Co-fermentation of sewage sludge and CO_2 boosted by alcohol-containing bioliquids: enhancing biomethane production in a two-phase anaerobic digestion process

摘要

Two-phase anaerobic digestion (TPAD) is an efficient technology for energy recovery from biomass and wastes, and represents an interesting contribution to address fossil fuels substitution. The use of CO_2 to improve solid degradation and methane production in the anaerobic digestion has been described for sewage sludge, as a result of a long-term R&D activity (1). The work carried out in the versatile 2.7 mc pilot plant, located in Bologna (Italy), revealed that the main advantages of this approach are improved productivity and lower greenhouse gas emissions. The activity is now focused on valorization of synergic effects of CO_2 and biomasses, such as alcohol-containing bioliquids.