Anaerobic co-digestion of chicken manure and corn stover in batch and continuously stirred tank reactor (CSTR)

•Co-digestion of CM and CS were investigated under batch and continuous conditions.•CSTR showed stable methane yield of 223±7mL/gVSadded at OLR of 4gVS/L/d.•Post-digestion of digestate gave extra energy yield up to 2.6MJ/kgVSadded.•Pyrolysis of digestate could produce valuable pyrolysis gas with LCV of 10.9MJ/m3. Anaerobic co-digestion of chicken manure and corn stover in batch and CSTR were investigated. The batch co-digestion tests were performed at an initial volatile solid (VS) concentration of 3gVS/L, carbon-to-nitrogen (C/N) ratio of 20, and retention time of 30d. The methane yield was determined to be 281±12mL/gVSadded. Continuous reactor was carried out with feeding concentration of 12% total solids and C/N ratio of 20 at organic loading rates (OLRs) of 1–4gVS/L/d. Results showed that at OLR of 4gVS/L/d, stable and preferable methane yield of 223±7mL/gVSadded was found, which was equal to energy yield (EY) of 8.0±0.3MJ/kgVSadded. Post-digestion of digestate gave extra EY of 1.5–2.6MJ/kgVSadded. Pyrolysis of digestate provided additional EY of 6.1MJ/kgVSadded. Pyrolysis can be a promising technique to reduce biogas residues and to produce valuable gas products simultaneously.