Method of obtaining a pure aromatic hydrocarbon from a sump product of

Abstract

The method of obtaining a pure aromatic hydrocarbon from a hydrocarbon starting mixture includes extractively distilling the hydrocarbon starting mixture with a selective solvent; feeding the sump product of the extractive distillation through a first and second auxiliary boilers connected in series to form a cooled sump product at a temperature from 105.degree. to 120.degree. C.; delivering the cooled sump product to a separator distillation column at an entry plate in an upper portion of a separator distillation column and operating the separator distillation column to form a reflux in the upper portion; collecting this reflux and heating it with solvent drawn from the sump of the separator distillation column in a third auxiliary boiler; returning the heated reflux to the separator distillation column at another plate under the entry plate to form a liquid phase on the other plate; conducting the liquid phase formed on the other plate through the second auxiliary boiler to form a vapor-liquid mixture by partial vaporization due to heat from the sump product; feeding the vapor-liquid mixture into a lower portion of the separator distillation column to form a vapor in the upper portion of the separator distillation column; wherein the pure aromatic hydrocarbon leaves the top of the separator distillation column.