煤吸附^(13)CH_4与^(12)CH_4的特性曲线及其应用  

The adsorption characteristic curves of ^(13)CH_4 and ^(12)CH_4 on coal and its application

作　　者：苏现波[1] 陈润[1] 林晓英[1] 郭盛强[1] 

机构地区：[1]河南理工大学资源与环境工程学院,河南焦作454000

出　　处：《煤炭学报》2007年第5期539-543,共5页Journal of China Coal Society

基　　金：国家重点基础研究发展规划(973)项目(2002CB211705);国家自然科学基金资助项目(50534070)

摘　　要：根据实测的4个不同煤阶煤的等温吸附实验数据,采用Dubinin建立的计算吸附空间的经验公式,分别计算了13CH4与12CH4在4个煤样的吸附势及其吸附空间,建立了煤吸附甲烷特性曲线的定量表达式.结果发现,13CH4在煤表面的吸附势普遍高于12CH4,也就是说13CH4与12CH4相比具有优先吸附、滞后解吸的特点.这种差异具有随压力增加而增加的特点.这一发现合理地解释了煤层气解吸实验中发现的先解吸甲烷δ13C偏轻、后解吸偏重的现象,同时也解释了浅部煤层甲烷碳同位素轻、深部重的地质现象.Based on the measured isotherm data of methane on 4 coal samples, the adsorption potential and volume of ^13 CH4 and ^12 CH4 on coal were calculated with adsorption potential theory, and then the adsorption potential characteristic curve was drawn. The curve indicates that the adsorption potential of ^13 CH4 on coal is higher than that of ^12 CH4, and it also increases with the pressure increasing. This implies that the coal is preference for ^13 CH4 adsorption and postponement for ^13 CH4 desorption. This mechanism can explain why the ^12 CH4 is firstly released from coal during the process of methane desorption and why the light δ^13 C of coalbed methane is distributed in the shallow part of basin and the heavy in the deep part of the basin.

关 键 词：煤 ^13 CH4与^12 CH4 吸附势 特性曲线 同位素分馏 

分 类 号：P618.11[天文地球—矿床学]