Methane production enhancement of a family-scale biogas digester using cattle manure and corn stover under cold climates

[Display omitted] •Performance of household-scale biogas digester in cold climate is improved.•Numerical method for preparing the co-digestion slurry is presented.•Co-digestion of milled corn stover and cattle manure allows improving C/N ratio.•Explicit increase in daily, cumulative and specific methane yield is observed.•Enhancement in the average methane content and biogas gained energy is achieved. The enhancement in methane production under cold climates is one of the essential prerequisites to enable year-round performance improvement of any biogas plant. In Egypt, the winter is reasonably cold which offers a good opportunity to study the enhancement in the methane yield and corresponding performance improvement of a family-scale biogas digester using the co-digestion technique. This work reports the field performance of floating-dome type biogas digester using anaerobic co-digestion (AcoD) of cattle manure (CM) with a milled corn stover (CS). The performance of AcoD is compared with the performance of anaerobic mono-digestion (AmoD) of CM under winter conditions. Moreover, a numerical method for preparing the digested slurry is defined for the ease of the farmers. Results revealed that using AcoD was led to a significant increase in the average daily, cumulative, and specific methane yield by 40.30, 42.43, and 39.65%, respectively over AmoD. Additionally, AcoD gave an explicit increment in the average methane volume, average daily, and total gained biogas energy by 11.42, 40.16, and 42.43%, respectively over AmoD. Hence, the major findings of the present work proved that the co-digestion of CM and CS improves the performance of biogas digester under open-field conditions in the winter season.