中文摘要：

本文利用量子化学计算方法计算了单个苯环、以及分别添加了羧基、醛基、羟基、甲基和亚甲基后的煤结构单元与甲烷分子的吸附作用能。通过计算，发现煤中含氧官能团会降低煤结构与甲烷的吸附作用，从而降低了煤对甲烷的吸附能力；而煤中脂肪侧链则会增大煤结构与甲烷的吸附作用，从而提高了煤对甲烷的吸附能力。利用煤结构化学、煤吸附理论知识以及本次量子化学计算结果，综合分析了煤吸附甲烷的langmuir体积随煤阶的变化规律，并从微观的角度很好的解释了煤吸附能力（langmuir体积）随煤阶的增加而变化的实验现象。

英文摘要：

The interactions of CH4 with one benzene ring and one benzene ring added by carboxyl , aldehyde, hydroxide, methyl and methylene have been studied by the quantum chemistry MP2 method. By the calcula- tion, the results show that the oxygen-containing functional groups can reduce the adsorption, consequently ruduce the adsorption capacity, but the pendant chains is opposite. Utilizing the knowledges of coal structure chemistry , coal adsorption theory and the calculation results, the varieties of the Langmuir volume with coal rank are analyzed, and the experiment phenomenon of coal adsorption capacity with coal rank are explained in this paper.