Study on Biogas Production by Dry Anaerobic Co-digestion of Animal Manure and Straw

Dry anaerobic co-digestion of animal manure and straw was conducted to produce biogas. Startup characteristics and biogas production perform of dry digestion were studied, and the effect of operation temperature and incubation amount on dry digestion was also investigated. The study result showed that under the conditions of C/N=25-30, TS=20% and T=(36 +/- 1)degrees C, dry digestion can start up quickly with acclimated thickening sludge as incubation sludge. Compared to dry digestion of chicken manure and pig manure, dry digestion of cow manure proceeded steadily with high biogas yield. It is found that incubation is necessary in the process of dry digestion and biogas yield increases with more incubation amount. The appreciate incubation ratio is about 10%. Temperature change has apparent effect on biogas production, and it is suggested that mesophilic temperature should be chosen in the scaled project of dry digestion.