Patent ID: 6508930
Filing Date: 2003-01-21
Classification: C10G,Y02P,Y10S

Abstract:
A method for controlling operation of a multiple-catalyst-employing FCC unit, said method comprising:(1) selecting an operating characteristic of the multiple-catalyst-employing FCC unit that is affected by each of at least two different catalyst species: catalyst A and catalyst B; (2) injecting an operating characteristic-affecting amount of catalyst A and an operating characteristic-affecting amount of catalyst B into the multiple-catalyst-employing FCC unit in a first catalyst A:catalyst B test ratio; (3) determining the effect of the first catalyst A:catalyst B test ratio on the operating characteristic; (4) injecting an operating characteristic-affecting amount of catalyst A and an operating characteristic-affecting amount of catalyst B into the multiple-catalyst-employing FCC unit in a second catalyst A:catalyst B test ratio that is not the same as the first catalyst A:catalyst B test ratio; (5) determining the effect of the second catalyst A:catalyst B test ratio on the operating characteristic; (6) establishing a unit response curve for the operating characteristic based, at least in part, upon the effect of the first catalyst A:catalyst B test ratio and the second catalyst A:catalyst B test ratio on said operating characteristic; (7) selecting a desired level of the operating characteristic that can be attained by the multiple-catalyst-employing FCC unit by some catalyst A:catalyst B ratio; (8) programming a unit response curve in a central processing unit that controls a catalyst addition system associated with the FCC unit; and (9) injecting at least one of the two catalysts (catalyst A or catalyst B) into the multiple-catalyst-employing FCC unit during subsequent normal operation of said unit in an amount that brings the catalyst A:catalyst B ratio in the unit to a value that correlates with a point on the unit response curve.