Quantitation of protons in the Argonne Premium coals by solid-state {sup 1}H NMR spectroscopy

Conference · Fri Dec 31 04:00:00 EST 1993

OSTI ID:441414

Rosa, L dela; Pruski, M; Gerstein, B ^[1]

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1. Iowa State Univ., Ames, IA (United States)

Quantitation of protons and moisture in the eight coals from the Argonne Premium Coal Sample Program was performed by using {sub 1}H NMR spectroscopy. The solid echo was used to determine the true line shape of the on-resonance {sup 1}H free induction decay (FID). A superposition of Gaussian and Lorentzian decay functions adequately described the FID of dry coals. The Gaussian fraction corresponds to rigid protons in the macrostructure of coal. The Lorentzian fraction is attributed to fragments in the coal exhibiting hindered molecular mobility. For wet coals, an additional slowly decaying Lorentzian fraction must be added to the description of the FID. Identification of the species responsible for the longest decay was made by liquid-state NMR spectroscopy of the condensate obtained by heating the sample at 100 {degrees}C under static vacuum, and high-resolution solid-state {sup 1}H NMR spectra of the coals were obtained before and after removing the volatile matter at 100 {degrees}C. The NMR quantitation results compared favorably with the results that were obtained by chemical and thermogravimetric analyses. 26 refs., 5 figs., 4 tabs.

• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 441414
• Report Number(s): CONF-891206--
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
40 CHEMISTRY
COAL
HYDROGEN
MOISTURE
NMR SPECTRA
NUCLEAR MAGNETIC RESONANCE
PROTONS
QUANTITATIVE CHEMICAL ANALYSIS
RESOLUTION
SPECTROSCOPY
VOLATILE MATTER