Experimental Research On Synergistic Fermentation Of Coal Combined With Corn Straw

In order to explore the characteristics and mechanism of synergistic biodegradation of coal combined with corn straw and the feasibility of clean and efficient utilization of solid residue and residue after synergistic biodegradation,the biogas production experiments were carried out using Yimin coal,Qianqiu coal,Quanling coal and corn straw in different proportions to choose the optimum proportion of the conversion of coal and corn straw to biomethane.The chemical and biological pretreatment of corn straw was used to observe the biogas production characteristics of the treated corn straw and coal samples.The COD,pH,GC-MS and 16S RNA gene tests of fermentation solution were carried out,and the change characteristics of cellulose,hemicellulose and lignin from the corn straw before and after synergistic biodegradation were analyzed to discuss the mechanism of synergistic biodegradation of coal combined with corn straw.Combustion tests were carried out using the solid residue to compare the change characteristics of calorific value,slagging characteristics and air pollutant emission before and after fermentation,and biogas production experiment was continued using residual liquid domesticated to find the characteristics of biomethane production to analyze the feasibility of clean and efficient utilization of solid residue and residue after fermentation experiments.The results show that:a.the optimum proportion of the conversion of lignite B and corn straw to biomethane is 2:1,and the optimum proportion of the conversion of bituminous coal D,bituminous coal C,and corn straw into biomethane is 3:1,and corn straw has different promotion effects on gas production for coals of different rank:Qianqiu coal>Quanling coal>Yimin coal.b.The biogas production of alkali treatmented corn straw or white-rot fungus treatmented corn straw and most of coal are lower than that of untreated corn straw and coal.c.The content of aromatic ring,heterocyclic and benzene derivatives decreased in the first 6days,the content of volatile fatty acids（VFA）and methyl compounds increased.After 6 days,the content of macromolecular substances began to increase.The consumption rate of low molecular substances by microorganisms was higher than the production rate,and the utilization of 4-methylphenol by methanogens was not high.d.The existence of Desulfovibrio bacteria and Pseudomonas bacteria,the different gene functional expression and the different nutritional sources of methanogens are one of the main reasons for the different methane production in three biogas experiments.e.The addition of coal samples can promote the degradation of cellulose,hemicellulose and lignin from corn straw.f.the total calorific value of solid residue and biomethane after synergistic biodegradation of Yimin coal,Qianqiu coal and Quanling coal combined with corn straw was higher than the original combination samples,and the slagging index and air pollutant emissions also decreased during the combustion of solid residue.g.The domestication of residual liquid can promote the synergistic biodegradation of coal and corn straw.h.With the repeated domestication of residue liquid,the removal rates of hemicellulose and lignin from corn straw of X₁-HM-1,X₂-HM-1,X₁-QM-2 and X₂-QM-2 are higher than that of corn straw of HM-1 and QM-2,while the removal rate of cellulose decreases constantly.For Qianqiu Coal Sample,the removal rates of hemicellulose and lignin shows a trend of high-low-high.i.From the determination experiment of main elements in fermented and domesticated coal samples,it is concluded that the content of carbon in Yimin coal and Qianqiu coal samples increases with the increase of gas production,while the content of hydrogen decreases;the content of carbon and hydrogen in Quanling coal samples decreases with the increase of gas production.l.According to the tests result of different fermentation solution,the mineralization,COD and OD₆₀₀ of three fermentation solution increased significantly compared with the original mine water.Technology research of synergistic biodegradation of coal combined with corn straw into biomethane can provide new ideas for clean and efficient utilization of coal and corn straw,which has important theoretical guidance and reference significance for bioengineering research of CBM.