高煤级Ⅲ无烟煤吸附甲烷的特征及其机制

Characteristics and mechanism of adsorbed methane in high rank Ⅲ anthracite

对福建、京西地区高煤级Ⅲ无烟煤煤样分别进行了30℃条件下的甲烷等温吸附试验。结果显示,高煤级Ⅲ无烟煤对甲烷的吸附量要低于相同条件下的烟煤和高煤级Ⅰ、Ⅱ无烟煤。通过综合分析煤样的低温液氮吸附试验结果及其孔隙特征,结合煤结构理论和前期研究成果,分析认为:高煤级Ⅲ无烟煤的孔隙发育不均衡性、比表面积与孔容极小性以及芳香度高度缩合性,导致了其对甲烷的吸附空间大大减少,对甲烷的吸附量显著降低。研究成果对于丰富完善煤吸附气体理论,指导高煤级Ⅲ无烟煤地区矿井瓦斯治理及地面煤层气勘探开发都具有重要意义。

Up to now, there is little research on the methane adsorption characteristics of high rank Ⅲ anthracite. The high rankⅢanthracite from Fujian and West Beijing was used to conduct the methane isothermal adsorption test under the temperature of 30℃.The results show that the adsorption capacity of the high rankⅢanthracite is lower than that of bituminous coal and other high rank Ⅰ, Ⅱ anthracite under the same conditions. Through the analysis of the low-temperature nitrogen adsorption test results, combined with the coal structure theory and pre-vious research results, this paper points out that the unbalance of the pores, the minimum of the specific surface area and pore volume, and the high aromatic condensation degree make the adsorption space of methane greatly decreased, and the adsorption quantity evidently reduced. This paper can enrich and perfect the coal adsorption theory, guide coal mine gas control and the ground CBM exploration and development of high gradeⅢanthracite.