Closed Operation of Multivessel Batch Reactive Distillation Processes

Closed operation of batch reactive distillation process with three vessels (reflux drum, reboiler drum, and middle vessel) is studied using Aspen Plus and Aspen Dynamics. The results show that the rate of accumulation of product in the middle vessel is an important optimization variable. Batch capacity increases and energy consumption decreases as the rate of accumulation increases; however, beyond a certain value the process is found to be infeasible because the reactive vessel dries out before the desired product purity can be achieved. In all cases the batch capacity is found to be higher and the energy consumption lower for closed operation compared to both conventional operation and operation with off-cut.