Characterization of vitrinite concentrates. 2. Magic-angle 13C nuclear magnetic resonance studies
| Autor: | Jack L. Koenig, John R. Havens, Deborah W. Kuehn, Alan Davis, Michael Starsinic, Paul C. Painter |
|---|---|
| Rok vydání: | 1983 |
| Předmět: |
Magic angle
Hydrogen Chemistry business.industry General Chemical Engineering Organic Chemistry Analytical chemistry Energy Engineering and Power Technology chemistry.chemical_element Aromaticity Hydrogen atom Fuel Technology Organic chemistry Coal Fourier transform infrared spectroscopy business Vitrinite Carbon |
| Zdroj: | Fuel. 62:103-111 |
| ISSN: | 0016-2361 |
| Popis: | The fraction aromaticity determined by 13 C n.m.r. with cross-polarization and magic-angle spinning of 19 vitrinite concentrates obtained from the Lower Kittaning seam shows a range of values from ≈ 0.65 for the samples of lowest rank (83 wt% C (dmmf) to about 0.83 for those of highest rank (91 wt%C (dmmf)). It was determined that the wt% aromatic carbon correlates to the wt% fixed carbon and is in good agreement with the results reported by other authors. The combination of the 13 C n.m.r. results with FTIR measurements allows a number of coal parameters to be estimated. The atomic ratios of aliphatic hydrogen to carbon were demonstrated to vary from 1.8–2.0 to between 2.4–2.6 and previous assumptions that a single value can be used in calculating structural parameters for coal of any rank are not strictly valid. The calculation of the aromatic H C ratio indicates that in mean structural units there is approximately one aromatic hydrogen atom for every six carbons in vitrinites of carbon content 83 wt%C (dmmf) and that this ratio changes progressively with rank to a value of about one aromatic hydrogen for every four carbons for vitrinites of carbon content 91 wt%C (dmmf). |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|