Patent ID: 6303839
Filing Date: 2001-10-16
Classification: C07C,Y02P

Abstract:
A process for producing light olefins comprising:a) admixing a feedstream comprising an alcohol or an ether having 1 to 4 carbon atoms per molecule with a catalyst recirculation stream to provide a feedstream/recirculation stream;b) passing the feedstream/recirculation stream to a fluidized reaction zone containing an aluminophosphate molecular sieve catalyst in the presence of a diluent at effective conditions to produce a light olefin product stream comprising ethylene, propylene, and heavier olefins and a spent catalyst having a carbon deposit thereon;c) passing the light olefin product stream to a separation zone to produce an ethylene stream, a propylene stream, and a mixed C.sub.4 -plus stream;d) withdrawing a portion of the spent catalyst from the fluidized reaction zone and passing the portion of the spent catalyst to a regeneration zone and therein contacting the spent catalyst with an oxygen-containing stream at effective regeneration conditions to produce a regenerated catalyst comprising less than about 1 weight percent carbon;e) passing a feed admixture comprising at least a portion of the C.sub.4 -plus stream and at least a portion of the regenerated catalyst to a riser reactor in fluid communication with the fluidized reaction zone at effective cracking conditions to at least partially crack the feed admixture to produce a second product stream comprising additional amounts of ethylene and propylene and at least partially carbonizing the regenerated catalyst to provide a partially coked catalyst comprising from about 2 to about 30 weight percent carbon; andf) passing the second product stream and the partially coked catalyst to the fluidized reaction zone.