Thermophilic anaerobic co-digestion of separated solids from acidified dairy cow manure

► This study using solid fraction of acidified manure (SFDCM) in anaerobic digestion (AD). ► Digester substituting 30% of manure with SFDCM showed a stable biogas production. ► 50% more methane yield was achieved when 30% of manure was substituted with SFDCM. ► SFDCM is a suitable biomass for co-digestion in AD at ratios up to 30%. ► Post digestion of digestates slurry can compensate for the reduced methane yield.