Theoretical insight and experimental exploration of indole extraction from wash oil with deep eutectic solvents

Lan Yi; Xiaoqin Wu; Shuguang Ouyang; Li Guo; Jialing Chen; Mario Gauthier; Wen-Ying Li

Arabian Journal of Chemistry (Dec 2023)

Theoretical insight and experimental exploration of indole extraction from wash oil with deep eutectic solvents

Lan Yi,
Xiaoqin Wu,
Shuguang Ouyang,
Li Guo,
Jialing Chen,
Mario Gauthier,
Wen-Ying Li

Affiliations

Lan Yi: Key Laboratory of Hubei Province for Coal Conversion and New Carbon Materials, School of Chemistry and Chemical Engineering, Wuhan University of Science and Technology, Wuhan 430081, PR China; Corresponding authors.
Xiaoqin Wu: Key Laboratory of Hubei Province for Coal Conversion and New Carbon Materials, School of Chemistry and Chemical Engineering, Wuhan University of Science and Technology, Wuhan 430081, PR China
Shuguang Ouyang: Key Laboratory of Hubei Province for Coal Conversion and New Carbon Materials, School of Chemistry and Chemical Engineering, Wuhan University of Science and Technology, Wuhan 430081, PR China
Li Guo: Key Laboratory of Hubei Province for Coal Conversion and New Carbon Materials, School of Chemistry and Chemical Engineering, Wuhan University of Science and Technology, Wuhan 430081, PR China
Jialing Chen: Key Laboratory of Hubei Province for Coal Conversion and New Carbon Materials, School of Chemistry and Chemical Engineering, Wuhan University of Science and Technology, Wuhan 430081, PR China
Mario Gauthier: Key Laboratory of Hubei Province for Coal Conversion and New Carbon Materials, School of Chemistry and Chemical Engineering, Wuhan University of Science and Technology, Wuhan 430081, PR China; Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
Wen-Ying Li: State Key Laboratory of Clean and Efficient Coal Utilization, Taiyuan University of Technology, Taiyuan 030024, PR China; Corresponding authors.

Journal volume & issue: Vol. 16, no. 12
p. 105341

Abstract

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The extraction of indole from wash oil is of economic value and practical significance. In this study, deep eutectic solvents (DESs) are investigated to extract indole from wash oil. Initially, density functional theory calculations were used to explore the association of indole with aromatic compounds in wash oil, and the feasibility of indole extraction with a tetraethylammonium chloride/p-toluenesulfonic acid (TEAC/2TsOH) DES. Then, the influence of the temperature, stirring time, DESs dose, initial indole concentration, and amount of water added were investigated, followed by discussions on the comparison with other extractants and the performance of extracting of indole from real wash oil. The results show that indole associates with aromatic compounds in wash oil through π−π interactions, but that a large electrostatic interaction energy of −52.8 kJ/mol between indole and the DESs is the main driving force for the extraction process. Under optimal conditions, TEAC/2TsOH extracts more than 63.5 ± 3% of indole from wash oil, and its extraction capacity is superior to other extractants.

Published in Arabian Journal of Chemistry

ISSN: 1878-5352 (Print)
Publisher: Elsevier
Country of publisher: Netherlands
LCC subjects: Science: Chemistry
Website: http://www.journals.elsevier.com/arabian-journal-of-chemistry/

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