Extractive Distillation

Name:
Extractive Distillation
Detailed information:
A variety of distillation that always involves use of a fractionating column and is characterized by use of a purposely added substance that modifies the vaporization characteristics of the materials undergoing separation to make them easier to separate. The additive is often called a solvent and is usually chosen to be much less volatile than any of the substances being separated. It is added to the down flowing liquid-reflux stream near the top of the column and is removed from the still pot or reboiler at the base. The addition of furfural to mixtures of butadiene and butene hydrocarbons to separate the butadiene more easily is an example of extractive distillation.