A Review on Effects of Nano Additives

International Journal of Applied Engineering Research, ISSN 0973-4562 Vol. 11 No.3 (2016) © Research India Publications; http/www.ripublication.com/ijaer.htm

A Review on Effects of Nano Additives withPongamiaBiodiesel in CI Engine Performance and Emission Characteristics G.Anbarasu2 Assistant Professor, Department of Thermal Engineering, Sri Ramakrishna Engineering College, Coimbatore-641022 [email protected]

L.Jeryrajkumar1 1 PG Student, Department of Thermal Engineering, Sri Ramakrishna Engineering College, Coimbatore-641022 [email protected]

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ABSTRACT The emissions from diesel engines seriously threaten the environment and are considered one of the major sources of air pollution. Many nations are evaluating a variety of alternative fuels for use in motor vehicles in an attempt to reduce greenhouse gas emissions and to improve the energy security of the country. Biodiesel and other bio fuels are substitute fuels efficient of replacing fossil fuels on large scale in the transportation sector. Biodiesels have great ignition attributes because of their long chain hydrocarbonstructure. On the other hand, their disadvantages include lower heating value, higher viscosity, higher pour point and poor volatility. The addition of fuel additives is one of the possible approaches for reducing these problems because of the obvious fuel oil constituent influences on engine performance and emission characteristics. According to the results of the review, additives are an effective method for obtaining the reduction in the particulate matter (PM), carbon monoxide (CO) and unburned hydrocarbons (UHC) emissions but minimum increase in the nitrogen oxides (NO x) emission. If the additives are added in the biodiesel at appropriate proportion, it will helpful to increase the engine combustion and performance characteristics. Nano additives are reduces the fuel consumption and improves the thermal efficiency during combustion the additives release the energy to the fuel. Index Terms– Nano Particles, Biodiesel, Fuel additive, Rhodium oxide, Cobalt oxide The problems related with the biodiesel, use of chemical constituent like fuel additives derived from organic and inorganic metals are uses.[2] A Nano additive commonly improves the combustion efficiency and reduces the emission. Metallic based compounds, such as cobalt, copper, rhodium,manganese, iron, copper and platinum etc.., it have been used as combustion catalyst for hydrocarbon fuel.[3] Recent advance in nano technology enables production, control and characterization of Nano scale energetic materials. Main benefit of using nano particle is its size, because the particles are micron sized so there is no way for clogging and fuel injector. The effects of using vegetable oil based additive combined with metal based additive on the exhaust emission of diesel engine fuelled with biodiesel [4]. Additive useful for engine to burn fuel better and excess air decrease the CO content. The temperature inside the engine’s cylinder during combustion was reduced due to the presence of additive in the blended fuel. Hence it decreases NOx emission. Study to improve the properties of ignition in diesel fuel and studied the influence of size and Quantity of

1.INTRODUCTION The increasing cost of crude oil and increasing demand of fuels in the world, with the help of bioenergy, it has provided an operational way to fight against the problem and the influence on environment. Biodiesel is an ecofriendly alternative fuel of diesel, it is prepared by transesterification of vegetable oils and animal fat.The major feedstock for biodiesel production in india is non-edible oils obtained from plants such as pongamia (pongamiapinnata), Jatropha (Jatropha curcas)and punnai (Calophyllum in ophyllum) due to the high cost of edible oils . The natural supply of Pongamia is along coasts and river banks and humid tropical lowlands. Pongamia oil available in large amount is a worthy feedstock for biodiesel production of 200 million tonnes of oil per year in India [1].The pongamiaseeds contains an average of 29-34% of oil with high percentage of polyunsaturated fatty acids. Pongamia methyl ester having higher Cetane number, oxygen content and it is clean. Biodiesel having disadvantages include lower heating value, higher viscosity, higher pour point and poor volatility. 553


Al and Al2O3nano particles in a diesel fuel [5]. Finally it was finished that the potential of reducing the evaporation time of droplets by the increasing the heat transfer and mass transfer properties of diesel fuel. It was secondary that it shortens the ignition delay and probability to increase the ignition of diesel.

active more than the dynamic oxygen and forms an intermediate. Nano particles (Rh2O3) are highly active materials and burns during the combustion process. All nano particles are coated with CTAB. The nano particles form a layer and hence droplets shape is swollen. At high temperature sudden explosion take place and the fuel are available in the core area of droplet 2.1.1.RESULT AND ENGINE PERFORMANCE DISCUSSION A. Brake specific Fuel consumption The difference of brake specific energy consumption (BSEC) for Pongamia biodiesel, biodiesel with Nano-fuel additives and the diesel fuel with brake mean effective pressure shows in figure 1. Biodiesel having lesser heating value compared to diesel fuel, hence to keep the same power output more amount of fuel was consumed during biodiesel operation. This leads to increase the fuel consumption of biodiesel compared to diesel. To increase the engine performance Nano additives was added with the biodiesel. The addition of Rhodium oxide additive resulted in 3% reduction in BSEC at full load due to chemical oxidation of fuel which in turn improves the combustion of fuel.

Table 1 Biodiesel Properties Properties

Diesel

Biodiesel

Density@ 15oC (Kg/m3)

810860

870-895

Viscosity(cSt)@40oC

2-3.5

3.5-5.5

Calorific Value (MJ/Kg)

42.5

40

Flash point (oC)

75

145

Fire Point (oC)

80

160

Cetane Number

40-50

45-65

Carbon (%)

86.7

76.6

Hydrogen (%)

13.1

12

Oxygen (%)

-

11.2

In the present review, Biodiesel was produced from Pongamia oil and investigation on performance and emission characteristics were evaluated using compression ignition engine and also investigated the addition of nano additive on biodiesel effects. The properties of biodiesel are shown in table 1. 2.EFFECTS OF FUEL ADDITIVE ON THE PERFORMANCE AND EMISSION CHARACTERISTICS OF THE ENGINE 2.1. ROHODIUM OXIDE A rhodium oxide (Rh2O3) has a hexagonal arrangement of corundum structure it transforms into an orthorhombic structure when heated above 7500. The former is an active site for CO oxidation because those having valence higher than +3 is highly unstable. CO oxidation mechanism be influenced by on two kinds of oxygen. The mobility of active oxygen is clearly affects by thermal treatment. Higher the temperature becomes the dynamic oxygen is more mobile. And the oxidation becomes easier. The lattice oxygen on the Rhodium oxide is

Figure 1.BMEP vs. BSFC B. Brake Thermal Efficiency The differences of brake thermal efficiency for pongamia biodiesel, biodiesel with additive and the diesel fuel with brake mean effective pressure is shown in Figure 2. Brake thermal efficiency is lowest for biodiesel at all loading conditions, because of lower volatility, lower calorific value, higher viscosity, and density compare to diesel fuel. Nearly 15-21% of fuel is normally converted in to mechanical energy. The remaining energy is emitted to the atmosphere as waste heat. In order to utilize the

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chemical energy available in the fuel, Nano-fuel additives (Rhodium oxide) were added and itseffects are reviewed in this study. For biodiesel there is a reduction in thermal efficiency compare with diesel, this is due to lower calorific value and ineffective utilization of heat energy due to higher molecular weight of methyl ester. The addition of Rhodium oxide leads to marginal improvement in thermal efficiency compare with biodiesel operation at full load. Because metal oxide additives reduces the evaporation time of the fuel and hence it reduces the physical delay. Rhodium Oxide having higher activity and can react with water vapour formed during combustion at high temperature and it generates hydrogen and increases the fuel combustion.

Figure 3. BMEP vs. HC The Rhodium oxide Nano fuel additive act as an oxygen buffer and donates its lattice oxygen and avoids fuel rich zone which results in 45 % reduction in HC emission compare to neat biodiesel operation. Hence mixing will be better and fuel burns completely. D. Oxides of nitrogen The variations of NOx emission for Pongamia biodiesel, biodiesel with Nano-fuel additive and the diesel fuel with brake mean effective pressure shown in the figure 4. More significant factor that cause NOx creation are higher combustion temperature and other factors likecombustion quality,injection period and injection timing. By increasing the proportion of biodiesel, NOx rises because the presence of fuel bound oxygen promotes better combustion and resulting in higher in cylinder temperature

Figure 2. BMEP vs. BTE 2.1.2.EMISSION CHARACTERISTICS C. Hydrocarbon The variation of HC emission for pongamia biodiesel, biodiesel with additive and diesel fuel with brake mean effective pressure are shown in figure 3. Hydrocarbon emission was reduced in case of neat biodiesel compare to diesel operation due to bound oxygen of fuel, which improves the combustion and reduces the fuel rich zone. The major reasons for HC emission areflame quenching, fuel rich zone, misfiring and desorption of lubrication oil. By addition of additives there is reduction in HC emission was observed.

Figure 4. BMEP vs. NOx The addition of nanoadditives resulted in an effective reduction in NOx emission. Rhodium oxide showing better reduction at all loads.

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Rhodium oxide is an active single metal oxide catalyst for NOx decomposition. Therefore it reduces the NOx. It was observed that operation, reduction is about 37% in case of Rhodium oxide nanoadditive. E.Carbon monoxide Figure 5 show the variation of carbon monoxide (CO) for Pongamia biodiesel, biodiesel with Nano fuel additive and diesel fuel with brake mean effective pressure. The major reason for higher CO emission is due to fuel rich combustion and an intermediate product formed during combustion. It is released in the exhaust stream when its progression to CO2 is not completed due to lack of oxygen and when engine is running in too rich condition. There is a reduction in COemission for biodiesel compare to diesel.This is due to 10 to12% oxygen possessed by biodiesel. By adding additives, there is an effective reduction in CO emission. Hence lower CO emission was observed. By adding Rhodium oxide, there is a 45% reduction in CO emission at full load .This is because Rhodium oxide acts as an oxygen buffer and donates surface lattice oxygen.

active oxygen. Higherthe temperature more mobile the active oxygen becomes. Andof course, the oxidation of CO also becomes easier The lattice oxygen on the Co3O4 is extra active than activeoxygen and form an intermediate, that is, bidentate carbonate,which could oxidize CO to produce CO2 2.2.1.RESULTS AND DISCUSSION ENGINE PERFORMANCE A. Brake specific Fuel consumption The Figure 6 shows the difference of brake specific energy consumption (BSEC) for Pongamiabiodiesel with Nano-fuel additives and diesel fuel with brake mean effective pressure.

Figure 6. BMEP vs. BSEC Pongamia biodiesel havinglesser calorific value compared to diesel fuel, henceto keepthe same power output excess amount of fuel wasconsumed during biodiesel operation. This leads toincrease fuel consumption of biodiesel compared to diesel. Toincreasethe engine performance nano additivewas added with the biodiesel. The addition ofcobalt oxide additive resulted in 2% reduction in BSEC at fullload due to chemical oxidation of fuel which in turnimproves the combustion of fuel.

Figure 5. BMEP vs. CO

B. Brake Thermal Efficiency The difference of brake thermal efficiency for Pongamiabiodiesel, biodiesel with additive and the diesel fuel with brakemean effective pressure is shown in Figure 7. Brake thermalefficiency is lowest for biodiesel at all of the loading conditions,because oflesser volatility, lower calorific value, higherviscosity, and density compare to diesel fuel. Nearly 25-31 %of fuel is normally converted into mechanical energy. Theremain energy is radiated to the atmosphere

2.2.COBALT OXIDE Cobalt oxide (Co3O4) has a spinal structurecontaining Co3+ in an octahedral coordination and Co2+ in tetrahedralcoordination. The previous is an active site for COoxidation, because those having valence higher than +3ishighly unstable. CO oxidation mechanism related ontwokinds of oxygen species, (i.e.) active oxygen on the surface ofCoO x and lattice oxygen on the surface Co3O4. The thermaltreatment clearly affects the mobility of

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as waste heat.In order to utilize the chemical energy available in the fuel, Nano additives were added. Forbiodiesel there is a decrease in thermal efficiency compared to diesel, this is due to lower calorific value and ineffectiveutilization of heat energy due to higher viscosity. Theaddition of cobalt oxide leads to increase in thermalefficiency compare to biodiesel operation at full load.Becausemetal oxide additive reduces the evaporation time of thefuel and hence it decreases the physical delay. Thus the effectiveutilization of fuel was achieved.

oxygen and avoids fuel rich zone which resultsin82 % reduction in HC emission at 75% load operation compare toneat biodiesel operation. D. Oxides of nitrogen Figure 9 show the variation of NO x emission for Pongamia biodiesel, biodiesel with Nano-fuel additive and the diesel fuel with brake mean effective pressure. The significant factor that cause NO x formation are higher combustion temperature and other factors likecombustion quality, injection period, and injection timing. By increasingthe proportion of biodiesel, NOx increases because the presence of fuel bound oxygenpromotesbettercombustion, resulting in higher in cylinder temperature. Theadditionof Nano-fuel additives resulted in aneffectivereductioninNOx emission. Cobalt oxide screening better reduction at all loads.Cobalt oxide(Co3O4) is an active single metal oxide catalystforNO decomposition. Hence it reduces the NOx. It was detected that at 75% load operation, reduction is about 47% in case ofcobalt oxide Nano-fuel additive. Figure 9. BMEP vs. NOx

Figure 7. BMEP vs. BTE EMISSION CHARACTERISTICS C. Hydrocarbon Figure8 portray the variation of HC emission forPongamia biodiesel, biodiesel with additive anddieselfuel. Hydrocarbon emission wasreduced in biodieseldue to fuel bound oxygen, which increasesthecombustion and reduces the fuel rich zone.

E.Carbon monoxide Figure 10 shows the variation of carbon monoxide CO) for Pongamia biodiesel, biodiesel with nano fuel additive and diesel fuel with brake mean effective pressure. The majorreason for higher CO emission is duetofuelprosperouscombustion and an intermediate product formed duringcombustion.It is free in the exhaust stream when its progress to CO2isnot completed due to lack of oxygenandwhenengineis running in rich condition. There is a reduction in CO emission due to 10 to11% oxygen possessed by biodiesel.By adding cobalt oxide, there is a 50% reduction in CO emission at 75% load.

Figure 8 BMEP vs. HC The main reasons for HCemission areflame quenching, fuel rich zone, misfiring and desorption of lubrication oil. By adding additives there is a reduction in HC emission was noticed. The cobaltoxide Nano fueladditive act as an oxygen buffer and givesits lattice

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nano and micron- sized aluminium particles,” Combustion and Flame, pp. 1-15, 2010. [4] Husnawan M, Masjuki H, Mahlia TM I, Mekhilef S, M.G Saifullah, “ Use of post flame metal-based and oxygenated additive combination for biodiesel-diesel blends,” Journal of Scientific & Industrial Research, vol. 68pp. 1049-1052, 2009. [5] HimanushuTyagi, Patrick E,Phelan, Ravi prasher, “Increased Hot -plate Ignition Probability for Nanoparticle –Laden Diesel Fuel,” Nano Letters, vol. 08, pp. 1410-1416, 2009. 3459.

Figure 10. BMEF vs CO

CONCLUSIONS

[6]S. Fernando, C. Hall, S. Jha, “NOx reduction from biodiesel fuels,” Energy Fuels2006; 20:376–82.

The present review, discussed the performance and emission characteristics of biodiesel fuelblend with additives. The conclusions drawn from the present study are the accompanying points:

[7]V.Pirozfar, A.Z.Moghadam, S.sepehri, M.R. Omidkhah, A.Ameri “Effect of additive ethanoldiesel blend fuel onPhysicochemicalproperties and emission”.

 Various nano-fuel additives are available which possess high oxygen content compared to diesel. If these additives areadded in biodiesel at appropriate proportion, it will increase the engine performance and emissioncharacteristics.

[8]T. Nibin, A. Sathiyagnanam, S. Sivaprakasam, “Investigation on emission characteristics of a diesel engine usingoxygenated fuel additive”.

 Based on the performance, minimum increment in Brake Specific Fuel Consumption (BSFC) and with higherimprovement in Brake Thermal Efficiency (BTE), has found by adding the additives to biodiesel.

[9]N Raghunadham, NV Deshpande N V,”Effect of bio-additives on IC engine performance. Natl Conf. on IC engines,VNIT, Nagpur.2004.

 Based on the emissions, decrease in CO, CO2, PM, NOx and UHC and minimum increase in NOx for biodiesel with additives is observed by previous studies. REFERENCES [1] Gaurav Dwivedi M.P. Sharma, “Prospects of biodiesel from Pongamia in India,” Renewable and Sustainable Energy Reviews, pp. 114-122, 2014. [2] Ganesh D, “Effect of Nano-fuel additive on emission reduction in a Biodiesel fuelled CI engine” IEEE, pp. 3453-3459, 2011. [3] Yanangan, Li Qiao, “Combustion Characteristics of fuel droplets with addition of

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