Increasing the biogas yield of manure by wet explosion of the digested fiber fraction

Increasing the biodegradability of the lignocellulosic fiber fraction of manure can ensure higher methane productivity in biogas plants, leading to process profitability and thus larger production of renewable energy. A new pretreatment method, wet explosion (WEx), was investigated to treat digested manure fibers from the effluent of an anaerobic digester for enhancing biogas production and exploring the untapped biomass potential. The increase in methane yield of the digested manure fibers was investigated by applying the WEx treatment under 5 different process conditions. The pretreatment condition of 180 ºC and a retention time of 10 minutes without addition of chemicals was found to be optimal, resulting in 136% increase in methane yield as compared to the untreated digested manure fibers.