Introduction
Biodegradation of municipal solid waste (MSW) under anaerobic
conditions converts organic waste into methane, a valuable
energy source. Anaerobic digestion (AD) of municipal solid waste
has been employed in Western Europe since the 1980s, where
200 facilities have a total capacity of 6 million metric tons (MMT)
per year (De Baere and Mattheeuws, 2010). The United States Environmental
Protection Agency has estimated that 2009 production
of MSW in the U.S. was 221 MMT, of which 120 MMT was landfilled
(U.S. EPA, 2010). Approximately 61.4 MMT (27.8%) of the
total MSW was kitchen waste and yard trimmings, of which 18.9
MMT was composted (U.S. EPA, 2010).