Thermophysical Properties Required for Selective Solvents

Typically, organic compounds are used as selective solvents. For a safe and efficient operation, all selective solvents for separation processes should have the following properties in common  

Additionally, in order to have little or no impurities in the distillate of the extractive distillation column and also to avoid separation problems in the regeneration column, selective solvents for extractive distillation should have a boiling point that is at least 40 °C higher than the boiling points of the components to be separated. In the case of extraction, of course, it is most important that the solvent shows a miscibility gap with the feed and the raffinate stream. At the same time, a high 

A large number of organic compounds are currently used for the various separation processes. One of the most popular ones is IV-Methylpyirolidone (NMP), used not only for extractive distillation and for extraction but also for the various absorption processes. Since the cost of the separation step is greatly influenced by the selectivity, new and better extractive solvents are continually being investigated. 

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