Waste wood fueled gasification demonstration project C.M. van der Meijden1 W. Sierhuis2 A. van der Drift1 1
ECN HVC group
2
Presented at the Renewable Energy World Europe Conference and Exhibition, 7 - 9 June 2011, Fiera Milano City, Milan, Italy
ECN-M--11-066
June 2011
Waste wood fueled gasification demonstration project C.M. van der Meijden1*, W. Sierhuis2 & A. van der Drift1 1
Energy research Centre of the Netherlands (ECN), P.O. Box 1, 1755 ZG Petten, The Netherlands 2
*
HVC group, P.O. Box 9199, 1800 GD, Alkmaar, The Netherlands
Corresponding author: Phone: +31 224-564582, Fax: +31 224-568487, E-mail:
[email protected]
ABSTRACT: The Energy research Centre of the Netherlands (ECN) has developed a new biomass gasification technology, called the MILENA technology. The MILENA gasification technology has a high cold gas efficiency and high methane yield, making it very suitable for gas engine application. Overall electrical efficiency of small scale installations (1 – 10 MWe) can be over 35%, using gas engines in combination with an Organic Rankine Cycle (ORC) and a biomass dryer, this is significantly higher than the efficiencies that can be achieved with steam cycles at this scale and at least competitive with other gasification concepts. HVC is a modern and innovative waste and energy company. HVC converts waste streams which cannot be recycled into usable forms of energy. HVC has a large waste wood boiler of almost 30 MWe in operation. HVC has decided to join ECN with the development, demonstration and implementation of the MILENA Bio-CHP technology. HVC and ECN plan to build a 11.6 MWth MILENA gasifier in combination with OLGA gas cleaning. The installation will be located in Alkmaar (the Netherlands). Originally is was the intention to use the gas in a gas engine and to produce green electricity and heat. Due to changing subsidies in the Netherlands the gas will now be upgraded to natural gas quality, which can be injected in the gas grid and will be sold as green gas. In other countries the subsidies to produce green heat and green electricity are still attractive. Several projects using the MILENA and OLGA technology in combination with gas engines are in the initial phase of development. The typical scales vary between 1 and 4 MWe. The basic engineering of the 11.6 MWth MILENA + OLGA demo plant was executed by Dahlman and ECN in 2010. Dahlman (www.dahlman.nl) is the supplier of the OLGA gas cleaning technology. Wood will be used as fuel. An extensive test program using demolition wood as fuel was done in the ECN pilot plant in order to generate the required engineering data. The project was delayed because of changes in the Dutch subsidies for green heat, electricity and gas. A new application for subsidy on green gas will be filed at the end of 2011. Start of construction of the 11.6 MWth demonstration plant producing green gas is scheduled for 2012. Keywords: allothermal conversion, bio-syngas, gasification, methane, combined heat and power generation (CHP), synthetic natural gas (SNG).
INTRODUCTION Energy is one of the essential ingredients of modern society. Nowadays energy comes for the greater part from fossil fuels like oil, natural gas and coal. The proven fossil oil and natural gas reserves are declining in North America and Europe [1]. According to a study of the Energy Research Centre of the Netherlands (ECN) the global production of oil might decline within 30 years [2]. According the International Energy Agency (IEA) the consumption of primary energy is expected to increase by 1.6% per year. By 2030 consumption is expected to have risen by just over 45% compared to 2006 [3]. On top of the problem of securing the supply, the combustion of fossil fuels produces CO2, which contributes to global warming. CO2 emissions from fossil fuels can to some extent be countered by sequestration of CO2. This CO2 sequestration, however, lowers overall efficiency significantly, resulting in a higher consumption of fossil fuels per unit of energy delivered. Biomass energy is expected to make a major contribution to the replacement of fossil fuels. The future world-wide available amount of biomass for energy is estimated to be 200 to 500 EJ per year by 2050, based on an evaluation of availability studies [4]. World-wide oil consumption was 161 EJ (82.5 million barrels of oil per day) in 2005 [1], so the potential of biomass energy is enormous. Biomass is considered a CO2 neutral fuel, as the amount of CO2 released on burning biomass equals the amount taken from the atmosphere during growth of the biomass. Biomass can be converted in a combustible gas via gasification. This gas can be used to generate electricity or can be upgraded into other valuable biofuels like Bio-Substitute Natural Gas (Bio-SNG), Fischer Tropsch Diesel, etc.. National governments are promoting the production of renewable electricity by subsidies. The market price (including subsidy) of renewable electricity can be as high as 175 €/MWh e [5]. This makes the development of highly efficiency Biomass power plants very attractive. Gas engines are to date the most efficient prime movers to produce heat and electricity at relatively small scale (
