中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
Investigation of methane diffusion in low-rank coals by a multiporous diffusion model

文献类型:期刊论文

作者Li, Zhentao1; Liu, Dameng1; Cai, Yidong1; Shi, Yunlong2
刊名JOURNAL OF NATURAL GAS SCIENCE AND ENGINEERING
出版日期2016-07-01
卷号33页码:97-107
关键词Gas diffusion Multiporous diffusion model Pore structure Pressure Moisture content
英文摘要To study the methane diffusion behaviors of low-rank coals (R-o,R-m of 0.45% and 0.58%), a combination of CO2 adsorption, N-2 adsorption/desorption, and mercury intrusion porosimetry (MIP) measurements were used to characterize the pore structure of coals, and a new multiporous diffusion model was established to model methane diffusion under dry and moist conditions during the methane adsorption process. The results indicate that the pore structure of low-rank coal samples exhibits a multimodal pore size/volume distribution and has a greater percentage of microporosity and mesoporosity. The multi porous model provides a better fit than the bidisperse model, which deviates significantly from the data, especially during the initial diffusion stage. Based on the multiporous diffusion model, the macropore diffusivity (10(-4)-10(-3) s(-1)) is generally one to three orders of magnitude greater than the mesopore diffusivity (10(-5)-10(-4) s(-1)) and micropore diffusivity (10(-6)-10(-5) s(-1)). Moreover, both the macropore diffusivity and micropore diffusivity show a decreasing trend with increasing pressure, whereas a strong positive correlation exists between the mesopore diffusivities and pressure, indicating that the effect of pressure on methane diffusion in pores with different sizes is different during the adsorption process. This difference may be due to the competition between the different mechanisms of gaseous methane diffusion and the swelling of the coal matrix caused by gas adsorption. Furthermore, the moisture reduced methane diffusivities is mainly due to the moisture in the coal matrix that adsorbs to the pore surface and occupies the pore space, as well as changes the pore structure according to the, effect of mineral swelling from the adsorbing moisture. Therefore, these results may have a significant implication for understanding the transport mechanism of methane in coals and the design of enhanced CBM recovery. (C) 2016 Elsevier B.V. All rights reserved.
收录类别SCI
语种英语
WOS记录号WOS:000381594000011
版本出版稿
源URL[http://ir.qdio.ac.cn/handle/337002/135881]  
专题海洋研究所_海洋环流与波动重点实验室
作者单位1.China Univ Geosci, Coal Reservoir Lab, Natl Engn Res Ctr, CBM Dev & Utilizat, Beijing 100083, Peoples R China
2.Chinese Acad Sci, Inst Oceanol, Key Lab Ocean Circulat & Waves, Qingdao 266071, Peoples R China
推荐引用方式
GB/T 7714
Li, Zhentao,Liu, Dameng,Cai, Yidong,et al. Investigation of methane diffusion in low-rank coals by a multiporous diffusion model[J]. JOURNAL OF NATURAL GAS SCIENCE AND ENGINEERING,2016,33:97-107.
APA Li, Zhentao,Liu, Dameng,Cai, Yidong,&Shi, Yunlong.(2016).Investigation of methane diffusion in low-rank coals by a multiporous diffusion model.JOURNAL OF NATURAL GAS SCIENCE AND ENGINEERING,33,97-107.
MLA Li, Zhentao,et al."Investigation of methane diffusion in low-rank coals by a multiporous diffusion model".JOURNAL OF NATURAL GAS SCIENCE AND ENGINEERING 33(2016):97-107.

入库方式: OAI收割

来源:海洋研究所

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