Fractionations of non-porphyrin complexes of vanadium and nickel from Boscan crude oil
Samples containing vanadium and nickel non-porphyrin complexes were isolated from Boscan crude oil from Venezuela. Chromatographic studies indicated that a broad molecular weight range of components existed so that silica packings having a 300 A average pore diameter were superior to those in the range 60 A to 100 A due to greater permeation. Solvents having widely different polarities and selectivities were needed for elution of non-porphyrins from 300 A pore diameter silica derivatized with trimethylchlorosilane. Successive solvents eluted different percentages of the metals and of uv-visible absorbing components. Larger molecular-weight species, which contained the bulk of the metals, were eluted by chloroform, methylene chloride, and tetrahydrofuran. Results also suggested the existence of slow equilibria between high and low molecular weight species within a particular non-porphyrin fraction. When asphaltenes were precipitated from a sample of crude oil by n-hexane, most of the vanadium and nickel was found in that higher molecular-weight fraction. Further fractionation of the soluble (maltene) fraction using neutral alumina showed that most of the maltenes could be recovered as separate hydrocarbon, porphyrin, non-porphyrin and tetrahydrofuran fractions. In contrast, only approximately fifty percent of the asphaltenes (and metals) were recovered by an analogous procedure. Furthermore, when separating the asphaltenes into porphyrin and non-porphyrin fractions, an approximately one-to-one split of vanadium and nickel between the porphyrins and non-porphyrins was observed for both, whereas most of the vanadium and nickel was isolated from the maltenes as non-porphyrins. Finally, it was found that a procedure utilizing sulfuryl chloride for non-porphyrin demetallation was superior to a procedure employing methane-sulfonic acid.
- Research Organization:
- Georgia Univ., Athens (USA). Dept. of Chemistry
- DOE Contract Number:
- AS09-76ER00854
- OSTI ID:
- 6183605
- Report Number(s):
- DOE/ER/00854-39; ON: DE83008555
- Country of Publication:
- United States
- Language:
- English
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Fractionations of nonporphyrin complexes of vanadium and nickel from Boscan crude oil
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Related Subjects
023000 -- Petroleum-- Properties & Composition
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400104* -- Spectral Procedures-- (-1987)
ABSORPTION SPECTROSCOPY
ALKANES
ASPHALTENES
ASPHALTS
BITUMENS
CHLORINATED ALIPHATIC HYDROCARBONS
CHLOROFORM
CHROMATOGRAPHY
COMPLEXES
DATA
DEMETALLIZATION
ELUTRIATION
ENERGY SOURCES
EXPERIMENTAL DATA
FOSSIL FUELS
FRACTIONATION
FUELS
FURANS
HALOGENATED ALIPHATIC HYDROCARBONS
HETEROCYCLIC COMPOUNDS
HEXANE
HYDROCARBONS
INFORMATION
LIQUID COLUMN CHROMATOGRAPHY
METHYLENE CHLORIDE
NICKEL COMPLEXES
NUMERICAL DATA
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
OTHER ORGANIC COMPOUNDS
PETROLEUM
PRECIPITATION
SEPARATION PROCESSES
SPECTROSCOPY
TAR
TETRAHYDROFURAN
TRANSITION ELEMENT COMPLEXES
VANADIUM COMPLEXES