Mechanistic Features of Oxidative Desulfurization Using Sono-Fenton-Peracetic Acid (Ultrasound/Fe super(2+)-CH sub(3) COOH-H sub(2)O sub(2)) System

This article attempts to identify the links between the chemistry of oxidative desulfurization and cavitation physics for an ultrasound-assisted oxidative desulfurization (UAOD) process using Fenton-peracetic acid as the oxidant. The model system employed was dibenzothiophene (as a model sulfur comp...

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Bibliographic Details
Published in:Industrial & engineering chemistry research 2013-07, Vol.52 (26), p.9038-9047-9038-9047
Main Authors: Bhasarkar, Jaykumar B, Chakma, Sankar, Moholkar, Vijayanand S
Format: Article
Language:English
Subjects:
Cavitation
Desulfurizing
Oxidants
Oxidizing agents
Radicals
Scavenging
Toluene
Ultrasound
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Summary:This article attempts to identify the links between the chemistry of oxidative desulfurization and cavitation physics for an ultrasound-assisted oxidative desulfurization (UAOD) process using Fenton-peracetic acid as the oxidant. The model system employed was dibenzothiophene (as a model sulfur compound) and toluene (as a model gasoline/diesel). Experiments were performed to assess the role of each component of the oxidant in the chemistry of the process. H sub(2)O sub(2) was found to be the key component of the oxidant that balances between several competing pathways and reactions in overall oxidative desulfurization process. Addition of Fe super(2+) to peracetic acid has a beneficial effect, whereas excess H sub(2)O sub(2) has an adverse effect on the process. This article also highlights the physical and mechanistic features of the UAOD process. Transient cavitation is revealed to play a negative role in the desulfurization process, whereas ultrasound has a positive effect. The former effect is a consequence of the scavenging of HO sub(2) super( times ) radicals in the aqueous phase by radicals generated by cavitation bubbles, whereas the latter effect is attributed to the generation of a fine emulsion between the oxidant and toluene phases as a result of strong micromixing generated by ultrasound. The results of this study clearly point out that less scavenging and effective interphase transfer of HO sub(2) super( times ) radicals are more crucial to the utilization of HO sub(2) super( times ) radicals for desulfurization than mere generation.
ISSN:0888-5885
1520-5045
DOI:10.1021/ie400879j