A direct measurement of expansion in coals and macerais induced by carbon dioxide and methanol

✍ Scribed by Philip L. Walker Jr; Shyam K. Verma; Jose Rivera-Utrilla; M.Rashid Khan

• Publisher: Elsevier Science
• Year: 1988
• Tongue: English
• Weight: 920 KB
• Volume: 67
• Category: Article
• ISSN: 0016-2361
• DOI: 10.1016/0016-2361(88)90305-5

✦ Synopsis

Coals and macerals show a measurable extent of expansion in CO, at ambient temperature which is a function ofC0, pressure. Equilibrium expansion is much more rapidly attained in CO, than in methanol. At similar relative pressures, expansion in methanol is significantly greater than in CO,. Volume expansion of coals in CO, at temperatures and pressures used to measure surface areas from CO, uptake (co.1 MPa, 298 K) is much less than the volume of CO, taken up under these conditions. Therefore, it is concluded that most of the CO, uptake is not due to imbibing of CO, within the coal structure but rather to CO, uptake in open and closed (to He) micropores. It is further concluded that the high surface areas of coals calculated from CO, uptake are at least semi-quantitatively correct and, thus, that coals have large microporosities.