Composition-temperature cascade control of vapor recompression assisted dividing wall column with side heat exchanger

Abstract The vapor recompression assisted dividing wall column with side heat exchanger configurations have high energy efficiency but low controllability. In this paper, the control strategies of these configurations are studied, and two composition-temperature cascade control structures of these configurations are proposed for the first time. For the vapor recompression assisted dividing wall column with side condenser configuration, the side condenser duty is chosen to control the bottom purity instead of the bottom reboiler duty. For the vapor recompression assisted dividing wall column with side reboiler configuration, both of bottom and side reboilers duties are chosen to control the bottom purity and the sensitive stage temperature respectively. The control results of two separation cases shown that the proposed control structures are effective for these two kinds of configurations. This work makes a contribution for the industrialization of the vapor recompression assisted dividing wall column with side heat exchanger processes.