Mobil Oil Corporation

Catherine L Markham

Joseph A Herbst

Gregory P Muldowney

Ajit V Sapre

Gerald J Teitman

Lloyd L Breckenridge

Joseph R Misiewicz

John P Schields

Michael S Edwards

David A Land

A process and apparatus for fluidized bed regeneration of FCC catalyst are disclosed. Oxides of nitrogen (NO.sub.x) emissions from an FCC regenerator operating in complete CO combustion mode, and hydrothermal catalyst deactivation, are reduced by reducing the average bed temperature. Dilute phase afterburning superheats catalyst entrained in the dilute phase region above the fluidized bed. Cyclone separators recover superheated, entrained catalyst and preferentially recycle this catalyst to the FCC reactor, permitting cooler operation of the dense phase fluidized bed.

Low NO.sub.x FCC regeneration process and apparatus

A process and apparatus for dense phase, at least partially co-current, fluidized bed regeneration of FCC catalyst are disclosed. Catalyst regeneration occurs in a dense phase fluidized bed, with catalyst flowing laterally from a spent catalyst inlet to a regenerated catalyst outlet. Regeneration air flows up through the dense bed into a dilute phase region defined at the base by the dense phase bed and at the top by a horizontal baffle. The plate has openings or baffles forcing the dilute phase, consisting of entrained catalyst and flue gas, to flow horizontally in the same direction as the lateral flow of catalyst in the dense bed. Concurrent flow of at least the dilute phase material and the dense bed material improves regeneration and can reduce NOx emissions.

Baffled FCC regeneration process and apparatus

A fluidized catalytic cracking process using a high efficiency regenerator comprising a coke combustor, a dilute phase transport riser, and a second fluidized bed with catalyst recirculation to the coke combustor, is operated to reduce NO.sub.x emissions in the regenerator flue gas. The amount of catalyst recirculation from the second fluidized bed to the coke combustor or combustion air addition or preferably both are adjusted based on continuous or periodic measurement of a process parameter of the FCC regenerator which directly or indirectly measures the NO.sub.x content of regenerator flue gas. Operation with restricted air or catalyst recirculation degrades coke combustor operation, shifts some regeneration to downstream portions of the regenerator, and reduces NO.sub.x emissions.

Process and apparatus for reducing NO.sub.x emissions from

A catalytic cracking process operates with enhanced stripper efficiency by subjecting spent catalyst to microwave radiation before catalyst regeneration. Preferably the microwave frequency is one which ignores the catalytic cracking catalyst and preferentially excites the hydrocarbon or coke on the spent catalyst, the stripping steam conventionally used, or both the stripping steam and the hydrocarbonaceous coke. In preferred embodiments, microwave frequencies are used which are selective for various impurities in the coke, such as sulfur and/or nitrogen impurities. Additives, such as ferrous materials, may be added to augment the efficiency of desulfurization during stripping. The process is applicable to fluidized catalytic cracking and moving bed catalytic cracking units.

High efficiency catalytic cracking stripping apparatus

High efficiency catalytic cracking stripping process

A dual-mode hydrocarbon conversion process is provided which comprises reforming a sulfur-, nitrogen- and/or olefin-containing hydrocarbon feedstock, e.g. an FCC gasoline, in a conversion unit operated under reforming conditions employing as catalyst a noble metal-containing crystalline silicate having a Constraint Index of not greater than about 2 and a framework SiO.sub.2 /Al.sub.2 O.sub.3 ratio of at least about 50 to provide a relatively high yield of high octane reformate and a relatively low yield of C.sub.3-4 hydrocarbons prior to or following hydrocracking the feedstock in the unit operated under hydrocracking conditions in the presence of the aforesaid catalyst to provide a relatively low yield of high octane hydrocrackate and a relatively high yield of C.sub.3-4 hydrocarbons. The latter can be separated from the liquid product and processed in a gas plant to provide LPG products. The dual-mode process of this invention offers the refiner increased flexibility in meeting rapidly fluctuating changes in demand for high octaine gasoline and LPG products.

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Thornton, PA, United States of America

Catherine L Markham