Desulfurisation of oils using ionic liquids: selection of cationic and anionic components to enhance extraction efficiency

Abstract

Extraction of dibenzothiophene from dodecane using ionic liquids as the extracting phase has been investigated for a range of ionic liquids with varying cation classes (imidazolium, pyridinium, and pyrrolidinium) and a range of anion types using liquid-liquid partition studies and QSPR (quantitative structure-activity relationship) analysis. The partition ratio of dibenzothiophene to the ionic liquids showed a clear variation with cation class (dimethylpyridinium . methylpyridinium . pyridinium # imidazolium # pyrrolidinium), with much less significant variation with anion type. Polyaromatic quinolinium-based ionic liquids showed even greater extraction potential, but were compromised by higher melting points. For example, 1-butyl-6-methylquinolinium bis{(trifluoromethyl)sulfonyl}amide (mp 47 uC) extracted 90% of the available dibenzothiophene from dodecane at 60 uC.

Liquid–Liquid Equilibria in Binary Solutions Formed by [Pyridinium-Derived][F4B] Ionic Liquids and Alkanols: New Experimental Data and Validation of a Multiparametric Model for Correlating LLE Data

“…More specifically, some pyridine derivatives (such as those used in this work) have produced good results in certain applications, such as sulfur extracting agents, 1 lubricants, 2 and chemical reactions. 3 Our research group has worked with three isomeric substances having a common nucleus of a pyridine derivative, [butyl-Xmethylpyridinium] (X = 2, 3,4) [tetrafluoroborate], 4À6 and other nonisomeric [butylpyridinium][tetrafluoroborate], 7 using water and several alkanols (methanol to pentanol) as solvents.…”

Ionic Liquids Made with Dimethyl Carbonate: Solvents as well as Boosted Basic Catalysts for the Michael Reaction

“…[3] Examples of such a quantitative structure-property relationship approach were recently described and used, for example, to correlate ionic liquid descriptors with their melting points [4] and with the partition ratios of dibenzothiophene in different ionic liquids. [5] Notwithstanding the complexity of the issue, it is accepted that in many instances ionic liquids are a viable green alternative to conventional molecular solvents. And that it is possible to design, optimise and apply the right ionic liquid for ones specific case.…”

Vapor Pressure of Water in Mixtures with Hydrophilic Ionic Liquids – A Contribution to the Design of Processes for Drying of Gases by Absorption in Ionic Liquids

“…Extraction of organic sulphur compounds from refinery streams, such as gasoline and diesel oil, by ILs indicate that such a process could be an alternative to common desulfurization by hydrotreating [5][6][7][17][18][19]. For diesel oil, the extracted S-species are hard to remove by distillation or stripping.…”