Patent ID: 6459009
Filing Date: 2002-10-01
Classification: B01D,C07C,Y02P,Y10S

Abstract:
A two-stage quench tower process for removing impurities from a superheated reactor effluent stream withdrawn from an oxygenate conversion complex, said process comprising:a) passing the superheated reactor effluent stream comprising light olefin, water, and organic acids to a feed/effluent exchanger to desuperheat said reactor effluent stream by indirect exchange with a vaporized feedstream to provide a desuperheated stream; b) passing the desuperheated stream to a first tower of a two-stage quench zone containing a first tower and a second tower, and contacting therein the desuperheated stream in an upper portion of the first tower with a neutralized water stream to condense at least a portion of the water to provide a first stage bottoms stream comprising water and neutralized organic acids and a first stage overhead stream comprising light olefins and water; c) passing the first stage overhead stream to the second tower and therein contacting the first stage overhead stream with a cooled purified water stream to provide a light olefin product stream and a purified water stream; d) cooling a first portion of the purified water stream to provide the cooled purified water stream; e) passing a second portion of the purified water stream to a water stripper column to provide a high purity water stream and a stripper overhead stream, admixing the stripper overhead stream with the first stage overhead stream, and cooling the first stage overhead stream prior to step (c), or passing a second portion of the purified water stream to a water stripper to provide a high purity water stream and a stripper overhead stream, cooling a portion of the first stage bottoms stream and admixing a neutralization stream and a third portion of the purified water stream therewith to provide the neutralized water stream, and admixing the stripper overhead stream with the first stage overhead stream; and f) returning a fourth portion of the purified water stream to the first tower.