Abstract: Low sulfur gasoline is produced from a catalytically cracked, sulfur-containing naphtha by fractionating the naphtha feed into a low boiling fraction in which the majority of the sulfur is present in the form of mercaptans and a high-boiling fraction in which the sulfur is predominantly in non-mercaptan form such as thiophenes. The low boiling fraction is desulfurized by a non-hydrogenatile mercaptan extraction process which retains the olefins present in this fraction. The second fraction is desulfurized by hydrodesulfurization, which results in some saturation of olefins and loss of octane. The octane loss is restored by treatment over an acidic catalyst, preferably an intermediate pore size zeolite such as ZSM-5, to form a low sulfur gasoline product with an octane number comparable to that of the feed naphtha but which contains some recombined sulfur in the form or mercaptans which are removed in a final hydrotreatment.

Abstract: Catalytic cracking of hydrocarbon feedstocks is improved by hydrotreating the cracking feed under conditions of relatively low temperature, typically below 390.degree. C. for start-of-cycle, and high pressure, typically above 10,000 kPa, preferably above 12,000 kPa. The use of these conditions favors aromatics saturation to produce a cracking feed of improved crackability so that higher conversion is achieved in the cracking step at constant cracking conditions with production of naphtha of good octane quality. At the same time, desulfurization is achieved to maintain cracker SO.sub.x emissions at required levels; the advantages of high pressure operation are more notable at high denitrogenation severities while still achieving a low catalyst aging rate.

Abstract: An apparatus for atomizing a liquid hydrocarbon feed and injecting it into a reaction zone, such as a riser conversion zone or a dense fluid bed reactor of a fluid catalytic cracking unit, is disclosed. The hydrocarbon feed passes through a central passage with steam flowing concurrently in a concentrically aligned passage. By providing a flow restriction means in each hydrocarbon passage and each steam passage, substantially equal quantities of hydrocarbon and steam can be supplied to each of a plurality of hydrocarbon-steam nozzles so as to provide a uniform dispersion of small droplets of hydrocarbons.

Abstract: A process and an apparatus for atomizing a liquid hydrocarbon feed and injecting it into a reaction zone, such as a riser conversion zone or a dense fluid bed reactor of a fluid catalytic cracking unit, is disclosed. The hydrocarbon feed passes through a central passage with steam flowing concurrently in a concentrically aligned passage. By providing a flow restriction means in each hydrocarbon passage and each steam passage, substantially equal quantities of hydrocarbon and steam can be supplied to each of a plurality of hydrocarbon-steam nozzles so as to provide a uniform dispersion of small droplets of hydrocarbons.

Abstract: The concentration of sulfur trioxides in an FCC unit regenerator is maintained within environmentally accepted limits, while maintaining an adequate amount of gas for fluidizing conditions in the regenerator, by admixing the regenerator oxygen-containing gas with an inert gas. The quantity of the inert gas is controlled by a control loop measuring the pressure drop in the regenerator, and adjusting the amount of the inert gas to maintain the pressure drop within the predetermined limits.

Abstract: Sulfur trioxide concentration in the flue gas of catalytic cracking regenerators is maintained at a predetermined level by controlling the flow rate of oxygen-containing regeneration gas into the regenerator, and, optionally, the amount of carbon monoxide combustion promoter in the regenerator.

Abstract: In a fluid catalytic cracking process, the regeneration temperature can be eliminated as an operating constraint, catalyst losses can be held constant or reduced, carbon on regenerated catalyst can be reduced and the coke burning capacity of the regenerator can be increased by the combination of cooling the hot regenerated catalyst and increasing the oxygen content of the inlet regeneration air.

Abstract: A stripper arrangement is provided in a regenerated catalyst standpipe for removing or displacing combustion flue gas products with fuel gas products of hydrocarbon conversion freed of hydrogen sulfide.

Abstract: A CHD reactor is modified to include a feed nozzle arrangement which hydrogen-saturates the charged liquid before distribution across the fixed catalyst bed by a pair of gas/liquid distributor trays. Product is recovered from the catalyst bed through an apparatus arrangement comprising Glitsch grid to maintain low pressure drop in the system.

Abstract: Upgrading of 350.degree. F plus product of Fischer-Tropsch Synthesis is accomplished by hydrotreating the Fischer-Tropsch Synthesis product and selective cracking the hydrotreated material boiling above about 600.degree. F. A product slate is recovered comprising LPG, gasoline, jet fuel, light and heavy oil fractions.

Abstract: Upgrading a product of Fischer-Tropsch Synthesis boiling above 300.degree. F is accomplished in a combination operation comprising hydrotreating of the 300.degree. F plus product and selective cracking portions of the hydrotreated product to provide a product slate comprising gas, gasoline, jet fuel, light and heavy oil fractions.