Recent advances in dividing wall column (DWC) have led to renewed interest in the design or redesign of many industrial processes. For the distillation system of cumene production, the existing design alternatives have the potentials of energy savings and consequently the reduction of total annual cost (TAC) and energy consumption. In this paper, cumene production based on the real industrial process is simulated in a conventional process using commercial process simulator Aspen Plus, and two DWC distillation processes are introduced. Then optimization study for the proposed DWC distillation processes is performed based on the TAC calculation with sensitivity analysis to investigate the effects of operating parameters. The results indicate that the optimum DWC distillation process works well for the production of cumene, and the corresponding TAC is reduced significantly accompanied by substantial energy savings. (C) 2015 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.