Process for Separation of Isoprene from C5 fraction of Cracked Naphtha by Extractive Distillation

摘要

PURPOSE: Provided is a process for separating isoprene from C5 fraction obtained from a naphtha cracker by an extractive distillation, which minimizes the energy consumption in the whole process. CONSTITUTION: The process comprises the steps of: (1) performing a first extractive distillation by contacting the C5 fraction and an extractant to separate isoprene from the C5 fraction; (2) recovering the extractant by distilling the mixture of the isoprene and the extractant; (3) removing the components with high boiling point by distilling the separated isoprene to prepare crude isoprene, wherein the sensible heat of the extractant recovered from the step(2) is supplied to a reboiler of a distillation column of the step(3) as a heat source; (4) performing a second extractive distillation by extraction-distilling the crude isoprene to remove triple bond components; (5) recovering the extractant used in the step(4) for removing the triple bond components; (6) removing the components with low boiling point from the isoprene to produce the isoprene in high purity, wherein the sensible heat of the extractant recovered from the step(5) is supplied to a reboiler of a distillation column of the step(6) as a heat source.