Fluid catalytic cracking process for upgrading a gasoline-range feed

Claim 1

A fluid catalytic cracking process for simultaneously cracking a gas oil feed and upgrading gasoline-range hydrocarbon feed which process comprises the steps of; a. contacting the gasoline-range feed with freshly regenerated catalyst in a relatively upstream portion of a short-time dilute-phase riser reaction zone maintained at first catalytic cracking conditions including a gasoline-range feed residence time of less than about 0.5 seconds in the presence of said catalyst, a temperature within the range of about 1250° F. to about 1500° F. and a catalyst to gasoline-range feed ratio of at least about 75 to 1; b. contacting the gas oil feed with used catalyst in a relatively downstream position of the short-time dilute phase riser reaction zone maintained at second catalytic cracking conditions including a gas oil residence time of less than about 10 seconds in the presence of used catalyst, a temperature in the range of from about 900° to about 1100° F. and a catalyst to gas oil feed ratio of from about 4 to about 25 to 1; c. passing catalyst and feed streams in admixture through the riser reaction zone to produce spent catalyst, containing coke, and product components including gasoline; d. discharging the mixture from said reaction zone into cyclone separators to effect the separation of spent catalyst from product components and any unreacted feed; e. recovering product components and any unreacted feed; f. passing spent catalyst to a first dense bed of fluidized particulate material maintained in a regeneration zone at oxidizing conditions and therein oxidizing coke to produce partially spent regeneration gas, containing CO, and freshly regenerated catalyst; g. passing said regenerated catalyst and partially spent regeneration gas to a dilute phase transport riser maintained in said regeneration zone at conversion conditions and therein essentially completely converting CO to CO 2 to produce spent regeneration gas; h. transferring within said transport riser at least a portion of the heat of combustion of CO to regenerated catalyst passing through the riser thereby heating said catalyst to a temperature of from about 1250° F. to about 1500° F.; and, i. separating regenerated catalyst from spent regeneration gas and passing regenerated catalyst into a second dense bed or particulate material from which freshly regenerated catalyst is returned to the reaction zone of (a) above.