Simultaneous co-digestion of cow manure and syngas at thermophilic conditions, process understanding and microbial community compositions

hydrothermal gasification of recalcitrant biomass such as lignocellulosic material produces syngas which consists of (50-60%) CO, (20-30%) H2, and (10-30%) CO2 which has a low calorific value in comparison to CH4. Biological syngas conversion into CH4 can be done both in-situ and ex-situ. In-situ syngas biomethanation is advantageous over the ex-situ processes as no additional space or capital costs are required and can be easily implemented into the existing anaerobic digestion reactors in biogas plants or wastewater treatment facilities. In this current study, syngas was co-digested with cow manure in continuously stirred tank reactors to convert them into CH4.