Chinese Journal of Chemical Engineering ›› 2020, Vol. 28 ›› Issue (4): 1062-1068.doi: 10.1016/j.cjche.2019.12.018

• Separation Science and Engineering • Previous Articles     Next Articles

Effect of pore size on CH4/N2 separation using activated carbon

Gaofei Chen1, Yaxiong An2, Yuanhui Shen2, Yayan Wang2, Zhongli Tang2, Bo Lu3, Donghui Zhang2   

  1. 1 Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China;
    2 The Research Center of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China;
    3 State Key Laboratory of Coal and CBM Co-mining, Jincheng 048000, China
  • Received:2019-09-29 Revised:2019-12-17 Online:2020-04-28 Published:2020-07-27
  • Contact: Donghui Zhang
  • Supported by:
    This work is part of the project supported by the Shanxi Coal-bed Methane Joint Research Fund (No. 2015012004).

Abstract: In this paper, a model of activated carbon was established by molecular simulation and the separation performance of N2 and CH4 on activated carbon was studied. In order to evaluate the adsorption selectivity and diffusion selectivity of N2 and CH4, Grand Canonical Monte Carlo and molecular dynamic methods were used to obtain equilibrium adsorption isotherms and mean square displacements of N2 and CH4 on activated carbon with different pore sizes. Research results showed that the difference in adsorption isosteric heat of N2 and CH4 at the pore size of 0.46 nm is the largest, which is 5.759 and 7.03 kcal·mol-1 (1 cal=4.184 J), respectively. Activated carbon with pore size of 0.46 nm has the best N2 and CH4 adsorption selectivity, while its diffusion selectivity is not obvious.

Key words: Activated carbon, Coalbed methane, GCMC, MD, Molecular simulation