中文摘要：

采用压汞法和氮气吸附容量法测试了甲醇萃取前后大雁块状褐煤的微孔结构，结果表明，萃取后大雁褐煤孔隙率从16．4％增加到了18．53％，在3nm-80nm的微孔径范围内，比表面积增加了2．6倍，孔容增加了2倍，但随孔径的分布却和原煤具有相似的规律，比表面积和孔容的增加只是微孔数量增加的结果．根据分析得到煤中微孔的最可几孔径，利用煤的胶态分子团结构模型观点，计算出大雁褐煤基本结构单元的粒径在8．9nm左右．同时发现，在煤炭地下气化过程中，使用甲醇不仅能够提高气化煤层的渗透性，而且煤比表面积的增加也使得气化反应活性得到增强，提高了地下气化效率．

英文摘要：

Before and after being extracted by methanol, the micro-pore structure of block Dayan lignite of China was investigated using mercury intrusion porosimetry （MIP） and nitrogen gas adsorption method. The results show that the porosity goes from 16.4% up to 18.53%. In the micropore diameter range from 3 nm to 80 nm, the specific surface area and pore volume in- creased by 2.6 folds and 2 folds. But the methanol extraction could not change the micropore dis- tribution obviously. The enlargement of the specific surface area and the pore volume of coal was mainly due to the increase of pore number in different pore size range. The radius of Dayan lignite colloid structure unit was calculated to 8.9 nm according to the most probability of pore radius. Due to the coal seam permeability and the specific surface area were enhanced by using methanol, then the reaction activity and efficiency of underground coal gasification were increased.