Solid-state co-digestion of expired dog food and corn stover for methane production

► Solid-state co-digestion of corn stover (CS) with expired dog food (DF). ► Co-digestion increased methane yield and reduced start-up time. ► The highest methane yield of 304.4 L/kg VSfeed was obtained at CS:DF ratio of 1:1. ► Anaerobic digestion process failed at high proportion of DF. ► Biogas production was mainly contributed by the degradation of DF.