Patent ID: 7208648
Filing Date: 2007-04-24
Classification: C07C,C10G,C23F,Y02P,Y10S

Abstract:
1. A process for reducing corrosion in an MTO effluent processing system, the process comprising the steps of: (a) directing a product stream from an MTO reactor to a quench unit through a quench unit inlet; (b) contacting the product stream with a quench medium in the quench unit under conditions effective to form a light product fraction containing light olefins, a heavy product fraction containing condensed components, and a condensed pumparound stream; (c) adding a neutralization agent to the condensed pumparound stream to form the quench medium, wherein the quench medium has a pH greater than the pH of the condensed pumparound stream; and (d) injecting the quench medium into the quench unit at an injection point oriented higher on the quench unit than the quench unit inlet; (e) compressing the light product fraction to form a compressed product fraction; directing the compressed product fraction to a C3− separation zone and Conning a C3− overhead stream and a C4+ bottoms stream; and (f) contacting at least a portion of the C3− overhead stream with caustic in a caustic wash unit and forming a caustic unit overhead stream and a caustic unit bottoms stream, wherein the caustic unit overhead stream contains a majority of the light olefins that were present in the light product fraction, and wherein the caustic unit bottoms stream contains at least partially spent caustic.