Modeling and Simulation of Distillation of a Binary Non-Reacting Mixture Using Rate-Based Approach in Packed Column under Total Reflux

Modeling and simulation of a distillation column are very important in many chemical industries where ever it requires separation or purification of a liquid mixture into its pure components. Particularly in the context of improving efficiency, process scale-up, intensification and control it requires a validated model. In this work, both experimental results and simulation results are obtained. A batch distillation equipment which consists of a reboiler, a packed column and a top condenser is used to distill a mixture of benzene and toluene with various heat inputs to the reboiler. The distillation process in the column is modeled by an evaporation rate-based approach using Raoult's law for driving force. This particular feature is different from the stage-wise equilibrium model. The evaporation mass transfer coefficients are obtained for benzene and toluene in lab-scale apparatus. The material balance equations for the two components are solved using a finite difference method. The distillate compositions at total reflux obtained from experiments and the simulations are compared for validating of model proportionally. Further insights are obtained in regard to throughput and distillation efficiency.