Process for producing polymer grade olefins

A process for producing polymer grade olefins comprising:

• a) passing an oxygenate feedstock comprising an alcohol or an ether having from 1 to 4 carbon atoms per molecule to a fluidized reaction zone containing an aluminophosphate molecular sieve catalyst in the presence of a diluent at conditions effective to convert the oxygenate feedstock to a light olefin product stream comprising ethylene, propylene, butylene and to produce a spent aluminophosphate molecular sieve catalyst;
• b) passing the light olefin product stream to a separation zone to separate the light olefin product stream into an ethylene stream, a propylene stream, and a mixed butylene and heavier stream;
• c) withdrawing at least a portion of the spent aluminophosphate molecular sieve catalyst from the fluidized reaction zone and passing the spent aluminophosphate molecular sieve catalyst to a regenerator to regenerate the spent aluminophosphate molecular sieve catalyst with an oxygen-containing stream to produce a regenerated catalyst;
• and,
• d) returning a first portion of the regenerated catalyst to the fluidized reaction zone and admixing a second portion of the regenerated catalyst with a portion of the mixed butylene and heavier stream to provide a feed admixture and passing the feed admixture to a cracking reaction zone at conditions effective to convert the mixed butylene and heavier stream to produce a second product stream comprising additional amounts of ethylene and propylene and to produce a third regenerated catalyst portion;
• and,
• e) passing at least a portion of the second product stream to the fluidized reaction zone.