Diffusion of gases in New Mexico coals: Final technical report
As part of the first phase of this study, characterization of the pore volume and surface area of coal was principally undertaken while the more extensive and complex diffusivity and high-pressure adsorption experiments were being built. The careful characterization work resulted in new understanding of the limitations of mercury porosimetry and nitrogen adsorption analysis for coal. Our results indicate that as the size of coal particles in a sample decreases, a spurious, intruded-pore volume is indicated in mercury porosimetry. Furthermore, at higher pressures of Hg, the penetration of Hg may actually be a measure of micropore crushing rather than pore structure information. Nitrogen adsorption measurements do not reflect the total surface area of the coal which is easily accessed and measured by carbon dioxide. At the same time we found that condensation of nitrogen and NMR relaxation experiments may lead to significantly new interpretations of coal porosity. We find that measurements of condensation of nitrogen gives a direct measure of large pore volume that can be contrasted to total pore volumes. Preliminary NMR results show remarkable differences in apparent pore structure for similar New Mexico coals. The extension of basic science of coal structure and development of a potential new method for characterization of coal are major, long range impacts of this work. 41 refs., 9 figs., 6 tabs.
- Research Organization:
- New Mexico Univ., Albuquerque (USA). Dept. of Chemical and Nuclear Engineering; New Mexico Univ., Albuquerque (USA). New Mexico Research and Development Inst.
- OSTI ID:
- 7127031
- Report Number(s):
- NMRDI-2-74-4122; ON: DE87900515
- Country of Publication:
- United States
- Language:
- English
Similar Records
Diffusion of gases in coals and chars: Quarterly technical progress report No. 8, June 15, 1987-September 14, 1987
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Related Subjects
010600* -- Coal
Lignite
& Peat-- Properties & Composition
ADSORPTION
ADSORPTION ISOTHERMS
ALKANES
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CARBONACEOUS MATERIALS
CHALCOGENIDES
COAL
CRYSTAL STRUCTURE
DATA ANALYSIS
DIFFUSION
ELEMENTS
ENERGY SOURCES
FOSSIL FUELS
FUELS
HYDROCARBONS
ISOTHERMS
MAGNETIC RESONANCE
MATERIALS
MEASURING INSTRUMENTS
MEASURING METHODS
METHANE
MICROSTRUCTURE
MOISTURE
NITROGEN
NONMETALS
NUCLEAR MAGNETIC RESONANCE
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PERMEABILITY
POROSIMETERS
POROSITY
PROPANE
RESONANCE
SORPTION
SORPTIVE PROPERTIES
SURFACE AREA
SURFACE PROPERTIES