Design and control of a plant-wide process for the production of epichlorohydrin

Epichlorohydrin (ECH) is a primary raw material in the production of some polymers. However, traditional ECH production methods suffer from several disadvantages. Hydrogen peroxide is relatively non-toxic and widely accepted as an environmentally friendly and green oxidant. In the study, we propose the plant-wide process design and control for ECH synthesis by the epoxidation of allyl chloride with hydrogen peroxides over the catalyst of TS-1 in the presence of methanol. In the plant-wide process, the product from a plug flow reactor is separated by a distillation column. Nitrogen gas is fed into the column top for safety concerns. The column bottom product containing mostly ECH and water is decanted into two liquid phases. High purity ECH and water are obtained from the bottoms of two strippers which the liquids of organic and aqueous phases in the decanter are respectively fed into. The control strategy is constructed by steady-state analysis for the plant-wide process and its performance is evaluated by dynamic simulation. Simulation results reveal that the process can be safely operated and product purities can be maintained around the desired values by temperature control in spite of disturbances.