Process for purifying epichlorohydrin, process for producing epichlorohydrin and apparatus for producing purified epichlorohydrin

摘要

A process and apparatus are disclosed for the purification of epichlorohydrin. The process includes distilling and/or fractionating a feed stream containing epichlorohydrin, dichlorohydrin(s), and one or more other substances, subjecting at least a portion of the liquid phase effluent to a dichlorohydrin dehydrochlorination process for converting residual dichlorohydrin(s) in the liquid phase effluent to epichlorohydrin, and recovering purified epichlorohydrin from the vapor phase effluent in which the distillation/fractionation pressure and/or temperature of step (1) is adjusted to retain at least 5 weight-percent epichlorohydrin in the liquid phase effluent and/or the distillation/-fractionation pressure and/or temperature of step (1) is adjusted to satisfy the equation: R –¡ 100000 –¡ P 100 –¡ T k wherein P represents the distillation pressure of the vapor phase effluent produced by step (1) in Pascal, T k represents the distillation temperature of the liquid phase effluent produced by step (1) in degrees Kelvin, and R represents the number 2.8. The apparatus for making purified epichlorohydrin includes a dehydrochlorination apparatus, a first liquid-vapor contacting apparatus, and a second liquid-vapor contacting apparatus connected to the dehydrochlorination apparatus for recycling a distillate to the dehydrochlorination apparatus. Advantages include more efficient recovery of epichlorohydrins and reduced capital investment in recovery equipment.