Patent ID: 6905591

Claim:
A process for the fluid catalytic cracking of hydrocarbonaceous feedstocks comprising: (a) cracking said hydrocarbonaceous feedstock in the presence of a cracking catalyst in a first catalytic cracking zone at a temperature ranging form about 925° F. to about 1350° F. and a weight hourly space velocity greater than about 50 hr −1 to produce an intermediate cracked product rich in gasoline; (b) cracking and intermediate cracked product rich in gasoline in the presence of said catalyst in a second catalytic cracking zone at a temperature ranging from about 900° F. to about 1250° F. and a weight hourly space velocity of less than about 30 hr −1 to produce a cracked product rich in propene and butenes and spent catalyst; and (c) separating said spent catalyst from said cracked product rich in propene and butenes.