Study on the Effectiveness of Simultaneous Recovery and Concentration of 1-Ethyl-3-methylimidazolium Chloride Ionic Liquid by Electrodialysis with Heterogeneous Ion-Exchange Membranes

Abstract

Due to the extensive range of ionic liquids (ILs) used in industry, an efficient recovery method is needed. In this study, the effectiveness of a simultaneous concentration and recovery method was investigated for 1-ethyl-3-methylimidazolium chloride ([Emim]Cl), an IL that was recovered using electrodialysis (ED). The optimal operational parameters for electrodialytic recovery were determined empirically. The variables that were investigated included the concentration of IL, applied voltage, linear flow velocity and the diluate-to-concentrate volume ratio. The recovery of [Emim]Cl, the concentration degree, the [Emim]Cl flux across membranes, the current efficiency, as well as the energy consumption were determined. The results of the experiments confirmed that [Emim]Cl concentration and recovery can be achieved using ED. The highest ED efficiency was obtained when a 2 V electric potential per one membrane pair was applied, using a 2 cm/s linear flow velocity, and by adjusting to 0.2 M IL in the feed solution. By using ED, a 2.35-fold concentration of [Emim]Cl with a recovery of 90.4% could be achieved when the diluate-to-concentrate volume ratio was 2. On the other hand, a 3.35-fold concentration of [Emim]Cl with a recovery of 81.7% could be obtained when the diluate-to-concentrate volume ratio was increased to 5.

Ion and Molecule Transport in Membrane Systems 3.0 and 4.0

“…Issues of ion separation in various membrane systems were studied in [11][12][13][14][15]. The simultaneous recovery and concentration of 1-Ethyl-3-methylimidazolium chloride ([Emim]Cl) ionic liquid were performed using electrodialysis by Babilas et al [11]. Heterogeneous ion exchange membranes were also applied.…”

Recovery of the N,N-Dibutylimidazolium Chloride Ionic Liquid from Aqueous Solutions by Electrodialysis Method

“…Depending on the treated ILs solution, alkyl chain length, and ILs concentration, the ILs recovery rate ranges from 40 to 95%. Therefore, it is important to check the effectiveness of ILs recovery for the specific ILs [ 29 , 30 , 31 , 32 , 33 , 34 , 35 ].…”