GB1575019A - Catalyst compositions - Google Patents

Description

PATENT SPECIFICATION ( 11) 1 575 019

Ch ( 21) Application No 25455/79 ( 22) Filed 17 Dec 1976 ( 19), c ( 62) Divided Out of No 1575018 ( 31) Convention Application No's 642541 ( 32) Filed 19 Dec 1975 in 4 ' 642545 Wf ( 33) United States of America (US) ( 44) Complete Specification Published 17 Sep 1980 ( 51) INT CL 3 BO 1 J 29/04 /I C 1 OG 11/04 11/18 ( 52) Index at Acceptance Bl E 1121 1180 1208 1212 1285 1298 1322 1476 1500 1617 1701 1705 1714 1722 1738 AA ( 54) CATALYST COMPOSITIONS ( 71) We, STANDARD OIL COMPANY, a corporation organised and existing under the laws of the State of Indiana, United States of America of 200 East Randolph Drive, Chicago, Illinois 60601, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: 5

The present invention relates to a catalyst composition and more particularly relates to a catalyst composition comprising a particulate physical mixture of a solid hydrocarbon cracking catalyst comprising a crystalline aluminosilicate in association with a matrix, and solid particles comprising at least two different metals in free or combined form and silica and/or alumina 10 Cracking catalyst which has become relatively inactive due to deposition of carbonaceous deposits, commonly called "coke", during the cracking of hydrocarbons in the reaction zone is continuously withdrawn from the reaction zone Such spent catalyst from the reaction zone is passed to a stripping zone where strippable carbonaceous deposits, namely hydrocarbons, are stripped from the catalyst which in turn is passed to a regeneration zone where the activity 15 of the catalyst is restored by removing the non-strippable carbonaceous deposits by burning the coke in an oxygen-containing gas to form carbon monoxide and carbon dioxide Hot regenerated catalyst is then continuously returned to the reactor to repeat the cycle.

In catalytic cracking, a problem arises from the incomplete combustion of carbon monoxide to carbon dioxide in the regeneration zone, leaving a significant amount of carbon 20 monoxide in the regeneration zone flue gases Apart from the undesirability of discharge of carbon monoxide to the atmosphere, carbon monoxide and residual oxygen in the regeneration zone flue gases tend to react and thereby cause burning in ducts and flues in the plant and damage to such structures by excessive temperatures.

Further, when high-sulfur feedstocks, that is, petroleum hydrocarbon fractions containing 25 organic sulfur compounds, are charged to a fluid-type catalytic cracking unit, the coke deposited on the catalyst contains sulfur During regeneration of the coked, deactivated catalyst, the coke is burned from the catalyst surfaces; in this combustion process, the sulfur present is converted to sulfur dioxide, together with a minor proportion of sulfur trioxide, and thus is included in the regeneration zone flue gas effluent stream When cracking a high-sulfur 30 feedstock, emissions of sulfur oxides are often in the region of substantially 1200 parts per million.

Pollution control standards have been developed for the emission of carbon monoxide and for particulate matter and are expected to be considered soon for other emissions, such as the sulfur oxides, particularly sulfur dioxide Consequently, much attention is being devoted to 35 reducing the level of emissions of various combustion products and particulates from regeneration zone effluent streams associated with petroleum cracking units It is necessary that the method selected for reducing such emissions should be effective without lowering the activity and selectivity of the cracking catalyst It is likewise necessary that the method selected should not overcome undesirable emission by presenting other problems, for exam 40 1,575,019 ple, an increase in particulate emission or operating costs In view of these considerations, a highly desirable approach to a reduction in the emission of carbon monoxide and sulfur oxides from petroleum cracking units lies in the use of a cracking catalyst which is modified to minimize emissions of both carbon monoxide and sulfur oxides, while maintaining catalyst activity, stability, and resistance to attrition, under conventional cracking conditions in either 5 existing or new cracking units.

With regard to carbon monoxide emissions, although metals are generally avoided in cracking catalysts and it is considered problematical to crack metalcontaining stocks in the presence of a cracking catalyst, U S Patent No 3,909,392, discloses the use in conjunction with cracking catalysts of combustion catalysts or promoters within the regeneration zone, 10 which include a metallic bar, mesh network, or screen in the combustion zofie; and fluidizable metal compounds, particularly powdered oxides of transition group metals, for example, ferric oxide, manganese dioxide, and rare earth oxides, which are added to the catalyst charge or confined within the regenerator vessel Belgian Patent No 826,266 ( 1975) discloses a method very similar to that of U S Patent No 3,909,392 which involves a catalytic cracking 15 catalyst in physical association with carbon monoxide-oxidation promoting catalyst of a metal having an atomic number of at least 20 and mentions metals from Groups IB, JIB, and III to VIII of the Periodic Table of the elements in particular, platinum, palladium, rhodium, molybdenum, tungsten, copper, chromium, nickel, manganese, cobalt, vanadium, iron, cerium, ytterbium, and uranium, as useful oxidation promoters Further, U S Patent No 20 3,808,121 discloses the regeneration of a cracking catalyst in the presence of a carbon monoxide oxidation catalyst which is retained in the regeneration zone.

Netherlands Patent Application No 7,412,423 discloses that a cracking catalyst containing fewer than 100 parts per million, calculated as metal, based on total catalyst, of at least one metal component consisting of a metal from Periods 5 and 6 of Group VIII of the Periodic 25 Chart, rhenium and compounds thereof, showed particularly spectacular reductions in the carbon monoxide content in flue gases from catalytic cracking catalysts This latter Patent also discloses a molecular sieve-type cracking catalyst which is prepared in the sodium form, ion-exchanged with ammonium ions, and then impregnated with rare earth metals.

Further, with regard to sulfur oxide emissions, although various methods for processing 30 flue gas have been devised, for example, washing or scrubbing, chemical absorption, neutralization, and chemical reaction or conversion, all such methods for the removal of sulfur oxides require extensive and expensive auxiliary equipment, thus increasing both operating and capital costs An approach set forth in U S Patent No 3,699,037 contemplates the addition of at least a stoichiometric amount of a calcium or magnesium compound to the 35 cracking cycle in relation to the amount of sulfur deposition on the catalyst This added material is intended to react with the sulfur oxides and then, being in a finely subdivided conditioniexit from the cracking cycle as particulate matter in the regeneration zone flue gas stream Continued addition of such material obviously increases operating costs Similarly, U S Patents Nos 3,030,300 and 3,030,314 disclose a catalytic cracking process which 40 involves adding continuously to a moving bed cracking process cycle one or more compounds of boron, alkali metals and alkaline earth metals so as to provide catalyst particles which have increased resistance against impact breakage and surface abrasion, and which comprise a siliceous catalyst particle having a microporous, catalytically active core which is provided with an adherent protective coating of a glaze comprising silica and one or more compounds 45 of boron, alkali metals and alkaline earth metals.

U.S Patent No 3,833,031 discloses a cyclic, fluidized catalytic cracking process which provides reduced emissions of sulfur oxides in the regenerator stack gases The method is operated with a catalyst which comprises a molecular sieve in a silicaalumina matrix and which is impregnated with one or more Group HA metal oxides U S Patents Nos 50 3,388,077; 3,409,390 and 3,849,343 disclose a method for effecting the conversion of a noxious waste gas stream containing carbon monoxide and sulfur oxides, which comprises contacting the stream with a catalytic composite of a porous refractory carrier material, a catalytically active metallic component, for example, a platinum group metal, and an alkaline earth component consisting of calcium, barium or strontium 55 It has now been found that a certain catalyst composition comprising a particulate physical mixture of a solid hydrocarbon catalyst comprising a crystalline aluminosilicate in association with a matrix, at least two different metals in free or combined state and silica and/ or alumina may be employed with advantage to help reduce noxious gas emissions from cracking processes whilst still effectively catalysing the actual cracking reaction 60 Accordingly, the present invention provides a catalyst composition comprising a particulate physical mixture of:

(a) a particulate solid hydrocarbon cracking catalyst comprising a crystalline aluminosilicate in association with a matrix wherein the amount of said cracking catalyst is in excess of 30 weight percent with respect to the particulate physical mixture; and 65 3 1,575,019 3 (b) a particulate solid other than said particulate cracking catalyst comprising at least one free or combined first metal selected from sodium, magnesium, calcium, strontium, barium, scandium, titanium, chromium, molybdenum, manganese, cobalt, nickel, antimony, copper, zinc, cadmium, lead and the rare earth metals, at least one free or combined second metal selected from ruthenium, rhodium, palladium, osmium, iridium, platinum and rhenium, and 5 at least one inorganic oxide selected from silica and alumina, wherein the amount of said first metal, calculated as the metal, is from 50 parts per million to 10 weight percent with respect to said particulate physical mixture, and the amount of said second metal, calculated as the metal, is from 0 1 part per million to 10 parts per million with respect to the particulate physical mixture 10 In a preferred embodiment, component (b) comprises:

( 1) a first particulate solid other than the particulate cracking catalyst comprising at least one free or combined first metal selected from sodium, magnesium, calcium, strontium, barium, scandium, titanium, chromium, molybdenum, manganese, cobalt, nickel, antimony, copper, zinc, cadmium, lead and the rare earth metals in association with at least one 15 inorganic oxide selected from silica and alumina, wherein the amount of said first metal, calculated as the metal, is from 50 parts per million to 10 weight percent with respect to said particulate physical mixture; and (II) a second particulate solid other than the particulate cracking catalyst comprising at least one free or combined second metal selected from ruthenium, rhodium, palladium, 20 osmium, iridium, platinum and rhenium in association with at least one inorganic oxideselected from silica and alumina, wherein the amount of said second metal, calculated as the metal, is from 0 1 part per million to 10 parts per million with respect to said particulate physical mixture.

The compositions of the present invention are useful in catalytic cracking processes in 25 which it is desired to reduce emission of noxious gases such as carbon monoxide and sulfur oxides and they are particularly useful in processes for the cyclic, fluidized, catalytic cracking of a hydrocarbon feedstock containing organic sulfur compounds Most preferably, the compositions of the present invention are employed in the invention disclosed and claimed in our co-pending British patent Application No 52755/76 (Serial No 1575018) of even date 30 herewith More particularly that application discloses and claims in a process for the cyclic, fluidized catalytic cracking of a hydrocarbon feedstock containing organic sulfur compounds wherein (i) said feedstock is subjected to cracking in a reaction zone with fluidized solid particles of a molecular sieve-type cracking catalyst; (ii) catalyst particles, which are deactivated by sulfur-containing carbonaceous deposits are separated from reaction zone effluent 35 and conveyed to a stripping zone wherein volatile deposits are removed from said deactivated catalyst by contact with a stripping gas; (iii) stripped catalyst particles are separated from stripping zone effluent and conveyed to a regeneration zone and regenerated by burning the non-strippable sulfur-containing, carbonaceous deposits from the stripped catalyst with an oxygen-containing gas and (iv) regenerated catalyst particles are separated from regenera 40 tion zone effluent and recycled to the reaction zone a method for reducing emissions of carbon monoxide and sulfur oxides in the regeneration zone effluent gas which comprises:

(a) circulating the cracking catalyst through the process cycle in combination with a metallic reactant which reacts with sulfur oxides in the regeneration zone, the combination of catalyst and reactant consisting of fluidizable solid particles, the reactant being either incor 45 porated into the particles of cracking catalyst or contained in a particulate solid other than the cracking catalyst and the metallic reactant being a free or combined metallic element which is selected from sodium magnesium, calcium, strontium, barium, scandium, titanium, chromium molybdenum manganese, iron, cobalt, nickel, antimony, copper, zinc, cadmium, lead a rare earth metal, or any mixture thereof; 50 (b) cracking said feedstock at a temperature within the range of from 850 'F to 1,200 'F, and in contact with the cracking catalyst and the metallic reactant; (c) stripping volatile deposits from the particles of said combination at a temperature within the range of from 8500 to 12000 F with a stripping gas which contains steam, wherein the ratio by weight of steam to the catalyst is within the range of from 0 0005 to 0 025 per unit 55 of time; (d) burning said sulfur-containing carbonaceous deposits from the stripped, solid particles at a temperature within the range of from 1,0500 to 1,450 F in the presence of at least one free or combined metallic promoter selected from ruthenium, rhodium, palladium, osmium iridium platinum, vanadium silver or rhenium, wherein the metallic promoter and 60 the metallic reactant are present in sufficient amounts to effect absorption of a major portion of the sulfur oxides produced in said regeneration zone and wherein the metallic promoter is present in sufficient amount to enhance said absorption of sulfur oxides and the conversion of carbon monoxide to carbon dioxide in the regeneration zone; (e) withdrawing an effluent gas containing molecular oxygen from the regeneration zone, 65 4 1,575,019 4 said effluent gas having a reduced concentration of sulfur oxides; and (f) substantially withdrawing said absorbed sulfur oxides as a sulfurcontaining material in the volatiles from the reaction and/or stripping zone.

The at least one free or combined second metal of the compositions of the present invention and/or the at least one free or combined first metal of the compositions of the 5 present invention may be incorporated into the inorganic oxide and can be circulated through the cracking process cycle Such incorporation can be achieved either before or after the particular substrate is introduced into the cracking process cycle Conditions are employed in the cracking process cycle such that a stable metal and sulfur-containing compound forms in the solid particles in the regeneration zone and a sulfur-containing gas is withdrawn from the 10 stripping zone.

The cracking catalyst matrix of the molecular sieve-type cracking catalyst is preferably a combination of at least two materials consisting of silica, alumina, zirconia, titania, magnesia, thoria or boria, and more preferably is silica-alumina This cracking catalyst matrix preferably contains from about 10 to about 65, more preferably from about 25 to about 60 weight 15 percent of alumina; preferably from about 35 to about 90, more preferably from about 35 to about 70 weight percent of silica; and preferably from about 0 5 to about 50, more preferably from about 5 to about 50 weight percent of crystalline aluminosilicate The molecular sieve-type cracking catalyst makes up preferably from about 10 to about 99 999, more preferably from about 30 to about 99 995, and most preferably from about 90 to about 20 99.995 weight percent of the solid particles.

As aforementioned, the at least one free or combined first metal of the compositions of the present invention is selected from sodium, magnesium, calcium, strontium, barium, scandium, titanium, chromium, molybdenum, manganese, cobalt, nickel, antimony, copper, zinc, cadmium, lead and the rare earth metals, preferably from sodium, magnesium, calcium, 25 strontium, barium, chromium, manganese, copper, zinc, cadmium and the rare earth metals, more preferably from sodium, magnesium and the rare earth metals, most preferably from sodium and the rare earth metals.

The at least one free or combined second metal of the compositions of the present invention is selected from ruthenium, rhodium, palladium, osmium, iridium, platinum and 30 rhenium, and ideally is selected from platinum and palladium.

The metals in the catalyst compositions of the present invention should be present in sufficient average amounts to produce substantially reduced emissions of carbon monoxide and sulfur oxides in the regeneration zone flue gases of a cracking process Accordingly, the at least one free or combined first metal of the compositions of the present invention is present 35 in an amount, calculated as the metal, of from 50 parts per million to 10 weight percent with respect to the particulate physical mixture, and the at least one free or combined second metal of the compositions of the present invention is present in an amount, calculated as the metal, of from 0 1 parts per million to 10 parts per million with respect to the particulate physical mixture 40 When a metal consisting of magnesium, zinc, calcium, cadmium, manganese, strontium, barium, scandium or cobalt is present, it is at an average level, calculated as the metal, preferably in the range of from 0 01 weight percent to 5 weight percent and more preferably in the range of from 01 weight percent to 0 5 weight percent of the with respect to the particulate physical mixture When chromium or antimony is present, it is at an average level, 45 calculated as the metal, preferably in the range of from 0 01 weight percent to 0 1 weight percent, and more preferably in the range of from 0 01 weight percent to 250 parts per million, with respect to the particulate physical mixture When sodium is present, it is at an average level calculated as sodium preferably in the range of from about 0 6 weight percent to about 3 weight percent, more preferably in the range of from about 0 8 weight percent to 50 about 2 weight percent, and most preferably in the range of from about 0 85 weight percent to about 1 5 weight percent with respect to the particulate physical mixture When titanium is present, it is at an average level, calculated as titanium, preferably in the range of from 0 5 weight percent to 1 weight percent, and more preferably in the range of from 0 5 weight percent to 0 8 weight percent with respect to the particulate physical mixture When a rare 55 earth metal is present, it is at an average level, calculated as the metal, preferably in the range of from 0 2 weight percent to 10 weight percent, more preferably in the range of from about 2 weight percent to about 6 weight percent, and most preferably in the range of from about 2 weight percent to about 4 weight percent with respect to the particulate physical mixture.

When nickel is present, it is present at an average level, calculated as nickel, preferably in the 60 range of from 50 parts per million to about 0 5 weight percent, and more preferably in the range of from 50 parts per million to 0 1 weight percent with respect to the particulate physical mixture.

Certain individual solids in the particulate solids of the present invention can contain an amount of at least one of the metals which is greater than the average amount thereof in the 65 1,575,019 1,575,0195 solid particles, provided that such certain individual solids are admixed with other individual solids in the solid particles containing a smaller amount of at least one of the metals such that the solid particles contain the above-mentioned average levels of the metals.

When used in a cyclic cracking process the stripped, deactivated catalyst is regenerated at regeneration temperatures in the range where a stable metal and sulfurcontaining compound is formed in the solid particles from the metal in the first metal component and the sulfur oxide The regeneration temperatures are preferably in the range of from 1,0500 F to 1,450 'F, and more preferably in the range of from 1,1800 F to 1,350 'F The hydrocarbon feedstock is cracked at reaction temperatures in the range where the metal and sulfurcontaining compound in the solid particles reacts to form a sulfide of the metal in the first 10 metal component The cracking reaction temperature when employing a compostion of the present invention is preferably in the range of from 850 'F to 1,200 'F, and more preferably in the range of from 870 'F to 1,1000 F The strippable deposits are stripped from the deactivated cracking catalyst with a steam-containing gas and at stripping temperatures in the range where the sulfide of the metal in the first metal component reacts with water to form 15 hydrogen-sulfide gas The stripping temperatures employed with the catalyst compositions of the present invention are preferably in the range of from 850 'F to 1, 2000 F, and more preferably in the range of from 870 'F to 1,1000 F The weight ratio of steam-to-molecular sieve-type cracking catalyst being supplied to the stripping zone is preferably in the range of from 0 0005 to 0 025, and more preferably in the range of from 0 0015 to 0 0125 The 20 regeneration zone flue gases contain preferably at least 0 01 volume percent and more preferably at least 0 5 volume percent of oxygen in order for the desired reduction of emissions of noxious gases to be achieved.

Either one or both types of metal component can be incorporated into the solid particles outside or else within the catalytic cracking process cycle, which comprises the cracking 25 reaction zone, the stripping zone and the regeneration zone If incorporated during the catalytic cracking process cycle, then at least one of the two types of metal can be introduced into the fluid catalytic cracking process cycle as an oil or watersoluble or -dispersible compound of the metal or metals in the first or second metal component in the form of a solid, liquid, or gas, and can be incorporated in situ into the solid particles Preferably, such 30 compound consists of a metal diketonate, metal carbonyl, metallocene, metal olefin complex of from 2 to 20 carbon atoms, metal acetylene complex, metal complex of alkyl or aryl phosphines or metal carboxylate having from 1 to 20 carbon atoms More preferably, one of such compounds is platinum acetylacetonate.

This invention enables the practice of an improved process for reducing emissions of 3 carbon monoxide and sulfur oxides in cracking catalyst regeneration zone effluent gas, involving the conversion of sulfur-containing hydrocarbon feedstocks wherein the cracking catalyst is deactivated by the deposition of sulfur-containing coke on the cracking catalyst surface The solid particles of this invention, comprising molecular sievetype cracking 40 catalyst, are circulated in well-dispersed physical association with one another throughout the cracking process cycle, which comprises the cracking zone, the stripping zone and the regeneration zone The conditions employed effect reduction of carbon monoxide and sulfur oxide in the regeneration zone flue gases.

The cracking catalyst, the at least one first metal and the at least one second metal of this invention serve separate and essential functions The cracking catalyst serves to catalyse the 45 cracking reaction, while the metals are substantially inert toward the cracking reaction and have little, if any, adverse effect on the catalytic conversion operation under the conditions employed With regard to the combustion of carbon monoxide, all metals and their compounds which can serve suitably as the at least one second metal component catalyse the oxidation of carbon monoxide to carbon dioxide within the regeneration zone With regard to 50 the reduction of sulfur oxides in the regeneration zone flue gas, the solid particles adsorb sulfur oxides in the regeneration zone The molecular sieve-type cracking catalyst itself often serves as an adsorbent for sulfur oxides The at least one second metal component catalyses the oxidation of sulfur oxide or of a sulfur oxide group in a metal compound, and the at least one first metal reacts with the adsorbed sulfur oxides to form a metal and sulfur-containing 5 compound, in particular, a metal sulfate, in the solid particles Provided that such metal and sulfur-containing compound is stable under the operating conditions in the regeneration zone, it is carried on the surfaces of the solid particles to the reaction zone and stripping zone where it is reduced and separated as a sulfur-containing gas, in particular, as hydrogen sulfide.

It is understood that the activity in reducing the emission of carbon monoxide and of sulfur 60 oxides in the regeneration zone flue gases may vary from metal to metal in the classes of those which may serve as a metal in the first or second metal component Similarly, many of the specific metals which may serve as a metal in the first or second metal component do not necessarily yield equivalent results when compared with other specific metals which may be 65 used in the first or second metal component, respectively, or when utilized under varying 6 1,575,019 6 conditions.

The solid particles of this invention are finely divided and have, for example, an average particle size in the range of from about 20 microns or less to about 150 microns, such that they are in a form suitable for fluidization Suitable cracking catalyst matrices includes those containing silica and/or alumina Other refractory metal oxides may be employed such as 5 thoria and/or boria, limited only by their ability to be effectively regenerated under the chosen conditions Admixtures of clay-extended aluminas may also be employed Preferred catalysts include combinations of silica and alumina, admixed with "molecular sieves", also known zeolites or crystalline aluminosilicates Suitable cracking catalysts contain a sufficient amount of crystalline aluminosilicate materially to increase the cracking activity of the 10 catalyst i e above 30 weight percent with respect to the particulate physical mixture, limited only by their ability to be effectively regenerated under the chosen conditions The crystalline aluminosilicates usually have silica-to-alumina mole ratios of at least about 2:1, for instance about 2 to 12:1, preferably from about 4 to about 6:1 Cracking catalysts with silica bases having a major proportion of silica, for example, from about 35 to about 90 weight percent 15 silica and from about 65 to about 10 weight percent alumina are suitable Such catalysts may be prepared by any suitable method, such as milling, co-gelling, and the like, subject only to provision of the finished catalyst in a physical form capable of fluidization.

Suitable molecular sieves include both naturally occurring and synthetic aluminosilicate 20 materials such as faujasite, chabazite, X-type and Y-type aluminosilicate materials, and ultrastable, large-pore crystalline aluminosilicate materials When admixed with, for example, silicaslumina to provide a petroleum cracking catalyst, the molecular sieve content of thefresh finished catalyst particles is suitably within the range of from about 0 5 to about 50 weight percent, desirably from about 5 to about 50 An equilibrium molecular sieve cracking 25 catalyst may contain as little as about 1 weight percent crystalline material The crystalline aluminosilicates are usually available or made in sodium form; the sodium component is then usually reduced to as small an amount as possible, generallly less than about 0 30 weight percent, through ion exchange with hydrogen ions, hydrogen-precursors such as ammonium ions, or polyvalent metal ions, including calcium strontium, barium, and the rare earth, such 30 as cerium lanthanum, neodymium, and naturally-occurring rare earths and their mixtures.

The usable crystalline materials are able to maintain their pore structure under the high temperature conditions of catalyst manufacture, hydrocarbon processing, and catalyst regeneration The crystalline aluminosilicates often have a uniform pore structure of exceedingly small size, the cross-sectional diameter of the pores being in the size range of from about 6 to 35 about 20 angstroms, preferably from about 10 to about 15 angstroms.

Catalytic cracking of heavy mineral oil fractions is one of the major refining operations employed in the conversion of crude oils to desirable fuel products such as high-octane gasoline fuels used in spark-ignited, internal combustion engines Illustrative of "fluid" catalytic conversion processes is the fluid catalytic cracking process wherein high molecular 40 hydrocarbon liquids or vapours are contacted with hot, finely-divided, solid catalyst particles, either in a fluidized bed reactor or in an elongate riser reactor, and the catalyst-hydrocarbon mixture is maintained at an elevated temperature in a fluidized or dispersed state for a period of time sufficient to effect the desired degree of cracking to lower molecular weight hydrocarbons typically present in motor gasoline and distillate fuels 45 Suitable hydrocarbon feeds for cracking processes employing the compositions of the present invention boil generally above the gasoline boiling range, for example, within the range of from about 400 'F to about 1,200 'F, and are usually cracked at temperatures ranging from about 850 'F to about 1,200 'F Such feeds include various mineral oil fractions boiling above the gasoline range such as light gas oils, heavy gas oils, wide-cut gas oils, 50 vacuum gas oils, kerosenes, decanted oils, residual fractions, reduced crude oils and cycle oils derived from any of these as well as suitable fractions derived from shale oils, tar sands processing, synthetic oils, coal liquefaction and the like Such fractions may be employed singly or in any desired combination.

The compositions of this invention can be employed in any conventional catalytic cracking 55 scheme but are advantageously used in a fluid catalytic cracking system where at least a substantial portion of the hydrocarbon conversion is effected in a dilutephase transfer line or riser reactor system utilizing very active catalysts employed at relatively high space velocities.

Preferably, cracking occurs essentially exclusively in the riser reactor and a following dense catalyst bed is not employed for cracking In a typical case where riser cracking is employed 60 for conversion of a gas oil, the throughput ratio, or volume ratio of total feed to fresh feed, may vary from about 1 to 3 The conversion level may vary from about 40 to about 100 weight percent, and advantageously is maintained above about 60 weight percent, for example, between about 60 and 90 weight percent By conversion is meant the percentage reduction by weight of hydrocarbons boiling above about 430 'F at atmospheric pressure by the formation 65 1,575,019 of lighter materials or coke The weight ratio of total cracking catalystto-oil in the riser reactor may vary within the range of from about 2 to about 20 in order that the fluidized dispersion will have a density within the range of from about 1 to about 20 pounds per cubic foot Desirably, the catalyst-to-oil ratio is maintained within the range of from about 3 to about 20, preferably 3 to about 7 The fluidizing velocity used in the riser reactor may range 5 from about 10 to about 100 feet per second The riser reactor genera Illy has a ratio of length-to-average diameter of about 25 For production of a typical naphtha product, the bottom section mixing temperature within the riser reactor is advantageously maintained at from about 1,0000 F to about 1,1000 F for vaporization of the oil feed, and so that the top section exit temperature will be about 950 'F For cracking residues and synthetic fuels, 10 substantially higher temperatures would be necessary Under these conditions, including provision for a rapid separation of spent catalyst from effluent oil vapour, a very short period of contact between the catalyst and oil will be established Contact time within the riser reactor will generally be within the range of from about 1 to about 15 seconds, and preferably within the range of from about 3 to about 10 seconds Short contact times are preferred 15 because most of the hydrocarbons cracking occurs during the initial increment of contact time, and undesirable secondary reactions are avoided This is especially important if higher product yield and selectivity, including lesser coke production, are to be realized.

Short contact time between catalyst particles and oil vapours may be achieved by varous means For example, catalyst may be injected at one or more points along the length ofa 20 lower, or bottom, section of the riser Similarly, oil feed may be injected at all the points along the length of the lower section of the riser reactor, and a different injection point may be employed for fresh and recycle feed streams The lower section of the riser reactor may, for this purpose, include up to about 80 percent of the total riser length in order to provide extremely short effective contact times inducive to optimum conversion of petroleum feeds 25 Where a dense catalyst bed is employed, provision may also be made for injection of catalyst particles and/or oil feed directly into the dense-bed zone.

While the conversion conditions set forth above are directed to the production of gasoline as fuel for spark-ignition combustion engines, the processing scheme may be suitably varied to permit maximum production of heavier hydrocarbon products such as jet fuel, diesel fuel, 30 heating oil and chemicals, in particular, olefins and aromatics whilst still using the compositions of the present invention.

In the catalytic process, some non-volatile carbonaceous material, or "coke", is deposited on the catalyst particles Coke comprises highly condensed aromatic hydrocarbons which generally contain a minor amount of hydrogen, such as about 4 to about 10 weight percent 35 When the hydrocarbon feedstock contains organic sulfur compounds, the coke also contains sulfur As coke builds up on the catalyst, the activity of the catalyst for cracking and the selectivity of the catalyst for producing gasoline blending stocks diminish The catalyst particles may recover a major proportion of their original capabilities by removal of most of the coke therefrom in a suitable regeneration process 40 The spent catalyst from the petroleum conversion reactor is stripped prior to entering the regenerator The stripping vessel for use in a fluidized bed catalytic cracking unit may suitably be maintained essentially at conversion reactor temperature in the range of from about 850 to about 1,200 'F and desirably will be maintained above about 870 'F The preferred stripping gas is steam, although steam-containing nitrogen or other steamcontaining inert or flue gas, 45 may also be employed The stripping gas is introduced at a pressure of generally at least about 10, preferably about 35 pounds per square inch gauge, suitable to effect substantially complete removal of volatile compounds from the spent conversion catalyst.

The compositions of this invention can be employed with any conventional cracking catalyst regeneration scheme but are advantageously employed with a regeneration system 50 involving at least one dense-bed and at least one dilute-phase zone Stripped spent catalyst particles may enter the dense-bed section of the regenerator vessel through suitable lines evolving from the stripping vessel Entry may be from the bottom or from the side, desirably near the top of the dense-bed fluidized zone Entry may also be from the top of the regenerator where catalyst has first been contacted with substantially spent regeneration gas 55 in a restricted dilute-phase zone.

Catalyst regeneration is accomplished by burning the coke deposits from the catalyst surface with a molecular oxygen-containing gas, such as air Many regeneration techniques are practised commercially whereby a significant restoration of catalyst activity is achieved in response to the degree of coke removal As coke is progressively removed from the catalyst, 60 removal of the remaining coke becomes most difficult and, in practice, an intermediate level of restored catalyst activity is accepted as an economic compromise.

The burning of coke deposits from the catalyst requires a large volume of oxygen or air.

Although the disclosed invention is not to be limited thereby, it is believed that oxidation of coke may be characterized in a simplified manner as the oxidation of carbon and represented 65 8 1,575,019 8 by the following chemical equations:

(a) C + 02 CO 2 (b) 2 C + O 2 2 CO (c) 2 C O + 02 2 C 02 5 Reactions (a) and (b) both occur under typical catalyst regeneration conditions wherein the catalyst temperature may range from about 10500 to about 1450 'F and are exemplary of gas-solid chemical interactions when regenerating catalyst at temperatures within this range.

The effect of any increase in temperature is reflected in an increased rate of combustion of 10 carbon and a more complete removal of carbon, or coke, from the catalyst particles As the increased rate of combustion is accompanied by an increased evolution of heat, whenever sufficient free or molecular oxygen is present, the gas-phase reaction (c) may occur This latter reaction is initiated and propogated by free radicals and can be catalysed.

The burning of sulfur-containing coke deposits from the catalyst also results in the forma 15 tion of sulfur oxides; and, although the disclosed invention is not to be limited thereby, this burning may be represented by the following chemical equations:

(d) S (in coke) + 02 SO 2 (e) SO 2 + 1/2 O 2 S 03 20 Reactions (d) and (e) also occur under typical cracking catalyst regeneration conditions.

While reaction (d) is fast, reaction (e) is relatively slow Reaction (e) can be catalysed by any catalyst which catalyses reaction (c) above Molecular sieves adsorb sulfur oxides, and therefore reaction (e) can occur on the cracking catalyst in the solid particles of this invention 25 Other components of the solid particles can also adsorb sulfur oxides The resulting sulfur trioxide can then react with a suitable metal, or more particularly an oxide of the metal in the first metal component, to form a stable metal sulfate in the solid particles When the solid particles are separated from the regeneration zone flue gases, the metal sulfate in the solid particles is circulated to the reaction zone Thus, the sulfur is rendered unavailable for exit as 30 gaseous sulfur oxide in the regeneration zone flue gas.

The sulfate remains on the solid particles as they pass to the cracking reaction zone and, in the reducing atmosphere therein, is converted, to the sulfide of the metal in the first metal component and possibly to hydrogen sulfide Upon stripping with a steamcontaining stripping gas in the stripping zone, the sulfur is converted to hydrogen sulfide and exits in the 35 stripping zone effluent stream The first metal component is thereby regenerated and made available again for reaction with sulfur oxides in the next pass through the regeneration zone.

Hydrogen sulfide can then be recovered with the cracking products from the stripping zone, separated and converted to elemental sulfur in conventional facilities.

Although the disclosed invention is not to be limited thereby, it is believed that these 40 reactions can be summarized as follows:

Regenerator Mx O + SO 2 + 1/202,-MNO + 503 M-SO 4 Reactor Mx SO 4 + 4 H 2->M S + 4 H 2 O-M O + H 2 S + 3 H 20 Stripper Mx S + H 2 O->M O + H 2 S 45 where x is the ratio of the oxidation state of the oxide ion to the oxidation state of the metal in the first metal component when combined with oxygen.

These reactions are made possible by the molecular sieve-type cracking catalyst, the first metal component and the second metal component of the compositions of this invention The 50 high cracking activity normally present in the molecular sieve catalyst remains substantially unaffected by the presence of either the first or second metal components so that the anticipated conversion of feedstock and yield of cracked products are realized together with the diminution of emission of carbon monoxide and sulfur oxides.

The first and/or second metal component, if in combined form, is preferably present as an 55 oxide, for example cerium oxide.

The first and second metal component are incorporated onto a suitable support The first and second metal component can be incorporated into the substrate simultaneously or at different times and by the same or different methods of incorporation Such support is at least one inorganic oxide selected from silica and alumina In such case, the supported first or 60 second metal component or both are then admixed with the molecular sievetype cracking catalyst The support is porous and frequently has a surface area, including the area of the pores on the surface, of at least about 10, preferably at least about 50, square meters per gram The supports used in the present invention are silica, alumina, and silica-alumina.

In the above cases, the precise manner in which the metal or metals of the first or second 65 9 1,575,019 9 metal component or both are incorporated into the inorganic oxide support is not known with absolute certainty The metals may enter into a complex combination with the carrier material and other components of the solid particles of this invention Therefore, it is understood that the use of the terms "first metal component" or "second metal component" and "incorporated" into the substrate connotes the metals of such components existing on 5 the carrier material in a combined form and/or in the elemental state.

The first and/or second metal components may be incorporated into the substrate by ion exchange, by impregnation, or by other means, by contacting the substrate or a component thereof with a solution or solutions of a compound or compounds of the metal or metals in the first or second metal components or both in an appropriate amount necessary to provide the 10 desired concentration of the first or second metal component or both within the scope of the present invention.

The first and/ or second metal component may be combined with the substrate either in any step during preparation of the substrate or after the substrate has been prepared One manner of incorporation is to subject the substrate to ion-exchange For example, it is 15 preferred to ion-exchange a crystalline aluminosilicate with a solution or solutions of a compound or compounds of the metal or metals in the first or second metal component or both, and then to composite the ion-exchanged product with a porous cracking catalyst matrix Also useful is the ion-exchanging of siliceous solids or clays with a solution or solutions of a compound or compounds of the metal or metals in the first or second metal 20 component or both Suitable compounds for this purpose include the metal halides, preferably chlorides, nitrates, amine halides, oxides, sulfates, phosphates and other water-soluble inorganic salts; and also the metal carboxylates of from 1 to 5 carbon atoms, and alcoholates.

Specific examples include palladium chloride, chloroplatinic acid, ruthenium penta-amine chloride, osmium chloride, perrhenic acid, dioxobis(ethylenediamine) rhenium (V) chloride 25 and rhodium chloride.

Another method of preparing the first or second metal component or both for use in the present invention is by impregnation of a suitable support with a water or organic solventsoluble or -dispersible compound or compounds of the metal or metals in the first and/or second metal component The impregnation may be practised in any way which will not 30 destroy the structure of the substrate.

Impregnation differs from cation-exchange Impregnation results in greater deposition and a primarily physical association on the surface of the substrate, while ion exchange results in a primarily chemical association and a greater diffusion and therefore less surface deposition.

In impregnation, the metal is deposited and no significant ion exchange occurs between the 35 metal and the substrate In impregnating a substrate, the metal or metals in the first or second metal component or both can be present in or as a water or organic solvent-soluble or -dispersible compound or compounds in water or an organic solvent, in an amount or amounts sufficient to contain the quantity of metal or metals desired on the substrate, and the substrate is contacted therewith The composite may be dried to remove the solvent, leaving 40 the first or second metal component or both deposited on the substrate.

Preferably, water-soluble nitrate salts are employed in the impregnating solution since residue from the thermal decomposition of nitrate salts is relatively innocuous to the activity of the hydrocarbon cracking catalyst The halogen and sulfate salts of the metal to be impregnated may also be employed; however, since halogen or sulfide may be evolved during 45 thermal degredation of the salt and may be deleterious to the activity of the hydrocarbon cracking catalyst, these salts are most often employed when depositing on substrates which are substantially inert to the cracking reaction and which do not significantly adversely affect the hydrocarbon cracking reaction.

Another method of physically depositing the first or second metal component or both on a 50 substrate, particularly porous substrates such as crystalline aluminosilicates, is adsorption of a fluid decomposable compound or compounds of the metal or metals in the first or second metal component or both on the substrate followed by thermal or chemical decomposition of the compound or compounds The substrate may be activated by heating to remove any adsorbed water and then contacted with a fluid decomposable compound or compounds of 55 the metal or metals in the first or second metal component or both, thereby adsorbing the compound or compounds onto the substrate Typical of such compounds are the metal carbonyls, metal alkyls volatile metal halides and the like The adsorbed compound or compounds may then be reduced thermally or chemically to its active state thus leaving uniformly dispersed on the substrate an active first or second metal component or both 60 Thermal reduction may be effected, for example, in the regeneration vessel during the regeneration process.

Both impregnation and adsorption can be performed with a substrate before it is introduced into the cracking process cycle However, it is also advantageous to introduce a compound or compounds of the metal or metals in the first or second metal component or 65 1,575,019 1,575,019 10 both into the cracking process cycle and incorporate it in situ into the substrate Such compound or compounds can be introduced in either oil or water-soluble or -dispersible form and in the solid, liquid, or gaseous state at any stage of the cracking process cycle used so that wide distribution in the solid particles is achieved For example, such compound or compounds can be admixed with the feestock or fluidizing gas in the reaction zone, with the 5 regeneration gas, torch oil, or water in the regeneration zone, or with the stripping gas in the stripping zone; or can be introduced as a separate stream Suitable compounds for in situ incorporation include metal salts, organo-metallic compounds, metal diketonates, carbonyls, metallocenes, olefin complexes of 2 to 20 carbons, acetylene complexes, alkyl or aryl phosphine complexes and carboxylates of 1 to 20 carbons Specific examples of these are 10 platinum acetylacetonate, tris (acetylacetonato) rhodium (III), triiodoiridium (III) tricarbonyl, cyclopentadienylrhenium (I) tricarbonyl, ruthenocene, cyclopentadienylsodium (I) dicarnonyl dimer, dichloro (ethylene) palladium (II) dimer, (cyclopentadienyl) (ethylene) rhodium (I), diphenylacetylenebis (triphenylphosphino) -platinum (O), bromrnoethylbis(triethylphosphino) palladium (II), tetrakis (triphenylphosphine) palladium (O), 15 chlorocarbonyl-bis (triphenylphosphine) iridium (I) palladium acetate, palladium naphthenate, zinc dimethyl and zinc diethyl.

The key features of activity and stability are more easily attainable by introducing at least one of the first and second metal components for producing reduced emissions of carbon monoxide and sulfur oxides into the cracking process cycle and incorporating it into the solid 20 particles in situ, rather than compositing it with the cracking catalyst during manufacture of the cracking catalyst Introducing at least one of the first and second the metal component into the cracking process cycle and incorporating it in situ as opposed to compositing it with the cracking catalyst during cracking catalyst preparation has been found to result in greater reduction in emissions of carbon monoxide and sulfur oxides in regeneration zone flue gases 25 Incorporating at least one of the first and second metal components during the cracking cycle is also advantageous in that a larger degree of control is maintained over any potential deleterious effect of such components on the cracking reaction as the rate and/or amount of metallic components introduced into the cracking cycle can be varied Also, such first and/or second metal components previously composited with the cracking catalyst before introduc 30 tion of the catalyst into the cracking process cycle can be lost as fines during attrition of the cracking catalyst Adding the first and/or second metal component to the cracking cycle and incorporating it into the solid particles in situ allows for maintenance of a desired amount of first and/or second metal component on the outside or accessible portions of the solid 35particles 35 A further method involves incorporating the first or second metal component or both with an inorganic oxide substrate precursor, for instance a silica gel or silica-alumina gel, prior to spray drying or other physical formation process, and drying the precursor to prepare the substrate The resultant substrate body may be calcined to form the active material Alternatively, heat treatment may be effected in the cracking cycle 40 The following Examples illustrate various methods suitable for preparing and testing components which are usable in the compositions of the present invention.

EXAMPLE 1

Two hundred grams of a calcined, equilibrium, commercially available, molecular sievetype cracking catalyst containing 5 3 percent of hydrogen and rare earth ion-exchanged, 45 Y-type crystalline aluminosilicate and silica-alumina, which contained 30 weight percent of alumina, were impregnated with 3 90 grams of a 50 weight percent manganese nitrate solution and 210 milliliters of water About 80 weight percent of the catalyst was in the 20 to micron range in size The impregnated catalyst particles were recovered and dried at 250 F, followed by calcination for 3 hours at 1250 F The resulting catalyst contained 0 3 50 weight percent of manganese.

EXAMPLE 2

The procedure of Example 1 was repeated, except that 1 265 grams of uranyl nitrate dissolved in 210 milliliters of water were employed as the impregnating solution The impregnated catalyst was dried at 250 F and then calcined for 3 hours at 1200 F The 55 catalyst contained 0 3 weight percent of uranium.

EXAMPLE 3

The procedure of Example 1 was repeated, except that 0 82 gram of ammonium metatungstate dissolved in 210 milliliters of water was employed as the impregnating solution The catalyst was dried at 250 F, then calcined for 3 hours at 1200 F The resulting catalyst 60 contained 0 3 weight percent of tungsten.

EXAMPLE 4

The procedure of Example 1 was repeated, except that 2 35 grams of ceric ammonium nitrate dissolved in 200 milliliters of water were employed as the impregnating solution The catalyst was dried and calcined as in Example 1 and contained 0 3 weight percent of cerium 65 1,575,019 11 1,575,019 11 EXAMPLE 5

The procedure of Example 1 was repeated, except that 2 73 grams of zinc nitrate hexahydrate dissolved in 200 milliliters of water were employed as the impregnating solution The catalyst was dried and calcined as in Example 1 and contained 0 3 weight percent of zinc.

EXAMPLE 6 5

The procedure of Example 1 was repeated, except that 4 35 grams of ferric nitrate dissolved in 200 milliliters of water were employed as the impregnating solution The impregnated catalyst was dried and calcined as in Example 1 and contained 0 3 percent of iron.

EXAMPLE 7 10

The procedure of Example 1 was repeated, except that 1 1 grams of ammonium molybdate in a 210 milliliter aqueous solution were employed as the impregnating solution The impregnated catalyst was dried at 250 'F for three hours, and then calcined at 1200 'F for three hours The resulting catalyst contained 0 3 weight percent of molybdenum.

EXAMPLE 8 15

The procedure of Example 1 was repeated, except that 5 0 grams of titanium sulfate dissolved in 25 milliliters of an aqueous 30 percent solution of hydrogen peroxide, which was diluted to 200 milliliters with water, were employed as the impregnating solution The solution was heated until the titanium salt was fully dissolved The catalyst was dried, at 250 'F and then calcined for 3 hours at 1200 'F The resulting catalyst contained 0 3 weight 20 percent of titanium.

EXAMPLE 9

The procedure of Example 1 was repeated, except that 1 2 grams of chromic oxide dissolved in 200 milliliters of water were employed as the impregnating solution The impregnated catalyst was dried for 3 hours at 250 'F and then calcined for 3 hours at 1200 'F 25 The resulting catalyst contained 0 6 weight percent of chromium.

EXAMPLE 10

The procedure of Example 1 was repeated, except that 2 12 grams of zirconyl chloride 3 dissolved in 200 milliliters of water were employed as the impregnating solution The impregnated catalyst was dried at 250 'F for 3 hours and then calcined for 3 hours at 1200 'F 30 The resulting catalyst contained 0 3 weight percent of zirconium.

EXAMPLE 11

The procedure of Example 1 was repeated, except that 0 2506 gram of a 50 percent manganese nitrate solution and 200 milliliters of water were employed as the impregnating solution The impregnated catalyst was dried at 250 'F for 3 hours and then calcined for 3 35 hours at 1200 'F The resulting catalyst contained 0 02 weight percent of manganese.

EXAMPLE 12

The procedure of Example 11 was repeated, except that 1 253 grams of a 50 percent solution of manganese nitrate in 210 milliliters of water were employed as the impregnating solution The resulting catalyst contained 0 1 percent of manganese 40 EXAMPLE 13

Fifty grams of an equilibrium, commercially available cracking catalyst, which had been calcined and was coke-free and contained 2-4 weight percent of molecular sieve in a silica-alumina matrix, were impregnated with a solution of 5 2 grams of magnesium nitrate trihydrate in 50 milliliters of water, sufficient completely to wet the cracking catalyst The 45 wetted catalyst was then dried at 250 'F for 3 hours and thereafter calcined at 1000 'F for 3 hours The catalyst contained 1 weight percent of magnesium.

EXAMPLE 14

The procedure of Example 13 was repeated, except that one-half the amount of mag-nesium nitrate was employed to provide a catalyst impregnated with 0 5 weight percent of 50 magnesium.

EXAMPLE 15

Eighty pounds of an equilibrium commercially available cracking catalyst, which had been calcined and was coke-free and contained 3 8 weight percent of molecular sieve in a silicaalumina matrix were impregnated in three batches with 4 2 pounds of magnesium nitrate 55 dissolved in 12 litres of water, sufficient just to fill the pore volume of the catalyst The wetted catalyst was dried at 250 'F and subsequently calcined at 1000 'F for 3 hours, to provide 05 weight percent of magnesium on the catalyst.

EXAMPLE 16

One hundred milligrams of chloroplatinic acid were dissolved in 1 liter of water, and 18 60 milliliters of this solution were diluted with enough water to wet 300 grams of an equilibrium, commercially available cracking catalyst which had been withdrawn from a commercial unit and then calcined at 10000 F for 5 hours, and contained 2 5 weight percent of molecular sieve and 0 6 weight percent of sodium The wetted catalyst was then dried at 250 'F for 3 hours and was calcined at 1000 F for 3 hours The catalyst contained 6 parts per million by weight 65 12 1,575,019 12 of platinum.

EXAMPLE 17

Ninety-five grams of commercially available alumina were wetted with a solution of 3 22 grams of ammonium vanadate and 5 grams of oxalic acid in 95 milliliters of water, and then dried at 250 'F for 3 hours and calcined at 1000 'F for 3 hours This vanadium-impregnated 5 alumina was next wetted with a solution of 9 3 grams of copper nitrate in 95 milliliters of water This wetted alumina was dried at 250 'F for 3 hours and calcined at 1000 'F for 3 hours The alumina contained 2 5 weight percent of vanadium and 2 5 weight percent of copper.

EXAMPLE 18 10

Ten grams of a solution of 6 9 grams of a lubricating oil additive which contained 9 2 weight percent of magnesium, distributed as magnesium hydroxide, magnesium carbonate, and magnesium polypropyl benzene sulfonate, dissolved in 33 1 grams of catalytic light cycle oil were cracked in a bench scale cracking unit having a fluidized bed of 220 grams of an equilibrium, commercially available cracking catalyst, which contained 2 5 weight percent of 15 molecular sieve and about 0 6 weight percent of sodium, and had been withdrawn from a commercial fluid catalytic cracking unit and then calcined The cycle oil was cracked at 700 'F, for 4 minutes After purging the catalyst bed with nitrogen for 10 minutes at 1250 'F, the catalyst bed was cooled to 7000 F, and the cracking-purgingregeneration cycle was repeated until the magnesium, zinc, and phosphorus contents of the catalyst reached the 20 levels of 1100, 703, and 59 parts per million, respectively Zinc and phosphorus were inherently present in the lubricating oil additive.

EXAMPLE 19

The procedure of Example 18 was repeated, except that the crackingpurgingregeneration cycle was repeated with a 10 g solution containing 6 5 g of the oil and 3 5 g of a 25 lube oil additive containing 1 6 wt %Zn, 1 3 wt %P, and 4 6 wt %Mg until the magnesium, zinc, and phosphorus contents of the catalyst reached 2400,1200, and 1097 parts per million, respectively.

EXAMPLE 20

The procedure of Example 19 was repeated, except that an equilibrium, commercially 30 available cracking catalyst which contained 3 3 weight percent of molecular sieve in a silica-alumina matrix, and had also been withdrawn from a commercial fluid catalytic cracking unit and calcined, was employed, and the cracking-purgingregeneration cycle was repeated until the magnesium, zinc and phosphorus contents of the catalyst reached 4600, 304, and 1,136 parts per million, respectively 35 EXAMPLE 21

A lubricating oil additive in the amount of 7 3 grams and containing 8 2 weight percent of magnesium, distributed as magnesium carbonate, magnesium hydroxide, and magnesium polypropylbenzene sulfonate, and a sufficient volume of xylene, was used to wet 2000 grams of an equilibrium, commercially available cracking catalyst which had been withdrawn from a 40 commercial catalytic cracking unit and calcined, and which contained 25 weight percent of molecular sieve in a silica-alumina matrix and about 0 6 weight percent of sodium The wetted catalyst was dried at 400 'F for 3 hours and calcined at 1000 'F for 20 hours The catalyst contained 3000 parts per million of magnesium.

Specific Examples demonstrating the effectiveness of the various components of the 45 compositions of the present invention in cracking processes are given in our aforementioned copending British Patent Application No 52755/76 (Serial No 1575018).

Claims (1)

1. WHAT WE CLAIM IS:

   1 A catalyst composition comprising a particulate physical mixture of:

   (a) a particulate solid hydrocarbon cracking catalyst comprising a crystalline alumino 50 silicate in association with a matrix wherein the amount of said cracking catalyst is in excess of weight percent with respect to the particulate physical mixture; and (b) a particulate solid other than said particulate cracking catalyst comprising at least one free or combined first metal selected from sodium, magnesium, calcium, strontium, barium, scandium, titanium, chromium, molybdenum, manganese, cobalt, nickel, antimony, copper, 55 zinc, cadmium, lead and the rare earth metals, at least one free or combined second metal selected from ruthenium, rhodium, palladium, osmium, iridium, platinum and rhenium, and at least one inorganic oxide selected from silica and alumina, wherein the amount of said first metal, calculated as the metal, is from 50 parts per million to 10 weight percent with respect to said particulate physical mixture, and the amount of said second metal, calculated as the 60 metal, is from 0 1 part per million to 10 parts per million with respect to the particulate physical mixture.

   2 A composition as claimed in Claim 1 wherein the free or combined second metal is selected from platinum and palladium.

   3 A composition as claimed in Claim 1 or Claim 2 wherein the free or combined first 65 1,575,019 1 metal is selected from sodium, magnesium, calcium, strontium, barium, chromium, manganese, copper, zinc, cadmium and the rare earth metals.

   4 A composition as claimed in Claim 3 wherein the free or combined first metal is selected from sodium, the rare earth metals and magnesium.

   5 A composition as claimed in Claim 4 wherein the free or combined first metal 5 comprises sodium and the amount of sodium, calculated as the metal, is from 0 6 to 3 weight percent with respect to the particulate physical mixture.

   6 A composition as claimed in Claim 1 or Claim 2 wherein the free or combined first metal is selected from magnesium, zinc, calcium, cadmium, manganese, strontium, barium, scandium and cobalt, and the amount of the first metal, calculated as the metal, is from 0 01 10 weight percent to 5 weight percent with respect to the particulate physical mixture.

   7 A composition as claimed in any of Claims 1 to 6 wherein the inorganic oxide is alumina.

   8 A composition as claimed in any of Claims 1 to 7 wherein the inorganic oxide has a surface area of at least 10 square meters per gram 15 9 A composition as claimed in Claim 8 wherein the inorganic oxide has a surface area of at least 50 square meters per gram.

   A composition as claimed in any of Claims ito 9 wherein the particulate solids have an average particle size in the range of from 20 microns to about 150 microns.

   11 A composition as claimed in any of Claims ito 10 wherein the matrix is selected from 20 silica, alumina, thoria and boria.

   12 A composition as claimed in Claim 11 wherein the matrix is a mixture of silica and alumina.

   13 A composition as claimed in Claim 12 wherein the matrix contains from 10 to 65 weight percent of alumina and from 90 to 35 weight percent of silica 25 14 A composition as claimed in any of Claims 1 to 13 wherein the cracking catalyst contains from O 5 to 50 weight percent of crystalline aluminosilicate.

   A composition as claimed in any of Claims 1 to 14 wherein the inorganic oxide comprises a major portion of the particulate solid other than said cracking catalyst.

   16 A composition as claimed in claim 1 wherein component (b) is 30 a particulate solid other than said particulate cracking catalyst comprising at least one free or combined first metal selected from the rare earth metals, at least one free or combined second metal selected from ruthenium, rhodium, palladium, osmium, iridium, platinum and rhenium, and at least one inorganic oxide selected from silica and alumina, wherein the amount of said first metal, calculated as the metal, is from 0 2 to 10 weight percent with 35 respect to said particulate physical mixture, and the amount of said second metal, calculated as the metal, is from 0 1 part per million to 10 parts per million with respect to the particulate physical mixture.

   17 A composition as claimed in Claim 16 wherein the amount of said first metal, calculated as the metal, is from 2 weight percent to 6 weight percent with respect to said 40 particulate physical mixture.

   18 A composition as claimed in Claim 16 or Claim 17 wherein the free or combined second metal is selected from platinum and palladium.

   19 A composition as claimed in any of Claims 16 to 18 wherein the inorganic oxide is alumina 45 A composition as claimed in Claim 19 wherein the alumina has a surface area of at least 50 square meters per gram.

   21 A composition as claimed in Claim 19 wherein the free or combined first metal comprises cerium.

   22 A composition as claimed in Claim 21 wherein the cerium is present as cerium oxide 50 23 A composition as set forth in Claim 21 wherein said cracking catalyst is comprised of about 0 5 to about 50 weight percent of a crystalline aluminosilicate distributed throughout a matrix containing from about 10 to about 65 weight percent of alumina and from about 35 to about 90 weight percent of silica.

   24 A composition as claimed in any of Claims 16 to 19 wherein the inorganic oxide 55 comprises a major portion of the particulate solid other than said cracking catalyst.

   A modification of composition as claimed in Claim 1 wherein component (b) comprises:

   (I) a first particulate solid other than the particulate cracking catalyst comprising at least one free or combined first metal selected from sodium, magnesium, calcium, strontium, 60 barium, scandium, titanium, chromium, molybdenum, manganese, cobalt, nickel, antimony, copper, zinc, cadmium, lead and the rare earth metals in association with at least one inorganic oxide selected from silica and alumina, wherein the amount of said first metal, calculated as the metal, is from 50 parts per million to 10 weight percent with respect to said particulate physical mixture; and 65 14 1 575,019 14 (II) a second particulate solid other than the particulate cracking catalyst comprising at least one free or combined second metal selected from ruthenium, rhodium, palladium, osmium, iridium, platinum and rhenium in association with at least one inorganic oxide selected from silica and alumina, wherein the amount of said second metal, calculated as the metal, is from 0 1 part per million to 10 parts per million with respect to said particulate 5 physical mixture.

   26 A composition as claimed in Claim 25 wherein said free or combined first metal is selected from sodium, magnesium, calcium, strontium, barium, chromium, manganese, copper, zinc, cadmium and the rare earth metals.

   27 A composition as claimed in Claim 26 wherein said free or combined first metal is 10 selected from sodium, the rare earth metals and magnesium.

   28 A composition as claimed in any of Claims 25 to 27 wherein said free or combined second metal is selected from platinum and palladium.

   29 A composition as claimed in any of Claims 25 to 28 wherein said inorganic oxide of said first and second particulate solid other than cracking catalyst is alumina 15 A composition as claimed in any of Claims 25 to 29 wherein the inorganic oxide of said first particulate solid other than cracking catalyst comprises a major portion of said first particulate solid.

   31 A composition as claimed in any of Claims 25 to 30 wherein the inorganic oxide of said second particulate solid other than cracking catalyst comprises a major portion of said 20 second particulate solid.

   32 A composition as claimed in Claim I substantially as herein described.

   ELKINGTON AND FIFE Chartered Patent Agents High Holborn House 25 52/54 High Holborn London WCI V 65 H Agents for the Applicants Printed for Her Majesty's Stationery (ffice, by Croyd-n Printing ( Lmpany l rmtcd, ( roydon, Surrey, 1980 Published by Ihe Patent Office, 25 Southampton Budldings, london, W( 2 A IA Yfrom which copies may be obhtained.