Anaerobic treatment of lignocellulosic material to co-produce methane and digested fiber for ethanol biorefining

Five different ratios of corn stover to swine manure were investigated to evaluate the performance of anaerobic digestion and the quality of anaerobically digested fiber (AD fiber) as a feedstock for bioethanol production. The stover-to-manure ratio of 40:60 generated 364 L biogas and 797 g AD fiber per kg of dry raw feedstock daily. The AD fibers after digestion were pretreated and hydrolyzed to release sugars for ethanol fermentation. The stover-to-manure ratio of 40:60 was able to produce 152 g methane and 50 g ethanol per kg of dry raw feedstock. The net energy generated from the ratio 40:60 was 5.5 MJ kg−1 dry raw feed, which was an 18% increase on net energy output compared to the other ratios and proved to be most beneficial for a biorefinery.