厌氧微生物降解原煤体吸附甲烷试验研究

Experiment study on anaerobic microbial degrading methane adsorbed by raw coal

为了研究厌氧型微生物对实体煤中吸附甲烷的降解效能,富集、纯化、分离了高效降解甲烷的厌氧型甲烷氧化菌;并在三轴应力渗流试验装置基础上,制作成模拟原始煤体赋存环境下厌氧微生物降解甲烷试验、分析系统。试验过程中通过定量、连续地控制、加载轴压和围压,同时将微生物菌液高压注入实体煤试件内,使菌液在煤体内均匀地扩散与分布。分析计算试验前后煤体吸附甲烷的减少量和二氧化碳的增加量。结果表明:在围压1~5 MPa、轴压1.5~7.5 MPa内随着加载轴压和围压的增大,该类厌氧型微生物降解甲烷的效率和二氧化碳产量均得到增加,甲烷降解率从24.22%增加到36.43%,二氧化碳产量从59.34 cm^3增加到102 cm^3,然而二氧化碳的增加量小于甲烷的减少量,推测其原因可能与降解甲烷中间过程生成存留部分碳氢化合物有关。

In order to study the degradation function of the anaerobic microbes to the adsorbed methane of the solid coal,an enrichment,purification and separation was conducted on the anaerobic methane oxidizing bacteria of the high efficient degraded methane.Based on triaxial stress seepage test device,an anaerobic microbe degradation methane experiment and analysis system were prepared under the simulated insitu coal deposition environment.During the experiment process,with the quantitative and continued control and the loading on the axial pressure and surrounding pressure,the microbes bacterial liquid were highy pressurized and injected into the solid coal samples and could be evenly diffused and distributed in the coal mass.Before and after the experiment,the methane adsorption reduction and carbon dioxide increment of the coal were analyzed and calculated.The results showed that within the surrounding pressure of 1 - 5 MPa and the axial pressure of 1.5 - 7.5 MPa,with the loaded axial pressure and surrounding pressure increased,the degradation methane efficiency with the anaerobic microbes and the carbon dioxide production were all increased evenly.The methane degradation rate was increased from 24.22%to 36.43 % and the carbon dioxide production was increased from 59.34 cm^3 to 102 cm^3.The increased value of the carbon dioxide production was lower than the reduction value of the methane and the cause could be related to the residual hydrocarbon generated in the degradation methane process.