煤吸附解吸CO_2变形特征的试验研究  

Experimental study of coal strain induced by carbon dioxide sorption / desorption

作　　者：祝捷[1] 张敏[1] 姜耀东[1,2] 唐俊[1] 

机构地区：[1]中国矿业大学(北京)力学与建筑工程学院,北京100083 [2]中国矿业大学(北京)煤炭资源与安全开采国家重点实验室,北京100083

出　　处：《煤炭学报》2015年第5期1081-1086,共6页Journal of China Coal Society

基　　金：国家重点基础研究发展计划(973)资助项目(2010CB226801);高等学校博士学科点专项科研基金资助项目(20120023120011);中央高校基本科研业务费资助项目(2010QL02)

摘　　要：无商业开采价值的煤层被认为是理想的CO2储存场所,煤吸附解吸CO2的变形特征是煤中CO2封存的重要问题。利用煤体吸附-解吸变形试验系统,在预定压力的CO2气体环境下,对取自赵各庄煤矿9号煤层煤样的轴向应变和径向应变进行了近600 h的观测,研究煤样在不同气体压力下吸附、解吸CO2的变形特征。实验结果显示:煤样吸附/解吸CO2产生的膨胀/收缩变形,煤样吸附变形需要12 h甚至更长时间才能趋于稳定,原煤样品的吸附解吸变形呈各向异性;经历了吸附和解吸CO2的煤样均有不同程度的残余变形,气体压力低于1.5 MPa时残余体积应变低于0.6×10-3,可近似认为煤样吸附解吸变形过程可逆。通过煤样吸附解吸变形实验数据的拟合发现,Langmuir方程可反映煤样吸附解吸CO2变形随气体压力的变化规律。Unminable coal beds have been recommended as good CO2 sequestration. Coal strain due to sorption / desorption of CO2 is an important issue on carbon dioxide sequestration. To investigate CO2 sorption / desorption induced coal strain,coal axial and radial strains under gas hydrostatic pressure were measured for nearly 600 hours by means of test system for sorption-induced strain. The coal samples were from No. 9 coal seam in Zhaogezhuang Mine. The experimental results indicate that coal swells when adsorbing CO2,shrinks when desorbing CO2. The sorption / desorption process is very slow and it takes 12 hours or even longer for the sorption-induced strain to stabilize. The coal strain due to sorption / desorption CO2 is anisotropy. Coal samples have different levels of residual deformation after a cycle of sorption and desorption. When gas pressure is less than 1. 5 MPa,coal residual volumetric strain undergoing a cycle of sorption and desorption is less than 0. 6 × 10-3. It is reasonable to consider that the process of coal deformation induced by adsorption and desorption is reversible. The fitting results of coal adsorption / desorption experimental data show that Langmuir equation is suitable to describe coal adsorption / desorption strain variation with CO2 gas pressure.

关 键 词：煤体变形 吸附解吸 CO2封存 LANGMUIR方程 

分 类 号：X511[环境科学与工程—环境工程]