Key Factors Affecting the Development of Oxidative Desulfurization of Liquid Fuels: A Critical Review

Abstract

Complete and effective sulfur removal from liquid fuels is essential to meet the sulfur standard requirements. The oxidative desulfurization (ODS) process has been extensively used for the desulfurization of liquid fuels. In the current study, a comprehensive survey was conducted on the most important factors of ODS, including the types of catalysts, oxidizing agents, extraction solvents, liquid fuels, and process operating conditions. Various types of catalysts, nanocatalysts, magnetic catalysts, photocatalysts, electrocatalysts, biocatalysts, and emulsion catalytic systems have been studied in the ODS process. According to the obtained results, desulfurization catalysts were categorized into 11 groups, including metal oxides, metal complexes, metal free, titanosilicates, ionic liquids, polyoxometalates, metal−organic frameworks, porous aromatic frameworks, covalent organic frameworks, enzymes, and Fenton and Fenton-like catalysts. The advantages and drawbacks of the ODS catalysts were reviewed. The results indicate that the development of experimental design, modeling, and simulation in the ODS process helps to identify the most important variables, facilitate future research, and achieve maximum sulfur removal. Using technologies assisted with ODS such as ultrasound, cold plasma, microwave radiation, hydrodynamic cavitation, photo/light, electrochemistry, magnetic field, and biotechnology can improve sulfur removal and reduce reaction time.

Valorisation of Waste Tyre via Pyrolysis: Advances and Perspectives

“…The main purpose of oil upgrading is to remove sulfur from the pyrolysis oil. In the literature, substantial studies were devoted to the chemical composition of sulfur in petroleum (see summarisation in a recent review paper) and the desulfurization of liquid fuel oils that originated from fossil resources (see recent review papers − ). Therefore, this review is focused on summarizing the work on sulfur removal from waste tyre pyrolysis oil.…”

Monooxygenase- and Dioxygenase-Catalyzed Oxidative Dearomatization of Thiophenes by Sulfoxidation, cis-Dihydroxylation and Epoxidation

“…Thiophenes and sulfur-containing polycyclic aromatic hydrocarbons (thiaarenes), present in the aromatic fraction of crude oil, include monocyclic thiophenes (e.g., dialkyl thiophenes), bicyclic thiaarenes (e.g., benzothiophenes), and tricyclic thiaarenes (e.g., dibenzothiophenes, naphthothiophenes) [13,14]. The requirement to remove these organosulfur constituents of crude oil stimulated interest in their oxidative biodegradation by Pseudomonas bacteria (biodesulfurization), as shown by the extensive studies of the Fedorak group [15][16][17][18][19][20][21][22][23][24][25].…”

“…While thiophenes are considered as contaminants of fossil fuels [14][15][16][17][18][19][20][21][22][23][24], the thiophene ring is regarded as a useful bioisosteric building block for many important drugs (Figure 5) [57]. The results from monooxygenase (CYP450)-catalyzed sulfoxidation of Scheme 9.…”

“…While thiophenes are considered as contaminants of fossil fuels [14][15][16][17][18][19][20][21][22][23][24][25], the thiophene ring is regarded as a useful bioisosteric building block for many important drugs (Figure 5) [57]. The results from monooxygenase (CYP450)-catalyzed sulfoxidation of thiophenes, in the context of metabolite identification, toxicity, and mechanism of drug metabolism, are rarely compared with sulfoxidations obtained using ring-hydroxylating dioxygenases.…”

Recent Advances and Challenges in Developing Technological Methods Assisting Oxidative Desulfurization of Liquid Fuels: A Review

“…18,19 The oxidative desulfurization process involves chemical reaction between an oxidizing agent and sulfur-containing compounds with/without catalyst at atmospheric pressure and relatively low temperature. 20,21 By using polar solvents or adsorbents, the obtained compounds (sulfones/sulfoxides) can be removed from the fuel.…”