4. Introduction
• Sulfides and thiophenes are the Organic Sulphur compounds (OSCs) which
are found in crude oil, and they are classified as reactive and non reactive
species respectively.
• These compounds are responsible for causing severe environmental damage,
metal corrosion in refineries.
5. Experiment
• Material and reagent:
• Methyl iodide, ethyl iodide, propyl iodide, silver tetrafluoroborate, silver nitrate, copper
chloride, 1,2-dichloroethane (DCE).
• HPLC grade solvents, toluene, tetrahydrofuran, dichloro-methane, methanol, acetonitrile,
acetone, ammonium hydroxide, n-heptane, and formic acid (FA).
• Sample:
• VGO (500mg) was mixed with n-heptane (50ml), stirred on magnetic plate for 90 minutes.
This mixture is stored in darkness. After 24 hours, the soluble n-heptane VGO Fraction was
separated from asphaltene by filteration. This extract was conserved for methylation.
6. Continue….
• Methylation:
• This reaction was employed to derivatize Sulphur containing compounds present in
whole VGO and DVGO extract.
• Extraction of Sulphur containing compounds by HPLC:
• Methylated fraction were dissolved in the mixture of toluene and methanol at the
concentration of 2000 ppm.
• Then, 20 µL of this solution was injected into a reversed-phase cyanopropyl (CN)
HPLC column to separate the methylated-sulfur compounds.
7. Result and Discussion
• The methylation reaction has been employed as a strategy to
characterize non-polar sulfides and thiophenes. This reaction allows the
derivatizing Sulphur containing compounds to more polar constituents
such as the methyl sulfonium salts.
8. Conclusion
• Derivatizing of sulphur compounds was carried out by methyl iodide as
methylation agent, which is present in VGO.
• Methyl Iodide provides the highest number of sulphur containing
compounds in methylation reaction. This is due to its low steric effect that
benefits the nucleophilic attack in methylation reaction.
• Analysis of methylated sulfur species from de-asphalted VGO
