Abstract:

The solvent for methylal production by extractive distillation was chosen according to basic selection rules. The appropriate solvent and solvent ratio were determined with Chemcad simulation and vapor-liquid equilibrium experiment. The results showed that N,N-dimethylformamide（DMF）as a solvent could eliminate the azeotropic point of the azeotrope methylal-methanol. The simulation of vapor-liquid equilibrium using UNIQUAC model for methylal-methanol system with and without DMF under atmospheric pressure were performed and the simulation results agreed well with the experimental data. Finally the separation of crude product of methylal-methanol by batch extractive distillation was performed. Under the operation conditions，the high purity product methyal of 99.9%（mass percentage）could be obtained at the top of the column .