Methane production from anaerobic co-digestion of the separated solid fraction of pig manure with dried grass silage

摘要

Anaerobic co-digestion of the solid fraction of separated pig manure (SPM) with dried grass silage (DGS) was evaluated in three identical continuously stirred tank reactors (CSTRs) at 35±1°C. The feedstock contained 20 DGS in CSTR1, 30 DGS in CSTR2 and 40 DGS in CSTR3 on a volatile solids (VS) basis. Organic loading rates (OLR) of 1.0, 1.5, 2.0 and 3.0kgVS/m ~3/d were studied and it was found that the OLR affected the digester performance more than the DGS proportion in the feedstock. Tripling the OLR increased volumetric methane yields by 88 and decreased specific methane yields by 38. At the OLR of 3kgVS/m ~3/d, post-methane production potentials of digestates ranged from 38 to 41 of total methane production potentials of the feedstock. An energy yield estimation on a 654-sow pig unit showed that 268-371MWh/a electricity and 383-530MWh/a heat would be generated.