Aromatic products of 340 °C supercritical-toluene extraction of two Turkish lignites: an n.m.r. study
| Autor: | Taner Tuǧrul, Derry W. Jones, Aral Olcay, Hooshang Pakdel, Raymond S. Matthews, Ayla Çalimli, Keith D. Bartle |
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| Rok vydání: | 1979 |
| Předmět: |
General Chemical Engineering
Organic Chemistry Extraction (chemistry) Analytical chemistry Energy Engineering and Power Technology chemistry.chemical_element Toluene Supercritical fluid chemistry.chemical_compound Fuel Technology chemistry Yield (chemistry) Organic chemistry Molecule Polar Carbon Asphaltene |
| Zdroj: | Fuel. 58:423-428 |
| ISSN: | 0016-2361 |
| DOI: | 10.1016/0016-2361(79)90082-6 |
| Popis: | Fractions of Elbistan and Seyitomer (Turkish) lignites, extracted with supercritical toluene at 340 °C and 8 MPa, have been separated by solvent extraction and silica-gel chromatography. Analyses by n.m.r. and i.r. spectroscopies and other methods have been combined in structural-analysis schemes to yield information about the average molecule in aromatic extracts. Carbon aromaticities, f a , derived from 22.63 MHz 1 H-decoupled pulse Fourier-transform (PFT) 13 C-n.m.r. are more widely spread for Elbistan (0.34–0.56) than for Seyitomer (0.40–0.43), and are lower than for supercritical-gas (SCG) products from bituminous coals. 13 C-n.m.r. also reveals the presence of aromatic ether-O in polar fractions. Narrow aromatic signals in 100 MHz 1 H-n.m.r. spectra suggest the presence of single-aromatic-ring average structures. In the hexane-soluble aromatics, 27% (Elbistan) and 29% (Seyitomer) of the available sites are substituted by alkyI groups, some of which are at least eight carbon atoms long; the hexane-soluble polar and asphaltene/asphaltol fractions contain fewer such groups. |
| Databáze: | OpenAIRE |
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