Effects of Percolate Recirculation on Dry Anaerobic Co-digestion of Organic Fraction of Municipal Solid Waste and Corn Straw

• Published in: Energy & fuels 2017-11, Vol.31 (11), p.12183-12191
• Main Authors: Qian, Mingyu, Zhang, Yixin, Li, Ruihua, Nelles, Michael, Stinner, Walter, Li, Yeqing
• Format: Article
• Language: English
• ISSN: 0887-0624; 1520-5029
• DOI: 10.1021/acs.energyfuels.7b01869

Garage-type dry fermentation (GTDF) technology is an appropriate method to co-digest the organic fraction of municipal solid waste and corn straw. In this study, anaerobic digestion (AD) performance of lab-scale GTDF under different frequency of percolate recirculation (FPR, daily percolate recirculation volume to total percolate volume) of 0.3, 0.6, 1.2, 2.4, and 4.8 was investigated, and their effects on volatile fatty acids (VFA) and methane generation were analyzed. Results indicated that higher FPR positively contributed to the hydrolysis and acidogenesis by its inoculation effect and the enhancement of mass transfer, but its washing effect also led to a fast VFA accumulation and a higher peak of VFA concentration. The highest methane yield of 166.33 mL CH4/gVS was obtained at an FPR of 0.3, which corresponds to 66.6% of the biochemical methane potential of the co-substrate. Additionally, in comparison to the AD performance of addition of solid digestate inoculum, a comparable methane yield can be reached through the mono-inoculation of percolate recirculation.