Novel plant-wide process design for producing dichlorohydrin by glycerol hydrochlorination

Dichlorohydrin is an important intermediate for synthesizing epichlorohydrin, a high volume of commodity chemical largely utilized in the production of epoxy resins. In this study, a green process using an 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 homogeneous catalyst of acetic acid. A more accurate kinetic model is firstly established. Two plant-wide processes with continuous stirred-tank reactors and reactive distillation columns are then proposed and analyzed. In these processes, dichlorohydrin is obtained by decanting the overhead product of the reactive distillation column and withdrawing from organic liquid. Furthermore, some amounts of byproduct water in the reactive distillation column is withdrawn from a side stream to increase the reaction conversion. Finally, a novel intensification scheme known as thermally coupled reactive distillation or reactive divided-wall distillation is used to design the dichlorohydrin synthesis process. Simulation results demonstrate that this novel intensified plant-wide process gives much economical benefit for the dichlorohydrin production by glycerol hydrochlorination.