摘要
Dichlorohydrin is an important intermediate for synthesizing epichlorohydrin, a high volume of commodity chemical largely utilized in the production of epoxy resins. It is commonly manufactured from propylene and chlorine as primary raw materials. However, this synthesis process suffers from some drawbacks such as low chlorine atom efficiency and formation of unwanted chlorinated organics. In this study, a green process using a more atom-efficient and environment-friendly route is used to synthesize dichlorohydrin by reacting glycerol, an available by-product in the biodiesel production, and hydrochloric acid under the catalyst of acetic acid. A more accurate kinetic model is established. Some plant-wide processes with different configurations of continuous stirred-tank reactors and reactive distillation columns are developed and examined. Dichlorohydrin is obtained by decanting the overhead product of the reactive distillation column and withdrawing from organic phase liquid. This policy avoids the use of entrainer to separate the azeotrope of dichlorohydrin and water and then much economical benefit can be achieved from the proposed processes. Furthermore, water by-product in the reactive distillation column is withdrawn from a side-draw to increase the reaction conversion. Simulation results demonstrate that this study provides a more economical plant-wide process design for the dichlorohydrin production by glycerol hydrochlorination.