SIMULATION OF PRESSURE-SWING DISTILLATION FOR SEPARATION OF ETHYLENE GLYCOL AND 1,2-BUTANDIOL

YANG Yanru, PAN Gaofeng, YANG Jinson, LIU Yanjie, DAI Chuanbo

ABSTRACT:A pressure-swing distillation process for separation of ethylene glycol and 1,2-butandiol is proposed on the basis of characteristic analysis on the ethylene glycol-1,2-butandiol azeotropic system. Simulation is performed by using Aspen Plus simulation software, aiming at minimizing the energy consumption and guaranteeing the concentrations of ethylene glycol and 1,2-butandiol products. The influences of total number of theoretical plate, reflux ratio, feeding position and other parameters on the separation efficiency are specified. The optimal process parameters for the atmospheric distillation column are as follows: the operating pressure is 100kPa, the number of theoretical plate is 45, the feeding position is between the 30-40th plate, and the reflux ratio is 7. The optimal process parameters for the vacuum distillation column are as follows: the operating pressure is 30kPa, the number of theoretical plate is 50, the feeding position is at the 20-40th plate, the reflux ratio is 4. Under the optimal parameters, the mass purity of ethylene glycol and 1,2-butandiol products exceed 99% and 98%, respectively, which meets industrial production requirements

Keywords:Ethylene glycol,1,2-butandiol, pressure-swing distillation, simulation.