Control of emissions in FCC regenerator flue gas
 A system is described for control of sulfur oxide in emissions to the atmosphere from regenerators of Fluid Catalytic Cracking Units (FCC) in a manner which provides an added controllable variable in heat balanced units. The cracking catalyst used has the capability of reversibly reacting with sulfur oxides in the regenerator flue gas to carry the sulfur back into the reactor where it is converted, at least in part, to hydrogen sulfide which is removed from reaction products in the normal course of treating the cracked products from the reactor. By the disclosed system, regenerator flue gas is cooled and then contacted with hot regenerated catalyst from the regenerator for sorption of sulfur oxides by the catalyst and to cool the catalyst for control of reaction parameters in the FCC reactor. 
Engelhard Minerals & Chemicals Corporation
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Y10S Y02A B01D C10G B01J C10G
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David B. John W.
Bartholic Byrne