1985 Volume 11 Issue 2 Pages 175-179
In many continuous processes, it is often found that plant performance deteriorates during the course of operation. A stage is eventually reached when further deterioration in plant performance is no longer tolerable. This could be either due to economic reasons or product quality limitations. At this point, the operator is forced to shut down the plant and go through the process of reactivation. Plants employing such cyclic stepwise operation require some appropriate methodology to determine the optimum switching time between production and regeneration processes.
In this study, an attempt has been made to maximize the productivity of such semicontinuous plants. Each process unit involved is separately modeled by a set of ordinary differential equations, and then the problem of finding the optimum switching time for maximizing the production rate is solved analytically. The proposed methodology has been applied to determine the optimum cyclic period of a plant which produces demineralized water, employing a fixed bed composed of a cation exchange resin (Amberlite IR 120B) and an anion exchange resin (Amberlite IRA 410).
