Patent ID: 7084319

Claim:
A process for producing light olefins, the process comprising the steps of: (a) contacting an oxygenate with a molecular sieve catalyst composition in a fluidized reactor under first conditions effective to convert the oxygenate to the light olefins; (b) directing the molecular sieve catalyst composition and the light olefins to a disengaging zone; (c) yielding the light olefins from the disengaging zone; (d) directing the molecular sieve catalyst composition from the disengaging zone to a standpipe; (e) fluidizing the molecular sieve catalyst composition in the standpipe with a fluidizing medium, wherein the fluidizing medium is selected from one or more of methanol, dimethyl ether, C4+ olefins, C4+ hydrocarbons, acetaldehyde, acetone, butanone, acetic acid, one or more byproducts formed in step (a), or a mixture thereof; and (f) transporting the molecular sieve catalyst composition in a fluidized manner from the standpipe back to the fluidized reactor.