Abstract: A process and an apparatus for the fluidized catalytic cracking of hydrocarbons are disclosed. A small vent conduit extends upward out of the flow diversion device mounted on the top of the riser reactor. This vent conduit preferably carries between about 2 and 10 percent of the vapor and catalyst leaving the top of the riser upward into the upper portion of the receiving vessel. This reduces coke deposits in the upper portion of the vessel. The remainder of the vapors and catalyst are preferably directed downward upon leaving the top of the riser.

Abstract: A fluid catalytic cracking process for simultaneously cracking a gas oil feed and upgrading a gasoline-range feed to produce high quality motor fuel. The gasoline-range feed is contacted with freshly regenerated catalyst in a relatively upstream portion of a short-time dilute-phase riser reaction zone maintained at first catalytic cracking conditions and the gas oil feed is contacted with used catalyst in a relatively downstream portion of the riser reaction zone which is maintained at second catalytic cracking conditions.Particularly suited to efficiently cracking a gas oil feed and upgrading a wide variety of gasoline-range feed, including the more refractory of such feeds, is a fluid catalytic cracking process comprising a short-time dilute-phase riser reaction zone and a regeneration zone in which CO, produced by the oxidation of coke, is essentially completely oxidized to CO.sub.2 and in which at least part of the heat of combustion is transferred to regenerated catalyst.

Abstract: A fluid catalytic cracking process for simultaneously cracking a gas oil feed and upgrading a gasoline-range feed to produce high quality motor fuel. The gasoline-range feed is contacted with freshly regenerated catalyst in a relatively upstream portion of a short-time dilute-phase riser reaction zone maintained at first catalytic cracking conditions and the gas oil feed is contacted with used catalyst in a relatively downstream portion of the riser reaction zone which is maintained at second catalytic cracking conditions.Particularly suited to efficiently cracking a gas oil feed and upgrading a wide variety of gasoline range-feed, including the more refractory of such feeds, is a fluid catalytic cracking process comprising a short-time dilute-phase riser reaction zone and a regeneration zone in which CO, produced by the oxidation of coke, is essentially completely oxidized to CO.sub.2 and in which at least part of the heat of combustion is transferred to regenerated catalyst.