Patent ID: 7943038

Claim:
A process for producing one or more olefins, comprising: doping a hydrocarbon cracking catalyst, comprising: fluidizing one or more coked-catalyst particles in the presence of one or more oxidants to provide a fluidized mixture; removing at least a portion of the coke from the one or more coked-catalyst particles to provide regenerated catalyst particles within the fluidized mixture; distributing one or more doping agents to the fluidized mixture; depositing the one or more doping agents onto a surface of the regenerated catalyst particles to provide doped catalyst particles; forming a reaction mixture comprising one or more hydrocarbon feeds and the doped catalyst particles; cracking at least a portion of the reaction mixture to provide a first product comprising propylene, ethylene, and butane; selectively separating at least a portion of the first product to provide a second product comprising propylene and a first recycle comprising butane; and recycling at least a portion of the first recycle to the one or more hydrocarbon feeds.