Multi-stage process and apparatus for recovering dichlorohydrins

Abstract

A process and apparatus for recovering dichlorohydrins from a mixture comprising dichlorohydrins, one or more compounds selected from esters of dichlorohydrins, monochlorohydrins and/or esters thereof, and multihydroxylated-aliphatic hydrocarbon compounds and/or esters thereof, and optionally one or more substances comprising water, chlorinating agents, catalysts and/or esters of catalysts is disclosed. The mixture is distilled or fractionated to separate a lower boiling fraction comprising dichlorohydrin(s) from the mixture to form a higher boiling fraction comprising the residue of the distillation or fractionation. The higher boiling fraction is distilled or fractionated to separate remaining dichlorohydrin(s) from the above mixture to form an even higher boiling fraction comprising the residue of the distillation or fractionation. At least some of the lower boiling fraction and the dichlorohydrin(s) are recovered. Advantages include more efficient recovery of dichlorohydrins for a given distillation column, less waste due to avoiding the conditions conducive to the formation of heavy byproducts, reduced capital investment in recovery equipment, and reduced energy utilization while maintaining the quality of dichlorohydrin product produced and not increasing the amount of undesired byproducts formed.