Abstract: An FCC apparatus uses a highly efficient separation device to remove product from the catalyst so that the reactor vessel receives a low volume of feed hydrocarbons and riser by-products. The separation device encloses an upwardly directed outlet end of a ballistic separation device in low volume disengaging vessel that collects disengaged catalyst from the riser in a dense bed. Immediate contact of the dense bed with a stripping fluid minimizes the amount of hydrocarbons that are carried out of the disengaging vessel into the open volume of the reactor vessel.

Abstract: A method of regenerating a sulfur-sensitive hydrocarbon conversion catalyst by employing sulfur-contaminated heat-transfer equipment of a hydrocarbon conversion process is disclosed. This method is useful for the regeneration of reforming catalysts comprising L-zeolite.

Abstract: An FCC process uses a highly efficient separation device to remove product from the catalyst so that the reactor vessel receives a low volume of feed hydrocarbons and riser by-products. The separation device encloses an upwardly directed outlet end of a ballistic separation device in low volume disengaging vessel that collects disengaged catalyst from the riser in a dense bed. Immediate contact of the dense bed with a stripping fluid minimizes the amount of hydrocarbons that are carried out of the disengaging vessel into the open volume of the reactor vessel.

Abstract: A diesel or jet fuel distillate product is recovered from a hydrocracking process in an integrated flowscheme wherein the distillate is removed from the hydrocracking zone product column and then passed into a catalytic dewaxing zone. The once-through hydrogen provided in the catalytic dewaxing zone is the makeup hydrogen for the hydrocracking zone. Large economies are realized in terms or reduced capital costs compared to the conventional flowscheme. In addition the severity of the hydrocracking operation is reduced thus extending the life of the hydrocracking catalyst.

Abstract: An FCC process and apparatus is arranged to provide a low volume dilute disengagement zone in a reactor vessel. A vented riser that provides an open discharge of catalyst and gaseous products is directly discharged into a reactor vessel. The interior of the reactor vessel is arranged such that the outlet of the reactor riser is located close to and directed at the top of the reactor vessel. The reactor vessel operates with a dense bed of catalyst having an upper bed level that is only a short distance below the outlet of the reactor riser. The cyclone separators are located to the outside of the reactor riser and circulate catalyst directly back to the reactor riser or directly to an independent stripping vessel that returns the catalyst to the regenerator.

Abstract: A FCC product recovery section operates at greater efficiency by recovering separate riser product streams and reactor product streams and quenching and absorbing lighter, more valuable hydrocarbon products from the reactor product stream in separate quench and absorption vessels. The quench and absorbtion vessels are intergrated with a main fractionator and gas concentration section of a typical FCC product recovery section. Heavy hydrocarbons, clarified oil and/or cycle oil absorb hydrocarbons from the reactor product stream in the quench and absorption vessels and return the absorbed products to the main fractionator while net gasoline product from the reactor product stream enter the primary absorber of the gas concentration section. This arrangement is particularly useful in increasing the product recovery capacity of an existing FCC product separation section.

Abstract: An FCC process and apparatus is arranged to provide a low volume dilute disengagement zone in a reactor vessel and a quench zone immediately downstream of the reactor vessel. A vented riser that provides an open discharge of catalyst and gaseous products is directly discharged into a reactor vessel. The interior of the reactor vessel is arranged such that the outlet of the reactor riser is located close to and directed at the top of the reactor vessel. The reactor vessel operates with a dense bed of catalyst having an upper bed level that is only a short distance below the outlet of the reactor riser. The cyclone separators are located to the outside of the reactor riser and circulate catalyst back to the dense bed of the reactor section. The quenching takes place downstream of the cyclone separators.

Abstract: An FCC process and apparatus is arranged to provide a low volume dilute disengagement zone in a reactor vessel. A vented riser that provides an open discharge of catalyst and gaseous products is directly discharged into a reactor vessel. The interior of the reactor vessel is arranged such that the outlet of the reactor riser is located close to and directed at the top of the reactor vessel. The reactor vessel operates with a dense bed of catalyst having an upper bed level that is only a short distance below the outlet of the reactor riser. The cyclone separators are located to the outside of the reactor riser and circulate catalyst back to the dense bed of the reactor section.

Abstract: An FCC process and apparatus is arranged to provide a low volume dilute disengagement zone in a reactor vessel. A vented riser that provides an open discharge of catalyst and gaseous products is directly discharged into a reactor vessel. The interior of the reactor vessel is arranged such that the outlet of the reactor riser is located close to and directed at the top of the reactor vessel. The reactor vessel operates with a dense bed of catalyst having an upper bed level that is only a short distance below the outlet of the reactor riser. The cyclone separators are located to the outside of the reactor riser and circulate catalyst back to the dense bed of the reactor section.

Abstract: Hydrocarbon feedstock is dispersed in an FCC riser by directing jets of atomized feed droplets into a flowing stream of catalyst particles in a direction substantially perpendicular to the axis of the riser. By directing the feed into the riser in a substantially perpendicular direction feed is more quickly dispersed across the entire cross section of the riser. By quickly dispersing feed the mixture of hydrocarbons and catalyst particles is completely mixed after traveling only a short distance along the riser from the point of feed introduction. Reducing this contact zone length improves the quality of riser products by eliminating variations in the contact time between the feed and catalyst. In addition to the short contact zone length this invention also combines the desirable features of catalyst pre-acceleration and feed atomization.

Abstract: Middle distillate petroleum streams are hydrotreated to produce a low sulfur and low aromatic product in a process employing two reaction zones in series. The effluent of the first reaction zone is purged of hydrogen sulfide by hydrogen stripping and then reheated by indirect heat exchange. The second reaction zone employs a sulfur-sensitive noble metal hydrogenation catalyst. Operating pressure and space velocity increase and temperature decreases from the first to second reaction zones.

Abstract: Middle distillate petroleum streams are hydrotreated to produce a low sulfur and low aromatic product in a process employing three reaction zones in series. Hydrogen flows between the reaction zones countercurrent to the hydrocarbons. Hydrogen sulfide is removed from effluent of the first two reaction zones by hydrogen stripping. The second and third reaction zones employ a sulfur-sensitive noble metal hydrogenation catalyst. Operating pressure increases and temperature decreases from the first to third reaction zones.

Abstract: An FCC process and apparatus is arranged to provide a low volume dilute disengagement zone in a reactor vessel. A vented riser that provides an open discharge of catalyst and gaseous products is directly discharged into a reactor vessel. The interior of the reactor vessel is arranged such that the outlet of the reactor riser is located close to and directed at the top of the reactor vessel. The reactor vessel operates with a dense bed of catalyst having an upper bed level that is only a short distance below the outlet of the reactor riser. The cyclone separators are located to the outside of the reactor riser and circulate catalyst back to the dense bed of the reactor section.

Abstract: A process for the production of alkylaromatic hydrocarbons uses a working fluid to reduce the costs of separating an unreacted aromatic feed substrate from aromatic hydrocarbon products. Unreacted aromatic substrate is combined with a light hydrocarbon, such as propane, to form a combined effluent stream. The combined effluent stream enters a flash separator where unreacted aromatic substrate is lifted overhead with the light hydrocarbon while heavier aromatic products are recovered below. The aromatic substrate and light hydrocarbon are easily separated in a simple separation zone. Lifting the aromatic substrate with the working fluid reduces the volume of aromatic substrate that remains with the aromatic product so that the more energy intensive separation of the aromatic substrate and aromatic product is performed on a reduced volume of material.

Abstract: A process for the fluidized catalytic cracking of an FCC feedstock uses a backmix catalyst cooler to heat FCC feed and control tube wall temperatures to avoid coking and thermal cracking. Heated FCC feed contacts the catalyst in a reactor riser to convert the feedstock. Prior heating of the feed raises its temperature so that it is more easily vaporized and better distributed throughout the riser. Using FCC catalyst to heat the feed maintains the heat balance between the reactor and the regenerator so that the catalyst circulation to the riser can remain unchanged. The backmix type cooler has heat exchange tubes located in a separate vessel. Catalyst from the dense bed of a regeneration zone is circulated to a section of the cooler located above the heat exchange tubes. One form of the invention uses two conduits to transfer catalyst to the section of the cooler above the exchange tubes and thereby control the temperature of the catalyst above the heat exchange tubes.

Abstract: A process for the production of alkylaromatic hydrocarbons uses a light hydrocarbon recycle to reduce the costs of separating an unreacted aromatic feed substrate from aromatic hydrocarbon products. Unreacted aromatic substrate is combined with a light hydrocarbon, such as propane, to form a combined effluent stream. The combined effluent stream enters a flash separator where unreacted aromatic substrate is lifted overhead with the light hydrocarbon while heavier aromatic products are recovered below. The aromatic substrate and light hydrocarbon are easily separated in a simple separation zone. Lifting the aromatic substrate with the light hydrocarbon reduces the volume of aromatic substrate that remains with the aromatic product so that the more energy intensive separation of the aromatic substrate and aromatic product is performed on a reduced volume of material.

Abstract: A process flow for hydrogen-producing processes such as reforming or dehydrocyclodimerization is disclosed. A portion of a C.sub.3 or C.sub.4 feed stream is flashed to provide reflux cooling for a product recovery fractionation column. The cool overhead of this column and a second portion of the feed stream are used to cool the still uncondensed portion of the partially condensed reaction zone effluent stream prior to passage of this uncondensed material into a final low temperature separation stage. A second feature is the reboiling of a fractionation column with hot compressed gas to perform interstage cooling in the product recovery compression section.