Patent ID: 8628604
Filing Date: 2014-01-14
Classification: B01D

Abstract:
1. A process for concentration of ethanol from a dilute feed solution comprising ethanol comprising the steps of (a) counter-current contacting of the dilute feed solution and a vapor phase input to a counter-current vapor-liquid contactor with the counter-current vapor-liquid contactor to produce a vapor phase output of the counter-current vapor-liquid contactor and an outgoing depleted feed solution; (b) condensing in a condenser of the vapor phase output of the counter-current vapor-liquid contactor, wherein the vapor phase output of the counter-current vapor-liquid contactor is conveyed to the condenser such that the composition of the vapor phase output is substantially maintained, to produce a condensed liquid product that leaves the condenser, with transfer of latent heat released by condensation to an evaporator; (c) evaporating of a liquid feed to provide the vapor phase input to the counter-current vapor-liquid contactor; (d) compressing of the vapor phase output of the counter-current vapor-liquid contactor or the vapor phase input to the counter-current vapor-liquid contactor, wherein compression of the vapor phase may occur before the counter-current vapor-liquid contactor, after the counter-current vapor-liquid contactor, or both before and after the counter-current vapor-liquid contactor, wherein the action of the compressor must result in a pressure that is higher in the condenser than in the evaporator, wherein no membrane is used in the process and whereby ethanol is concentrated; and (e) reducing by a heat exchanger the temperature of the outgoing depleted feed solution leaving the counter-current vapor-liquid contactor to a temperature close to the temperature of the dilute feed solution before said dilute feed solution enters said heat exchanger.