华亭烟煤地下气化污染物分布及富集规律

煤炭地下气化为我国清洁、低碳、安全、高效现代能源建设开辟新的途径。为研究华亭烟煤地下气化污染物的富集、分布规律，以评估华亭烟煤地下气化的环境影响因素，采用地下气化模拟实验平台系统，通过不同富氧—水气化实验、不同尺度煤样的热解实验，研究煤层气化过程中焦油及气化残留物中重金属元素的富集规律。结果表明:随着烟煤的尺度（块体大小）增加，烟煤热解焦油呈增加趋势，而焦油产率呈先增加后减小的趋势；烟煤在N₂、CO₂气氛中热解时，热解焦油中主要成分为酚类、萘类以及烃类污染物；气化后残留重金属Ni、Cr、Zn、Cu、As这5种元素在氧化区最为富集、还原区次之、干馏干燥区最不富集，而Hg在氧化区富集程度最高、干馏干燥区次之、还原区最次，Pb在还原区富集程度最高、氧化区次之、干馏干燥区最次；重金属元素残留程度由高到低依次为Zn、As、Hg、Cr、Ni、Cu、Pb。针对华亭矿区，煤层气化后应重点检测重金属元素Zn、As、Hg。在后期实际煤层气化生产阶段，应结合华亭矿区煤层特征及地下水特征，在项目选址、气化工艺等方面进行污染物防控。在当前生态环境保护形势严峻的当下，研究成果对煤炭地下气化开采的污染物处置和减排具有一定的指导意义。 

Distribution and enrichment of pollutants from underground gasification of bituminous coal in Huating Mining Area

In order to study the enrichment and distribution of pollutants from the underground gasification of bituminous coal in Huating Mining Area, and to evaluate the environmental factors of the underground gasification of bituminous coal, with an underground gasification simulation experimental platform system, this paper studies the enrichment of heavy metal pollutants in tar and gasification residues during gasification process by means of different oxygen-rich-water gasification experiments and pyrolysis experiments of coal samples in different sizes. The results show that the pyrolytic tar of bituminous coal tends to increase as its size increases, and the yield increases first and then decreases. When bituminous coal is pyrolysed in N₂ and CO₂, the main components of pyrolysis tar are phenols, naphthalenes and hydrocarbon pollutants. The concentrations of Ni, Cr, Zn, Cu and As after underground gasification are the highest in the oxidation zone, followed by the reduction zone and the dry distillation zone. And the enrichment of Hg is the highest in the oxidation zone, followed by the dry distillation zone and the reduction zone, while Pb is the most concentrated in the reduction zone, followed by the oxidation zone and the dry distillation zone. The residual degree of heavy metal elements from high to low is Zn, As, Hg, Cr, Ni, Cu and Pb. In Huating mining area, heavy metal elements Zn, As and Hg should be detected after gasification. In the later stage of production, combined with the characteristics of coal seams and groundwater, pollution prevention and control should be carried out in terms of project site selection and gasification process. Given the current severe situation of eco-environmental protection, the research results have certain guiding significance for the disposal and emission reduction of pollutants from underground coal gasification mining.