Patent ID: 7033971

Claim:
A process for protecting catalytic activity of a silicoalumino-phosphate molecular sieve, comprising the steps of: a) 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.; b) cooling the regenerated catalyst particles to a temperature of from 400° C. to 550° C.; and c) mixing the regenerated 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.