Promoting Effect And Mechanism Analysis Of Different Strains Of Pretreatment On Coal-to-biogas

In order to explore the effect of different microbial pretreatments on the promotion of coal-based biogas,this paper takes lignite from Baiyinhua Mine as the research object,and single pure strain Phanerochaete chrysosporium(fungi),Streptomyces viridosporus(actinomycetes),Pseudomonas sp.(bacteria)were used for pretreatment experiments on raw coal respectively.SEM and anaerobic fermentation experiments were performed on the pretreated residual coal,the gas production characteristics of the coal after biological pretreatment were analyzed,and the improved Gompertz equation was used to simulate the production of methane to evaluate the kinetics of gas generation;GC-MS was performed on the pretreated precipitates And three-dimensional fluorescence test to analyze the soluble organic matter components of coal degraded by microbial pretreatment;elemental analysis of pretreated residual coal,FTIR test to find out the characteristics of the influence of biological pretreatment on coal structure,and the residual coal after biogas production XPS and mercury injection tests were performed to analyze the effect of biogas production on coal structure.The results show that: a.Compared with raw coal,the surface morphology and roughness of microbially pretreated coal increased significantly,showing unevenness,and crack pores significantly increased.The coal-solubility of the three pretreated bacteria was Phanerochaete chrysosporium > Streptomyces viridosporus > Pseudomonas sp.and its ability to adhere on coal surface is Pseudomonas sp.> Streptomyces viridosporus > Phanerochaete chrysosporium.b.Microbial pretreatment is positively correlated with coal-made biogas,and the pretreatment’s ability to promote gas production is Phanerochaete chrysosporium >Streptomyces viridosporus > Pseudomonas sp.,which simulates the kinetics of methanogenesis,and concludes that the microbe pretreatment compared with raw coal,the later coal has increased potential and maximum rate of methane production.c.With the addition of lignite sample solution,humic acid humus and fulvic acid humus increased,and the DOM in the water sample was in a strong autogenic source.d.The content of phenol,alcohol,OH group of carboxylic acid,C=C skeleton of benzene ring,C-H of aldehyde group,and C-H bond in aromatic hydrocarbon after coal pretreatment are decreasing compared with raw coal.e.The relative content of C,H and N elements in coal after microbial pretreatment increased to varying degrees.f.The compounds detected in the solution after pretreatment are mainly oxygenated compounds and mainly butyric acid.g.In the process of anaerobic biogas production,phenol carbon or ether carbon(C-O),carbonyl(C=O),and carboxyl(O-C=O)will fall off from coal and enter the fermentation liquid,and participate in the final generation of hydrogen,carbon dioxide and methane.h.According to the width of the hysteresis loop of the mercury pressure curve of the coal sample after the gas production of each pretreated coal and the raw coal,and the volume of the mercury advance and retreat,it can be seen that the pores of the Streptomyces viridosporus pretreated coal samples are mostly semi-closed pores,and the pore connectivity is not good.The pretreatment effect of the Phanerochaete chrysosporium is centered,and the pore connectivity was better in the coal sample pretreated by Pseudomonas sp.The research in this paper provides a reference for improving the efficiency of coal conversion of biomethane.