Experimental Study And Application Of Complex Anaerobic Bacteria To Degrade Coal And Wood Chips For Gas Production

In China,resources such as deep coal,shallow thin coal seams,and residual coal are difficult to exploit using conventional technical methods.At the same time,the production of sawdust is abundant and it is convenient to obtain materials.Collaborative fermentation of the two is an efficient and clean fluidized coal mining technology.This thesis aims to study the law and mechanism of co fermentation gas production under different ratios.High efficiency anaerobic methane bacteria were obtained through iterative cultivation.The degradation effects of collaborative fermentation on different coal rank samples and the stimulation effect of alkali treatment of sawdust were analyzed in a preliminary experiment;The experiments of co fermentation with different ratios of low rank coal and sawdust as substrates were conducted.The results showed that among the collaborative fermentation experiments of different coal ranks,low rank coal had the best effect on gas production,and wood chips treated with alkali were used in the collaborative fermentation experiment,which had a significant promoting effect on gas production;At the same time,the gas production effect of collaborative fermentation was significantly better than that of single substrate fermentation,in which the mass ratio of coal and sawdust had a significant impact on gas production.The best gas production effect is obtained when the ratio of coal to sawdust is 4:1.The liquid and solid products of anaerobic fermentation were comprehensively analyzed using a combination of microbial community analysis,GC/MS organic matter,cellulose content,and total calorific value.The results showed that the abundance of Lenticrobium,Desulfovibro,and Sedimmentibacter was one of the main reasons for the difference in gas production in the collaborative fermentation experiment;Archaea mainly uses small molecular organic compounds for methane conversion,among which Metanosarcina,Bathyarcaeia,and Bathyarcaeia are key strains for gas production;Through liquid phase product detection,51 organic compounds including alcohols,ketones,aldehydes,phenols,etc.were identified.In anaerobic fermentation,organic substances are degraded by microorganisms through two metabolic pathways,acidification methanation and alcohol methanation,to produce methane.The abundance of intermediate products 1,3-dimethylbenzene,ethylbenzene,and dibutyl phthalate is the highest;The degradation effect of microorganisms on cellulose in wood chips is the best(58%),while the degradation effect on lignin is the worst(12.5%).The addition of coal plays a catalytic role;Through the collaborative fermentation of coal and sawdust,the fermentation efficiency and gas production can be significantly improved.At the most suitable ratio,the yield increase and heat increase effect can reach 17%,with a very significant application prospect.Aiming at the problems existing in the process of raw coal mining and utilization,the solution idea of microbial gasification technology is proposed.Achieved efficient and clean biotransformation of coal resources.This thesis contains 42 figures,17 tables and 106 references.