化学预处理增产生物成因煤层气研究

发布时间：2018-03-25 11:15

本文选题：生物煤层气　切入点：化学预处理　出处：《太原理工大学》2017年硕士论文

【摘要】：作为一种非常规能源资源,煤层气的开发与利用,一方面可以大大降低煤炭资源的开采成本,另一方面可以确保能源的可持续发展。按照形成原因,煤层气可以分为两类:生物成因煤层气和热成因煤层气。目前普遍认为,生物成因煤层气的生成过程主要是由煤层中的本源产甲烷菌群将煤中的大分子有机物逐步转化为小分子有机化合物,进而转化为生物甲烷。由此,生物成因煤层气能够在一定程度上实现煤层气的“再生”,对改变我国“富煤少气”的能源结构具有重要作用,科学及现实意义重大。然而,多种因素导致生物成因煤层气的产气效率较低。目前普遍认为,生物降解煤的限制因素主要是煤结构的复杂性和难降解性。本文提出采用有效方法在生物转化之前对煤进行预处理,来降低煤分子的复杂性,提升煤分子的生物有效性,以提高生物煤层气的产生效率。本文采用传代、富集的方法从沁水盆地煤层气田产出水中获得了无烟煤降解高效菌群,并确定了最佳生长条件;利用FTIR、X-RD、GC-MS技术,通过煤官能团、煤晶核、降解中间产物3方面初步分析了菌群的降解机理。在此基础上,研究了不同浓度硝酸、高锰酸钾、双氧水、氢氧化钠预处理煤的生物煤层气增产效果,以产气量为核心评价指标,优选出最佳的预处理条件,并通过FTIR、X-RD技术分析了预处理及随后的产气过程中煤官能团和煤晶核的变化情况,初步分析了预处理增产生物甲烷的机理。研究发现:(1)成功培育出降解无烟煤的高效菌群,其最佳产气条件为:温度,35℃;耐盐度,1.1%~1.2%;粒径,0.15~0.25mm;p H,8~9;煤(g)与菌液(ml)之比,1:5;最佳接种时间,20d。在降解煤产甲烷的过程中,酚、醇、醚、脂的C-O的伸缩振动以及苯环骨架振动的吸收峰面积逐渐减小;煤的晶核结构不断减小,煤的芳环结构变得膨胀疏松;培养液中的中间代谢产物有芳香族物质、长链脂肪酸、甲酸、乙酸、酚、醇、醚、脂等物质出现。整个降解过程遵循了厌氧生物典型发酵理论的模式,即煤的大分子不断降解为小分子,最终被微生物利用产生甲烷的过程。(2)优选出最佳煤预处理条件为:30%的H_2O_2处理12h和1.5M Na OH处理12h,产气量分别提高12.5%和15.5%。(3)H_2O_2预处理过程中,煤官能团主要体现在取代芳烃以及苯环的骨架振动的吸收峰不断减小,煤晶核结构主要体现在其体积的缩小,这是以双氧水对其外部分子的氧化作用为前提而完成的,即这是一个使小分子被氧化脱落的过程。Na OH预处理过程中,煤官能团主要体现在甲基、亚甲基的吸收峰不断减小,这是碱机理作用的结果,而煤的晶核结构的减小,主要是氢氧化钠的强腐蚀性的原因造成的。(4)H_2O_2预处理后煤产气过程中,煤官能团主要体现在酚类、醇类、醚类物质的C-O吸收峰以及苯环的骨架振动的吸收峰的面积是不断减小的,这说明经H_2O_2处理后,以酚类、醇类、醚类以及芳香族物质作为主要产气基质的物质更易被利用;煤的晶核结构呈现出不断减小的趋势,这表明在微生物的作用下,其堆砌高度以及延展度都有所减小,这正与产甲烷过程中煤中有机质的降解过程相对应。Na OH预处理后的煤产气过程中,煤官能团主要体现在含有苯环的骨架振动的吸收峰不断减小,这说明煤的大分子不断降解,进而转化为酚类、醇类等物质,进而被利用产气;煤的晶核结构虽有所减小,但减小量并不是特别显著。(5)H_2O_2预处理增产生物煤层气,主要是由于其本身的氧化性发生作用,Na OH预处理增产生物煤层气,主要是碱作用的结果。(6)煤的生物降解产甲烷过程十分复杂,在煤的生物转化之前,采用有效的预处理方式对煤进行处理,如H_2O_2和Na OH对煤进行处理,可有效提高生物甲烷的产生效率。
[Abstract]:As a kind of unconventional energy resources, development and utilization of coal-bed gas, on the one hand, can greatly reduce the cost of the exploitation of coal resources, on the other hand can ensure the sustainable development of energy. According to the causes of CBM can be divided into two types: biogenic coalbed gas and heat for Coalbed gas. It is generally believed that generation the process of biogenic coalbed gas in coal seam is mainly composed of the origin of methanogens macromolecular organic compounds in coal gradually transformed into small molecular organic compounds, and then converted into bio methane. Thus, biogenic coalbed gas can to a certain extent in the CBM "regeneration" to change China's "rich coal less gas" energy structure plays an important role in the scientific and practical significance. However, many factors lead to biogenic coalbed methane gas production efficiency is relatively low. It is generally believed that limits the biodegradation of coal The main is the complexity of coal structure and refractory. This paper adopts the effective method in the bioconversion of coal before pretreatment, to reduce the complexity of coal molecules, biological effectiveness of coal molecule, which is in order to improve the efficiency of biological gas. This paper uses the method of subculture, enrichment from Qinshui Basin Coalbed gas output the water won the anthracite degrading bacteria, and the optimum growth conditions were determined by FTIR, X-RD, GC-MS; technology, through the coal group coal nuclei, 3 degradation intermediates, preliminary analysis of the degradation mechanism of bacteria. On this basis, the effects of different concentrations of nitric acid, hydrogen peroxide, Potassium Permanganate, biogenic coalbed gas effect of NaOH pretreatment of coal to gas production as the core of the evaluation index, select the optimal pretreatment conditions, and through FTIR, X-RD analysis of the pretreatment and subsequent gas production in the process of official Can group and the change of coal nuclei, preliminary analysis of the mechanism of production of biogenic methane. The study found that: (1) successful breeding of high efficient bacteria degradation of anthracite, the best gas production conditions: temperature, salinity, 35 DEG C; 1.1%~1.2%; 0.15~0.25mm; P diameter, H, 8~9; coal (g) and bacteria (ML) ratio, 1:5; the best time of inoculation, 20d. in the degradation process of coal methane production, phenol, alcohol, ether, ester C-O stretching vibration and benzene skeleton vibration absorption peak area gradually decreases; crystal structure of coal decreases, the aromatic ring structure of coal the expansion has become loose; aromatic substances in the liquid culture of intermediate metabolites, long chain fatty acid, formic acid, acetic acid, phenol, alcohol, ether, fat and other matter. The degradation process followed the anaerobic fermentation of typical theory model, namely coal macromolecular continuously degraded into small molecules, the final process (methane producing by microorganisms. 2) the best coal pretreatment conditions: H_2O_2 12h and 1.5M Na 30% OH 12h, gas production increased by 12.5% and 15.5%. (3) H_2O_2 in the process of pretreatment, coal group mainly decreases in substituted aromatic and benzene skeleton vibration absorption peak, mainly reflected in the crystal structure of coal the volume reduction, this is the external molecules with hydrogen peroxide oxidation is the premise to complete, which is a small molecule is oxidized off process of.Na OH pretreatment process, coal is mainly reflected in the methyl groups, the absorption peak of methylene decreases, this is the result of base mechanism. The crystal structure of coal decreases, is mainly caused by the corrosive reason of sodium hydroxide. (4) H_2O_2 after pretreatment of coal gas production process, coal group is mainly reflected in the phenol, alcohol, ether substance absorption peak at C-O and benzene ring skeleton The vibration absorption peak of the area is decreasing, indicating that after H_2O_2 treatment with phenols, alcohols, ethers and aromatic substances as the main gas producing matrix material is more easily used; crystal structure of coal showed a decreasing trend, suggesting that the microorganisms were used, the the stack height and the ductility is reduced, which is working with the degradation process of organic matter in coal methane production in the process of coal gas production process corresponding to.Na OH after pretreatment, coal groups mainly reflected absorption peaks in the skeleton vibration containing benzene ring decreases, indicating that the coal macromolecular continuous degradation, and then into the phenols, alcohols and other substances, and then by using gas production; crystal structure of coal was decreased, but the reduction is not particularly significant. (5) H_2O_2 pretreatment increased biogenic coalbed gas, mainly due to its oxidation effect, Na OH pretreatment The biological yield of coalbed gas, mainly alkali effect. (6) the biodegradation process of coal methane production is very complex, before the conversion of coal by biological pretreatment, effective treatment for coal, such as H_2O_2 and Na OH on coal processing, can effectively improve the production efficiency of biogenic methane.

【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE37

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