Additive for vanadium capture in catalytic cracking
AssigneeMobil Oil Corporation
InventorsArthur A. Chin, Ivy D. Johnson, Charles T. Kresge, Michael S. Sarli
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Abstract
A catalytic cracking process especially useful for the catalytic cracking of high metals content feeds including resids in which the feed is cracked in the presence of a catalyst additive comprising a dehydrated magnesium-aluminum hydrotalcite which acts as a trap for vanadium as well as an agent for reducing the content of sulfur oxides in the regenerator flue gas. The additive is used in the form of a separate additive from the cracking catalyst particles in order to keep the vanadium away from the cracking catalyst and so preserve the activity of the catalyst.
Claims20
A catalytic cracking process for the conversion of a high boiling hydrcarbon feedstock containing a vanadium contaminant by circulating a cracking catalyst in a cracking zone, a disengaging zone and a regeneration zone, contacting the feedstock in the cracking zone under catalytic cracking conditions with a solid, particulate cracking catalyst to produce cracking products of lower molecular weight while depositing carbonaceous material on the particles of cracking catalyst, separating the particles of cracking catalyst from the cracking products in the disengaging zone and oxidatively regenerating the cracking catalyst by burning off the deposited carbonaceous material in a regeneration zone, in which the cracking is carried out in the presence of solid particles of an additive composition comprising at least one magnesium-aluminum hydrotalcite which is present in an amount sufficient to passivate the vanadium from the feed.
In a fluid catalytic cracking process in which a hydrocarbon feedstock containing a vanadium contaminant in an amount of at least 5 ppmw is cracked under fluid catalytic cracking conditions with a solid, particulate cracking catalyst to produce cracking products of lower molecular weight while depositing carbonaceous material on the particles of cracking catalyst, separating the particles of cracking catalyst from the cracking products in the disengaging zone and oxidatively regenerating the cracking catalyst by burning off the deposited carbonaceous material in a regeneration zone, the improvement comprising reducing the make-up rate of the cracking catalyst by carrying out the cracking in the presence of a particulate additive composition for passivating the vanadium content of the feed, comprising a dehydrated magnesium-aluminum hydrotalcite.
Dependencies are inferred from the claim text.