溶剂萃取前后煤吸附甲烷特征对比及机理研究
Study on Features Comparison and Mechanism of Methane Adsorbed by Coal Before and After Solvent Extraction
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摘要: 为分析溶剂萃取前后煤吸附甲烷气体的特征差异,采用四氢呋喃溶剂对不同地区不同变质程度的4个煤样(长焰煤、气煤、焦煤、无烟煤)进行了萃取试验,并对原煤和萃取后煤样进行了低温液氮吸附试验和甲烷等温吸附试验,同时对萃取物进行了气相色谱-质谱分析。结果表明,平衡水分条件下原煤对甲烷的吸附量要高于萃取后的煤,干燥条件下萃取后的煤对甲烷的吸附量要高于原煤。通过综合分析,指出煤的变质程度、孔隙结构和水分是造成不同煤阶煤萃取前后吸附差异的主要因素,由此进一步探讨了溶剂萃取前后煤中芳香结构与脂肪类化合物对煤吸附气体的综合影响。Abstract: In order to discuss the features difference of methane adsorbed by coal before and after solvent extraction, a tetrahydrofuran solvent was applied to the extraction experiments on four coal samples (long flame coal, gas coal, coking coal and anthracite) and with different metamorphic degree from different areas.A cryoge nic nitrogen adsorption experiment and methane isothermal adsorption experiment was conducted on the raw coal and the coal samples after extraction.The gas chrom atography-mass spectrometry experiment analysis was conducted on the extracts.The results showed that the methane adsorption value of the raw coal under the condi tion of equllibrium moisture would be higher than the coal after extraction and the methane adsorption value of coal after extraction under the dry condition would be hig her than raw coal.The comprehensive analysis showed the different metamorphic degree, porous structure and moisture of the coal would be the major factors to cause the adsorption difference of different rank coal before and after extraction.Thus the paper discussed the aromatic structure and aliphatic compounds in coal before and after solvent extraction comprehensively affected to the coal adsorption gas.