Hydrogen-1 spin-echo NMR relaxation studies of dried and swollen Argonne premium coals
| Autor: | Bernard G. Silbernagel, John W. Larsen, Xiaolin Yang |
|---|---|
| Rok vydání: | 1993 |
| Předmět: |
Chemistry
business.industry General Chemical Engineering Gaussian Relaxation (NMR) Analytical chemistry Energy Engineering and Power Technology chemistry.chemical_element complex mixtures Solvent chemistry.chemical_compound symbols.namesake Fuel Technology Pyridine Proton NMR Spin echo symbols Coal business Carbon Nuclear chemistry |
| Zdroj: | Energy & Fuels. 7:439-445 |
| ISSN: | 1520-5029 0887-0624 |
| DOI: | 10.1021/ef00040a001 |
| Popis: | 1 H NMR relaxation techniques were used to study the mobility of coals swollen with pyridine-d 5 and N-methyl-2-pyrrolidinone-d 9 (NMP) as a function of solvent loading at room temperature. A spin-echo technique was found to give better results than 90° pulse and solid-echo techniques. Both linear-least-squares and nonlinear numerical fitting procedures were used to deconvolute the data into a set of Gaussian and Lorentzian decays which represent the relatively immobile and mobile components of the organic matter, respectively. Dried Illinois No. 6 coal shows only Gaussian behavior; when swollen with pyridine-d 5 (solvent-to-coal mass ratio 2:1), the Gaussian component of the signal fell to only 26% of the protons in the coal, suggesting dramatic changes in the mobility of the organic structure of the swollen coal |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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