A floating coverage system for digestate liquid fraction storage

Anaerobic digestion is booming in the nations of Europe. In fact, Italy alone has approximately 500 plants in operation or in some phase of start-up. Previous studies have made evident the potential that lies in digested manure residual biogas. Nevertheless, much of the potential goes unrealized when enormous amounts of digestate are produced, but are then stored in uncovered tanks. This research work designed, constructed, and tested a low-cost digestate storage tank cover system capable of abating CO(2)eq atmospheric emissions and then recovering the biogas. The experiment, carried out at a 1 MW electric anaerobic digestion plant, demonstrated that collecting the residual biogas from the digested liquid fraction storage tank made it possible to avoid atmospheric emissions of up to 1260t CO(2)eq annually and to increase the methane yield of the installation by 3%. (C) 2013 Elsevier Ltd. All rights reserved.