蒸汽爆破/氧化钙联合预处理对水稻秸秆厌氧干发酵影响研究

Research on effect of combination of steam explosion and calcium oxide pretreatment on rice straw solid-state anaerobic digestion

为了提高水稻秸秆在厌氧干发酵中的利用效率,采用蒸汽爆破、氧化钙以及蒸汽爆破/氧化钙联合预处理(以下简称"联合处理")水稻秸秆,考察不同处理方式对水稻秸秆的理化性质和厌氧干发酵的影响。结果表明:从扫描电子显微镜照片观察到,联合处理组与其他处理方式相比对水稻秸秆结构破坏最彻底。木质素含量测试结果显示,经过联合处理水稻秸秆中木质素含量从17.2%下降到12.2%,去除率可达29.1%。纤维素酶水解实验中,联合处理组的葡萄糖产量与木糖产量分别为877.56 mg·L^(-1)和400.85 mg·L^(-1),比CK组提高了85.43%和1 283.39%。在厌氧干发酵实验中,联合处理组产甲烷延滞期最短(5 d),比CK组缩短了约6 d,第30 d累积产甲烷量占总产甲烷量(60 d)的86.4%,而CK组仅占55.7%,原料产甲烷率提升最明显(0.24 L·g-1VS),比CK组提高了20.0%。动力学模型拟合结果表明,与蒸汽爆破处理、氧化钙处理相比,联合处理组对厌氧干发酵的促进作用最显著。

In order to enhance the utilization of rice straw,the methods steam explosion（SE）, calcium oxide（Ca O）and combination of SE/Ca O were used to pretreat rice straw,and the characteristic of rice straw and solid-state anaerobic digestion were also investigated. The results showed that the structure of rice straw was destroyed seriously, as while as the lignin content of rice straw decreased from 17.2% to12.2% and the removal rate of lignin was 29.1% in the condition of SE/Ca O pretreatment. The results of cellulose hydrolysis indicated that yield of glucose and xylose which pretreat by SE/Ca O were 877.56 mg·L^（-1）and 400.85 mg·L^（-1）, and were increased by 85.43% and 1 283.39%compared with the untreated samples. The solid-state anaerobic digestion experiment showed that the lag phase of samples pretreat by SE/Ca O was 5 days which shorter 6 day than the untreated samples.The cumulative methane production in previous 30 days accounted 86.4%of total cumulative methane production in the condition of SE/Ca O pretreatment, and the untreated was only 55.7%. The methane production potential of samples pretreat by SE/Ca O was 0.24 L·g-1VS which was the highest in three pretreatment, and increased 20.2% than the untreated. The fitting results of kinetic model indicated that SE/Ca O pretreatment was the more suitable method to pretreat rice straw which compared with SE pretreatment and Ca O pretreatment.