Anaerobic digestion of extruded OFMSW

Organic fraction of municipal solid waste (OFMSW) was used to feed two pilot plants of 10001 working in anaerobic conditions. The OFMSW had previously been treated using a system of extrusion which, due to exerted pressure, separates the undesired fractions of waste from organic waste and reduces the organic fraction in a kind of homogeneous jam. Pilot tests were performed in semi-continuous conditions with a stepwise progressive increase of the total solids content (TS) of the input material from 3% TS w/w (1.5 g VS l(-1) d(-1) organic loading rate) to 10% TS w/w (4.3 g VS l(-1) d(-1) organic loading rate) using activated sludge as diluting agent. The average specific biogas production obtained was 600 l kg(-1) VS. When the input IS content was increased to 10% w/w, the biogas average specific production went up to 8001 kg(-1) VS. The methane content in the biogas was always higher than 60% measured by volume. (C) 2011 Elsevier Ltd. All rights reserved.