Computer evaluation of parastillation process

A mathematical model and an iterative method is developed for simulating parastillation processes, where the uprising vapour stream is divided into two equal parts at the bottom of the distillation column and the whole amount of the falling liquid is stage-by-stage alterantively contacted with both parts of the vapour. According to our parametric study and simulated industrial examples this arrangement increases the number of theoretical stages per unit height of column, ensures lower column pressure drop and provides considerable energy savings for the same separation, when compared to a conventional column. The advantages especially at low pressures seem to be promising.