煤矿采空区微生物驯化及抑制煤自燃特性

Microbial acclimatization and inhibition of coal spontaneous combustion in coal mine goaf

  • 摘要: 煤自燃的发生主要与煤炭的化学结构组成及其特性有关,而微生物对煤结构具有一定的作用能力。因此提出利用特定微生物对煤表面结构溶解−抑制煤自燃的思路,从褐煤中分离、提纯、定向驯化得到2种采空区煤源微生物,Aureobasidium pullulans (DA. pu) 和Staphylococcus pettenkoferi (DS. pe),经处理煤样后,探讨煤源驯化微生物对煤低温氧化过程微观结构及氧化性能的影响特征。结果表明:不同微生物对煤活性结构作用效果具有差异性。DA. pu减少煤中羟基,但DS. pe却使羟基峰面积比例大幅增大。煤中的脂肪烃、含氧官能团面积比例均呈现出不同程度的减少。其中,DS. pe对煤中脂肪烃的破坏能力最强,可完全溶解—CH3,对芳醚键也具有较强的溶解能力,降低率高达66.37%。DS. pe将煤中芳香烃中四取代烃峰面积降为0,单取代烃的减少率达到了58.52%。处理煤样的γ峰与002峰的峰面积,堆砌高度与芳香片层数均减小。综合微观结构的变化特征,DA. puDS. pe对结构参数作用能力更为显著。微生物作用延迟了煤样的临界温度T1DA. pu将燃烧阶段的活化能增大了4 428.11 J/mol,延缓了煤自燃发展进程。微观结构及氧化性能的表现一致,表明DA. pu抑制能力更强。这是由于微生物能够有效的溶解煤分子结构,降低煤分子的反应活性,使得煤的反应活化能增加,氧化性能降低。该研究结果为探索煤矿采空区微生物驯化及抑制煤自燃的设想提供了理论依据。

     

    Abstract: The occurrence of coal spontaneous combustion (CSC) is related to the chemical structure and characteristics of coal,while microorganisms can act on its structure. The idea of using specific microorganisms to dissolve the surface structure of coal and inhibit CSC was proposed. Two coal-derived microorganisms from goaf, Aureobasidium pullulans (DA. pu) and Staphylococcus pettenkoferi (DS. pe), were separated, purified and domesticated from lignite. After processing the coal, the influence characteristics of coal-derived microorganisms on the microstructure and oxidation performance of coal during low-temperature oxidation were explored. The results show that different microorganisms have varing effects on functional groups of coal. DA. pu reduces the hydroxyl content in coal, but DS. pe significantly increases the hydroxyl content.The contents of aliphatic hydrocarbons and oxygen-containing functional groups in coal decreased to varying degrees. DS. pe has the strongest destructive ability to aliphatic hydrocarbons in coal and can completely dissolve —CH3. It also has a strong dissolving ability for aromatic ether bonds, with a reduction rate of up to 66.37%. DS. pe reduces the peak area of tetrasubstituted hydrocarbons in the aromatic hydrocarbons in coal to 0, and the reduction rate of monosubstituted hydrocarbons reached 58.52%. The peak areas of γ and 002 peaks, stacking height and number of aromatic flakes of treated coals were reduced.Based on the changing characteristics of the microstructure, DA.pu has a more significant impact on the structural parameters of coal than DS.pe. The microbial action delays the characteristic temperature T1 of the coal, and DA. pu increases the activation energy of the combustion stage by 4 428.41 J/mol, delaying the development of CSC.The microstructure and oxidation performance are consistent, indicating that DA. pu has stronger inhibition ability. This is because microorganisms can effectively dissolve the molecular structure of coal and reduce the reactivity of coal molecules, which increases the reaction activation energy of coal and reduces its oxidation performance. The research results provide a theoretical basis for exploring the concept of microbial domestication in coal mine goafs and inhibiting CSC.

     

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