Bioenergy from landfill gas (LFG) in Taiwan

Greenhouse gases (GHGs) emissions are becoming significant energy and environmental issues relating to municipal solid waste (MSW) deposited in landfills in Taiwan. The nation, although not a Party to the Montreal Protocol and Kyoto Protocol, has diligently striven to mitigate and phase out them. The landfill gas (LFG), which is now considered as a renewable energy with emphasis on electricity generation, has been recognized as one of the main GHGs emissions associated with its composition mostly consisting of methane (CH4) and carbon dioxide (CO2). The objective of this paper is to present an updated overview of LFG-to-electricity in Taiwan. The description is thus centered on biogas sources and their energy utilizations, and then aimed at MSW generation and management. Using the International Panel on Climate Change (IPCC) recommended methodology, anthropogenic methane emissions from MSW landfills in Taiwan during 1992–2003 were estimated to be around 360 thousand metric tons annually during 1992–1999, then decreased to approximately 103 thousand metric tons in 2003 due to the MSW recycling and incineration policies during this period. The promotion measures relating to LFG-to-electricity are also summarized in the paper. Finally, we overview four LFG-to-electricity facilities currently commercialized in Taiwan, and briefly evaluate their economic and environmental benefits. It is shown that total LFG-to-electricity is around 1.6×108kW-h/yr based on the LFG generation rate of 1.0×108m3/yr, heating value of 5500 kcal/m3, and energy efficiency of 25%.