Diffusion of gases in coals and chars. Technical progress report No. 2, December 15, 1985-March 14, 1986
Coal surface areas have been measured using nitrogen adsorption at 77 K for 8 coals. Coal samples are prepared by grinding such that the particles pass through a 270 mesh screen but are retained on a 325 mesh screen. The samples are dried at about 383 K for 3 hours in a drying oven. The true density of the samples is measured using helium displacement and the samples are subsequently weighed into capillary adsorption cells for the Quantasorb surface area analyzer. Capillary cells are used to minimize thermal diffusion effects which are commonly encountered when measuring small surface area materials with nitrogen. Nigrogen uptake is measured at 5 different nitrogen/helium concentrations. The equilibration time is on the order of 20 to 30 minutes. The surface area is calculated using the BET theory and assuming a nitrogen cross-sectional area of 0.162 nm/sup 2/. Nitrogen surface areas for the eight coals completed to date are presented in Table 2. The surface areas are reported on a dry, mineral matter containing basis. Since the ash contents vary considerably from sample to sample (3.68 to 19.97%), the variation in mineral matter content may play a significant role in the surface area variation. This point will be explored after completion of the CO/sub 2/ adsorption work. As expected, the surface areas are quite low (<10 m/sup 2//g). The one exception to this rule is PSOC-1354, the Illinois No. 6 coal, which has a N/sub 2/ surface area of 40.47 m/sup 2//g. 2 refs., 1 fig., 3 tabs.
- Research Organization:
- New Mexico Univ., Albuquerque (USA). Powders and Granular Materials Lab.
- DOE Contract Number:
- FG22-85PC80519
- OSTI ID:
- 6136437
- Report Number(s):
- DOE/PC/80519-2; ON: DE86009288
- Country of Publication:
- United States
- Language:
- English
Similar Records
Diffusion of gases in coals and chars. Technical progress report: quarterly report No. 1, September 15-December 14, 1985
Diffusion of gases in coals and chars: Final report, September 15, 1985--September 14, 1988
Related Subjects
010600* -- Coal
Lignite
& Peat-- Properties & Composition
ADSORPTION
ASH CONTENT
CARBONACEOUS MATERIALS
COAL
COMMINUTION
DATA
DENSITY
DIFFUSION
DRYING
ELEMENTS
ENERGY SOURCES
EXPERIMENTAL DATA
FLUIDS
FOSSIL FUELS
FUELS
GASES
GRINDING
HELIUM
INFORMATION
LOW TEMPERATURE
MACHINING
MATERIALS
NITROGEN
NONMETALS
NUMERICAL DATA
PHYSICAL PROPERTIES
RARE GASES
RESEARCH PROGRAMS
SORPTION
SORPTIVE PROPERTIES
SURFACE AREA
SURFACE PROPERTIES