Patent ID: 7355086
Filing Date: 2008-04-08
Classification: B01J,C10G,Y02P

Abstract:
1. A process for forming polyolefins, comprising: a) converting an oxygenate feedstock into olefins by exposing the oxygenate feedstock to silicoaluminophosphate molecular sieve catalyst particles; b) regenerating silicoaluminophosphate molecular sieve catalyst particles to contain less than about 1% coke by weight relative to a weight of molecular sieve material within the regenerated catalyst particles at a temperature of at least 580° C.; c) cooling the regenerated catalyst particles to a temperature of from 400° C. to 550° C.; d) mixing the regenerated silicoaluminophosphate molecular sieve catalyst particles at a temperature of less than 550° C. with coked catalyst particles containing at least 2% coke by weight relative to a weight of molecular sieve material within the coked catalyst particles to maintain the catalytic activity of the mixed catalyst particles at a predetermined level, wherein during the mixing of the regenerated catalyst particles with the coked catalyst particles, carbon contained in the coke is the only carbon present and oxygen contained within the catalyst is the only oxygen present; and e) forming polyolefins from the olefins of step a).