高级检索

白腐菌对煤孔隙结构及自燃倾向性的作用机理

Mechanism of white rot fungi on coal pore structure and spontaneous combustion tendency

  • 摘要: 微生物抑制煤自燃成为煤自燃防控的新兴研究方向。为探究白腐菌对煤体孔隙结构与自燃倾向性的作用机理,通过单因素试验结合响应面法优化溶煤条件,采用压汞试验、N2吸附试验、CO2吸附试验,结合优势孔径段的优选,构建全尺度孔隙联合表征体系;基于分形理论全尺度定量分析孔径的分形特征变化,并通过氧化动力学试验验证白腐菌对自燃倾向性的抑制效应。结果表明:白腐菌显著改变了煤体孔隙结构,其最佳溶煤条件为煤浆质量0.40 g、培养时间26 d、接种量6 mL;在此条件下,多尺度孔隙表征显示,煤体总孔容降低34.25%,孔径为1 000~100 000 nm是孔容损失的主体区间,比表面积减少43.79%,孔径为0.3~0.6 nm是比表面积损失的主体区间,综合分形维数Dz降低0.04;氧化动力学试验证实煤样综合判定指数I上升了22.06%,自燃倾向性显著降低。白腐菌对煤自燃的抑制作用可源于物理隔氧-化学阻化的协同机制:形成生物膜覆盖煤表面阻断氧气扩散,降解类木质素组分弱化孔隙连通性;分解煤中C=O、—OH等活性基团抑制链式氧化反应。这2重路径通过重塑孔隙结构与化学结构,共同抑制煤氧复合作用的发生。本研究首次建立“溶煤参数-孔隙演化-自燃倾向性”的定量关联,为煤自燃防控提供新思路,为微生物防治煤自燃提供理论基础与技术参数。

     

    Abstract: Microbial inhibition of coal spontaneous combustion has become a new research direction of coal spontaneous combustion prevention and control. To explore the mechanism of white rot fungus on the pore structure and spontaneous combustion tendency of coal, the single factor experiment combined with response surface method was used to optimize the coal dissolution conditions. The mercury intrusion test, N2 adsorption experiment, CO2 adsorption experiment, combined with the optimization of the dominant pore size segment, the full-scale pore joint characterization system was constructed. The fractal characteristics were quantitatively analyzed in full-scale with fractal theory, and the inhibition effect of pore rot fungus on spontaneous combustion tendency was verified by oxidation kinetics experiment The experimental results showed that white rot fungi significantly changed the pore structure of coal, and the optimal coal dissolving conditions were: coal slurry quality 0.40 g, incubation time 26 d, and inoculation amount 6 mL; under these conditions, the multi-scale pore characterization showed that the total pore volume of coal decreased by 34.25%, 1 000−100 000 nm was the main range of pore volume loss, and the specific surface area decreased by 43.79 %, and 0.3-0.6 nm was the main range of specific surface area loss. The comprehensive fractal dimension Dz decreased by 0.04; The oxidation kinetics experiment confirmed that the comprehensive judgment index I of coal sample increased by 22.06%, and the spontaneous combustion tendency decreased significantly. The inhibitory effect of white rot fungi on coal spontaneous combustion stems from the synergistic mechanism of physical oxygen isolation and chemical resistance: Biofilm is formed to cover the coal surface to block the diffusion of oxygen; Degradation of lignin like components weakens pore connectivity; Decomposition of active groups such as C=O, —OH in coal inhibits the chain oxidation reaction. These two paths inhibit the occurrence of coal oxygen recombination by reshaping the pore structure and chemical structure. This study establishes the quantitative correlation of “coal dissolution parameters pore evolution spontaneous combustion tendency” for the first time, which provides a new idea for the prevention and control of coal spontaneous combustion, and provides a theoretical basis and technical parameters for the prevention and control of coal spontaneous combustion by microorganisms.

     

/

返回文章
返回