ESTIMATION OF THE AVERAGE STRUCTURAL PARAMETERS FROM ASPHALTITES AND OIL SHALES-PYROLYSIS PRODUCTS BY H-1 AND C-13 NMR-SPECTROSCOPY


ONEN A. , SARAC A., ONEN A. , EKINCI E.

FUEL PROCESSING TECHNOLOGY, cilt.32, ss.151-158, 1992 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 32 Konu: 3
  • Basım Tarihi: 1992
  • Doi Numarası: 10.1016/0378-3820(92)90029-p
  • Dergi Adı: FUEL PROCESSING TECHNOLOGY
  • Sayfa Sayıları: ss.151-158

Özet

Two samples of asphaltites and oil shales were pyrolised under controlled conditions at a heating rate of 5-degrees-C/min, and maintained at 540-degrees-C by using a Heinze retort. The oils produced from retorting of asphaltites and oil shales are more complex than crude petroleum, and these products consist of complex mixtures of aliphatic, polycyclic aromatic and polar aromatic compounds containing N, O and S heteroatoms. Pyrolysis products of asphaltites and oil shales were separated into various fractions by solvent extraction and column chromatography on silica gel. Average structural parameters for the neutral aromatic pentane-soluble fractions of asphaltites and oil shales-pyrolysis products are reported based on H-1 and C-13 NMR spectroscopy combined with elemental and molecular weight analyses. Pyrolysis products of asphaltites are consistent with aromatic systems substituted with naphthenic groups and alkyl chains. Aromatic ring condensation reactions are not important during pyrolysis of oil shales, and alkene content depends strongly on the heating rate during pyrolysis while average normal chain lengths do not. The analytical results, especially C-13 NMR spectroscopy, can only be considered approximate, since they present an over-simplified picture of very complex mixtures containing a wide range of components.