Preferential adsorption behaviour of CH_4 and CO_2 on high-rank coal from Qinshui Basin,China  

作　　者：Yu Hongguan Jing Renxia Wang Panpan Chen Lihui Yang Yongjie 

机构地区：[1]Key Laboratory of Mine Disaster Prevention and Control, Shandong University of Science and Technology [2]School of Chemical and Environmental Engineering, Shandong University of Science and Technology

出　　处：《International Journal of Mining Science and Technology》2014年第4期491-497,共7页矿业科学技术学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Nos.51174127 and 21176145);the Natural Science Foundation of Shandong Province(No.ZR2011DM005);the Open Research Fund Program of Key Laboratory of Mine Disaster Prevention and Control(Shandong University of Science and Technology)(No.MDPC0806)

摘　　要：In order to better understand the prevailing mechanism of CO2 storage in coal and estimate CO2 sequestration capacity of a coal seam and enhanced coalbed methane recovery （ECBM） with CO2 injection into coal, we investigated the preferential adsorption of CH4 and CO2 on coals. Adsorption of pure CO2, CH4 and their binary mixtures on high-rank coals from Qinshui Basin in China were employed to study the preferential adsorption behaviour. Multiple regression equations were presented to predict CH4 equi- librium concentration from equilibrium pressure and its initial-composition in feed gas. The results show that preferential adsorption of CO2 on coals over the entire pressure range under competitive sorption conditions was observed, however, preferential adsorption of CH4 over CO2 on low-volatile bituminous coal from higher CH4-compostion in source gas was found at up to 1O MPa pressure. Preferential adsorp- tion of CO2 increases with increase of CH4 concentration in source gas, and decreases with increasing pressure. Although there was no systematic investigation of the effect of coal rank on preferential adsorp- tion, there are obvious differences in preferential adsorption of gas between low-volatile bituminous coal and anthracite. The obtained preferential adsorption gives rise to the assumption that CO2 sequestration in coal beds with subsequent CO2-ECBM might be an ootion in Qinshui Basins, China.In order to better understand the prevailing mechanism of CO2 storage in coal and estimate CO2 sequestration capacity of a coal seam and enhanced coalbed methane recovery(ECBM) with CO2 injection into coal, we investigated the preferential adsorption of CH4 and CO2on coals. Adsorption of pure CO2,CH4 and their binary mixtures on high-rank coals from Qinshui Basin in China were employed to study the preferential adsorption behaviour. Multiple regression equations were presented to predict CH4 equilibrium concentration from equilibrium pressure and its initial-composition in feed gas. The results show that preferential adsorption of CO2 on coals over the entire pressure range under competitive sorption conditions was observed, however, preferential adsorption of CH4 over CO2on low-volatile bituminous coal from higher CH4-compostion in source gas was found at up to 10 MPa pressure. Preferential adsorption of CO2 increases with increase of CH4 concentration in source gas, and decreases with increasing pressure. Although there was no systematic investigation of the effect of coal rank on preferential adsorption, there are obvious differences in preferential adsorption of gas between low-volatile bituminous coal and anthracite. The obtained preferential adsorption gives rise to the assumption that CO2 sequestration in coal beds with subsequent CO2-ECBM might be an option in Qinshui Basins, China.

关 键 词：Coal Preferential adsorption Coalbed methane Gas mixtures CO2 sequestration 

分 类 号：O647.3[理学—物理化学]