Abstract: An apparatus for the fluidized catalytic cracking of hydrocarbons comprising two independent transfer line reactors, each of which is associated with an independent cyclone separation system and wherein the cyclone separation systems are located within a common reactor vessel. The apparatus is suitable for use in the simultaneous fluidized catalytic cracking of dissimilar hydrocarbon feedstocks without commingling either the feedstocks or the products therefrom.

Abstract: A process and system for sequentially cracking hydrocarbon. A first hydrocarbon feed is cracked at high severity low residence times and the cracked effluent is quenched by a second hydrocarbon feed which is coincidentally cracked at low severity.

Abstract: A process is disclosed for the conversion of asphaltines-containing mineral hydrocarbon oil to distillate gas oil by a processing sequence comprising thermal cracking, flashing, atmospheric fractionation, vacuum fractionation, thermal cracking, catalytic cracking or hydrocracking, and atmospheric fractionation with certain recycle of intermediate streams to achieve efficient, economic operations.

Abstract: A process for the preparation of gas oil from residual oils by combination of two stages of thermal cracking, cyclone separation, vacuum distillation, deasphalting, atmospheric distillation, and recycling of certain streams.

Abstract: A mild thermal cracking of gas oil in the presence of added olefinic naphtha increases the yield of middle distillate.

Abstract: A catalytic cracking of hydrocarbons in the presence of an added olefin-containing naphtha increases the selectivity and yield of middle distillate.

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.