Effect of pre-oxidation on the rate of formation of sulfur-containing aromatic compounds during vacuum gas oil thermal cracking

• Published in: Journal of analytical and applied pyrolysis Vol. 183; p. 106798
• Main Authors: Sviridenko, Yulia A., Sviridenko, Nikita N., Krivtsov, Evgenii B.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-10-2024
• Subjects: Dibenzothiophene; Oxidative desulfurization; Sulfur-containing compounds; Thermal cracking; Vacuum gas oil; Oxidative desulfurization; Sulfur-containing compounds; Thermal cracking; Vacuum gas oil; Dibenzothiophene
• ISSN: 0165-2370
• DOI: 10.1016/j.jaap.2024.106798

It was shown that oxidation followed by heat treatment is an effective method for desulfurization of vacuum gas oil. Patterns of changes in the quantitative content of the thiophene series compounds in liquid cracking products of vacuum gas oil and liquid cracking products of pre-oxidized vacuum gas oil are described. A mixture of hydrogen peroxide and formic acid (molar ratio 3:4) was used as the oxidation system. The hypothetical mechanism for the formation of thiophene, benzo- and dibenzothiophene and their homologues from high-molecular weight components of the initial vacuum gas oil and its oxidation products is proposed. Presumably, main path of formation considerate compounds is thermal decomposition of high-molecular weight sulfur-containing components. On the basis of IR spectroscopy and structure-group analysis data, the averaged structures of such components were constructed. The influence of pre-oxidation and its conditions on the value of the rate constants for the formation of thiophene, benzo- and dibenzothiophene and their homologues during thermal cracking of initial and oxidized vacuum gas oils is studied.
•Oxidation followed by heat treatment is an effective way to desulfurize vacuum gas oil.•Hypothetical formation mechanism of sulfur aromatic compounds during cracking is proposed.•Pre-oxidation feedstock affects on the formation rate of sulfur compounds during cracking.