Engelhard Corporation

Engelhard Minerals & Chemicals Corporation

Atlantic Richfield Company

John W Byrne

Barry Keven Speronello

David B Bartholic

James M Chen

William J Reagan

Francis L Himpsl

Stanley M Brown

Harry E Jacobs

A zeolite catalyst composition is provided in which a first or upstream zone of the catalyst has a lower metal (e.g., iron or copper) promoter loading than the metal promoter moter loading of the second or downstream zone of the catalyst. The first zone may contain from none up to about 1 percent by weight of the promoter and the second zone may contain from about 1 to 30 percent by weight promoter. The zeolite may be any suitable zeolite, especially one having a silica-to-alumina ratio of about 10 or more, and a kinetic pore size of about 7 to about 8 Angstroms with such pores being interconnected in all three crystallographic dimensions. The method of the invention provides for passing a gaseous stream containing oxygen, nitrogen oxides and ammonia sequentially through first and second catalysts as described above, the first catalyst favoring reduction of nitrogen oxides and the second catalyst favoring the oxidation or other decomposition of excess ammonia.

Staged metal-promoted zeolite catalysts and method for catalytic

A zeolite catalyst composition is provided in which a first or upstream zone of the catalyst has a lower metal (e.g., iron or copper) promoter loading than the metal promoter loading of the second or downstream zone of the catalyst. The first zone may contain from none up to about 1 percent by weight of the promoter and the second zone may contain from about 1 to 30 percent by weight promoter. The zeolite may be any suitable zeolite, especially one having a silica-to-alumina ratio of about 10 or more, and a kinetic pore size of about 7 to about 8 Angstroms with such pores being interconnected in all three crystallographic dimensions. The method of the invention provides for passing a gaseous stream containing oxygen, nitrogen oxides and ammonia sequentially through first and second catalysts as described above, the first catalyst favoring reduction of nitrogen oxides and the second catalyst favoring the oxidation or other decomposition of excess ammonia.

A method in accordance with the invention comprises passing through a zeolite catalyst as described below, a gaseous stream containing nitrogen oxides, ammonia and oxygen to selectively catalyze the reduction of nitrogen oxides and, if excess or unreacted ammonia is present, to oxidize the excess of unreacted ammonia with oxygen to hydrogen and water. The method includes the use of a zeolite catalyst composition which comprises a metal (e.g., iron or copper) promoted zeolite, the zeolite being characterized by having a silica to alumina ratio of at least about 10 and a pore structure which is interconnected in all three crystallographic dimensions by pores having an average kinetic pore diameter of at least about 7 Angstroms. Promoted zeolites of the above type have demonstrated high tolerance for sulfur poisoning, good activity for the selective catalytic reduction of nitrogen oxides with ammonia, good activity for the oxidation of ammonia with oxygen, and the retention of such good activities even under high temperature operations, e.g., 400.degree. C. or higher, and hydrothermal conditions.

Method for reduction of nitrogen oxides with ammonia using promoted

Sulfur oxides are removed at least partially from the gaseous regenerator effluent of a fluid catalytic cracking unit operated with feedstock containing sulfur compounds and converted to hydrogen sulfide in the cracking zone by associating sulfur oxides in the gas with at least one rare earth compound, preferably cerium or a rare earth mixture rich in cerium, supported on discrete particles of alumina. The alumina particles may be a component of particles of a composite fluid cracking catalyst or separate fluidizable entities other than cracking catalyst and physically admixed with the catalyst particles.

Catalytic cracking with reduced emissions of sulfur oxides

The present invention is directed to a fluid catalytic cracking catalyst comprising a blend of a catalytically active first component and a second component for reducing the emissions of oxides of sulfur from the regenerator of a catalytic cracking unit and the use of that catalyst to crack sulfur containing petroleum feedstocks. The catalytically active first component contains Y-faujasite zeolite and comprises about 10-70% by weight, preferably about 25-50% by weight, of the catalyst. The second component of the catalyst comprises about 30-90% by weight, preferably about 50-75% by weight, of the catalyst. The second component comprises fluidizable particles containing at least about 70% by weight, preferably at least about 90% by weight, alumina and having an equilibrium surface area in the range of about 40-100 m.sup.2 /g., preferably in the range of about 50-90 m.sup.2 /g.

Fluid catalytic cracking catalyst for cracking sulfur containing

Whole crude and residual fractions from distillation of petroleum and like feed stocks are subjected to selective vaporization to prepare heavy fractions of reduced Conradson Carbon and/or metals content by short-term, high temperature riser contact with a substantially inert solid contact material of low surface area in a selective vaporization zone. High boiling point components of the charge which are of high Conradson Carbon number and/or high metal content remain on the contact material as a combustible deposit which is then burned off in a combustion zone whereby the contact material is heated to a high temperature for return to the selective vaporization zone to supply the heat required therein. Equilibrium FCC catalyst, previously treated to reduce catalytic cracking activity and surface area, is used as the substantially inert solid.

Pretreating hydrocarbon feed stocks using deactivated FCC catalyst

A system is described for control of sulfur oxide in emissions to the atmosphere from the combined flue gases of selective vaporization and FCC cracking of the improved charge stock resulting from selective vaporization. The invention provides for reduction in sulfur oxide content of the waste gases from the FCC regenerator and the selective vaporization burner and adds a new controllable variable for a heat balanced FCC Unit. The cracking catalyst used has the capability of reversibly reacting with sulfur oxides in the combined flue gases 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, the blend of 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.

Control of emissions in 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.

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Saddle Brook, NJ, United States of America

John W Byrne