Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Diffusion of gases in coals and chars. Quarterly technical progress report No. 4, June 15-September 14, 1986

Technical Report ·
OSTI ID:5189488

Surface areas of 13 PSOC coals have been measured by nitrogen adsorption at 77 K and carbon dioxide adsorption at 273 K. The 13 PSOC coals studied include the 8 coals of group A as well as 5 additional coals from Group B for which we had suitable sample quantity. As discussed in previous reports, nitrogen at 77 K will not penetrate micropores and is therefore, a measure of the pore surface area for pores greater than or about 2 nm. The exact size of the pore size cut-off for which nitrogen cannot enter is not precisely known and is presumedly a function of coal chemistry, particle size and equilibration time. Surface areas calculated from nitrogen adsorption reported in a previous quarterly report were for a particle size of <325 mesh. This quarter, we have repeated the nitrogen adsorption experiments for a narrower particle size range, 325 to 400 mesh, for the eight Group A coals. Surface areas were extracted from nitrogen adsorption isotherms using the BET theory. Mercury intrusion experiments were conducted on narrow cut samples (325 to 400 mesh) of all eight Group A coals using an Autoscan-33 scanning mercury porosimeter. NMR pore structure analysis was also undertaken during this quarter by taking spin-lattice relaxation measurements of water contained in the pore space of 13 PSOC coals.

Research Organization:
New Mexico Univ., Albuquerque (USA). Dept. of Chemical and Nuclear Engineering
DOE Contract Number:
FG22-85PC80519
OSTI ID:
5189488
Report Number(s):
DOE/PC/80519-4; ON: DE87000822
Country of Publication:
United States
Language:
English