Exploration of the effects of pressure on the controllability of extractive distillation for separating pressure-sensitive azeotropes

摘要

Exploring the influence of steady-state process parameters on dynamic control structures is receiving increasing attention from researchers. In this work, the effects of pressure on dynamic control structures and anti-disturbance were discussed based on the minimal total annual cost. Ethanol-benzene and ethanol-ethyl acetate, two binary azeotropic systems, were used to investigate the influence of pressure on the dynamic controllability. For ethanol-benzene, the control structures with two solvents, 1,2-propanediol and p-xylene, under the optimal pressure were both more complex than that under normal pressure. In addition, when the deviation from the initial set value was small, a slight increase in the purity of the product could be adopted instead of introducing a component controller. The optimal pressure needs to be determined by balancing cost and control. For ethanol-ethyl acetate, the influence of pressure on the dynamic controllability was not obvious, and the optimal pressure can be only determined by economy. The results showed that pressure had different effects on the dynamic controllability of different systems.