Diffusion of gases in coals and chars: Final report, September 15, 1985--September 14, 1988
Eight PSOC coals representing a wide range of rank and geographic origin have been subjected to a wide range of pore structure analysis methods as well as gas diffusion measurements. Pore structure analysis techniques employed included carbon dioxide and nitrogen adsorption, helium pycnometry, mercury porosimetry, and low-field NMR spin-lattice relaxation measurements. In principle, NMR pore structure analysis avoids many of the problems associated with conventional pore structure methods such as pore structure changes during drying, sample compression, network/percolation effects, pore shape assumptions, and a limited pore size range. Spin-lattice relaxation measurements were conducted at a proton frequency of 20 MHz and 303 K using water contained in the coal pores. Pore size distributions were obtained via deconvolution of the NMR relaxation measurements using the method of regularization and application of the ''two fraction-fast exchange'' model of pore fluid behavior. A qualitative comparison of the NMR pore size distributions and surface areas (CO/sub 2//N/sub 2/) yielded good agreement. Monodisperse and bidisperse pore size distributions were noted with pore volume in the size range of <0.5 nm to 0.5 ..mu..m. Effective diffusivities of methane and nitrogen were measured at 303 K and ambient pressure using a pulse tracer analysis method. 37 refs., 14 figs., 5 tabs.
- Research Organization:
- New Mexico Univ., Albuquerque (USA). Powders and Granular Materials Lab.
- DOE Contract Number:
- FG22-85PC80519
- OSTI ID:
- 6524232
- Report Number(s):
- DOE/PC/80519-T1; ON: DE89005257
- Country of Publication:
- United States
- Language:
- English
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Diffusion of gases in coals and chars. Technical progress report No. 3, March 15-June 14, 1986
Diffusion of gases in coals and chars. Quarterly technical progress report No. 4, June 15-September 14, 1986
Related Subjects
010600* -- Coal
Lignite
& Peat-- Properties & Composition
ALKANES
CARBONACEOUS MATERIALS
CHARS
COAL
DATA
DIFFUSION
DOCUMENT TYPES
ELEMENTS
ENERGY SOURCES
EQUATIONS
EXPERIMENTAL DATA
FOSSIL FUELS
FUELS
HYDROCARBONS
INFORMATION
MAGNETIC RESONANCE
MATERIALS
METHANE
NITROGEN
NONMETALS
NUCLEAR MAGNETIC RESONANCE
NUMERICAL DATA
ORGANIC COMPOUNDS
PHYSICAL PROPERTIES
POROSITY
PROGRESS REPORT
PYROLYSIS PRODUCTS
RELAXATION
RESONANCE
SPIN-LATTICE RELAXATION