牛粪和玉米秸秆厌氧消化产甲烷潜力及动力学

为了评价牛粪和玉米秸秆的产甲烷潜力,研究其厌氧消化过程动力学方程,采用自制序批式厌氧发酵实验装置对某养殖场牛粪和秸秆的最大甲烷生产潜力及其发酵过程进行研究。通过实验研究,测得接种物、牛粪和玉米秸秆的累计甲烷产量分别为64.87、244.0和466.54 mL CH4/g VS。根据实测的产气量变化曲线,按照modified Gompertz equation模型进行方程拟合,牛粪组和玉米秸秆组拟合方程的相关性系数分别为0.983和0.991,表明运用modified Gompertz equation模型预测牛粪和玉米秸秆的产甲烷潜力方法可行。通过对产甲烷过程的动力学研究得到:接种物、牛粪和玉米秸秆的最大产甲烷潜力分别为66.07、213.93和458.57 mL CH4/g VS,与实测值的误差率分别为1.8%、12.3%和1.7%;牛粪和玉米秸秆的最大甲烷日产气率(Rm)和延滞期时间(λ)分别是13.14 mL CH4/(g VS·d)、30.76 mL CH4/(g VS·d)和0.35 d、0.71 d。综上,玉米秸秆厌氧消化的停滞期长,但总产气量和最大甲烷日产期率都比牛粪高。

Biochemical methane potential and kinetics of anaerobic digestion of cattle manure campared with corn stover

The biochemical methane potential (BMP) of cattle manure and corn stover, and their anaerobic digestion, were induced with a set of self-made anaerobic sequencing batches to determine their respective methane production potentials and anaerobic digestion kinetics equations. The cumulative methane production values of inoculum, cattle manure, and corn stover were 64.87, 2.44, 466.54 mL CH4/g VS, respectively. The modified Gompertz equation model was fitted based on the methane production curve of each fermation material. Their correlation coefficients to the cattle manure group and the corn stover group were 0.983 and 0.991, respectively. Hence, the modified Gompertz equation model can predict the methane production potential of cattle manure and corn stover. Some of the kinetics parameters could also be determined, involving the methane production potentials (Pm) of inoculum, cattle manure, and corn stover, which were 66.07, 213.93, and 458.57 mL CH4/g VS; the respective maximum methane production rate (Rm) and the leg phase (λ) of cattle manure and corn stover were 13.14 mL CH4/(g VS·d), 30.76 mL CH4/(g VS·d), and 0.35 d, 0.71 d. Thus, compared with cattle manure, the λ of corn stover is long, but its Pm and Rm values are higher.