Study on Anaerobic Digestion of Straw Stalk

The biogas yield,concentration of acetic acid and percentage of methane during anaerobic digestion of straw stalk under different temperatures(thermophilic,mesophilic and ambient) were investigated.The removal rates of total solid(TS) and volatile solid(VS) and biogas yield per kilogram were compared among different treatments.The results showed that the anaerobic digestion of straw stalk in every temperature can successfully progress,the biogas conversion rates at thermophilic temperature reached 0.24 m3·kg-1 TS,increasing by 42% and 21% compared to that at mesophilic and ambient digestion respectively,but acidification in thermophilic anaerobic digestion had serious effect on the normal function of the system.The percentage of methane in mesophilic and ambient digestion was up to over 50% on the 8th day.Considered the energy generating and consuming and biogas production,the anaerobic digestion under mesophilic condition,with quickly starting up and steadily functioning,could be one of the effective approaches for deposal of straw stalk.