不同联合预处理对褐煤厌氧发酵产甲烷的影响

高效实用的预处理方式对提高甲烷产量具有重要的作用，但单一的预处理方式往往较难获得满意效果，尤其是针对组成成分复杂的褐煤而言，对其后续产甲烷性能的影响更是存在不确定性。为探讨不同联合预处理对褐煤厌氧发酵产甲烷的影响，以1.00%HCl+5.00%H₂O₂(1号)、6.00%NaOH+5.00%H₂O₂(2号)、1.00%HCl+10.00 g木质素酶(3号)、6.00%NaOH+10.00 g木质素酶(4号)、5.00%H₂O₂+10.00 g木质素酶(5号)等不同联合预处理褐煤为实验组，未经预处理煤样为对照组(6号)，在适宜菌种来源和环境条件下进行厌氧发酵产甲烷实验。利用比色法、气质联用法、扫描电镜等对联合预处理产甲烷过程中的糖类、挥发性脂肪酸含量及煤降解特征进行分析，以揭示其影响机理。结果表明:①不同联合预处理均可以增加褐煤发酵产甲烷量。4与5号联合预处理效果较好，累积甲烷产量分别是20.36 mL/g与8.83 mL/g，相比6号对照样分别提高了24.24倍与10.51倍。②各实验组COD(化学需氧量)去除率均高于对照组，且反应前后菌液pH波动值小。③反应初期3号实验组多糖含量最低(0.37 μg/mL)，6号多糖含量最高(2.15 μg/mL)，且均呈现出先下降后上升的总体趋势。④ 2、3与5号实验组还原糖含量在整个反应过程中保持较高值，且反应末期各产气组糖类含量均不为零。⑤不同联合预处理均可以促进乙酸、丁酸的降解并提高产气率。不同条件下的褐煤产甲烷量与转化率变化特征，证实了联合预处理煤增产生物甲烷的有效性，可为煤制生物气技术的产业化应用提供借鉴。 

Effects of different combined pretreatments on biogenic methane production by anaerobic digestion of lignite

It is crucial to choose efficient and practical pretreatment for increasing methane production. However, the treatment effect is often unsatisfactory through a single pretreatment method. In particular, it has an uncertain influence on the methane production of lignite with complex composition. In order to explore the effect of fermenting methane from lignite through the different joint pretreatment, with 1.00% HCl + 5.00% H₂O₂(group 1), 6.00% NaOH + 5.00% H₂O₂(group 2), 1.00% HCl + 10.00 g(group 3), 6.00% NaOH + 10.00 g(group 4), and 5.00% H₂O₂ + 10.00 g ligninase(group 5) as the experimental groups, and with the unpretreated coal samples (group 6) as the control group, the experiments of methane production through anaerobic fermentation were carried out under suitable strain sources and environmental conditions. The colorimetry, the gas chromatography-mass spectrometry and the scanning election microscopy were used to analyze the saccharide, the volatile fatty acid content and the degradation characteristics n the process of joint pretreatment of methane so as to reveal its influence mechanism. The results showed the following: (1) Different joint pretreatment increased methane yield similarly. The treatment of groups 4 and 5 with the cumulative methane production up to 20.36 mL/g and 8.83 mL/g respectively, proved to be more effective for the degradation of coal. Compared with the group 6, the methane production of the two groups has increased by 24.24 and 10.51 times respectively. (2) The COD removal rate of each experimental group was higher than that of the control group, and the pH variation was also relatively small. (3) At the beginning of the reaction, the lowest polysaccharide content belonged to group 3(0.37 μg/mL), whereas the highest number fell into group 6(2.15 μg/mL). The polysaccharide content of the two groups showed the same variation tendency(first decreasing and then increasing). (4) The reducing sugar contents of experimental groups 2, 3, and 5 remained at relatively high level on the whole. At the end of the reaction, the carbohydrate content of each gas-producing group was not zero. (5) All the joint pretreatments promoted the degradation of acetate and butyrate, and improved the carbon conversion rate. This research demonstrated the effectiveness of enhancing biogenic methane from coal through the joint pretreatment. It is hoped that the methods and the findings of this study may shed light on the industrialization applications of biogas production from coal.