Abstract: A catalytic process for hydrocracking C.sub.5.sup.+ hydrocarbons or mixtures thereof into a C.sub.2 -C.sub.5 mixture paraffin stream in the presence of a palladium/Group IIA, e.g. Be Mg, or IIIB, e.g. Sc, Y, ZSM-20 hydrocracking catalyst, and thermally cracking this mixture to recover ethylene and propylene.

Abstract: By manipulating the degree of stripping of the used or spent catalyst leaving the cracker, the afterburning in a regenerator is controlled both efficiently and rapidly.

Abstract: A process for the separation of specific C.sub.2 to C.sub.6 hydrocarbons from a gaseous feed stream containing C.sub.1 to C.sub.6 -plus hydrocarbons. The feed stream enters an absorber and is first contacted by a primary lean liquid which is a portion of the bottoms product of the stripping column to which the rich absorber liquid is charged. The primary lean liquid contains the specific hydrocarbons which it is desired to separate from the feed stream. The feed stream is then contacted by a secondary lean liquid which does not contain these hydrocarbons and which is produced by fractionating a second portion of the stripper bottoms.

Abstract: Maximum removal of asphaltic material, including high molecular weight metallic contaminants, from a hydrocarbonaceous charge stock is achieved through the utilization of a solvent extraction zone provided with direct heating facilities in an upper portion thereof.