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Submitted Chris Haslego, Nov 21 2011 11:21 AM | Last updated Nov 21 2011 01:29 PM

Category:	Refining
Question:	What is the role of catalyst coolers in the production of gasoline?
Keywords:	catalyst,cooler,fcc,fluidized,catalytic,crackers
Answer:	Catalyst coolers can be used whenever the delta coke on the catalyst (the coke yield divided by the cat/oil ratio), becomes too high. The symptoms of high delta coke are high regenerator bed temperatures and low cat/oil ratios. The consequences are reduced conversion, high dry gas yields, and more rapid catalyst deactivation. With modern reactor and catalyst technology, high delta coke problems generally occur on units processing at least some resid. But, they can and do occur at times on units processing poor quality gas oils. Catalyst coolers reduce the regenerator bed temperature and thus, allow higher catalyst circulation rates. This is their primary function. Since catalyst deactivation is a function of regenerator bed temperature (among other factors) catalyst coolers do reduce deactivation as well. Modern catalysts, however, are fairly stable up to at least 730 ⁰C and probably up to 760 ⁰C. Thus, the effect of catalyst coolers on deactivation is generally limited to units with high delta coke operations.