Advanced NMR-based techniques for pore structure analysis of coal. Quarterly report No. 7, April 1, 1993--June 31, 1993

Technical Report · Wed Sep 01 04:00:00 EDT 1993

DOI:https://doi.org/10.2172/10176114· OSTI ID:10176114

Smith, D M

One of the main problems in coal utilization is the inability to properly characterize its complex pore structure. Coals typically have micro/ultramicro 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{sub 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: 10176114
• Report Number(s): DOE/PC/91296--7; ON: DE93019780
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010600
440800
47 OTHER INSTRUMENTATION
ACTIVATED CARBON
ADSORPTION
ADSORPTION ISOTHERMS
CARBON DIOXIDE
COAL
METHANE
MISCELLANEOUS INSTRUMENTATION
NITROGEN 15
NUCLEAR MAGNETIC RESONANCE
PORE STRUCTURE
PROGRESS REPORT
PROPERTIES AND COMPOSITION
SMALL ANGLE SCATTERING
SORPTIVE PROPERTIES
TEMPERATURE DEPENDENCE
X RADIATION
XENON 129