Effects of Different Alkaline Pretreatment on Biogas Production of Corn Straw under Mesophilic Anaerobic Fermentation

ZHANG Ming; LIU Fang; LIU Chang; WANG Shuangbiao; LI Yaping

doi:10.19672/j.cnki.1003-6504.2018.05.002

Abstract：Effects of three kinds of alkaline including Na OH, KOH and Ca (OH)2 pretreatment on anaerobic fermentation of corn straw at mesophilic temperatures (35 ℃) were studied using the self-designed"system of anaerobic fermentation technology".The results showed that the effect of Na OH pretreatment corn straw mesophilic anaerobic fermentation was better than that of Ca (OH)2 pretreatment, and corn straw pretreatment with KOH could not improve biogas production rate and cumulative biogas yields. The effect of 4‰ Ca (OH)2, 4‰ 和 8‰ Na OH pretreatment corn straw were better than tap water treatment, and the stay phenomenon of biogas production was not appeared during the experiments, and they could get fully fermentation in 115, 116, 118 days, respectively. Compared with tap water treatment, cumulative biogas yields were respectively increased by 17.70％, 21.87％ and 2.34％ at the end of anaerobic fermentation. The superior combination forecasting model showed that the optimum concentration of Na OH pretreatment corn straw was 4‰ at mesophilic temperatures, and it was reached fully fermentation after 120 days of anaerobic fermentation, and the rate of biogas production was 51.07 m L/d, and the maximum cumulative biogas yields of dry matter was 383.00 m L/g. The optimum concentration of Ca (OH)2 pretreatment corn straw was 2‰ at mesophilic temperatures, and it was reached fully fermentation after 114.9 days of anaerobic fermentation, and the rate of biogas production was 46.43 m L/d, and the maximum cumulative biogas yields of dry matter was 348.22 m L/g. It is feasible to use 4‰ Na OH and 2‰ Ca (OH)2 pretreatment corn straw under mesophilic anaerobic fermentation, and the effect of 4‰ Na OH pretreatment corn straw was better than that of 2‰ Ca (OH)2.