Selection of Imidazolium-Based Ionic Liquids for Vitamin E Extraction from Deodorizer Distillate

Deodorizer distillate as a byproduct of vegetable oil refining is an important source of natural vitamin E. Simple and green extraction can be employed to recover vitamin E from deodorizer distillate, and its performance strongly relies on the solvent used in the process. In order to screen an imidazolium-based ionic liquid (IL) as entrainer, a methodology integrating theoretical and experimental evaluations was applied. ILs composed of 47 types of anions were first investigated by COSMO-RS to figure out the most promising one, and the effect of the alkyl chain on the imidazolium ring was addressed by experiments. The IL [C6MIm]Ac was finally determined as the most promising solvent with the selectivity of 108.23 and the partition coefficient of 8.182 for α-tocopherol. The liquid–liquid equilibrium data and the extraction result for corn oil deodorizer distillate indicate its superior performance for the extraction process dealing with a low concentration of vitamin E.