Study on the recovery of 1-butyl-3-methylimidazolium-based ionic liquids

Nowadays, ionic liquids have been widely used in desulfurization process. However, the synthesis costs, performance efficiencies and problems related to waste waters contaminated with ionic liquids are the major issues that need to be considered. Thus, recovery method is one of the alternatives to overcome the current issues. 1-butyl-3-methylimidazolium-based ionic liquids with three different anions: dicyanamide (N(CN)2), thiocyanate (SCN) and methylsulfate (CH3SO4) were chosen for the study because they are the common ionic liquids used in desulfurization. The recovery process used is water washing which is the cheapest and easiest recovery method. Even though the contaminants in the spent ionic liquids can easily be removed, we found that the recovered ionic liquids contained higher percentage of water as compared to the pure and spent ionic liquids. Thus, the aim of this current work is to study on the feasibility of the spent ionic liquids to be recovered and their performance on desulfurization after being recovered. © 2014 Trans Tech Publications, Switzerland.