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

Advanced NMR-based techniques for pore structure analysis of coal. Quarterly report No. 6, January 1, 1993--March 31, 1993

Technical Report ·
DOI:https://doi.org/10.2172/10171237· OSTI ID:10171237
One of the main problems in coal utilization is the inability to properly characterize its complex pore structure. Coals typically have micro/ultra-micro pores but they also exhibit meso and macroporosity. Conventional pore size techniques (adsorption/condensation, mercury porosimetry) are limited because of this broad pore size range, microporosity, reactive nature of coal, samples must be completely dried, and network/percolation effects. Small angle scattering is limited because it probes both open and closed pores. Although one would not expect any single technique to provide a satisfactory description of a coal`s structure, it is apparent that better techniques are necessary. Small angle scattering could be improved by combining scattering and adsorption measurements. Also, the measurement of NMR parameters of various gas phase and adsorbed phase NMR active probes can provide pore structure information. We will investigate the dependence of the common NMR parameters such as chemical shifts and relaxation times of several different nuclei and compounds on the pore structure of model microporous solids, carbons, and coals. In particular, we will study the interaction between several small molecules ({sup 129}Xe, {sup 3}He, {sup 2}H{sub 2}, {sup 14}N{sub 2},{sup 14}NH{sub 3}, {sup 15}N{sup 2}, {sup 13}CH{sub 4}, {sup 13}CO{sub 2}) and the pore surfaces in coals.
Research Organization:
New Mexico Univ., Albuquerque, NM (United States). Center for Micro-Engineered Ceramics
Sponsoring Organization:
USDOE, Washington, DC (United States)
DOE Contract Number:
FG22-91PC91296
OSTI ID:
10171237
Report Number(s):
DOE/PC/91296--6; ON: DE93018305
Country of Publication:
United States
Language:
English