Study On The Interaction Of Lignite And Rice Straw In Methane Production By Co-degradation

Biogenic coalbed methane is produced by the degradation of coal by a variety of in-situ microorganisms in coal seams.It is widely used,easy to develop and has high economic benefits.Microbial stimulation of coalbed methane technology can promote anaerobic microbial degradation of coal to produce methane and increase the output of biomethane.The co degradation of coal and straw can effectively solve the problem of low methane yield of coal as a single substrate.The interaction between coal and straw in the process of co-degradation is the key to increase methane production.This paper takes lignite and rice straw as the research object,uses the high-efficiency methanogenic flora to establish the experimental system of co-degradation of lignite and rice straw to study the succession law of organic matter,microorganism and substrate structure in the process of co-degradation of lignite and rice straw,the promoting effect of rice straw on the metabolism of refractory components of lignite,and the effect of lignite on the metabolism of refractory components of rice straw,To reveal the interaction mechanism of co-degradation and methanogenesis of lignite and rice straw.The main results of the experiment are as follows:(1)The co-degradation of lignite and rice straw can increase the biogenic methane production,and the maximum methane production can reach 388.47 μmol/g,the yield of methane was 116.53% higher than that of coal and straw.The relative abundance of cellulose degrading bacteria such as Clostridium and Paraclostridium in the co degradation system was significantly increased,which promoted the degradation of cellulose in straw.The aromatic carbon ratio of lignite decreased more after co-degradation,which promoted the degradation of aromatic compounds in coal.In addition,co-degradation promotes the formation of organic acids and jointly increases the production of biomethane.(2)Lignite has great potential for methane production,and the cumulative methane production from biodegradation can reach 969.38 μmol/g.After biological treatment,the aromatic carbon rate decreased significantly,aromatic compounds were degraded and consumed,and the addition of rice straw could not increase methane production.It shows that the co-degradation of rice straw and refractory components of lignite can not increase methane production,but can increase methane production by promoting the degradation of aromatic compounds in the original lignite.(3)The methane production potential of rice straw is also large,and the cumulative methane production of its biodegradation can reach 582.47 μmolg.After biological treatment,the peak intensity of-OH group decreased significantly,cellulose was degraded,and adding lignite could not increase methane production.It shows that the co-degradation of lignite and the refractory components of rice straw can not increase methane production,and the methane production can be increased by promoting the degradation of cellulose in the original straw.(4)When lignite and rice straw are co-degraded,microbial community structure and organic matter metabolism are important factors for increasing methane production.The effect of increasing methane production is different,and its type and content are also different.When co-degrading and increasing methane,the relative abundance of Clostridium and Paraclostridium increased significantly.When the refractory components and lignite / straw are co-degraded without yield increasing effect,Desulfomicrobium occupies the most dominant position.Organic succession is also an important factor.The effect of increasing methane production is different,and the content of organic matter is different.(5)The interaction of co-degradation of lignite and rice straw to increase methane production promotes the utilization of easily biodegradable parts,such as cellulose in straw and aromatic compounds in lignite,and releases their methane production potential in advance,so that the co-degradation of lignite and rice straw has a significant effect on increasing methane production.The research results can enrich the theoretical research on the co-degradation of coal and straw to promote the production of biomethane,and provide detailed and reliable data for practical application,which is beneficial to the development of the practical application of microbial stimulation of coalbed methane technology.It can promote the development of China’s energy industry and the improvement of energy structure,comply with the national development strategy and promote the development of the national economy.