Study of the spin dynamics of a bituminous coal using high resolution solid-state carbon-13 NMR techniques

Thesis/Dissertation · Thu Jan 01 04:00:00 EST 1981

OSTI ID:5745438

Sullivan, M J

A detailed NMR relaxation study was performed on Powhatan number5 mine coal (high volatile B bituminous) using solid-state cross polarization, magic-angle spinning (CP/MAS) /sup 13/C NMR techniques. A variety of relaxation parameters were measured for this coal, including T/sub 1//sup H/, T/sub 1//sup C/, T/sub 1rho//sup H/, T/sub 1rho//sup C/ and T/sub CH/. A novel means for obtaining /sup 13/C T/sub 1/ relaxation times in solids using cross polarization is presented. The interrupted-decoupling technique was applied to this coal. Variable-temperature /sup 13/C CP/MAS spectra were obtained over the temperature range from 56/sup 0/C to -141/sup 0/C. Spectra of Powhatan number5 mine coal were recorded at three field strengths of 1.4, 2.3 and 4.7 T. Sources of line broadening in coal spectra were investigated using a selective irradiation experiment and a two-dimensional NMR approach. The CP/MAS results on Powhatan number5 mine coal were compared to standard pulse FT spectra obtained using proton decoupling and magic-angle spinning. The NMR relaxation data shows that quantitative /sup 13/C intensities can be obtained on this coal using the CP/MAS technique. It was demonstrated that enhanced structural resolution can be obtained in relaxation experiments on coal due to the differences in the relaxation times for various carbon types.

• OSTI ID: 5745438
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010600* -- Coal
Lignite
& Peat-- Properties & Composition
BITUMINOUS COAL
BLACK COAL
CARBON 13
CARBON ISOTOPES
CARBONACEOUS MATERIALS
COAL
ENERGY SOURCES
EVEN-ODD NUCLEI
FOSSIL FUELS
FUELS
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
MATERIALS
NUCLEAR MAGNETIC RESONANCE
NUCLEI
RELAXATION
RESONANCE
STABLE ISOTOPES