SCI和EI收录∣中国化工学会会刊

Chinese Journal of Chemical Engineering ›› 2022, Vol. 42 ›› Issue (2): 120-129.DOI: 10.1016/j.cjche.2021.06.028

Previous Articles     Next Articles

Nitrogen rejection from low quality natural gas by pressure swing adsorption experiments and simulation using dynamic adsorption isotherms

Xinran Zhang1, Hua Shang1, Jiangfeng Yang1,2, Libo Li1,2, Jinping Li1,2   

  1. 1. Research Institute of Special Chemicals, College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024, China;
    2. Shanxi Key Laboratory of Gas Energy Efficient and Clean Utilization, Taiyuan 030024, China
  • Received:2021-05-01 Revised:2021-06-23 Online:2022-03-30 Published:2022-02-28
  • Contact: Jiangfeng Yang,E-mail:yangjiangfeng@tyut.edu.cn

Nitrogen rejection from low quality natural gas by pressure swing adsorption experiments and simulation using dynamic adsorption isotherms

Xinran Zhang1, Hua Shang1, Jiangfeng Yang1,2, Libo Li1,2, Jinping Li1,2   

  1. 1. Research Institute of Special Chemicals, College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024, China;
    2. Shanxi Key Laboratory of Gas Energy Efficient and Clean Utilization, Taiyuan 030024, China
  • 通讯作者: Jiangfeng Yang,E-mail:yangjiangfeng@tyut.edu.cn

Abstract: In order to remove N2 from low quality natural gas, a mathematical model has been established by Aspen adsorption, using the CH4-selective sorbent silicalite-1 pellets. The dynamic adsorption isotherm was first simulated by breakthrough simulation of a CH4/N2 mixture at different adsorption pressures and feed flow rates based on breakthrough experiments. The resulting simulated CH4 dynamic adsorption amounts were very close to the experimental data at three different adsorption pressures (100, 200, and 300 kPa). Moreover, a single-bed, three-step pressure swing adsorption (PSA) experiment was performed, and the results were in good agreement with the simulated data, further corroborating the accuracy of the gas dynamic adsorption isotherm obtained by the simulation method. Finally, based on the simulated dynamic adsorption isotherm of CH4 and N2, a four-bed, eight-step PSA process has been designed, which enriched 75% (vol) CH4 and 80% (vol) CH4 to 95% (vol) and 99% (vol), and provided 99% (vol) recovery.

Key words: Natural gas, Silicalite-1, Simulation, Dynamic adsorption, Pressure swing adsorption process

摘要: In order to remove N2 from low quality natural gas, a mathematical model has been established by Aspen adsorption, using the CH4-selective sorbent silicalite-1 pellets. The dynamic adsorption isotherm was first simulated by breakthrough simulation of a CH4/N2 mixture at different adsorption pressures and feed flow rates based on breakthrough experiments. The resulting simulated CH4 dynamic adsorption amounts were very close to the experimental data at three different adsorption pressures (100, 200, and 300 kPa). Moreover, a single-bed, three-step pressure swing adsorption (PSA) experiment was performed, and the results were in good agreement with the simulated data, further corroborating the accuracy of the gas dynamic adsorption isotherm obtained by the simulation method. Finally, based on the simulated dynamic adsorption isotherm of CH4 and N2, a four-bed, eight-step PSA process has been designed, which enriched 75% (vol) CH4 and 80% (vol) CH4 to 95% (vol) and 99% (vol), and provided 99% (vol) recovery.

关键词: Natural gas, Silicalite-1, Simulation, Dynamic adsorption, Pressure swing adsorption process