Sustainable Production of Biogas in Large Bioreactor under Psychrophilic and Mesophilic Conditions

Abstract

This study reports the sustainability of a large semicontinuous anaerobic reactor (3,000 L) for biogas production from food wastes for a period of 324 days. The methane potential ranged from 418.3 to 13.9 mL CH4/g VSadded during the experiment. An average 54.8% reduction was observed in biogas production during the winter season compared with summer. Results showed that food wastes could be utilized in a low-temperature range (0°C–15°C) as well as a high-temperature range (15°C–27°C). The total microbial community analysis revealed mixed consortia representing acetotrophic, hydrogenotrophic, and methylotrophic archaea (e.g., Methanobacterium, Methanosarcina, and Methanospirillum), indicating a syntrophic pathway for methane production. The bacterial community was well represented by two major phyla: Proteobacteria (31.3%) and Bacteroidetes (14.92%). The highest maximum specific biogas production (Rm) and maximum biogas production potential (A) were 134.5 mL CH4/g VS/day and 34.1 L CH4/g VS for modified Gompertz and first-order equations, respectively. The methane production data were modeled, and showed substantial agreement with experimental results; however, the first-order equation had the best agreement with the experimental data (R2=0.99).