外源菌群煤生物气化初步研究:菌群结构、煤种及煤孔(裂)隙

A preliminary study of biological coal gasification by exogenous bacteria:Microbiome composition,coal type,pore and seam fracture

以河南义马煤矿、山西山阴煤矿和双柳煤矿不同煤阶煤为研究对象,利用沼液经逐步驯化得到的外源产甲烷菌群为菌源,在千克级的水平上进行了煤生物气化模拟实验。采用16S rDNA测序对驯化得到的菌源进行初步确定,并研究了驯化菌源对不同煤种的气化效果,采用扫描电镜初步研究了驯化微生物形态与煤孔(裂)隙的可能作用。结果表明,不同煤样外源菌群煤生物气化均存在产气周期,可分为快速、缓慢和抑制3个阶段,而不同煤种气化阶段存在明显差异。16S rDNA测序结果显示,甲烷丝状菌属(Methanothrix)占0.02%,而典型的和煤的骨架芳香结构降解相关的微生物类群占约8%,表明降解步骤是煤生物气化的速控步骤。扫描电镜观察发现,驯化后的菌群以球状和杆状为主,部分微生物进入煤的孔裂隙。当以块状煤为底物长期驯化菌源时,菌群的产气效率明显降低。

With the coal samples from Yima in Henan Province,Shanyin in Shanxi Province and Shuangliu in Shanxi Province,the biological coal gasification by exogenous bacteria were studied at the kilogram levels. The microbiome composition was identified by 16 S rDNA method. Morphology of microorganisms and the interaction of microorganisms and coal were investigated by scanning electron microscope. The results show that the biological coal gasification by exogenous bacteria can be divided into three stages:a rapid growth stage,a stable stage,and an inhibition stage. There are apparent differences at the three stages between the different coal samples. 16 S rDNA sequence analysis show that Methanothrix accounts for only 0. 02%,while other typical microorganisms related to degradation of coal account for 8%. Scanning electron microscope observation show that the microorganisms are mainly spherical and rod-shaped. Some of the mi-croorganisms can enter the coal fissure /pore,which account for a small proportion of coal. With the lump coal for the substrate long-term domestication bacterium source,the gas efficiency of bacteria obviously decreases.