Dehydration of ethanol and water-ethanol mixtures involves azeotropic distillation with cyclohexane in a system comprising dehydration and regeneration columns, with a vapor jet compressor for recycling energy

摘要

A energy-saving method for dehydrating aqueous ethanol by azeotropic distillation in a system comprising a dehydration column (CD) and a regeneration column involves recycling available energy from the top of CD with the aid of a vapor jet compressor and heat exchangers/condensers. An energy-saving method for the dehydration of ethanol and water-ethanol mixtures by azeotropic distillation involves using: (a) a dehydration column (CD) operating under pressure, which heats the regeneration column (CR) for the heavy phase (operating under reduced pressure or vacuum) in a double-action system involving a heat exchanger (E2); (b) a system for recycling available energy from the top of CD (energy not used for heating CR) to the bottom of the same column, comprising a vapor jet compressor (T) charged with high-pressure vapor (Vhp) and two heat exchangers (E1) and (E4); (c) a system for utilizing the calories in the condensed vapor from (E4) by recovering the perceptible heat; (d) a system for adding water to the condensed azeotrope taken from (CD) and supplying the phase separator (D); (e) a heat exchanger (R) for heating up the hydrated starting material (Ah) by using the dehydrated product (Ad).