Process for separating relatively easily soluble hydrocarbons from a hydrocarbon mixture

Abstract From the Canadian patent

In a process for separating a specified relatively easily soluble hydrocarbon from a hydrocarbon mixture which comprises extractively distilling the hydrocarbon mixture in an extractive distillation apparatus composed of two stages of a unit consisting of an extractive distillation column and a stripping column using a polar extractive solvent the, improvement wherein a first-stage extractive distillation column is operated at a higher bottom pressure than the bottom pressure of a second-stage extractive distillation column and a pre-stripping column, is provided between the first-stage extractive distillation column and a first-stage stripping column, and by operating the pre-stripping …