Extractive distillation simulation of tert-butanol/water using TRIS as entrainer

Abstract

The mixture of tert-butanol and water cannot be separated by conventional distillation methods. The distillate composition will always be the same until all of the liquid is evaporated. The separation is difficult because the tert-butanol and water systems have azeotropic behaviour. The azeotrope occurs at a mole fraction of 0.643 and temperature of 353 K. Extractive distillation is one of the methods which can be used to separate the azeotropic behaviour effectively. The system uses two columns namely extractive distillation column and recovery distillation column. The extractive distillation column requires a third component called entrainer. The novel, environmentally friendly and non-corrosive entrainers is Tris (hydroxymethyl) aminomethane (TRIS). In this study a simulation of extractive distillation of the tert-butanol / water system was carried out using a TRIS entrainer. The optimization results show that the extractive column design configuration is the number of stages 19, binary feed stage 11, entrainer feed stage 4, reflux ratio 0.5, mixed feed temperature 78°C, and entrainer feed temperature 25°C. This configuration is capable of producing 0.996 tert-butanol purity with a reboiler load of 1255.95 kW and a condenser load of -327.29 kW.