The effect of pore structure and gas pressure upon the transport properties of coal: a laboratory and modeling study. 1. Isotherms and pore volume distributions

通过bossliu

The effect of pore structure and gas pressure upon the transport properties of coal: a laboratory and modeling study. 1. Isotherms and pore volume distributions

C.R. Clarksona,R.M.Bustinb

Abstract

The effect of coal composition upon pore structure and adsorption characteristics of four bituminous coals of the Cretaceous Gates Formation coal is investigated. All the coals have multi-modal pore volume distributions as determined from low-pressure (<127 kPa) nitrogen adsorption at 77 K, carbon dioxide adsorption at 273 K, and high-pressure (up to 200 MPa) mercury porosimetry. The individual lithotypes, however, differ in their pore volume distributions and adsorption characteristics. The dull coals (high inertinite, high ash content) have a greater percentage of mesoporosity and less microporosity than bright or banded bright coals (high vitrinite, low ash content) of the same rank. In addition, one banded bright coal has a greater amount of macroporosity than the other coals.

High-pressure (up to ∼8 MPa) methane isotherms determined on dried and moisture-equilibrated coals, and carbon dioxide isotherms (up to ∼ 5 MPa) determined on dried coal at 303 K, show that bright coals tend to adsorb more gas than dull coals. The Dubinin–Astakhov equation provides a better fit to coal gas isotherm data, particularly for carbon dioxide, than the conventionally used Langmuir equation. There is a linear correlation between high-pressure methane and carbon dioxide Langmuir volumes and Dubinin–Radushkevich micropore volumes, indicating that micropore volume is a primary control upon high-pressure gas adsorption for the Gates coals.

Keywords

Coal; Isotherms; Pore volume distributions


相关文件下载地址
*该资源需回复评论后下载,马上去发表评论?
©下载资源版权归作者所有;本站所有资源均来源于网络,仅供学习使用,请支持正版!

关于作者

bossliu administrator

清醒 专注 努力

发表评论

Captcha Code