Solid-State Anaerobic Digestion of Corn Stover for Biogas Production

Abstract

The effects of temperature, feedstock/inoculum (F/I) ratio, and total solid (TS) content on biogas production from corn stover by solid-state anaerobic digestion (SS-AD) were studied. At an F/I ratio of 3.44, polysaccharide conversion under thermophilic conditions (55C) was 32% higher than under mesophilic conditions (37C), resulting in higher biogas yield. SS-AD performed as expected in the TS content range of 22% to 27% at 37C, while an increase in TS content from 22% to 27% resulted in a 29.8% decrease in biogas yield at 55C. Particle size reduction of corn stover from 15 to 5 mm had no significant improvement on biogas yield (p > 0.05). The highest biogas production of 403.7 L kg-1 volatile solids (VS) fed was obtained at 55C with TS content of 22%, F/I ratio of 4.58, and particle size of 5 mm.