Application of catalytic distillation for the aldol condensation of acetone: a rate-based model in simulating the catalytic distillation performance under steady-state operations

Catalytic distillation (CD) combines reaction and separation into a single unit, but the kinetics and mass transfer behaviour are confounded into a complex domain. Recently, we developed a new CD process for the aldol condensation of acetone to produce diacetone alcohol (DAA) and mesityl oxide (MO). Chemical kinetics and mass transfer were found to affect the product yield and selectivity. The present study is focussed on the development of a rate-based model to simulate the performance of the CD process for the aldol condensation of acetone. By modifying the classic MESH equations and incorporating the mass transfer correlations and the kinetic data obtained in our laboratory, a new set of equations including mass, energy and component balances, rate expressions, equilibrium and summation (MECRES) equations for a CD process were generated. Using the MECRES equations, the CD process of aldol condensation of acetone in a 1 in CD column was simulated. The model predictions of the temperature profile, product yield and selectivity are in good agreement with experimental data. This model also verified that the amount of catalyst and the condensation rate are important design variables for this CD process and the selectivity to DAA could be enhanced via improved mass transfer between the catalyst and the bulk liquid. (C) 1998 Elsevier Science Ltd. All rights reserved.