煤层生物氢形成机理及其向甲烷的转换条件研究

With the mechanism of biomethane being revealed, coalbed biohydrogen has gradually been found as well. As we all know, hydrogen is a cleaner energy than methane, in order to define the respective share of resource contributions of biological hydrogen and biological methane, there is a need of ascertaining the way of biological hydrogen's formation.Furtherly，a investigation of the mechanism of its generation and the transformation conditions and the process of producing methane should be done. This project intends to regard the different-rank coals as the research objects, and analyzes the characteristics of coal rock, coal quality and underground water; anaerobic culture technique is adopted to isolate and purificate the hydrogen-producing and methane-producing microbes in the coal resources; the microbes can be identified by analyzing its morphological and molecular features and then the intermediate products can also be detected during the process of coals' degradation by means of GC, FTIR, MS, NMR, IRMS, etc. The proiect conducts a simulation experiment of hydrogen-producing microbe's degradation under the conditions of statics and continuous current, which is for the purpose of finding out what kinds of microbes and hydrogenase work for the generation of biohydrogen and the types of intermediate products of the degradation process and its change laws. Meanwhile it investigates the major influencing factors of the generation of biological hydrogen, including temperature, pH, Eh, trace elements, coal rank and coal quality, etc. What's more, it probes into the transforming and controlling mechanism of coal two-phase hydrogen producing and methane producing in order to further reveal the mechanism of the generation of biohydrogen and biomethane in the coalseams, by which achieving biological mining, residual mining and energy saving and emission reduction can be supported theoretically.

随着生物甲烷气的机理被揭示，煤层生物氢也逐渐被认识，氢气是比甲烷更清洁的能源，为了明确生物氢和生物甲烷的资源贡献，需要查明生物氢的形成途径，并对其生成机理及与产甲烷的转化条件和过程进行深入探讨。 本项目拟以不同变质程度的煤为研究对象，分析煤岩、煤质以及地下水特征；采用厌氧培养技术对煤源产氢和产甲烷微生物进行分离和纯化；通过形态特征分析和分子特征分析，并对微生物进行鉴定；利用GC、FTIR、MS、NMR、IRMS等测定微生物降解煤的中间产物（各类气体和小分子有机物）。进行静态条件和连续流的产氢微生物降解模拟实验，查明生物氢气生成过程中起作用的微生物及其氢化酶种类、煤降解中间产物的类型及其变化规律，探讨生物氢生成的温度、pH值、Eh值、微量元素、煤阶、煤质等主要影响因素，并探讨煤两相产氢产甲烷过程中的转换和控制机制，从而更深入地揭示煤层生物氢和生物甲烷的生成机理。

煤生物产气技术经过多年的研究和发展，在煤层气的勘探开发领域已占有一席之地，对煤层气资源利用的贡献度也越来越高，但其产出条件、转换过程以及资源贡献量的定量评价等研究仍存在严重不足。本项目拟以不同煤层本源含菌水，褐煤、长焰煤、焦煤、瘦煤等中低煤阶煤为研究对象，在实验室条件下进行近似地质环境下的煤微生物降解产气实验。应用高通量测序技术研究煤层本源微生物群落的多样性，并结合煤层环境因子查明煤层中优势产氢产乙酸菌和产甲烷菌的种类和差异性。分析煤岩、煤质以及地下水特征，探讨温度、pH值、Eh值、金属离子、煤阶、煤质等主要影响因子对煤层生物氢形成及其向甲烷转换条件的影响；查明煤制生物氢过程中糖类、丙酮酸及其他有机体液相产物的变化规律；利用气相色谱法、离子色谱法、GC-MS、FTIR等分析煤生物降解过程中气相产物、VFA、酶活性、COD等变化特征；对反应前后的煤样进行元素分析和XRD测试，并分析了煤样进行酸碱预处理之后的产气量与煤结构变化特征，从而揭示煤层生物氢的形成机理及其向甲烷的转换条件，为实现生物采煤、生物采残煤和节能减排提供理论支撑。