煤发酵制生物氢和甲烷的模拟实验

An experimental study of hydrogen and methane production from fermentation of coal

为查明煤发酵制生物氢和甲烷,以及连续发酵产氢产甲烷的最佳产气条件,以河南省鹤壁四矿的瘦煤为发酵底物,分别利用自主研发的产氢培养基和产甲烷培养基富集地层水中的混合菌群,并以其为接种物,分析了在不同条件下生物氢气和生物甲烷的生成量,并利用发酵产氢后的废料为基底,使用不同方法进行处理,研究了生物甲烷的生成量。实验结果表明:①发酵产氢最适宜的初始pH值在6.0左右;②金属离子络合剂EDTA二钠可显著提高氢气产率,当EDTA二钠浓度为2.0g/L时,氢气产率达到最大值;③产甲烷发酵时,将白腐菌液和富集培养后的地层水菌液同时作为接种物时的甲烷产率最高;④向产氢后的废料中补加碱液以及新鲜地层水,均可实现废料再生甲烷,且直接补碱液时的甲烷产率更高;⑤相比于单独发酵产甲烷工艺,连续产氢产甲烷工艺可获得更高的甲烷浓度和甲烷产率。该成果为微生物采煤技术提供了实验依据。

To investigate the optimal gas-produced conditions for independent fermentation of coals producing hydrogen and methane and the continuous fermentation of hydrogen and methane, samples from the Hebi No.4 colliery were utilized as coal substrates, and specific media prepared in advance in laboratory for the production of hydrogen and methane respectively were used as inocula after the enrichment of mixed strain in stratum water, and the content of produced hydrogen and methane under various conditions were further examined. After that, the waste of fermentative hydrogen production was applied as substrates to investigate the production of methane with different pre-treatments. The results showed that the optimal initial pH value for fermentative hydrogen production was around 6.0; the disodium EDTA was able to significantly increase the hydrogen production which reached a maximum when the disodium EDTA was added at 2.0 g/L; the mixture of white-rot fungi and enriched strain in stratum water was the optimal inoculum for a highest production of methane; a reproduction of methane was achieved by the addition of alkali liquor and fresh stratum water in the waste of fermentative hydrogen production, and was in a comparatively higher production rate when the alkali liquor was directly added; and the continuous fermentation obtained a better methane production as compared with the independent methane fermentation. This experimental study provides a reference for the research of microbial biomass methane production following coal mining.