Isobaric Vapor–Liquid Equilibria and Extractive Distillation Process Design for Separating Methanol and Methylal

Methanol and methylal form a minimum boiling point azeotrope and cannot be separated by conventional distillation. In this paper, the azeotrope was separated by extractive distillation with cyclohexanol as the entrainer. First, the vapor–liquid equilibrium data of methanol + cyclohexanol and methylal + cyclohexanol were measured at 101.3 kPa, and the thermodynamic consistency of the experimental data was tested by the van Ness and pure component...