E.s.r. of Alberta tar sand bitumen and thermally hydrocracked products
| Autor: | Kailash Chandra Khulbe, David J. Patmore, A. Manoogian, Bei Wah Chan |
|---|---|
| Rok vydání: | 1986 |
| Předmět: |
Chloroform
General Chemical Engineering Radical Organic Chemistry Energy Engineering and Power Technology Vanadium chemistry.chemical_element Thermal treatment law.invention chemistry.chemical_compound Fuel Technology chemistry law Oil sands Organic chemistry Electron paramagnetic resonance Tetrahydrofuran Nuclear chemistry Asphaltene |
| Zdroj: | Fuel. 65:1594-1599 |
| ISSN: | 0016-2361 |
| DOI: | 10.1016/0016-2361(86)90338-8 |
| Popis: | A study of the vanadium and free radical species present in Athabasca bitumen and thermally upgraded products from a hydrocracking pilot plant was carried out. The samples were separated into asphaltene, chloroform resin, tetrahydrofuran resin and oil components, and the fractions studied by electron spin resonance. All samples except the oil fraction contained vanadyl (VO2+) ions and free radicals. It was found that even mild thermal treatment of bitumen produced considerable redistribution of vanadyl groups among the fractions, whereas at the severest hydrocracking conditions 94 wt% of all vanadyl groups were associated with the asphaltene fractions compared with only 58.5 wt% in the original bitumen. As the hydrocracking severity increased, the asphaltene vanadyl concentration initially increased above the value for unreacted bitumen and then decreased to a lower value. On the other hand, the resin vanadyl concentration decreased continuously and more rapidly than asphaltene vanadyl concentration. This indicates that vanadyl groups associated with the resin fractions are less stable than those associated with the asphaltenes and also suggests that transfer of vanadyl groups from the resin fractions to asphaltene predominates at low severity while removal of vanadyl groups predominates at high severity. The average spin Hamiltonian parameters showed that the chemical environment of vanadyl ions in the THF resins was significantly different from the vanadyl environment in the other two fractions. |
| Databáze: | OpenAIRE |
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