B Boelo Schuur

Extractive Distillation with Ionic Liquids: Pilot Plant Experiments and Conceptual Process Design

Ionic liquids (ILs) can replace conventional solvents in separation processes, such as extractive distillation (ED), because of their ability to selectively separate azeotropic/close boiling mixtures. Four case studies were selected: ethanol/water (1-ethyl-3-methylimidazolium dicyanamide, [emim][N(CN)2], and ethylene glycol, EG), 1-hexene/n-hexane (no suitable IL found), methylcyclohexane/toluene (1-hexyl-3-methylimidazolium tetracyanoborate, [hmim][B(CN)4], and N-methyl-2-pyrrolidone, NMP), and ethylbenzene/styrene (4-methyl-N-butylpyridinium tetrafluoroborate, [4-mebupy][BF4], and sulfolane). Pilot plant experiments proved that the developed models for ED could well describe the experimental results.

2.52 – Chiral Separations

The most abundantly used route toward enantiopure chemical and biological products is through chiral separation of racemates. Several methods are available, of which crystallization is most used in industry, and chromatography is the most common analytical technique. The frequent use of crystallization in industrial applications is because of the relative cheapness of the technology and its maturity. Chiral chromatography is also a mature technology and very broadly applicable. Probably any racemate can be separated by means of chromatography, for which reason it is the most commonly applied technique for analytical purposes. Because it might be difficult to find a crystallizing agent, and because chromatography is expensive on large scale, several other techniques such as electrophoresis, liquid–liquid extraction, membrane-assisted separations, inclusion distillation, and inclusion precipitation have been developed. All these technologies are covered in this article.