中低煤阶煤的生物气生成特征

Biogas formation features of low and medium rank coal

为得到中低煤阶煤的生物气生成特征,以龙口褐煤和淮南肥煤为产气母源进行生物气生成模拟试验,在控制其他影响因素相同的情况下,同时进行7组试验,其中6组试验组分别添加褐煤和肥煤样品为底物,通过统计和分析生物气的产气量、产气速率,探讨中低煤阶煤的生物气生成特征。结果表明:90 d的煤生物气生成模拟试验中,褐煤和肥煤试验组的生物甲烷气生成量和生气速率总体表现为煤阶越低,生气累积量和生气速率越大;在试验组生物气生成整体上经历了3个阶段:第一个阶段是迅速上升期,第二阶段是平稳下降期,第三阶段为趋于稳定期。但第一个阶段的不同煤阶煤样生气特征存在差异:淮南肥煤较龙口褐煤生气较早。生物气生成前期,生物产甲烷菌种主要以培养基中营养液为主要原料,生气速率较高,到生物气生成后期,生物产甲烷菌种消耗煤中有机质产气,从而导致生气速率降低。

In order to have the biogas formation features of the low and medium rank coal,the biogas formation simulation experiments were conducted with Longkou lignite and Huainan fat coal as the gas maternal sources. Under the same conditions to control other influence factors,while seven group experiments were conducted,the lignite and fat coal samples as the bottom materials were added to the six group experiments individually. With the statistics and analysis on the gas production volume and the gas production rate of the biogas,the paper discussed the biogas formation features of the low and medium rank coal. The results showed that in the 90 days biogas formation simulation experiments of the coal,the bio-methane gas formation volume and the gas formation rate of the lignite and fat coal experiment groups would have higher gas formation accumulated volume and gas formation rate as the lower of the coal rank generally. The biogas formation of the experiment groups would have three stages generally. The first stage was the rapid uplifting period,the second stage was the stable dropping period and the third stage was tended to the stable period. At the first stage,there were differences between the different rank coal samples and the gas generation of Huainan fat coal was early than Longkou lignite. At the early period of the biogas formatted,the methane strains from bios would be the nutrient solution in the culture medium as the main material and the gas formation rate would be high. At the late period of the biogas formation,the methane strains from the bios would consume the organic gas in the coal and thus would cause the gas formation rate decreased.