[yurikagarin]

I have read a process that is Recovering MEK from water by distillation.
It said recovering  MEK from water by fractional distillation is uneconomical but recovering MEK from water by using Toluene to extract MEK, dehydrate the extract by simple distillation,producing MEK/Toluene stream to be seperated by fractional distillation, toluene will be recycled to the extractor is more economical. I want to know why?

[Stepan]

Not sure why. Maybe the MEK partition between water and Toluene is heavily shifted toward toluene, and you can work with smaller volumes and save on energy? Also boiling of toluene is cheaper than boiling of water.