US Patent 7754933 Rejuvenating deactivated molecular sieve

This invention is directed to a method of rejuvenating a molecular sieve that has decreased catalytic activity as a result of contact with moisture, and a method of using the rejuvenated catalyst to make an olefin product from methanol feed. The molecular sieve can be rejuvenated by heating at a rate sufficient to increase the catalytic activity of the molecular sieve. The molecular sieve is considered to be rejuvenated when the molecular sieve has a CMCPS that is increased by at least 5% relative to that at a heat rate basis of 40° C./min over a temperature range of from 25° C. to 475° C.