Author/Authors :
Du, Xidong Key Laboratory for Digital Land and Resources of Jiangxi Province - East China University of Technology, Nanchang, China , Wu, Tengfei Key Laboratory for Digital Land and Resources of Jiangxi Province - East China University of Technology, Nanchang, China , Sun, Fulong China Coal Technology and Engineering Group Shenyang Research Institute, Fushun, China , Hou, Zhenkun Guangzhou Institute of Building Science Co., Ltd., Guangzhou, China , Liu, Zhenjian College of Civil Engineering - Yancheng Institute of Technology, Yancheng, Jiangsu, China , Huo, Liang Key Laboratory for Digital Land and Resources of Jiangxi Province - East China University of Technology, Nanchang, China , Hao,Yu College of Mining and Environmental Engineering - Chongqing Vocational Institute of Engineering, Chongqing, China , Zhao, Yuan Sinohydro Bureau 8 Co. Ltd. - POWERCHINA, Changsha, China
Abstract :
Adsorption isotherms of CH4 and CO2 on Qinshui Basin anthracite were obtained at the temperatures of 283 K, 303 K, and 323 K using the gravimetric method. The feasibility of the displacement of CH4 by injecting CO2 on this anthracite was verified by calculating the selectivity factor of CO2 over CH4 , adsorption affinities, and thermodynamic properties of CH4 and CO2. Results show that the values of are more than 4.0. Henry’s constant of CH4 is smaller than that of CO2, and CH4 has a weaker affinity with coal surface. As temperature improves, of CO2 and CH4 decrease. Gibbs free energy change and surface potential of CO2 are more negative than those of CH4, indicating that CO2 adsorption on anthracite is more spontaneous and favorable. The absolute values of and of CH4 and CO2 increase with pressure rises. Isosteric heat of adsorption of CH4 is lower than that of CO2. With increasing loading, and entropy loss of CH4 decrease, while and of CO2 increase. The higher of CO2 reveals that the adsorbed CO2 molecules constitute a more stable rearrangement than CH4 molecules. High temperature reduces of CH4 and CO2.
Keywords :
Thermodynamic Analysis , CO2 , CH4 , Qinshui Basin Anthracite
