Carbon distribution in coals and coal macerals by cross polarization magic angle spinning carbon-13 nuclear magnetic resonance spectrometry

Journal Article · Sun Jan 01 00:00:00 EST 1984 · Anal. Chem.; (United States)

DOI:https://doi.org/10.1021/ac00270a018· OSTI ID:6464593

Wilson, M A; Pugmire, R J; Karas, J; Alemany, L B; Woolfenden, W R; Grant, D M; Given, P H

Conventional and dipolar dephasing CP/MAS /sup 13/C NMR experiments are reported on 63 coals and coal macerals from lignite to anthracite ranks (from the US, the United Kingdom, and Australia). While the conventional experiment can yield only f/sub a/ (the fraction of carbon that is sp/sub 2/ hybridized), the dipolar dephasing experiments provide estimates of four other structural parameters. Examination of the dipolar dephasing data reveals an overall increase. While loss of substituents from aromatic rings with little aromatic cross-linking occurs until the anthracite stage is reached, the dipolar dephasing experiments also yield decay constants for different functional groups that are similar to the decay constants obtained with simple organic compounds. Because full characterization of a sample by the dipolar approach has been developed for obtaining less precise f/sub a/sup a,H/, f/sub a/sup H/, f/sub Me/, and H/sub a/ values. The data so obtained are particularly useful for quickly comparing samples. 43 references, 7 tables, 9 figures.

• Research Organization: Univ. of Utah, Salt Lake City
• OSTI ID: 6464593
• Journal Information: Anal. Chem.; (United States), Vol. 56:6
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
01 COAL, LIGNITE, AND PEAT
CARBON
NMR SPECTRA
CARBON 13
NUCLEAR MAGNETIC RESONANCE
COAL
STRUCTURAL CHEMICAL ANALYSIS
EXPERIMENTAL DATA
MACERALS
RELAXATION LOSSES
CARBON ISOTOPES
CARBONACEOUS MATERIALS
DATA
ELEMENTS
ENERGY LOSSES
ENERGY SOURCES
EVEN-ODD NUCLEI
FOSSIL FUELS
FUELS
INFORMATION
ISOTOPES
LIGHT NUCLEI
LOSSES
MAGNETIC RESONANCE
MATERIALS
NONMETALS
NUCLEI
NUMERICAL DATA
RESONANCE
SPECTRA
STABLE ISOTOPES
400104* - Spectral Procedures- (-1987)
010600 - Coal
Lignite
& Peat- Properties & Composition