以风化煤为底物制取生物甲烷的潜力分析

我国拥有丰富的风化煤储量,因其高度被氧化的独特性质,可应用的领域极为有限,目前主要被作为改善土壤性质的肥料和制取腐殖酸的来源。以风化煤为底物制取生物甲烷是一种具有探索性的全新生物发酵工艺,探究其可行性及模拟实验过程中风化煤的物性特征变化有利于拓宽风化煤的资源利用和环境改善,并可以进一步丰富煤生物产气理论。实验选取内蒙古乌海和山西晋城两地不同风化程度煤样,以煤层矿井水为菌种来源,在适宜环境条件下开展模拟产气实验,通过生物产气模拟和红外光谱测试,分析不同风化程度煤的生物产气能力及其内在因素,以揭示其产气潜力及物性变化特征。结果表明:①随着煤的风化程度加深,可燃基CH 4产气量明显增加,两组煤样中可燃基CH 4生成量最高分别达到7.13,4.20 mL/g;②不同风化程度的煤样均出现了产气高峰,时间基本都出现在15~30 d,各组中随着煤样风化程度不断加深,产气高峰出现时间也越来越早;③随着煤的风化程度加深,煤中芳环被不断打开,大分子结构被破坏,同时煤中羟基、氨基等基团含量趋于降低,脂碳结构逐渐解体,含氧官能团成为主要结构,氧含量比例不断增高,更容易被微生物降解;④菌群鉴定表明风化煤不仅含有大量产生生物气所需的第1阶段和第2阶段细菌,更含有甲烷杆菌属、甲烷球菌属等多种类型的产甲烷菌群,具有把风化煤转化为生物甲烷的环境条件。实验结果最终反映了风化煤具有转化为生物甲烷的潜力,并有利于提高我国风化煤的资源利用率。

Potential analysis of biological methane production with weathered coal

China has abundant weathered coal resource,but it has limited application because of its highly oxidized unique properties.At present,it is mainly used to improve soil properties and produce humic acid.Biomethane production with weathered coal as substrate is an exploratory new bio-fermentation process,exploring its feasibility and the change of physical characteristics of weathered coal in the process of simulation experiment is conducive to broadening the utilization of weathered coal resource and improving the environment,and can further enrich the theory of biogas production from coal.Coal samples with different weathering degrees from Wuhai in Inner Mongolia and Jincheng in Shanxi were selected for the experiment.Using coal mine water as the source of microbial community,the simulated gas production experiments were carried out under suitable environmental conditions,and the biogas production capacity and internal factors of coal with different weathering degrees were analyzed through biogas simulation and infrared spectroscopy test,to reveal its gas production potential and physical characteristics.The study results show that①with the deepening of weathering degree of coal,the gas production of com-bustible CH 4 was increased.The highest production of combustible CH 4 in two groups of coal samples reached 7.13 mL/g and 4.20 mL/g respectively.②Coal samples with different weathering degrees had gas production peaks and the time basically appeared between 15 and 30 days.The peak of gas production was getting earlier and earlier with the deepening of weathering degree of coal samples in each group.③With the increase of weathering degree of coal,the aromatic ring in coal was continuously opened and the macromolecular structure was destroyed.At the same time,the content of hydroxyl and amino groups in coal tended to decrease,the structure of lipid-carbon was disintegrated,and the oxygen-containing functional groups became the main structure,the proportion of oxygen content increased continuously,which made it easier to degrade for microorganisms.④The identification of microbial community structure indicated that weathered coal contained the first and second stage bacteria needed to produce biogas,also had Methanobacteriales and Methanococcales,which had the environmental conditions for converting weathered coal into biomethane.The experimental results show that weathered coal has the potential to transform into biomethane,and is conducive to improving the utilization of coal resources in China.