DEHYDRATION OF DILUTIONS OF COMPOUNDS FORMING AN AZEOTROPE WITH WATER

摘要

A process and a column configuration for dehydration of an aqueous dilution of a compound forming an azeotrope with water, such as raw grade bioethanol, formic acid or chloroform, to form a concentrate with a concentration above azeotropic level. A preconcentration section (26, 40, 55) with a reboiler (29, 42, 57) and an extractive distillation section (22, 41, 52) are thermally coupled. The aqueous dilution is fed to the preconcentration section, where it is separated into water and a preconcentrate. The water is discharged via the reboiler, and the preconcentrate is fed to the extractive distillation section. A solvent is fed to the extractive distillation section at a higher level than the preconcentrate. In the extractive distillation section the final concentrate is separated from a mixture of the solvent and water.