Effect of different temperatures on dry anaerobic digestion of animal manure and straw.

Dry anaerobic digestion has advantage over wet anaerobic digestion by reducing the volume of the reactor,producing a more easily transportable fertilizers and high organic loading rates.Dry anaerobic digestion of animal manure and straw was conducted to produce biogas.Under the conditions of C/N=28.3 and TS=21.3%,three different temperature levels of room temperature,mesophilic temperature(36 ℃) and thermophilic temperature(55 ℃) were applied to investigate the effect of operation temperature on dry digestion.The result showed that dry digestion under room temperature started up slowly with low biogas production,so normal temperature was unfit for dry digestion.Dry digestion under 55 ℃ and 36 ℃ proceeded steadily with high biogas yield and mesophilic temperature was more suitable for dry digestion.The organic loading rates under 55 ℃ and 36 ℃ were 1.69 kg·m-3·d-1 and 1.89 kg·m-3·d-1 respectively with TS biogas production rates of 0.237 m3·kg-1 and 0.208 m3·kg-1,and volume biogas production rates of 0.401 m3·m-3·d-1 and 0.393 m3·m-3·d-1 respectively.These results could provide instructive meaning to the engineering application of dry anaerobic digestion.