油菜秸秆厌氧发酵产气特性与工艺参数优化

Characteristics of biogas production and optimal technological parameters for anaerobic fermentation of rape straw

为了探索油菜秸秆厌氧发酵产沼气的潜力,本文采用正交试验设计的方法,研究了温度、总固体浓度、接种率和C/N对油菜秸秆厌氧发酵过程中产气量随时间的变化规律和产气特性。结果表明,油菜秸秆厌氧发酵最高日产气量达到4.25 L/d(厌氧消化器容积为2.5 L),发酵周期中的最高累积产气量达到70.665 L,产气潜力达到0.36973 L/g。通过对实验结果的方差和极差分析,得到厌氧发酵的最佳工艺参数为发酵温度40℃,总固体浓度10%,接种率20%,C/N=25:1。各因素对产气量的影响主次依次为:温度(A)>总固体浓度(B)>接种率(C)>C/N(D)。温度对产气量的影响显著,总固体浓度和接种率对产气量的影响不显著。通过对试验结果的分析,得出油菜秸秆在最优条件下的总产气量和TS产气量分别将达到72.6619 L和0.39576 L/g。

This research was used an orthogonal experiment design method to determine the effects of fermentation temperature, total solids concentration, inoculum ratios and C/N on accumulate biogas production of anaerobic fermentation, in order to explore the potential biogas production of rape straw. The results indicate that, the highest daily biogas production reached to 4.25 L/day （ the volume of anaerobic digester is 2.5 L）. During the whole period of fermentation, the accumulate biogas production reached to 70.665 L, and the potential of biogas production was up to 0.36973 L/g. Through the analysis of variance （ANOVA） and range analysis, the optimum orthogonal design method was proposed to be at a fermentation temperature 40℃, total solids concentration 10%, inoculum ratios 20% and C/N = 25 ： 1. The order of various factors to facilitate the impact of gas production arranged as following： Fermentation temperature （A） 〉Total solids concentration （B） 〉Inoculum ratios （C） 〉C/N （D）. Fermentation temperature has a significant effect on biogas production, while total solids concentration and inoculum ratios has no marked influence on it. From the results analysis, we concluded that the total biogas yield and total solid biogas yield is projected to reach 72.6619 L and 0.39576 L/g respectively, under optimal conditions.