thermal energy (heat) storage has gained considerably less attention. Given the fact that approximately half of the total energy consumption of a household consists of thermal energy, there is an urgent demand for long term stable heat storage materials as there is a large amount of heat available but not on the right spot and time. Present concepts for heat storage materials make use of the heat capacity (sensible heat), phase changes (PCM = Phase Change Materials) or chemical transitions (TCM = Thermo-Chemical Materials). TCMs generally have the advantage of higher energy densities implying smaller storage volumes. Salt hydrates are considered as a promising class of TCMs. Charging a salt hydrate happens via dehydrating the salt crystal at elevated temperatures and low water pressures. Discharging occurs via rehydration, where heat is released. The major drawback is in the fact that (dis)charging processes involve solid-solid transitions. To illustrate the physics of heat storage with salt hydrates, several aspect of the (de)hydration of salts like MgSO4, CuSO4 and CuCl2 are discussed. Combined NMR and TGA studies on MgSO4 reveal that its (de)hydration involves liquid-like intermediate states and that reversible cycling is not possible. At that point CuSO4 and CuCl2 behave for more stable. At present the connection between cycling stability and the nature of the lattice rearrangements is under study. Although valuable, this detailed study does not help to select for an appropriate application. Therefore a database of 650 hydration reactions has been compiled. Based on filters for the energy density and p-T characteristics a long list of about 30 salt hydrates is compiled that are the most suitable for usage in household applications. However, after applying non-technological criteria only three candidates were left. One of these candidates is K2CO3. With the help of K2CO3 the major challenges for materials engineering of TCMs are discussed: boosting the energy density, manipulating the p-T characteristics and improving cyclic stability. The physical-chemistry of cycling (de)hydration reactions will be discussed in detail. Keywords: heat storage; thermo-chemical material; salt hydrate; hydration References [1] P.A.J. Donkers, et al., A review of salt hydrates for seasonal heat storage in domestic applications, submitted as publication (2016). [2] M.A. Stanish, et al., Kinetics of Hydration-Dehydration Reactions Considered as Solid Transformation, AIChE J., 30(4), 557 (1984).

56


Study of interdigitated back contact silicon heterojunctions solar cells by 2Dnumerical simulations N. Berrouba-Tani and K. Ghaffour Département of Electrical and Electronic Engineering Abou-Bakr Belkaïd University,Faculty of Technology Tlemcen, Algeria

In this paper, we will present the interdigitated back contact silicon hetero-junction (IBC–SHJ) solar cells. That shows how the amorphous/crystalline silicon technology can be implemented in the interdigitated back contact solar cell design. In this paper, various ways to optimize the IBC-SHJ solar cell with enhanced efficiency, steered by two-dimensional numerical modeling are discussed, using ATLAS 2-D device simulation software. Two approaches to improve the efficiency are evaluated: (1) modify the contact spacing, (2) reduce the gap region (width between BSF and emitter). The influence of these parameters has been tested by generating the current– voltage (I–V) curves under AM1.5 illumination, and so extract the output characteristics, namely the open circuit voltage (VOC), as well as the short-circuit current density (JSC), the fill factor (FF) and the conversion efficiency η of the cell. Keywords: Amorphous Silicon; Back-junction; Hetero-junction Silicon; Interdigitated Contacts; Silvaco ATLAS Simulation

57


The formation of SnS thin films by physical vapor transport Dongha Lim and Jaeyeong Heo Department of Materials Science and Engineering, and Optoelectronics Convergence Research Center, Chonnam National University, Gwangju, 500-757, Korea

Tin monosulfide(SnS) has been researched widely as a good candidate for earth-abundant photovoltaic absorber. SnS has a direct band with the bandgap of 1.2~1.5 eV and high optical absorption coefficient over 104 cm-1, which is nearly optimum for photovoltaic solar energy conversion. Even though SnS has many advantages, it is difficult to grow pure-phase SnS because of easy formation of secondary phases such as SnS2 and Sn2S3. [1] In this research, SnS films were deposited by vapor phase deposition using SnS powder in a horizontal furnace. We changed the temperature of the SnS powder and the substrates and tried to find the optimal condition to obtain phase-pure SnS thin films. It was found that the substrate temperature influences the final phase of the deposited sulfides. Figure 1 shows the SnS phases changed by growth temperature in one step. More details on structural, optical, and electrical properties will be discussed in the presentation. [2]

4 m

4 m

3.25 m

2.72 m

2 m SnS2 - Yellow

4 m

3.06 m

2 m Sn2S3 - Black

2 m SnS - Gray

Fig. 1 SnxSy Phases changed by growth temperature, SEM images. Keywords: Tin sulfide; Solar cell; Absorber; Earth-abundant References [1] Prasert Sinsermsuksakul, Leizhi Sun, Sang Woon Lee, Helen Hejin Park, Sang Bok Kim, Chuanxi Yang, and Roy G. Gordon, Adv. Energy Mater. 2014, 4(15), 1400496 [2] Lee A. Burton, Diego Colombara, Ruben D. Abellon, Ferdinand C. Grozema, Laurence M. Peter, Tom J. Savenije, Gilles Dennler, and Aron Walsh, Chem. Mater. 2013, 25(24), 4908

58


The outdoor performance of four different PV technologies in Poland A. Zdyb, P. Dragan, S. Gułkowski, E. Krawczak and K. Cieślak Faculty of Environmental Engineering, Lublin University of Technology, Nadbystrzycka 40B, 20-618 Lublin, Poland

Over the past twenty years the number of photovoltaic individual systems and power plants installed in the world increased significantly. The PV systems work in countries located in diverse climate zones not only in typical sunny regions. Although manufacturers provide normal rated performance parameters at standard test conditions (STC), the energy yield delivered by photovoltaic modules depends on the real outdoor conditions in which they work. STC (250C, 1000 W/m2, AM 1.5) represent the set of values that is rarely met in the environment so the outdoor testing of various types of solar modules in different climate conditions is an important issue in the context of predicting the profitability of the photovoltaic power system. The performance of modules depends also on the kind of PV technology. An interesting alternative to traditional crystalline and polycrystalline silicon modules is thin film technology which is tested in many countries [1-3]. The objective of this work is to assess the suitability of different photovoltaic technologies under Polish climatic conditions. The present research is the testing of four kinds of PV modules such as polycrystalline Si (poly-Si), and thin film arrays consisting of amorphous Si (a-Si), cadmium telluride (CdTe) and copper indium gallium selenide (CIGS). All the research data analyzed in this study come from the PV power plant located in Bordzilowka, east part of Poland. The PV system consists of poly-Si modules of 1.39 MWp total power output, a-Si (3.42 kWp), CdTe (3.3 kWp) and CIGS (3.72 kWp). Solar radiation was measured by pyranometer tilted in the plane of arrays and temperature of the modules by thermocouple sensors. The data have been collected every 10 seconds since January 2015. Our results show the differences in the performance of the investigated modules types and indicate CIGS modules as the best one during the whole year independently on the weather conditions. Keywords: photovoltaics; PV power plant; thin film technology; outdoor conditions References [1] V. Sharma et al., Energy 58 (2013) 511. [2] A.G. Gaglia et al., Renewable Energy 101 (2017) 236. [3] T. Ozden et al., Renewable Energy 101 (2017) 182.

59


TiO2 solar cells using natural extracts G.T. Tractz, A.P.C. Matheus, A. Viomar, G.J.T. Alves, M.T. da Cunha and P.R.P. Rodrigues* GPEL, Laboratório do Grupo de Pesquisas em Eletroquímica, Departamento de Química, Universidade Estadual do CentroOeste, Rua Simeão Varela de Sá , n. 03, CEP: 85040-080, Guarapuava, Paraná, Brazil * Corresponding author: e-mail: [email protected]

Due to the high polluting gases emission from fossil fuels comsuming, the research of new energy conversion methodologies have high importance in the world scenario [1]. Third generation solar cells, produced with nanometric TiO2 and with a suitable photosensitizer, have a great study focus, because they have good efficiency on energy conversion and high chemical stability [2]. Although these have several positive points, the large scale production is still not feasible, due to the photosensitive dye cost used in this system, which guides for new materials research to use in these devices [3,4]. In this context, new studies have a great importance to solve this problem. This work aims to produce solar cells using four different natural products extracts: Brazil grape, urucum, eggplant and mate herb. The electrochemical techniques used were current density vs potential curves (j x V), photocronoamperometry and electrochemical impedance spectroscopy (EIS). The results showed that the cell produced with the eggplant extracted dye presented better energy efficiency (ƞ = 0.07%), with a approximately current density of j = 44 μA cm-2, as shown in Figure 1. It be concluded that natural products can be used in low-cost third-generation solar cells production. Berinjela

50

-2

j (A.cm )

40

30

20

10

0

-100

0

100

200

300

400

500

600

700

t(s)

Fig. 1 TiO2 cell photocronoamperometry with eggplant extracted dye under 100 mW cm-2 light intensity. Keywords: renewable energy; gratzel cell; natural dyes. Acknowledgments: To Finep, FAU-UNICENTRO, CNPq and CAPES for research financial support. References [1] Carvalho, E. F. A.; Calvete, M. J. F. Energia Solar: Um passado, um presente…um futuro auspicioso. Revista Virtual de Química, p. 1-12.2010. ISSN-1984-6835. [2] Gratzel, M. Photoelectrochemical cells. Nature.Vol.414.2001. [3] Hangfeldt, A. Boschloo, G. Sun, L; Kloo, L; Pettersson, H. Dye sensitized Solar Cells. Chemical Reviews. Vol.110. N.11. 2010. [4] Maia, G. A. R; Larsson, L. F. G; Viomar, A; Mattos, L. A. C; Antunes, S. R. M; Maia, E. C. R; Oliveira, M. F; Cunha, M. T; Rodrigues, P. R. P. Influence of zinc oxide morphology in hybrid solar cells of poly (3-octylthiophene). Journal Of Material Science. 2016.

60

Fuel Cells


Analysis of the anode diffusion layer properties on a passive direct methanol fuel cell (DMFC) using electrochemical impedance spectroscopy (EIS) B.A. Braz, V.B. Oliveira and A.M.F.R. Pinto CEFT, Department of Chemical Engineering, Faculty of Engineering University of Porto, Rua Dr. Roberto Frias s/n 4200465 Porto, Portugal

In developing countries and rural areas where the grids are unreliable, small decentralized power systems are seen as a way to keep communications open even when the power goes out. Fuel Cells (FC) are in the Energy Agenda and have market potential in education, auxiliary power systems, recreational and military applications [1,2]. Compact fuel cells (FC) using methanol as fuel without a reforming step appear as a good solution to develop advanced portable FC to overcome systematic limitations of conventional batteries [1]. There are two types of fuel and oxidant supply in Direct Methanol Fuel Cells (DMFC): an active and a passive one. Passive systems use natural forces, diffusion and convection to achieve all processes without any additional power consumption. Therefore, these systems become much more simpler and compact being more suitable for portable power sources [3,4]. Accordingly, many companies are making major efforts in the development of DMFC prototypes to replace batteries. However, many scientific challenges must be overcome to make these systems a reality. DMFCs have high cost, due to the noble metals used as catalyst and its higher loadings (4 mg/cm2 Pt/Ru on the anode side and 4 mg/cm2 of Pt on the cathode side), and low power outputs due to the slow electrochemical reactions and water and fuel crossover. One of the most significant problems in DMFCs is the methanol crossover, since it diffuses through the membrane, towards the cathode, generating heat but no power. This problem can be reduced if the cell operates with low methanol concentrations. However, more concentrated solutions would be preferable to achieve the energy densities needed for portable applications. In addition, low methanol concentrations mean that a large amount of water is presented on the anode reservoir, which will produce no power and will take up a large volume on it. Also for this operating condition, water crosses the membrane towards the cathode leading to cathode flooding and a performance decrease. Therefore, low fuel and water crossover are essential requirements to the DMFC technology [3]. Towards that, it is extremely important to clearly understand and study the effect of the different configuration parameters on the cell performance, fuel and water crossover to propose new optimized designs [3,4]. Further research and developments in this area could significantly improve power and energy density, efficiency, cost and reliability of passive DMFC systems. In the present work, experimental studies were performed to elucidate the effect of anode diffusion layers properties on fuel crossover and cell performance. Towards reduction of costs, a membrane with a reduced catalyst loading on both anode and cathode electrodes (3 mg/cm2 Pt/Ru on the anode and 1.3 mg/cm2 of Pt on the cathode) was used. Most works, regarding the experimental diagnosis of DFMCs performance have been limited to the use of polarization measurements. Despite this technique gives very useful information and point out the various losses that affect the cell performance, it does not allow to evaluate its contribution independently, since the information provided is the sum of the various losses. On the contrary, the electrochemical impedance spectroscopy (EIS) technique, allows to determine the individual contributions of the various factors that affect the overall fuel cell performance (ohmic, activation and mass transport losses). Such evaluation signalizes the major parameters having a negative impact on the cell performance and provides useful information for its optimization. Therefore, in this study, EIS measurements were obtained to evaluate the performance of a passive DMFC cell with different anode diffusion layer properties (materials, thicknesses and surface treatment). Keywords: passive DMFC; anode diffusion layer; EIS; methanol crossover; power output Acknowledgments: B. A. Braz acknowledges the Ph.D. fellowship (BEX 12997/13-7) supported by CAPES Foundation, Ministry of Education of Brazil. V.B. Oliveira acknowledges the post-doctoral fellowship (SFRH/BDP/91993/2012) supported by the Portuguese “Fundação para a Ciência e Tecnologia” (FCT), POPH/QREN and European Social Fund (ESF). POCI (FEDER) also supported this work via CEFT. References [1] U.B. Demirci, J. Power Sources 169:239-46, 2007. [2] K. Sundmacher, Ind. Eng. Chem. Res. 49:10159–82, 2010. [3] V.B. Oliveira, D.S. Falcão, C.M. Rangel, A.M.F.R. Pinto, Int. J. Energ. Res. 37:991–1001, 2013. [4] V.B. Oliveira, J.P. Pereira, A.M.F.R. Pinto, Int. J. Hydrogen Energ. 41:19455–62, 2016

63


Cluster of boron as a liquid anodic fuel S. Ould Amara1, P.G. Yot2 and U.B. Demirci1 1 2

Institut Européen des membranes, Université de Montpellier, Place E. Bataillon, CC047, F-34095, Montpellier, France Institut Charles Gerhardt Montpellier, Université de Montpellier, Place E. Bataillon, F-34095 Montpellier, France

The use of a liquid anodic fuel (LAF) is an important alternative to hydrogen storage. There are many LAFs like ethanol, methanol, and formic acid [1, 2]; they can be oxidizes while generating electrons, but the oxidation of these carbonaceous LAFs also produce carbon monoxide leading to electrocatalyst poisoning. Alternatively, carbon-free LAFs can be considered [3,4]. Sodium borohydride NaBH4 (in alkaline solution) is a candidate. With it, the theoretical number of electrons exchanged by direct electrooxidation is of 8 electrons [1,4]. Some other boron- based LAFs could be seen alternatives to NaBH4. Sodium octahydrotriborate NaB3H8, with the B3H8- anion in aqueous solution, is one example: it can be oxidized in the presence of an appropriate electrocatalyst given that theoretically 18 electrons are involved. The theoretical oxidation reaction is as follows [1]: B3H8- + 20OH- → 3BO2- + 14H2O + 18e-. Recently, we have explored new boron-containing compounds, especially compounds that ate stable in aqueous solution at any pH. Sodium closo-dodecaborane (Na2B12H12; Figure 1), sodium closo-decaborane (Na2B10H10) and sodium oxaborate (NaB11H12O) have been studied. Such boron clusters have also a high thermic stability. For example, Cs2B10H10 is unchanged at 600°C. Further, many of the boron clusters presents low toxicity [5,6] in comparison to NaBH4 or NaB3H8. Such proprieties have encouraged us to study these materials as LAFs of direct liquid fed fuel cells.

Fig. 1 Anionic polyborane B12H122-

The EMR2017 conference will be a great opportunity to present, for the first time, our results about the aforementioned novel materials intended to be considered as potential LAFs of low temperature fuel cells. Acknowledgement the authors thank both LabEX CheMISyst ANR-10-LABX-05-01 and la Région Languedoc Roussillon (Project C3 “Chercheur(se)s d'Avenir 2013”) for financial support. Keywords: borane; cluster of boron; direct liquid fed fuel cell; liquid anodic fuel References [1] S. Pylypko, A. Zadick, M. Chatenet, P. Miele, M. Cretin, U.B. Demirci, J. Power Sources 286 (2015) 10-17. [2] U.B. Demirci, J. Power Sources 169 (2007) 239-246. [3] J.H. Kim, H.S. Kim, Y.M. Kang, M.S. Song, S. Rajendran, S.C. Han, D.H. Jung, J.Y. Lee, J. Electro. Soc 151 (2004) 1039-1043. [4] M.C. Sison Escano, R.L. Arevalo, E. Gyenge, H. Kasai, J. Phys. Condens. Matter 26 (2014) 353001-353015. [5] E.L. Muetterties, J.H. Balthis, Y.T. Chia, W.H. Knoth, H.C. Miller, Inorg. Chem 3 (1964) 444-451. [6] P.V. Schleyer, K. Najafian, A.M. Mebel, Inorg. Chem 37 (1998) 6765-6772.

64


Corrosion of nickel-coated stainless steel for OER catalyst in alkaline electrolysis Hee Sook Ro1, DongHoon Song2, MinJoong Kim2 and EunAe Cho2 1 2

Agency for Defence Development, Bugyuseong-daero 488 beon-gil, Yuseong-gu, Daejeon, Republic of Korea Department of Materials Science and Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, Republic of Korea

Alkaline electrolysis, which uses KOH solution as electrolyte, is system that applies electric energy to water and produces hydrogen and oxygen. Non-precious metals, which have low cost, are applicable at various parts of electrolyser such as catalysts, and separator. Due to the low cost of production, alkaline electrolyser is widely used for commercial water electrolyser system. Stainless steel is one of the electrode materials in alkaline electrolyser, but its low activity and corrosion resistance leads the system to have low efficiency. Therefore, corrosion of stainless steel in alkaline electrolyte, and its prevention, and increment .of efficiency have to be studied. Herein, we report nickel-coated stainless steel as stable electrode material for alkaline oxygen evolution reaction (OER). We prepared three kinds of samples: pure nickel, 316L, and nickel-coated 316L. Nickel layer was coated by electrodeposition on 316L substrate. Open circuit potential (OCP) showed that nickel-coated 316L showed the highest stability in alkaline media and the lowest for 316L. Furthermore, anodic polarization curve revealed that nickel-coated 316L has the lowest exchange current density, which implies high corrosion resistance of nickelcoated 316L substrate. To check morphology change of substrates, we operated chronoamperometry test for OER at potential of actual cell operation. After 10 hours, 316L and nickel substrate showed morphology change due to the corrosion, but almost no change occurred for nickel-coated 316L. Through OCP, exchange current density and morphology change results, nickel coating for OER catalyst and corrosion resistant layer made 316L as more stable electrode material in alkaline condition. Keywords: OER; stainless steel; corrosion; nickel; coating

65


Electrochemical and degradation behaviour study of different SOFC compounds A. Wain-Martin1, K. Vidal1, A. Larrañaga1, J. Rodríguez2, M.A. Laguna-Bercero3, R. Campana2 and M.I. Arriortua1,4 1

Departamento de Mineralogía y Petrología, Universidad del País Vasco (UPV/EHU), Sarriena s/n, 48080 Leioa, Spain Centro Nacional del Hidrógeno, Prolongación Fernando el Santo, s/n 13500 Puertollano, Spain 3 Instituto de Ciencia de Materiales de Aragón, ICMA, CSIC-University of Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain 4 BCMaterials, Basque Center for Materials, Edificio No.500, Parque Tecnológico de Zamudio, 48160 Derio, Spain 2

The present work is focused on manufacturing processes of the solid oxide fuel cell (SOFC) components with previously self-synthesized materials by combustion method [1-2]. The configuration used consists of planar electrolyte-supported symmetric cells, with dense yttria-stabilized zirconia (YSZ) membranes about 20mm diameter and a thickness near 300µm. Ni-yttria-stabilized zirconia cermet (Ni-YSZ) [3] and La0.6Sr0.4FeO3 (LSF40) [4] layers were deposited on the surfaces of the electrolyte as anode and cathode, respectively. In order to decrease the interlayer reactivity and improve the contact between them, Ce0.8Sm0.2O1.9 (SDC), LaNi0.6Fe0.4O3 (LNF60) and MnCo1.9Fe0.1O4 (MCF10) were added in different combinations as protection barrier [5], contact layer [6] and protective layer [7] material, respectively. The deposition of the different compounds has been carried out by manual colloidal spraying, using an organic base solution, or by screen printing. Cross section SEM images have been done to study morphologically the different starting layers. In order to study the degradation of the samples after 500h of exposure time at a temperature of 800 ºC, the energy-dispersive X-ray spectroscopy analysis of the cross sectional micrographs has been evaluated. Electrochemical impedance spectroscopy was used to characterize the electrochemical properties of the different components and multilayer structures. Keywords: SOFC; YSZ; anode cermet Ni-YSZ; cathode LSF40; SDC; LNF60; MCF10 References [1] K. Vidal, A. Larrañaga, A. Morán Ruiz, A.T. Aguayo, M.A. Laguna-Bercero, M.P. Yeste, J.J. Calvino, M.I. Arriortua, International Journal of Hydrogen Energy, 41 (2016) 19810-19818. [2] R.B. Nuernberg, M.R. Morelli, Ceramics International, 42 (2016) 4204-4211. [3] T. Kawashima, S. Miyoshi, Y. Shibuta, S. Yamaguchi, Journal of Power Sources, 234 (2013) 147-153. [4] A. Morán-Ruiz, K. Vidal, M.A. Laguna-Bercero, A. Larrañaga, M.I. Arriortua, Journal of Power Sources, 248 (2014) 1067-1076. [5] Z. Wang, X. Huang, Z. Lv, Y. Zhang, B. Wei, X. Zhu, Z. Wang, Z. Liu , Ceramics International, 41 (2015) 4410-4415. [6] M. Perz, E. Bucher, W. Sitte, T. Griesser, Solid State Ionics, 273 (2015) 30-34. [7] X. Montero, F. Tietz, D. Sebold, H.P. Buchkremer, A. Ringuede, M. Cassir, A. Laresgoiti, I. Villarreal, Journal of Power Sources, 184 (2014) 172-179.

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Electrochemical polymerization of polyaniline and polypyrrole modified carbon cloth anode for high performance of microbial fuel cells Praveena Mishra Schools of Studies in Chemistry, Jiwaji University, Gwalior 474011, India

The development of highly efficient anode materials is critical for enhancing the current output of microbial fuel cells. In this study, an approach of improving power production and biocompatibility of microbial fuel cells (MFCs) by using conducting polymers modified carbon cloth (CC) anode is reported. The modification of CC anode is accomplished by electrochemical deposition of aniline and pyrrole with multiwalled carbon nanotubes (MWCNTs). CC offers conducting porous surface for the development of the macroporous polymer composite network. Biocompatibility of modified electrodes has been evaluated and compared with unmodified carbon cloth (CC) electrode in a microbial fuel cell setup as anodes. A mediatorless dual-chamber MFC reactor filled with sewage waste water as substrate has been used in the comparative study of current and power production using different anodes. During MFC experiment with the polyaniline/polypyrrole/MWCNTs-MnO2 anode achieved a maximum power density of 2768.37 mW m-2, which is higher than the corresponding values of the MFC with other anodes. The SEM images taken after 45 days of the experiment confirm biocompatibility of modified anodes. Evidence from the electrochemical tests confirmed that the electrochemical activity of the modified anode is enhanced. Stability and charge transfer is facilitated by polyaniline (PANI), Polypyrrole (PPy) and MWCNT modification. All the results illustrated that the PANI and PPy modification of the carbon cloth surface is an efficient approach for enhancement of the performance of MFCs, while the chemical composition, size and shape of the nanocomposite determine the extent of the enhancement. Keywords: Microbial Fuel Cells; Conducting polymers; Electrochemistry; Metal oxides

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Imaging the formation of PtCu3/C clectrocatalyst by In-Situ Annealing Transmission Electron Microscopy F. Ruiz-Zepeda1, M. Gatalo1, P. Jovanović1, N. Hodnik2, M. Bele1 and M. Gaberšček1 1 2

Department of Materials Chemistry, National Institute of Chemistry, Hajdrihova Ulica 19, 1000 Ljubljana, Slovenia Department of Catalysis and Chemical Reaction Engineering, National Institute of Chemistry, Hajdrihova Ulica 19, 1000 Ljubljana, Slovenia

While vehicles with proton exchange membrane fuel cells (PEMFC) are already commercially available, its most vital part - the electrocatalyst - still contains too high quantities of the very precious platinum. In order to make the electrocatalyst cheaper, one has to further enhance the kinetics of the slow oxygen reduction reaction (ORR) by alloying Pt with other transition metals; a principle known already for a long time.[1] In addition to improving the kinetics of the electrocatalyst, one has to also consider the scalability of the electrocatalyst synthesis. In this work, we reveal insight into the annealing step of already patented [2] in-house made gram scale synthesis of a PtCu3/C catalyst by a highly advanced characterization method in-situ annealing transmission electron microscopy (TEM). Record breaking specific and mass activities of Pt-based electrocatalysts in thin film rotating disc electrode setups (TF-RDE) are being reported on an annual basis.[3] Although such materials show immense potential of Pt-based electrocatalysts for further commercialization of PEMFC, all of their synthesis processes are based on the poorly scalable polyol type synthesis with average scale of 30-50 mg per batch and make them unsuitable for transition from TF-RDE to membrane electrode assembly (MEA). Our in-house patented synthesis process [2] of PtCu3/C electrocatalyst on the other hand enables synthesis of up to 20 gram electrocatalyst batches in a laboratory setup. As described in the patent, the process involves a partial galvanic displacement of copper on carbon support (Cu/C) with a platinum precursor salt (K2PtCl4). Obtained composite (Fig. 1a) is then further annealed in order to form PtCu3 nanoparticles with an ordered pm3m structure (Fig. 2a).[4] Herein we provide insight into the annealing part of the synthesis by a highly advanced method called in-situ annealing TEM. The results are further complimented by ex-situ X-ray diffraction (XRD) analysis and electrochemical measurements using TF-RDE. a)

25 oC

800 oC

b)

Fig. 1 TEM image of the PtCu composite (a) prior to thermal annealing step of the synthesis and (b) after thermal annealing step of the synthesis on the same location. Keywords: Pt-based electrocatalyst; scalable synthesis; in-situ annealing TEM; PEMFC References [1] P. Stonehart, Development of Advanced Noble Metal-Alloy Electrocatalysts for Phosphoric Acid Fuel Cells (PAFC), Berichte Der Bunsengesellschaft Für Phys. Chemie. (1990) 913–921. [2] M. Bele, M. Gaber, G. Kapun, N. Hodnik, S. Ho, others, Electrocatalytic composite (s), associated composition (s), and associated process (es), (2015). [3] M. Li, Z. Zhao, T. Cheng, A. Fortunelli, C.-Y. Chen, R. Yu, et al., Ultrafine jagged platinum nanowires enable ultrahigh mass activity for the oxygen reduction reaction, Science (80-. ). (2016). [4] N. Hodnik, C. Jeyabharathi, J.C. Meier, A. Kostka, K.L. Phani, A. Rečnik, et al., Effect of ordering of PtCu3 nanoparticle structure on the activity and stability for the oxygen reduction reaction, Phys. Chem. Chem. Phys. 16 (2014) 13610–13615. 68


Implantable glucose fuels cells – molybdenum phthalycayanine complexes as bio inspired oxidation catalysts J. Sonnenfeld, S. Rauscher, D. Herbstritt and Ph. Kurz Institute for Analytical und Inorganic Chemistry, Albert-Ludwigs-University Freiburg, Albertstrasse 21, 79104 Freiburg, Germany

The design of implantable fuel cells (IFCs) for supplying power to electronic medical implants is a continuing scientific challenge. IFCs are able to convert endogenous substances (e.g. glucose) and oxygen into electricity. Since the reactants are replenished from the body fluids, they can operate independently over extended time periods. This feature makes them an interesting alternative to batteries as IFCs don’t have to be recharged or replaced. On the other hand, the development of catalysts that can operate in serum is difficult.[1] Phthalocyanine metal complexes are very attractive catalysts not only due to their accessibility in terms of large scale preparation and low cost, but also because of their thermal and chemical stability. Furthermore they are structurally related to porphyrins, which are widely used in biological systems in the active sites of enzymes responsible for aerobic oxidations.[2] Molybdenum phthalocyanine complexes with various functional groups were prepared, characterized and investigated. The presentation will deal with their spectroscopic properties and their reactivity with glucose under eletrochemical conditions. For example, we found the water-insoluble oxidophthalocyanatomolybdenum(IV) ([OMoIVPc]) on carbon support materials is able to oxidize glucose with an overpotential of 950 mV at a current density of 1 mA/cm2. This overpotential is very large compared to noble metals as for instance platinum, but the same is true for the current density, as smooth platinum electrodes only reach about 1 µA/cm2.[1,3] In the future mechanistic studies with water-soluble complexes are planned. 1,2

current [mA cm-2]

1,0

0,8

0,6

0,4

0,2

0,0 0

20

40

60

time [min]

Fig. 1 left: structure of OMoPc. right: current densities vs. time for carbon felt electrodes at 800 mV vs. RHE; dashed lines: uncoated support, drawn through lines: electrodes coated by [OMoIVPc] via PVD; electrolyte 1 M KNO3 (black lines) + 0.1 M glucose (red lines), pH 7. Keywords: fuel cells; anode materials References [1] S. Kerzenmacher, J. Ducrée, R. Zengerle, F. von Stetten, J. Power Sources 2008, 182, 1–17. [2] A. B. Sorokin, Chem. Rev. 2013, 113, 8152–8191. [3] A. J. Appleby, C. van Drunen, J. Electrochem. Soc. 1971, 118, 95.

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Improved Gas Diffusion in Solid Oxide Fuel Cells through using Cellulose Microfibrils as a Pore Formers in Electroless Co-Deposited Anodes Rob Turnbull, Neil Shearer and Callum Wilson Edinburgh Napier University Edinburgh EH10 5DT, Scotland, United Kingdom

A study was conducted to investigate the feasibility of Cellulose Microfibrils (CMF) as a pore former in the manufacture of Solid Oxide Fuel Cell (SOFC) anodes using Electroless Co-Deposition (ECD). Previous work into the use of ECD to produce SOFC anodes has found that the lack of porosity restricted the maximum power density of the cell [1]. This lack of porosity not only reduces the number of possible reaction sites easily accessible to the reactants, but restricts the movement of reactants and products to and from these reaction sites. At higher power densities, these reactants are used quicker than they can be replenished by the pore network, which causes a build-up of products around these sites. Since the products are not able to disperse out of the pore network quickly enough, an accumulation of products not only blocks the reactions sites but can lead to the oxidation and irreparable damage of the electrode. This build-up of products around the reaction sites also leads to a dilution of the reactants being supplied, further reducing the reaction rate of the overall cell. Therefore an electrode must have a suitable pore network to allow the free flow of reactants and products from the reaction sites to sustain a higher reaction rate. This can be achieved by using a pore former within the ECD process to produce an interconnected pore network. Previous studies which have used rice starch as a pore former have nearly doubled the power density of a cell due to the increased porosity [2]. As the choice of pore former is closely related to the size and shape of pores produced, a whisker shaped pore former will produce a more cylindrical pore once removed[3]. These cylindrical pores will increase the chances of producing an interconnected pore network compared with more spherical pores previously used, therefore improving the gas diffusion throughout the anode Previous work by the author on using cellulose as a pore former has shown that a 20μm cellulose powder pore former was able to increase the porosity and total pore surface area within the electrode. Samples were produced using four different cellulose powders as pore formers, ranging from 20μm to 200μm with varying morphologies. The 20μm cellulose increased the porosity by 218% and total pore surface area by 2910%. This increase in porosity and pore surface area will allow for a greater density of reaction sites within the electrode as well as improved gas diffusion throughout the electrode. However the 20μm cellulose had a particulate morphology as the whisker cellulose was too large to have a significant inclusion within the coating. Therefore a new cellulose pore former with similar size but with a whisker morphology is required which will produce the interconnected pore network required. Cellulose Microfibrils (CMF) typically has a size of ranging from 10μm to 50μm (average: 30μm) with a whisker structure. Coatings were produced with a bath loading of 10g/l, 5g/l and 2g/l of 1% CMF solution to determine the optimum bath loading to produce the required microstructure. These coatings were then characterized using a Scanning Electron Microscope to determine the pore structure via a cross sectional analysis and a mercury porosimeter to determine their pore content. A 10g/l bath loading of CMF increased Porosity by 200%, which was similar to the 20μm particulate cellulose previously used. However it only produced an increase of 313% in the total pore surface area compared with the 2910% produced by the 20μm cellulose powder. A 5g/l bath loading of CMF actually reduced the porosity by 71%, which was similar to the reduction of 29% by the 100μm cellulose powder. Both the 5g/l CMF and the 100μm powder also reduced the total pore surface, by 75%and 98% respectively. However the 2g/l CMF increased the porosity by 133%, yet it increased the total pore surface area by 4771%. Therefore CMF is suitable to use as a pore former within the ECD process as it is able to produce a greater increase in the total surface area than the cellulose powder, whilst using a lower bath loading. Keywords: Solid Oxide Fuel Cell; Electroless Co-deposition; Porosity; Cellulose; Cellulose Microfibrils References [1] N. B. Baba, “Novel Processing of Solid Oxide Fuel Cell Anodes,” Edinburgh Napier University, 2011. [2] L. Lu, “Studies of Anode Supported Solid Oxide Fuel Cells (SOFCs) Based on La and Ca-doped SrTiO3,” 2015. [3] W. P. Pan, Z. Lü, K. F. Chen, Y. H. Zhang, B. Wei, Z. H. Wang, and W. H. Su, “Enhanced Performance of Solid Oxide Fuel Cell by Manipulating the Orientation of Cylindrical Pores in Anode Substrate,” Fuel Cells, vol. 12, no. 1, pp. 41– 46, 2012. 70


Influence of the carbon support properties on the PdSn/C ethanol oxidation reaction in alkaline medium E. Leal da Silva1, A. Cuña1,2, M. Cadorin1 and C. de Fraga Malfatti1 1

LAPEC/PPGE3M, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9500, setor 4, prédio 75, sala 232 91501-970 – Porto Alegre/RS, Brazil 2 Cátedra de Fisicoquímica, DETEMA, Facultad de Química, Universidad de la República - Avenida General Flores 2124, CC 1157, Montevideo, 11800, Uruguay

In recent years, the study of Alkaline Direct Ethanol Fuel Cells (DEFCs) has received significant attention. Alkaline DEFCs are a promising source of clean energy due to its high efficiency, low pollution and the possibility of using renewable fuels such as ethanol [1]. In the other hand, in alkaline medium, the fastest ethanol oxidation reaction (EOR) providing the possibility of using other metal catalysts, such as palladium. Besides, aiming to improve the cell efficiency, stability and prevent poisoning, Pd-based alloys have been widely studied and Sn was found to be a good co-catalyst [2]. Recently, we have investigated the preparation and characterization of different biomass derived activated carbons, usually called as activated biocarbon (aBCs), as support catalyst [3, 4, 5]. Studies regarding the characteristic of aBCs as the PdSn catalyst support for EOR in alkaline medium have been not reported. In this work, aBC and Vulcan carbon supported PdSn catalysts were studied as electrocatalysts for EOR in alkaline medium. The morphology, structure and chemical composition of different electrocatalyst were determined by transmission electron microscopy (TEM), X-ray diffraction (XRD), Rutherford backscattering spectrometry (RBS) and Thermogravimetric analysis (TGA). These properties were correlated to their electrocatalytic performance determined by cyclic voltammetries using a 1.0 mol L-1NaOH solution and 1.0 mol L-1 ethanol + 1.0 mol L-1 NaOH solution as electrolyte. Additionally, the EOR mechanism pathways and product distributions at different potentials were studied by in-situ Fourier Transform Infrared Spectroscopy in Attenuated Total Reflectance (in-situ ATR-FTIRS). The results obtained shown a clearly difference in the morphological and structural properties of PdSn nanoparticles depending to the carbon support. As it can be observed in TEM micrograph (Figure 1b), the PdSn particles obtained on aBC support are more agglomerated than the PdSn particles deposited on the Vulcan support (Figure 1a). These can explain the best EOR electrocatalytic performance of the Vulcan supported PdSn electrocatalyst. The in-situ ATR-FTIRS analysis demonstrates that there are no substantial differences in the EOR product formation. For both PdSn electrocatalyst (Vulcan and aBC supported), the most important product EOR in alkaline medium is the acetate ion.

Fig. 1 TEM micrograph of a) PdSn/V and b) PdSn/aBC. Keywords: Alkaline direct ethanol fuel cells; PdSn catalyst; Biocarbon; Ethanol oxidation reaction References [1] R. Dillon, S. Srinivasan , A.S. Aricò, V. Antonucci, J. Power Sources 2016, 127, 112. [2] A. Zalineeva, A. Serov, M. X. Serov, U. Martinez, K. Artyushkova, S. Baranton, C. Coutanceau, P. Atanassov, Electrochem. Comm. 2015, 57, 48. [3] E. Leal da Silva, M.R. Ortega Vega, P.S. Correa, A. Cuña, N. Tancredi, C.F. Malfatti, Int. J. Hydrogen Energy 2014, 39, 14760. [4] E. Leal da Silva, A. Cuña, M.R. Ortega Vega, C. Radtke, G. Machado, N. Tancredi, C.F. Malfatti, Appl. Catal. B 2016, 193, 170. 71


New electrocatalysts for PEM Fuel cell application based on platinum supported on nanostructured carbon support M. Heitzmann, S. Louisia, Y. Thomas, E. Remy and PA Jacques CEA-Liten, 17 Avenue des Martyrs, 38000 Grenoble, France

Carbon blacks supported Pt, currently widely used as electrocatalysts in Polymer Electrolyte Membrane Fuel Cells (PEMFC) are thermochemically unstable in PEMFC operating conditions. This is especially true at the cathode side where, on top of relatively elevated temperature (80°C) and acidic conditions, both the potential and the relative humidity may be high. The resulting carbon oxidation is partially responsible for the PEMFC performance decrease observed over time. Hence, long term durability still needs to be improved in order to consider PEMFC as credible alternatives to conventional power sources for automotive, stationary or portable applications. Many efforts have been directed to identify and synthesize alternative carbon materials as catalyst supports for PEMFCs. One strategy to decrease carbon support corrosion is to use carbon with high extent of graphitization, which is supposed to decrease defect sites on the carbon structure, where carbon oxidation starts [1], [2]. However, high graphitic content of carbon can be a brake for particle nucleation and dispersion. Among the different forms of carbon, graphene and carbon nanotubes have attracted tremendous interest over many conventional catalyst support materials for various energy applications [3], [4]. In this work, platinum and bimetallic (PtM, M=Co or Ni) nanoparticles catalysts have been prepared on N-doped Multi-Walled Carbon Nanotubes (MWCNTs) (home synthetized and commercial) and Few Graphene Layers (FGLs). The Platinum loading, the dispersion and size of metallic nanoparticles were analyzed by UV, XRD, SEM. We investigated these new Pt and PtM catalysts for electrocatalysis of oxygen reduction. By comparing the electrochemical properties of these hybrid materials with a commercial Pt/C catalyst using carbon blacks as carbon support, it is found that this hybrid material demonstrated an enhancement of electro-catalyst performances in RDE tests. Moreover accelerated stress tests in fuel-cell setup demonstrated that the use of these nanostructured carbon supports can be promising in effectively reducing the carbon corrosion and then increase lifetime of the cell. This work is funded by the FP7 NANOCAT European program (SP1-JTI-FCH.2012.1.5). Keywords: PEMFC; MWCNTs; Graphene; nanostructured catalyst support; durability/stability References [1] Xin Wang , Wenzhen Li , Zhongwei Chen , Mahesh Waje , Yushan Yan, “Durability investigation of carbon nanotube as catalyst support for proton exchange membrane fuel cell”, Journal of Power Sources, 2006, 158, pp 154–159 [2] D. Bom, R. Andrews, D. Jacques, J. Anthony, B. Chen, M. S. Meier, John P. Selegue , “Thermogravimetric Analysis of the Oxidation of Multiwalled Carbon Nanotubes: Evidence for the Role of Defect Sites in Carbon Nanotube Chemistry”, Nano Letters, 2002, 2, pp 615-619 [3] Yingwen Cheng, Songtao Lu, Hongbo Zhang, Chakrapani V. Varanasi٣, and Jie Liu, “Synergistic Effects from Graphene and Carbon Nanotubes Enable Flexible and Robust Electrodes for High-Performance Supercapacitors”, Nano Letters, 2012, 12 (8), pp 4206–4211 [4] Zhou, X., Qiao, J., Yang, L. and Zhang, J ”A Review of Graphene-Based Nanostructural Materials for Both Catalyst Supports and Metal-Free Catalysts in PEM Fuel Cell Oxygen Reduction Reactions”, Adv. Energy Mater., Vol. 4, (2014) p.1301523

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Pd/biocarbon electrocatalyst for ethanol oxidation reaction in alkaline medium: correlation between physicochemical properties an electrocatalytic performance in EOR by in-situ ATR-FTIRS E. Leal da Silva1, A. Cuña1,2, S. Khan1, M. Cadorin1, J. Marcuzzo3, S. Pianaro4 and C. de Fraga Malfatti1 1

LAPEC/PPGE3M, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9500, setor 4, prédio 75, sala 232 91501-970 – Porto Alegre/RS, Brazil 2 Cátedra de Fisicoquímica, DETEMA, Facultad de Química, Universidad de la República - Avenida General Flores 2124, CC 1157, Montevideo, 11800, Uruguay 3 Laboratório Associado de Sensores e Materiais, Instituto Nacional de Pesquisas Espaciais, 12245-010, São José dos Campos/SP, Brazil 4 Departamento de Engenharia de Materiais, Universidade Estadual de Ponta Grossa, Av. Carlos Cavalcanti, 4748 - Bloco L - Campus de Uvaranas, 84030900 - Ponta Grossa/PR, Brazil

Alkaline Direct Ethanol Fuel Cells (DEFCs) have attracted considerable interest due to their wide range of technological application as alternative power sources [1]. The alkaline DEFC anode requires the use of electrocatalysts to promote the ethanol oxidation reaction (EOR). In recent years, to improve the cell efficiency, a considerable attention has been paid to the preparation and characterization of anode electrocatalysts. In alkaline medium, Pd and PdM (M = Ni, Sn, Au, Ru, and Cu) based electrocatalysts have been widely investigated [2, 3], and carbon materials are one of the most important materials used as catalyst supports. Different types of carbon materials have been studied and employed for this application [4]. Recently, attention has focused on wood as carbon material precursor, because of its sustainability and also because the obtained carbons have excellent final properties [5, 6, 7]. Until now, studies regarding the influence of activated biocarbon (aBCs) characteristic, as Pd catalyst support, for EOR in alkaline medium were not performed. In the present work, aBC and Vulcan carbon supported Pd catalysts were studied as electrocatalysts for EOR in alkaline medium. The morphology, structure and chemical composition of the electrocatalysts were determined by transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS), respectively. These properties were correlated to their electrocatalytic performance determined by cyclic voltammetries using a 1.0 mol L-1NaOH solution and 1.0 mol L-1 ethanol + 1.0 mol L-1 NaOH solution as electrolyte. Additionally, the EOR mechanism pathways and product distributions at different potentials were studied by in-situ Fourier Transform Infrared Spectroscopy in Attenuated Total Reflectance (in-situ ATR-FTIRS).The results obtained demonstrated that the acetate ion is the main product of EOR on the Pd/V and Pd/aBC electroctalyst in the alkaline medium. The principal difference was observed for the negative peak at 1046 cm-1, which is associated to the ethanol consumption, and presented less intensity in infrared spectra for the Pd/aBC compared to Pd/V. This is consistent with the electrochemical results that indicated the lower catalytic activity for Pd/aBC electroctalyst . Keywords: Direct ethanol fuel cells; Pd catalyst; Carbon support; Biocarbon; Ethanol oxidation reaction; in-situ ATRFTIRS References [1] R. Dillon, S. Srinivasan , A.S. Aricò, V. Antonucci, J. Power Sources 2016, 127, 112. [2] E. Antolini, E. R. Gonzalez, J. Power Sources 2010, 195, 3431. [3] A. Zalineeva, A. Serov, M. X. Serov, U. Martinez, K. Artyushkova, S. Baranton, C. Coutanceau, P. Atanassov, Electrochem. Comm. 2015, 57, 48. [4] P. Serp, B. Machado. Nanostructured Carbon Materials for Catalysis. Royal Social of Chemistry, Londres 2015. [5] E. Leal da Silva, M.R. Ortega Vega, P.S. Correa, A. Cuña, N. Tancredi, C.F. Malfatti, Int. J. Hydrogen Energy 2014, 39, 14760. [6] E. Leal da Silva, A. Cuña, M.R. Ortega Vega, C. Radtke, G. Machado, N. Tancredi, C.F. Malfatti, Appl. Catal. B 2016, 193, 170. [7] A. Cuña, C. Reyes Plascencia, E.L. da Silva, J. Marcuzzo, S. Khan, N. Tancredi, M.R. Baldan, C. de Fraga Malfatti, Appl. Catal., B 2017, 202, 95.

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Study on hydrogen production via diesel-hydrogen peroxide fuel processor for subsea applications Sungbaek Cho1, Gwangwoo Han2 and Joongmyeon Bae2 1 2

Agency for Defence Development, Bugyuseong-daero 488 beon-gil, Yuseong-gu, Daejeon, Republic of Korea Department of Mechanical Engineering, KAIST, 291 Gwahangno, Yuseong-gu, Daejeon, Republic of Korea

A novel type of diesel fuel processor that uses hydrogen peroxide as an oxidant has been developed to produce hydrogen required for fuel cell operation. This fuel processor was specialized to enhance submerged operation of the subsea application such as submarine or unmanned underwater vehicles (UUV). By using this fuel processor, hydrogen could be effectively obtained to drive fuel cell air independent propulsion (AIP) for subsea applications. Diesel fuel could be the most ideal hydrogen source for subsea application due to its high hydrogen density and its globally well-equipped infrastructure. In addition, hydrogen peroxide not only can supply oxygen and water, which are required for diesel fuel processing, but also can produce decomposition heat, which can be used for enhancing thermal efficiency of the fuel processor. To effectively produce hydrogen using diesel and hydrogen peroxide, fuel processor should be composed of core parts of the reformer, hydrogen peroxide decomposer, water-gas shift reactor, and hydrogen permeable membrane. Only when these several parts are well integrated, complete fuel processor can fully function, which makes it possible to drive a fuel cell. In this study, characteristics of each component were investigated depending on various operating conditions. In the reformer and hydrogen peroxide decomposer parts, temperature profile and reforming performance were investigated depending on load change. In case of water gas shift and hydrogen permeable membrane parts, catalytic performance tests were conducted depending on temperature and pressure variation. From the experimental tests, appropriate operating conditions of each part for enhancing hydrogen production performance were confirmed. Keywords: Diesel; Hydrogen peroxide; Hydrogen; Reforming; Subsea application References [1] Han G, Lee S, Bae J. Diesel autothermal reforming with hydrogen peroxide for low-oxygen environments. Applied Energy 2015; 156: 99-106. [2] Han G, Lee K, Ha S, Bae J. Development of a thermally self-sustaining kWe-class diesel reformer using hydrogen peroxide for hydrogen production in low-oxygen environments. Journal of Power Sources 2016; 326: 341-348.

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The Relationship between Stability and Activity for Pt/C and PtM/C Electrocatalysts: the Role of Morphology and Architecture of Nanoparticles V.E. Guterman, S.V. Belenov and A.A. Alekseenko Chemistry Faculty, Southern Federal University, 7 Zorge st., Rostov-on-Don, 344090, Russia

Efficiency of the platinum electrocatalyst in low temperature fuel cell (LTFC) is primarily determined by the value of mass activity (Jmass) and its conservation during the operation, i.e. durability (stability). An increase in catalyst electrochemically active surface area (ESA) caused by decreasing nanoparticle (NP) size could increase its mass activity and reduce the stability. Despite a large number of publications devoted to the study of the relationship between the microstructure of electrocatalysts and their activity or stability, available data cannot give a clear answer to the question, what range of ESA values corresponds to the optimal combination of mass activity and stability. In addition, the relationship between activity and stability of the two-component PtM/C electrocatalysts, as well as the systems containing nanoparticles with complex architecture, is poorly studied. In the present paper we have investigated the nature of correlation between the values of activity and stability for some Pt/C, including commercial ones, and for several bimetallic Pt-M/C (M=Cu, Co) electrocatalysts. It was important to offer criteria for selecting catalysts with the optimal combination of activity and stability, as well as to evaluate the feasibility of obtaining materials, that significantly exceed available analogues by the ratio of these important functional characteristics. Note that despite poisoning effect of the anode and polymeric membrane of PEMFC, Cu@Pt/C electrocatalysts are still convenient object for determination the nature of influence of the composition and architecture of nanoparticles on the behavior of bimetallic catalysts. Commercial or homemade Pt/C electrocatalysts with an average crystallite (NP) size from 1 to 4 nm and ESA from 18 to 150 m2/g(Pt) were investigated to elucidate the nature of the correlation between stability and Jmass of electrocatalysts in the reaction of oxygen electroreduction (ORR). Pt-M/C electrocatalysts obtained by joint or sequential chemical reduction of M2+ and Pt(IV), have also been studied as comparison objects. XRD, TEM, Xray fluorescent analysis, thermogravimetry, CV on stationary and rotated electrodes and some other methods were used for the study. The method of prolonged CV in a three-electrode cell at the potential range of 0.6 ~ 1.4 V (SHE), corresponding to the LTFC work in the start/stop mode, has been selected as a rapid method to evaluate the stability of electrocatalysts. The presence of a strong linear correlation (R2=0.9419) between the values of Jmass and ESA has been confirmed for the Pt/C catalysts. Indeed, the ESA value depends not only on the size and size distribution of NP, but also reflects the contribution of the processes of coalescence and aggregation of the nanoparticles and, consequently, the effect of the metal loading in the catalyst. Kinetics of the degradation of Pt C and Pt-M/C catalysts in the stress test is also largely depends on the initial ESA, although is associated with composition and architecture of nanoparticles too. During the stress test, catalysts characterized by small size of NP, predominantly degraded by mechanisms, associated with the dissolution and reprecipitation of Pt, as well as with coalescence of the nanoparticles. For the catalysts with low values of ESA and large NP, a degradation of carbon support is a prevailing factor. The relationship between the ORR activity and stability of M@Pt/C electrocatalysts containing M-core - Pt-shell nanoparticles doesn’t obey to correlation which was set for Pt/C. Relatively high stability of NP in such electrocatalysts is caused by their relatively large size and strong adhesion to the surface of the carrier, compared with Pt NPs. In the case where NP of M@Pt/C electrocatalyst has a very thin Pt-shell, it cannot provide a high stability, but is highly sensitive to M-promoting effect in ORR. Thus, the electrocatalysts based on bimetallic NPs with M-core - Pt-shell architecture may show the combination of higher mass activity and stability values compared to the Pt/C electrocatalysts with the same Pt-loading. The approach connected with the definition for each electrocatalyst the field of its marker location on the correlation diagram "mass activity - stability", in our opinion, could be used for initial choice of the samples, which combining high values of activity and stability. At the same time, selecting promising catalysts, it is necessary to consider not only a change in ESA during accelerated stress test, but its (ESA) absolute values. The authors express their gratitude to the Russian Science Foundation (grant 16-19-10115), which has supported this work. Keywords: Pt/C electrocatalyst; platinum alloy; core-shell nanoparticles; fuel cell; durability; ORR activity; accelerated stress-test 75

Hydrogen


3-D electrodes for large-scale electrochemical H2 production Joris Proost*, Thomas Dalne and Quentin de Radiguès Division of Materials and Process Engineering, Université catholique de Louvain, 1348 Louvain-la-Neuve, Belgium * Corresponding author: email: [email protected]

Hydrogen is a promising and well-accepted energy vector to store electricity produced by intermittent sources, such as solar panels and wind turbines. In this respect, the electrochemical production of H2 from water electrolysis is at present considered to be the technologically most viable route. However, the efficiency of lowcost electrolysers must still be improved before they can actually be used industrially on a large scale. Such improvements can be obtained by increasing the rate of electron transfer between water and the electrode, or by improving mass transport of reactants and gaseous products. This presentation will focus on a most simple way to increase the efficiency of water electrolysis by the use of 3-D porous electrodes. These will be shown to allow for a significant reduction in overpotential, while at the same time improving the intrinsic mass transfer characteristics of a conventional electrochemical cell [1]. As a result, both the energy requirement and the technological cost of water electrolysers can be significantly reduced, while keeping low-cost Ni as electrode material. More specifically, we will discuss the electrochemical performance of macro-porous Ni electrodes during water electrolysis in alcaline electrolytes, using a commercial filter-press cell in flow-by mode. Commercial Ni cathodes with different geometries were compared, including 1-D wires, 2-D plates and 3-D foams, the latter with porosities of 30, 60 and 100 ppi. This resulted in effective surface area's varying over more than 3 orders of magnitude, from 2.8 10-3 dm2 and 1.9 10-1 dm2 for the wires and plates, respectively, upto 2.4, 4.9 and 8.3 dm2 for the 30, 60 and 100 ppi foams, respectively. From a quantitave analysis of chrono-potentiometric and linear sweep polarisation measurements, it was found that the required (over-)potential to drive the macroscopic current is lowest for the 3-D foam electrodes (Fig. a, left). Moreover, for the wire and plate electrodes, a sharp and sudden increase in potential was observed which was taken as indicative for the appearance of a limiting current (Fig. b, right). This can be associated with mass transfer limitations for the hydrogen evolution reaction at these 1-D and 2-D electrodes.

0

0

3-D foam

3-D foam

2-D plate

-1

2-D plate

E (V/SHE)

E (V/SHE)

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-2

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1-D wire 1-D wire -3

-3

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-1 I (A)

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Fig. 1 Recorded cathode potential as a function of imposed current in linear coordinates (a, left), and as a function of current density on a semi-logarithmic scale (b, right). Keywords: 3-D electrodes; H2 production References [1] Q. de Radiguès, P.-Y. Sévar, R. Santoro, F. Van Wonterghem and J. Proost, Industrial & Engineering Chemistry Research 51 (2012) 14229–14235.

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All that glitters isn´t gold  Plasmonic coinage metal particles in visible-light driven H2 production watched by in situ spectroscopy J.B. Priebe1, J. Radnik2, C. Kreyenschulte1, A.J.J. Lennox3, Henrik Junge1, M. Beller1 and A. Brückner1 1

Leibniz-Institut für Katalyse e. V. (LIKAT), Albert-Einstein-Str. 29a, 18059 Rostock, Germany Bundesanstalt für Materialforschung und –prüfung (BAM), Unter den Eichen 44-46, 12203 Berlin, Germany 3 Department of Chemistry, University of Wisconsin, Madison, 1101 University Ave, Madison, WI 53706, United States 2

Surface plasmon resonance (SPR) absorption is known to be the reason for visible-light activity of supported gold particles (e. g. Au/TiO2) in photocatalytic hydrogen evolution from water [1]. Despite their much lower prices and, thus, potential economic benefits, Ag and Cu have been rarely explored for photocatalytic water reduction, though they also show the SPR effect. This is particularly true for the cheapest among the coinage metals, namely Cu, which has been widely tested for photocatalytic water reduction using UV-containing light sources only, while the behaviour of plasmonic Cu particles in H2 production under pure visible light has hardly been explored explicitly [2]. Moreover, spectroscopic in situ studies of structure-reactivity relationships of plasmonic metal particles, which could support knowledge-based catalyst design, are mostly restricted to gold only [1]. In this work, monometallic Cu/TiO2 (P25) and bimetallic CuAu/P25 catalysts with a total metal content of 0.4 – 1.0 % have been prepared by impregnation (IM), simultaneous (CP) or sequential (SP) reductive precipitation. They were thoroughly characterized by HR-STEM and XPS, catalytically tested in UV- and visible light-driven water reduction and analyzed for structure-reactivity relationships by different in situ methods (EPR, UV-vis and XANES spectroscopy).

H2 production [mmol / gmetal h]

We show that formation of plasmonic metal particles is a crucial requirement for H2 evolution with visible 450 light and depends sensitively on the catalyst synthesis 400 procedure: reductive precipitation being much more 350 efficient than impregnation. This is due to the fact that 300 IM produces only highly dispersed Cu species but no 250 clear metal particles, while the latter are formed by 200 both SP and CP methods. Interestingly, the bimetallic 150 CuAu/P25-CP catalyst even outperforms our best 100 Au/P25 catalyst [1c] in visible-light driven water 50 reduction when the H2 production rate is related to the 0 total mass of coinage metal in the catalyst (Fig. 1). Cu-IM Cu-RP CuAu-SP CuAu-CP Au-RP* This is due to the formation of uniform 4-8 nm CuAu alloy particles, which are created already by visible Fig. 1. H2 production rate under visible light (400-700 nm). light, with evidence from in situ XANES. In contrast, *value from [1c]. I the SP method leads to separated Au particles and Cu species that obviously do not contribute to H2 evolution under visible light. In summary, we have shown that it is possible to replace noble Au partly by less expensive non-noble Cu without loss of activity. This may open new economically attractive ways to visible-light active water reduction catalysts. Keywords: plasmonic H2 production; CuAu/TiO2 catalysts References [1] C. Gomes Silva, R. Juárez, T. Marino, R. Molinari, H. García, J. Am. Chem. Soc. 2011, 133, 595-602; b) J. B. Priebe, M. Karnahl, H. Junge, M. Beller, D. Hollmann, A. Brückner, Angew. Chem. Int. Ed. 2013, 52, 11420-11424; c) J. B. Priebe, J. Radnik, A. J. J. Lennox, M. M. Pohl, M. Karnahl, D. Hollmann, K. Grabow, U. Bentrup, H. Junge, M. Beller, A. Brückner, ACS Catal. 2015, 5, 2137-2148. [2] T. Montini, V. Gombac, L. Sordelli, J. J. Delgado, X. Chen, G. Adami, P. Fornasiero, ChemCatChem 2011, 3, 574-577; b) P. Gomathisankar, K. Hachisuka, H. Katsumata, T. Suzuki, K. Funasaka, S. Kaneco, Int. J. Hydrogen Energ. 2013, 38, 11840-11846.

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Ammonia borane confinement in graphene oxide 3D structures for H2 storage Simon Champet1, Agata Godula-Jopek2 and Duncan H. Gregory1 1 2

WestCHEM, School of Chemistry, University of Glasgow, University Avenue, G12 8QQ Glasgow, United Kingdom Airbus Group Innovations, TXDI, Willy-Messerschmitt-Straße 1, 81663 Ottobrunn, Germany and Institute of Chemical Engineering, Polish Academy of Sciences, 44100 Gliwice, Poland

Hydrogen fuel cells can provide an elegant solution to the challenge of generating electrical power without emissions. Efficient hydrogen storage however is one factor preventing the immediate wider use of fuel cells, particularly in terms of mobile applications. In order to unlock this limitation, new approaches to storage are required but to date no system meets all the requirements. Our study focuses on whether graphene-based materials can fulfil their predicted potential as hydrogen stores. Graphene, a one-atom-thick planar sheet of sp2bonded carbon atoms1, is a relatively recently discovered material and thus under investigation in many different fields. Such a material, composed of carbon, is light, abundant and relatively cheap. State of the art graphene-based materials could theoretically achieve the US Department of Energy criteria for automotive hydrogen storage (system: 7.5 wt. %.; 0.07 kg H2 L-1 and $ 266 kg-1 H2 while H2 itself costs 2-4 USD/gge at the pump)2, 3. Numerous calculations predict a great potential for graphene-based materials as a superior storage material. With a high specific surface area (pristine graphene has a theoretical specific surface area of 2630 m2g-1); light metal decorated graphene is particularly highlighted by theorists as being able to match hydrogen storage requirements4, 5. Such material should indeed have a gravimetric density of ca. 10 wt.%4. However, our experimental studies have revealed that physisorption provides low gravimetric densities and requires operating conditions that are unfavourable for mobile applications. Therefore, our current research focuses on composites that exhibit stronger hydrogen binding. Hydrogen compounds (including metal hydrides, complexes and boron nitrogen hydrides) are known for their high gravimetric density but also for their air sensitivity and/or toxic by-products. There are currently two major methods under investigation to eliminate these by-products: catalysis and nanoconfinement. Here we focus on the latter approach. Our host material is a new, porous graphene-derived material which acts so as to lower the dehydrogenation temperature and enhance the selectivity of the released gas. Both host and composite are characterized via N2 isothermal adsorption, Helium pycnometry, SEM/EDX analyses and both Raman and IR spectroscopy. Hydrogen release performance is assessed using Simultaneous Thermal Analysis coupled to mass spectrometry (STA-MS). Our results demonstrate that nanocomposites confining ammonia borane (AB) into graphene oxide (GO) 3D structures of controlled radial porosity, lead to the elimination of classic AB by-products such as borazine and diborane. The high purity hydrogen can thus be stored at gravimetric density exceeding most metal hydrides with a release onset temperature lower than 100 °C. Keywords: Hydrogen storage; graphene oxide References [1] Graphene: An Introduction to the Fundamentals and Industrial Applications, Madhuri Sharon and Maheshwar Sharon, 2015, Scrivener Publishing LLC, chapter 2, pages 1-21 [2] US DoE: http://energy.gov/sites/prod/files/2014/02/f8/hstt_roadmap_june2013.pdf [3] High capacity hydrogen storage materials: attributes for automotive applications and techniques for materials discovery, Yang et al., Chem. Soc. Rev., 2010, 39, 656. [4] Prospects for hydrogen storage in graphene, Tozzini and Pellegrini, Phys. Chem. Chem. Phys., 2013, 15, 80. [5] Hydrogen storage in porous graphene with Al decoration, Ao et al., Int. J. Hydrogen Energy, 2014, 39, 16244.

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Boron- and nitrogen-based compounds for chemical hydrogen storage U.B. Demirci* IEM (Institut Europeen des Membranes), UMR5635 (CNRS, ENSCM, UM), Universite de Montpellier, Place Eugene Bataillon, CC047, F-34095, Montpellier, France * Corresponding author : email : [email protected]

Hydrogen storage is one of the major issues hindering the development of a near-future “hydrogen economy”. There are several solutions that are under intense investigation and among them one can cite liquid- and solidstate chemical hydrogen storage materials [1]. An example of liquid-state chemical hydrogen storage material is aqueous alkaline sodium borohydride NaBH4. An example of solid-state chemical hydrogen storage material is ammonia borane NH3BH3. Both belong to the family of boron- and nitrogen-based compounds that have attracted much attention since the early 2000s thanks [2]. Attractively they display high theoretical gravimetric hydrogen densities (10.8 wt% H for NaBH4 and 19.5 wt% H for NH3BH3) and “low” dehydrogenation temperatures (20-50°C and