中国物理B ›› 2016, Vol. 25 ›› Issue (6): 68102-068102.doi: 10.1088/1674-1056/25/6/068102

• INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY • 上一篇    下一篇

Coalbed methane adsorption and desorption characteristics related to coal particle size

Yan-Yan Feng(冯艳艳), Wen Yang (杨文), Wei Chu(储伟)   

  1. 1 Department of Chemistry and Bioengineering, Guilin University of Technology, Guilin 541006, China;
    2 Department of Chemical Engineering, Sichuan University, Chengdu 610065, China
  • 收稿日期:2015-12-01 修回日期:2016-01-28 出版日期:2016-06-05 发布日期:2016-06-05
  • 通讯作者: Wei Chu E-mail:chu1965chengdu@163.com
  • 基金资助:

    Project supported by the National Basic Research Program of China (Grant No. 2011CB201202).

Coalbed methane adsorption and desorption characteristics related to coal particle size

Yan-Yan Feng(冯艳艳)1,2, Wen Yang (杨文)1,2, Wei Chu(储伟)2   

  1. 1 Department of Chemistry and Bioengineering, Guilin University of Technology, Guilin 541006, China;
    2 Department of Chemical Engineering, Sichuan University, Chengdu 610065, China
  • Received:2015-12-01 Revised:2016-01-28 Online:2016-06-05 Published:2016-06-05
  • Contact: Wei Chu E-mail:chu1965chengdu@163.com
  • Supported by:

    Project supported by the National Basic Research Program of China (Grant No. 2011CB201202).

摘要:

Effects of particle size on CH4 and CO2 adsorption and desorption characteristics of coals are investigated at 308 K and pressures up to 5.0 MPa. The gas adsorption and desorption isotherms of coals with particle sizes ranging from 250 μm to 840 μm are measured via the volumetric method, and the Langmuir model is used to analyse the experimental results. Coal particle size is found to have an obvious effect on the coal pore structure. With the decrease of coal particle size in the process of grinding, the pore accessibility of the coal, including the specific surface area and pore volume, increases. Hence, coal with smaller particle size has higher specific surface area and higher pore volume. The ability of adsorption was highly related to the pore structure of coal, and coal particle size has a significant influence on coal adsorption/desorption characteristics, including adsorption capacity and desorption hysteresis for CH4 and CO2, i.e., coal with a smaller particle size achieves higher adsorption capacity, while the sample with a larger particle size has lower adsorption capacity. Further, coal with larger particle size is also found to have relatively large desorption hysteresis. In addition, dynamic adsorption performances of the samples are carried out at 298 K and at pressures of 0.1 MPa and 0.5 MPa, respectively, and the results indicate that with the increase of particle size, the difference between CO2 and CH4 adsorption capacities of the samples decreases.

关键词: particle size, coalbed methane, adsorption, desorption

Abstract:

Effects of particle size on CH4 and CO2 adsorption and desorption characteristics of coals are investigated at 308 K and pressures up to 5.0 MPa. The gas adsorption and desorption isotherms of coals with particle sizes ranging from 250 μm to 840 μm are measured via the volumetric method, and the Langmuir model is used to analyse the experimental results. Coal particle size is found to have an obvious effect on the coal pore structure. With the decrease of coal particle size in the process of grinding, the pore accessibility of the coal, including the specific surface area and pore volume, increases. Hence, coal with smaller particle size has higher specific surface area and higher pore volume. The ability of adsorption was highly related to the pore structure of coal, and coal particle size has a significant influence on coal adsorption/desorption characteristics, including adsorption capacity and desorption hysteresis for CH4 and CO2, i.e., coal with a smaller particle size achieves higher adsorption capacity, while the sample with a larger particle size has lower adsorption capacity. Further, coal with larger particle size is also found to have relatively large desorption hysteresis. In addition, dynamic adsorption performances of the samples are carried out at 298 K and at pressures of 0.1 MPa and 0.5 MPa, respectively, and the results indicate that with the increase of particle size, the difference between CO2 and CH4 adsorption capacities of the samples decreases.

Key words: particle size, coalbed methane, adsorption, desorption

中图分类号:  (Carbon/carbon-based materials)

  • 81.05.U-
89.30.ag (Coal)