NL1013966C2 - Sulfur reduction in gasoline in fluidized catalytic cracking. - Google Patents

Description

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Short designation: Sulfur reduction in gasoline in fluid catalytic cracking.

This invention relates to the reduction of sulfur in gasolines and other petroleum products prepared by the catalytic cracking process. The invention provides a catalytic composition for reducing product sulfur and a method for reducing product sulfur using this composition.

Catalytic cracking is a petroleum refining process that is widely used commercially, particularly in the United States, where most of the refinery's gasoline blending stock 15 is prepared by catalytic cracking with almost all of it coming from the fluidized catalytic cracking process. them (FCC). In the catalytic cracking process, heavy hydrocarbon fractions are converted to lighter products by reactions that take place at elevated temperature in the presence of a catalyst, with the major part of the conversion or cracking taking place in the vapor phase. The feed is thus converted to gasoline, distillate and other liquid cracking products as well as lighter gaseous cracking products having four or less carbon atoms per molecule. The gas consists partly of olefins and partly of saturated hydrocarbons.

During the cracking reactions, some heavy material, known as coke, is deposited on the catalyst. This reduces its catalytic activity and regeneration is desired. After removal of closed hydrocarbons from the spent cracking catalyst, regeneration is carried out by burning off the coke and then catalytic activity is restored. It is therefore possible to distinguish three characteristic steps of catalytic cracking: a cracking step in which the hydrocarbons are converted into lighter products, a stripping step to remove hydrocarbons adsorbed on the catalyst and a regeneration step to burn off the coke from the catalyst . The regenerated catalyst is then reused in the cracking step.

Catalytic cracking feeds usually contain sulfur in the form of organic sulfur compounds such as mercaptans, sulfides 40 and thiophenes. The products of the cracking process have the same 1013966

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It tends to contain sulfur impurities even when half of the sulfur is converted to hydrogen sulfide during the cracking process mainly by catalytic discharge of the non-thiophene sulfur compounds. The distribution of sulfur in the cracking products depends on a number of factors including the feed, the type of catalyst, the additives present, the conversion and other processing conditions, but in any case a certain proportion of the sulfur tends to the light or heavy petrol fractions end up so that it goes along in the product-10 stock. Where increasing environmental regulation has been applied to petroleum products, for example, in the reformulated gasoline controls (RFG), the sulfur content of the products has generally decreased in response to concerns surrounding the release of sulfur oxides and other sulfur compounds to the air following combustion. 15 business processes. Reducing sulfur in gasoline is critical not only for SOx emissions but also for sulfur poisoning the catalysts in cars. Poisoning catalytic converters in cars will cause other emissions problems such as NOx.

Environmental concerns are particularly focused on the sulfur content of gasoline for cars in view of its exceptional position in the United States as a vehicle fuel for passenger cars. However, this concern has also extended to the high boiling distillate fractions including light cycle oil (LCO) and fuel oil fractions (light fuel oil, LFO, and heavy fuel oil, HFO) obtained from the catalytic cracking processes. These products have long used hydrodesulfurization to reduce the sulfur contents in the product fractions and have generally proved effective. However, the higher boiling fractions are not as susceptible to desulfurization as the lower boiling fractions because of the increasing heat-resistant nature of the sulfur compounds, especially the substituted boiling thiophenes. In the LCO hydrodesulfurization process, methyl and / or alkyl substitution of benzothiophene and dibenzothiophene makes the desulfurization reactivity of the organic sulfur species considerable! 35 less and they become "hard sulfur" or "refractory sulfur". An example of LCO sulfur GC is shown in Figure 1 with sulfur GC formation. A review by Girgis and Gates, Ind. Spooky. Chem., 30, 1991, 2021-2058, reported that substitution of a methyl group in the 4 position or in the 4 and 6 positions decreases the desulfurization activity by an order of magnitude. Houalla et al. Reported efficiencies of 1-10 orders of magnitude, M. Houalla et al., Journal of Catalysis, 61, 1980, 523-527. Lamure-Meille et al. Suggested that sterically hindering the alkyl group causes the low reactivity of methyl-substituted dibenzothiophenes, Lamure-Meille et 5 al., Applied Catalysis A: General 131, 1995, 143-157. Given the use of the higher boiling catalytic cracking products as feedstocks for hydrodesulfurization processes, the incentive to reduce the occurrence of the more heat resistant organic sulfur compounds in these cracking fractions becomes apparent.

One approach has been to remove sulfur from the FCC feed by treating it with hydrogen before initiating cracking. While highly effective, this approach tends to be expensive in terms of capital cost of the equipment as well as in implementation since hydrogen consumption is high. Another approach is to remove the sulfur from the cracked products by treating with hydrogen. While again effective, this solution has the drawback that the valuable product may lose octane when the high octane olefins are saturated.

From an economic standpoint, it would be desirable to achieve sulfur removal in the cracking process itself since it would effectively desulfurize the major component of the gasoline blending stock without further treatment. Various catalytic materials have been developed to remove sulfur during the FCC work-25 cycle, but so far most developments have focused on removing sulfur from the flue gas regenerator. An earlier approach, developed by Chevron, used aluminum trioxide compounds as additives to cracking catalyst stock to absorb sulfur oxides in the FCC regenerator; the absorbed sulfur compounds entering the process in the feed were released as hydrogen sulfide during the cracking portion of the cycle and passed to the product recovery portion of the unit where they were removed. See Krishna et al., Additives Improve FCC Process, Hydrocarbon Processing, November 1991, pp. 59-66. The sulfur 35 is removed from the flue gases of the regenerator, but the product sulfur contents are not greatly affected, if at all.

An alternative technology for the removal of sulfur oxides in regenerator removal is based on the use of 40 magnesium aluminum spinels as additives for the circulating catalyst stock in the FCCU. Under the designation DESOX ™ used for the additives in this process, the technology has achieved remarkable commercial success. Patents exemplary of this type of sulfur dilating ring additives include US-A-4 963 520; 4,957,892; 4,957,718; 4 790 982 and others. Again, however, product swell levels are not greatly reduced.

A catalyst additive for reducing sulfur levels in liquid cracking products has been proposed by Worms-10 becher and Kim in U.S. Patents 5,376,608 and 5,525,210 using a cracking catalyst additive of an aluminum trioxide-supported Lewis acid for preparing gasoline with reduced sulfur content, but this system has had no apparent commercial success. The need for an effective additive for reducing the sulfur content of liquid catalytic cracking products therefore remains.

U.S. Patent Application Nos. 09/144 607 filed August 31, 1998 (Mobil IP Case 10061) disclose catalytic materials for use in the catalytic cracking process which are capable of reducing the sulfur content of the liquid products of the reduce cracking process. These sulfur reduction catalysts comprise, in addition to a porous molecular sieve component, a metal in an oxidation state greater than zero in the interior of the pore structure of the sieve. The molecular sieve is in most cases a zeolite and may be a zeolite with properties consistent with large pore zeolites such as zeolite beta or zeolite USY or with the medium pore size zeolites such as ZSM-5. Non-zeolitic molar sieves such as MeAPO-5, MeAPSO-5, as well as the mesoporous crystalline materials, such as MCM-41, can be used as the sieve component of the catalyst. Metals such as vanadium, zinc, iron, cobalt and gallium have been found to be effective in reducing sulfur in gasoline, vanadium being the preferred metal. When used as a single particle addition catalyst, these materials are used in combination with the active catalytic cracking catalyst (usually a faujasite such as zeolite Y, especially as zeolite USY) to process hydrocarbon feeds in the catalytic cracking unit (FCC) to prepare products with a low sulfur content. Since the sieve component of the sulfur reduction catalyst can be an active cracking catalyst per se, for example zeolite USY, it is also possible to use the sulfur reduction catalyst in the form of an integrated cracking / sulfur reduction catalyst system USY as working 5. a cracking component and the screen component of the sulfur reduction system together with the added matrix material, such as silicon dioxide, clay and the metal, e.g. vanadium, which provides the sulfur reduction functionality.

Another consideration in the preparation of FCC catalysts 10 was the stability of the catalyst, especially the hydro-thermal stability since cracking catalysts are exposed to repeated cycles of reduction (in the cracking step) followed by steam stripping and then by oxidative regeneration which gives large amounts of steam from the combustion of the coke, a carbon-rich hydrocarbon, which is deposited on the catalyst particles during the cracking part of the cycle. Early in the development of zeolitic cracking catalysts, it was found that low sodium was required not only for optimum cracking activity but also for stability and that rare earth elements such as cerium and lanthanum provided greater hydrothermal stability. See, for example, Fluid Catalytic Cracking with Zeolite Catalysts, Venuto et al., Marcel Dekker, New York, 1979, ISBN 0-8247-6870-1.

New catalytic materials for use in the catalytic cracking process have now been developed, which are capable of improving the sulfur content reduction of the liquid products of the cracking process, including, in particular, the gasoline and the middle distillate cracking fractions. . The present sulfur reduction catalysts are similar to those described in U.S. Application No. 09/144 607 in that a metal component in an oxidation state greater than zero is present in the pore structure of a molar sieve component of the catalyst composition, again preferred is given to vanadium. However, in the present case, the composition also includes one or more rare earth elements, preferably cerium. It has been found that the presence of the rare earth component increases the stability of the catalyst compared to the catalysts containing only vanadium or another metal component, and that in certain favorable cases, in particular with cerium as rare earth 40 component, the sulfur reduction activity also increases

10138S

- 6 - due to the presence of the rare earth elements. This is surprising since the rare earth cations do not have sulfur reducing activity per se.

The present sulfur reduction catalysts can be used in the cracking unit in the form of an addition catalyst in combination with the active cracking catalyst, ie in combination with the usual major component of the circulating cracking catalyst stock usually consisting of a zeolite-containing catalyst in a matrix based on a faujasite-10 zeolite, usually zeolite Y. Otherwise, they can be used in the form of an integrated cracking / product sulfur reduction catalyst system.

According to the present invention, the sulfur removal catalyst composition comprises a porous molecular sieve containing: (i) a metal in an oxidation state greater than zero in the interior of the pore structure of the sieve and (ii) a rare earth component.

The mole screen is in most cases a zeolite and can be a zeolite with properties corresponding to large pore zeolites such as zeolite beta or USY or medium pore size zeolites such as ZSM-5. Non-zeolitic molecular sieves, such as MeAPO-5, MeAPSO-5 as well as the mesoporous crystalline materials, such as MCM-41, can be used as the sieve component of the catalyst. Metals such as vanadium, zinc, iron, cobalt and gallium 25 are effective. When the selected screen material has sufficient cracking activity, it can be used as an active catalytic cracking catalyst component (usually a faujasite such as zeolite Y) or can be otherwise used in addition to the active cracking component, whether it has any cracking activity or not.

The present compositions are useful for treating hydrocarbon feeds in fluidized catalytic cracking (FCC) units to prepare low sulfur gasoline and other liquid products, for example, light cycle oil, which can be used as a low sulfur diesel blending component. 35 content or as heating oil. In addition to obtaining a very significant reduction in the sulfur content of the cracked gasoline fraction, the present sulfur reduction catalyst materials allow the sulfur contents of light cycle oil and fuel oil products (light fuel oil, heavy fuel oil) to be reduced. Sulfur reduction in LCO occurs with the 1013966-7 substantially substituted benzothiophenes and substituted dibenzothiophenes; removing these more refractory species will improve the efficiency of the sulfur reduction in the subsequent LCO hydrodesulfurization process. Reducing in HFO black-5 sheets can allow upgrading of cooking products from the oil to premium coke.

While the mechanism by which the metal-containing zeolite catalyst compositions remove the sulfur compounds commonly present in cracked hydrocarbon products is not precisely understood, it relates to the conversion of organic sulfur compounds in the feed to inorganic sulfur so that the process is a true catalytic process. In this method, it is believed that a zeolite or other molecular sieve provides shape selectivity with varying pore size and that the metal sites in zeolite provide adsorption sites for the sulfur materials.

The drawings consist of graphs showing the performance of the present sulfur reduction compositions described below.

20 FCC procedure

The present sulfur removal catalysts are used as a catalytic component of the circulating catalyst stock in the catalytic cracking process, which is almost invariably a fluid catalytic cracking (FCC) process these days. For convenience, the invention will now be described with reference to the FCC method, although the present additives could be used in the older type moving bed cracking method (TCC) with suitable particle size adjustments to meet the requirements of the method . In addition to adding the present additive to the catalyst stock and any possible changes in the product recovery portion, as discussed below, the mode of operation of the process will remain unchanged. For example, conventional FCC catalysts can be used, for example zeolite based catalysts with a faujasite cracking component as described in the original review by Venuto and Habib, Fluid Catalytic Cracking with Zeolite Catalysts, Marcel Dekker, New York 1979, ISBN 0-8247- 6870-1 as well as many other 1013966-8 sources such as Sadeghbeigi, Fluid Catalytic Cracking Handbook, Gulf Publ. Co. Houston, 1995, ISBN 0-88415-290-1.

Briefly stated, the fluid catalytic cracking process, in which the heavy hydrocarbon feed containing the organo-sulfur compounds, will be cracked into lighter products, takes place by contacting the feed in a cyclic catalyst recirculation cracking process with a circulating fluid. sable catalytic cracking catalyst stock consisting of particles having a particle size of 20 to 100 microns. The significant 10 steps in the cyclic process are: (i) the feed is catalytically cracked in a catalytic cracking zone, usually a riser cracking zone, which operates under catalytic cracking conditions by contacting the feed with a source of warm regenerated cracking catalyst to prepare an effluent comprising cracked products and spent catalyst containing coke and strippable hydrocarbons; (ii) the effluent is vented and separated, usually in one or more cyclones, into a vapor phase rich in cracked product and a solid rich phase comprising the spent catalyst; (iii) the vapor phase is removed as a product and fractionated in the FCC main column and its associated side columns to form liquid cracking products, including gasoline, (iv) the spent catalyst is stripped, usually with steam, to remove entrapped hydrocarbons. remove the catalyst and the stripped catalyst is oxidatively regenerated to prepare warm regenerated catalyst which is then recycled to the cracking zone to crack further amounts of feed.

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The feed for the FCC process will typically consist of a high boiling feed of mineral oil origin, usually with an initial boiling point of at least 290 ° C (550 ° F) and in most cases above 315 ° C (600 ° F). Most refinery cutoffs for FCC

Power will be at least 345 ° C (650 ° F). The end point will vary depending on the precise nature of the feed or on the operating characteristics of the refinery. Feeds may consist of distillate, typically with an end point of 550 ° C (1020 ° F) or higher, for example 590 ° C (1095 ° F) or 620 ° C (1150 ° F) or otherwise may be resi-40 du- (not -distillable) material are present in the food and can include all or most important part of the raw material. Distillable feeds include virgin feeds such as gas oils, for example heavy or light atmospheric gas oil, heavy or light vacuum gas oil, as well as cracked feeds such as light coke gas oil, heavy coke gas oil. Hydrotreated feeds can be used, for example, hydrotreated gas oils, especially hydrotreated heavy gas oil, but since the subject catalysts are able to effect a significant reduction in sulfur, it may be possible to abandon the first hydrogen treatment when the goal is to reduce sulfur although improvements in crackability can still be obtained.

In the present invention, the sulfur content of the gasoline portion of the liquid cracking products is effectively brought to lower and more acceptable levels by performing catalytic cracking in the presence of the sulfur reduction catalyst.

FCC Cracking Catalyst 20 The present sulfur reduction catalyst compositions may be used in the form of a separate particulate additive which is added to the main cracking catalyst in the FCCU or otherwise they may be used as constituents of the cracking catalyst to provide an integrated cracking / sulfur-25 catalyst. provide sheet reduction catalyst system. The cracking component of the catalyst, which is usually present to effect the desired cracking reactions and the preparation of lower boiling cracking products, is usually based on an active cracking component based on faujasite zeolite, which usually consists of zeolite Y in one of its forms such as calcined rare earth exchanged type Y zeolite (CREY), the preparation of which is described in US-A-3 402 996, ultrastable type Y zeolite (USY) as described in US-A-3 293 192, as well as various partially exchanged type Y zeolites as described in US-A-35 3 607 043 and 3 676 368. Cracking catalysts such as these are widely available in large quantities from various commercial suppliers. The active cracking component is routinely combined with a matrix material, such as silicon dioxide or aluminum trioxide, as well as a clay to provide the desired mechanical properties (wear resistance, etc.) as well as activity control for the highly active zeolite component or components. The particle size of the cracking catalyst is typically in the range of 10 to 100 microns for effective fluidization. When used as a separate particulate additive, the sulfur-reduction catalyst (and any other additive) is typically selected to have a particle size and density comparable to that of the cracking catalyst to prevent component separation during the cracking cycle.

10 Sulfur reduction system - sieve component

According to the present invention, the sulfur removal catalyst comprises a porous molar screen containing a metal in an oxidation state greater than zero within the interior of the screen's pore structure. The molar sieve is in most cases a zeolite and can be a zeolite with properties consistent with the large pore zeolites such as zeolite Y, preferably such as zeolite USY, or zeolite beta or with medium pore size zeolites such as ZSM-5, with the first class being preferred.

The molar sieve component of the present sulfur reduction catalysts may, as indicated above, be a zeolite or a non-zeolite molar sieve. When used, zeolites can be selected from large pore size zeolites or medium pore size zeolites (see Shape Selective Cata-25 lysis in Industrial Applications, Chen et al., Marcel Dekker Inc., New York 1989, ISBN 0-8247- 7856-1, for a discussion of zeolite classifications by pore size according to the base scheme as shown by Frilette et al. In J. Catalysis 67, 218-222 (1981)). Small pore size zeolites, such as zeolite A and erionite, in addition to lacking stability for use in the catalytic cracking process, will generally not be preferred because of their molecular size exclusion properties which tend to be constituents of the to exclude cracking food as well as many constituents of the cracked products. However, the pore size of the screen does not appear to be critical there; as indicated below, both medium and large pore size zeolites have been found to be effective as well as the mesoporous crystalline materials such as MCM-41.

Zeolites with properties consistent with the existence of a large pore structure (12 rings) which can be used to prepare the present sulfur reduction catalysts include zeolites Y in its various forms such as Y, REY, CREY, ÜSY, of which the the latter is preferred, as are other zeolites such as zeolite L, zeolite beta, mordenite including deionized mordenite, and zeolite ZSM-18. Generally, the large pore size zeolites are characterized by a pore structure with a ring opening of at least 0.7 nm and the medium or intermediate pore size zeolites will have a pore opening less than 0.7 nm but larger than 0.56 nm. Suitable medium-10 pore size zeolites that can be used include the penta-sil zeolites such as ZSM-5, ZSM-22, ZSM-23, ZSM-35, ZSM-50, ZSM-57, MCM-22, MCM- 49, MCM-56 which are all known materials. Zeolites can be used together with metal elements in the framework other than aluminum, for example boron, gallium, iron, chrome. The use of zeolite USY is particularly desirable since this zeolite is typically used as the cracking active component of the cracking catalyst and it is therefore possible to use the sulfur reduction catalyst in the form of an integrated cracking / sulfur reduction catalyst system. The USY zeolite used as a cracking component can also advantageously be used as a sieve component for a particulate addition catalyst as it continues to contribute to the cracking activity of the total catalyst contained in the unit. Stability is associated with a small unit-25 cell size in USY, and for optimal results the UCS for the USY zeolite in the final catalyst should be 2.420 to 2.460 nm, preferably 2.420 to 2.455 with the range 2.420 to 2.445 nm, at preferably 2.435 to 2.440 nm is very suitable. After exposure to repeated steaming of the FCC cycles, further reductions in UCS will occur to a final value typically in the range of 2.420 to 2.430 nm.

In addition to the zeolites, other molecular sieves can be used although they may not be as beneficial since it appears that some acid activity (usually measured by the alpha value) is required for optimal behavior. Test data indicate that alpha values greater than 10 (sieve without metal content) are suitable for adequate desulfurization activity, with alpha values in the range 1013966 - 12 - from 0.2 to 2,000 usually being appropriate.1 Alpha values from 0.2 to 300 represent the common area of acid activity for these materials when used as additives.

Typically, non-zeolite screen materials, which provide suitable metal component support components of the present sulfur reduction catalysts, include silicates (such as the metallosilicates and titanosilicates) with varying silica-aluminum trioxide ratios, metalloaluminates (such as germanium aluminates), the aluminophosphates, aluminophosphates. 10 metalloaluminophosphates, referred to as metal integrated aluminophosphates (MeAPO and ELAPO), metal integrated silicoalumino phosphates (MeAPSO and ELAPSO), silicoaluminophosphates (SAPO), galloger manates and combinations thereof, A description of the structural coverage of SAPOs, AIPOs, MeAPOs and MeAPSOs can be found in a number of sources including Stud. Surf. Catal. 37, 13-27 (1987). The AIPOs contain aluminum and phosphorus, while in the SAPOs part of the phosphorus and / or part of both phosphorus and aluminum has been replaced by silicon. In the MeAPOs, various metals are present, such as Li, B, Be, Mg, Ti, Mn, Fe, Co, An, Ga, Ge and 20 As in addition to aluminum and phosphorus, while the MeAPSOs contain additional silicon. The negative charge of the MeaAlbPcSidOe lattice is compensated by cations in which Me is magnesium, manganese, cobalt, iron and / or zinc. MexAPSOs are described in US-A-4 793 984. SAPO type sieves are described in US-A-4 440 871; MeAPO 25 type catalysts are described in US-A-4 544 143 and 4 567 029;

ELAPO catalysts are described in US-A-4 500 651, and ELAPSO

catalysts are described in European patent application 159 624. Specific molecular sieves are described, for example, in the

following patents: MgAPSO or MAPSO US-A-4 758 419, MnAPSO

30 US-A-4 686 092; CoAPSO US-A-4 744 970; FeAPSO US-A-4 683 217 and

ZnAPSO US-A-4 935 216. Specific silicoaluminophosphates used 1 1013966 1 The alpha test is a suitable method for measuring total acidity, including both internal and external acidity / of a solid material such as a molecular sieve. The test is described in US-A-3 354 078; in the J. of Catalysis, Vol. 4, p. 527 (1965); vol. 6, p. 278 (1966); and Vol. 61, p. 395 (1980). The alpha values reported in this description were measured at a constant temperature of 538 ° C.

- 13 - include SAPO-11, SAPO-17, SAPO-34, SAPO-37; other specific sieve materials include MeAPO-5, MeAPSO-5.

Another class of crystalline support materials that can be used is the group of mesoporous crystalline materials, exemplified by MCM-41 and MCM-48 materials. These mesoporous crystalline materials are described in US-A-5 098 684; 5 102 643 and 5 198 203. MCM-41 described in US-A-5 098 684 is characterized by a microstructure with an even hexagonal distribution of pores with diameters of at least 1.3 nm; after 10 calcination it shows an X-ray diffraction pattern with at least one d-spacing greater than 1.8 nm and a hexagonal electron diffraction pattern that can be indexed with a d100 value greater than 1.8 nm corresponding to the d- distance from the peak in the X-ray diffraction pattern. The preferred catalytic form of this material is the aluminosilicate although other metallosilicates can also be used. MCM-48 has a cubic structure and can be prepared by the same preparation method.

Metal Constituents Two metal constituents are included in the molecular sieve support material to prepare the subject catalytic compositions. A constituent is a rare earth element such as lanthanum or a mixture of rare earth elements such as cerium and lanthanum. The other metal component can be considered as the primary sulfur reduction component although the manner in which it accomplishes sulfur reduction is not clear as discussed in Application Serial No. 09/144 607, which is referenced for a description of the sulfur reduction catalyst compositions containing vanadium and other metal components which are for this purpose. For convenience, this component of the composition will be referred to in this application as the primary sulfur reduction component. To be effective, this (these) metal (s) must be contained within the pore structure of the screen component. Metal-containing zeolites and other molecular sieves can be prepared by (1) subsequently adding metals to the sieve or to a catalyst containing the sieve (sieves), (2) preparing the sieve (sieves) containing metal atoms in the sieve. framework structure contains (s) and through. lazy 3356 - 14 - (3) preparation of the sieve (sieves) with voluminous metal ions trapped therein in the zeolite pores.

Following the addition of the metal component, washing must be done to remove unbound ion species, and drying and calcination must be carried out. These techniques are all known per se. Subsequent addition of the metal ions is preferred because of the simplicity and economy which allows available sieve materials to be converted for use as the present additives. A wide variety of post-metal addition processes can be used to prepare a catalyst of this invention, for example, aqueous metal ion exchange, solid state exchange using metal halide salt (s), impregnation with a metal salt solution, and depositing metals in the vapor. In any case, however, it is important to carry out the addition of the metal (s) in such a way that the metal component enters the pore structure of the screen component.

It has been found that when the metal of the primary sulfur reducing component is present as exchanged cotton species in the pores of the screen component, the hydrogen transfer activity of the metal component is reduced to the point where hydrogen transfer reactions that occur during the cracking process with the preferred metal components can usually be kept at an acceptably low level. Thus, the production of coke and light gas during cracking increases slightly but they remain within permissible limits. Since the unsaturated light end products can in any case be used as an alkylation feed and thus be recycled to the gasoline supply, there is no significant loss of hydrocarbons in the gasoline range by using the present additives.

Because of concerns about excessive production of coke and hydrogen during the cracking process, the metals included in the additives must not exhibit a significant degree of hydrogenation activity. For these reasons, the noble metals such as platinum and palladium, which have strong hydrogenation dehydrogenation functionality, are not desirable. Base metals and combinations of base metals with a strong hydrogenation functionality such as nickel, molybdenum, nickel-tungsten, cobalt molybdenum and nickel molybdenum are not desirable for the same reason. The preference

ü LJ ii O

Base metals are the metals from Period 4, Groups 5, 8, 9, 12, 13 (IUPAC classification, previously referred to as Groups VB, VIII, IIB, UIA) of the Periodic Table of the Elements. Vanadium, zinc, iron, cobalt and gallium are effective with vanadium being the preferred metal component. It is surprising that vanadium can be used in an FCC catalyst composition in this manner since vanadium is commonly thought to have a very serious impact on zeolite cracking catalysts and much effort has been put into developing vanadium suppressants. See, e.g., 10 Wormsbecher et al., Vanadium Poisoning of Cracking Catalysts: Mechanism of Poisoning and Design of Vanadium Tolerant Catalyst System, J. Catalysis 100, 130-137 (1986). It is believed that the position of the vanadium within the pore structure of the screen immobilizes the vanadium and prevents it from forming vanadium acidic materials which can adversely combine with the screen component; in any event, the present zeolite-based sulfur reduction catalysts containing vanadium as a metal component have undergone repeated cycles between reductive and oxidative / steam conditions representative of the FCC cycle while maintaining the characteristic zeolite structure to provide a different environment for the metal.

Vanadium is particularly suitable for sulfur reduction in gasoline when carried by zeolite USY. The application structure of the V / USY sulfur reduction catalyst is particularly interesting. While other zeolites, upon addition of the metals, exhibit sulfur reduction of gasoline, they tend to convert gasoline to C3 and C4 gas. Although even much of the converted C3 "and C4" can be alkylated and remixed with the gasoline stock, the high wet C4 'gas yield can be a concern as many refineries are limited in the capacity of their wet gas compressor. metal-containing USY has the same yield structure as current FCC catalysts, this advantage could allow the V / ÜSY zeolite content in a catalyst mixture to be set at a target desulfurization level without limitations of the FCC unit. on Y zeolite catalyst, the zeolite being represented by USY, is therefore a particularly favorable combination for reducing sulfur in gasoline in FCC The USY which has been found to give particularly good results is a unit cell size USY in the region 40 from 2.420 to 2.460 nm, preferably in the range from 2.420 to 16-16.450, for example 2.435 to 2.450 nm (after treatment). Base metals such as vanadium / zinc as the primary sulfur reduction component may also be beneficial in terms of total sulfur reduction.

The amount of primary sulfur reducing metal component in the sulfur reducing catalyst is usually from 0.2 to 5 wt%, typically 0.5 to 5 wt%, (as metal relative to the weight of the screen component) but amounts outside this range, for example, from 0.10 to 10% by weight can also be found to provide some sulfur removal effect. When the screen is in a matrix, the amount of primary sulfur reduction metal component, expressed relative to the total weight of the catalytic composition, for practical formulation purposes, will typically range from 0.1 to 5, more typically from 0, 2 15 to 2% by weight of the entire catalyst.

The second metal component of the sulfur reduction catalyst composition includes a rare earth metal or metals that are present within the pore structure of the molecular sieve and are considered to be present in the form of 20 cations exchanged on the interchangeable locations present on the screen component. The rare earth (RE) component significantly improves catalytic stability in the presence of vanadium. For example, a higher cracking activity can be obtained with a RE + V / USY catalyst compared to a 25 V / USY catalyst while achieving a comparable sulfur reduction in gasoline. Rare earth elements of the lanthanum range of atomic number 57 to 71, such as lanthanum, cerium, dysprosium, praseodymium, samarium, europium, gadolinium, ytterbium and lutetium can be used in this way but from the point of view of commercial availability, lanthanum and mixtures of cerium and lanthanum are usually preferred. Cerium has proven to be the most effective rare earth component from the viewpoint of sulfur reduction as well as catalytic stability and its use is therefore preferred although good results can also be obtained with other rare earth elements as indicated below.

The amount of rare earth is typically from 1 to 10% by weight of the catalyst composition, in most cases from 2 to 5% by weight. Relative to the weight of the sieve, the amount of 40 rare earth will usually be 2 to 20% by weight and in most cases from 1013966 - 17 - 4 to 10% by weight of the sieve, depending on the sieve: matrix- ratio. Cerium can be used in amounts from 0.1 to 10, usually 0.25 to 5% by weight of the catalyst composition, and will generally be from 0.2 to 20, in most 5 cases, from 0.5 to 5 wt% 10 wt%.

The rare earth component can conveniently be incorporated into the mole screen component by exchange on the screen, either in the form of the un-matrixed crystal or of the matrixed catalyst. When formulating the composition with the preferred USY zeolite screen, a very effective manner of incorporation is to add the rare earth ions to the USY screen (unit cell size typically 2.445-2.465 nm) followed by further steam calcination to unit unit size of the USY to a value typically in the range of 2.420 to 2.460 nm, after which the primary metal component, if not already present, may be added. The USY must have a low alkali metal (mainly sodium) content for both stability and satisfactory cracking activity; this will usually be ensured by the ammonium exchange performed during the ultra-stabilization process to a desired low sodium content of no more than 1 wt%, preferably no more than 0.5 wt% on the screen.

The metal components are incorporated into the catalyst composition in a manner that ensures that they enter the internal pore structure of the screen. The metals can be incorporated directly into the crystal or into the matrix-containing catalyst. When the preferred USY zeolite is used as a screen component, it can be conveniently performed as described above, by recalcifying a USY cracking catalyst containing the rare earth component to ensure a low unit cell size and then incorporating the metal, for example vanadium, by ion exchange or by impregnation under conditions which allow the exchange of cations to take place so that the metal ion is immobilized in the pore structure of the zeolite. Alternatively, the primary sulfur reduction component and the rare earth metal component in the screen component, for example USY zeolite or ZSM-5 crystal, may be incorporated after any necessary calcination to remove organics from the synthesis, after which the metal-containing component 40 the final catalyst composition formulated can be 1 '·.' '; . ? By adding the cracking and matrix components, the formulation can be spray dried to form the final catalyst.

When the catalyst is formed as an integrated catalyst system, it is preferable to use the active cracking component of the catalyst as the sieve component of the z wave 1 reduction system, preferably in the form of a faujasite, e.g. zeolite USY, both for the simplicity of preparation and for maintaining the controlled cracking properties. However, it is possible to incorporate another active cracking screen material such as zeolite ZSM-5 into an integrated catalyst system and such systems may be useful when the properties of a second active screen material are desired, for example, the properties of ZSM-5. In both cases, the impregnation / exchange process must be carried out with a controlled amount of metal so that the required number of places on the screen are left to allow the cracking reactions that may be desired from the active cracking component or any secondary cracking components present, for example ZSM-5, to catalyze.

20

Use of the sulfur reduction catalyst composition

Typically, the most convenient way of using the sulfur reduction catalyst will be to use it as a separate particulate additive to the catalyst stock. In its preferred form with USY sieve component, adding the catalyst additive to the catalyst stock of the unit will not result in a significant reduction in total cracking due to the cracking activity of the USY zeolite. The same applies when another active cracking material is used as a sieve component. When used in this way, the composition can be used in the form of the pure screen crystal, pelleted (without matrix but with added metal components) to the proper size for the FCC application. However, the metal-containing screen will usually be matrixed to obtain suitable particle abrasion resistance and to maintain satisfactory fluidization. Conventional cracking catalyst matrix materials such as aluminum trioxide or silica-aluminum trioxide, usually with added clay, will be suitable for this purpose. The amount of matrix relative to the screen will usually be in weight of -1 -1 ί Λ f1?

I U i ÜcOO

- 19 - 20:80 to 80:20. Conventional matrix forming techniques can be used.

The use of a separate particulate catalyst additive allows to optimize the ratio of sulfur reducing and cracking catalyst components according to the amount of sulfur in the feed and the desired degree of desulfurization; when used in this manner, it is typically used in an amount of 1 to 50% by weight of the entire catalyst stock in the FCCU; in most cases the amount will be from 5 to 25 wt%, for example 5 to 15 wt%. About 10% represent a standard for most practical applications. The additive may be added in the usual manner, with make-up catalyst to the regenerator or by any other suitable method. The additive remains effective for removing sulfur for an extended period of time, although feeds with a very high sulfur content can lead to loss of sulfur removal activity in a short time.

The alternative to using the separate particulate additive is to use the sulfur reduction catalyst incorporated in the cracking catalyst to form an integrated FCG cracking / gasoline sulfur reduction catalyst. When the sulfur reducing metal constituents are used in combination with a screen other than the active cracking constituent, for example on ZSM-5 or zeolite beta when the main active cracking constituent is USY, the amount of sulfur reducing constituent (screen plus metals) will typically be up to 25 wt. .% of the whole catalyst or less according to the amounts in which it can be used as a separate particulate additive as described above.

Other catalytically active ingredients can be present in the circulating stock of catalytic material in addition to the cracking catalyst and the sulfur removal additive. Examples of such other materials include the octane-increasing catalysts, which are based on ZSM-5 zeolite, CO combustion promoters, which are based on a supported precious metal such as platinum, flue gas desulfurization additives such as DESOX ™ (magnesium aluminum spinel), vanadium traps and additives. agents for cracking the bottom fractions, such as those described in Krishna, Sadeghbeigi, on cit and Scherzer, Octane 40 Enhancing Zeolitic FCC Catalysts, Marcel Dekker, New York, 1990, 1013966 - 20 - ISBN 0-82478399 -9. These other ingredients can be used in their usual amounts.

The effect of the present additives is to reduce the sulfur content of the liquid cracking products, especially the light and heavy gasoline fractions although reductions are also obtained with the higher boiling distillate products including light cycle oil and light and heavy fuel oil fractions which more susceptible to hydrodesulfurization techniques by removing the more heat resistant sulfur compounds. The distillate fractions can then be hydrodesulfurized under less severe, more economical conditions to prepare distillate products suitable for use as a diesel or domestic fuel oil blend composition.

The cracking process itself can be carried out in the normal manner with addition of the sulfur reduction catalyst, either in the form of an additive or as an integrated catalytic cracking / sulfur reduction catalyst (single particle catalyst). The cracking conditions can be the usual ones.

The sulfur removed during the cracking process by using the catalyst is converted to inorganic form and released as hydrogen sulfide which can be recovered in the product recovery portion of the FCCU in the usual manner in the same manner as the hydrogen sulfide usually released at the cracking process. The increased hydrogen sulfide load may impose further acid gas / water treatment requirements, but with the significant reductions in sulfur in gasoline obtained these are not likely to be considered limiting.

Very significant reductions in sulfur of the cracked product can be obtained by using the present catalysts, in some cases up to 50% from the starting point using a conventional cracking catalyst, at constant conversion using the preferred form of the above described catalyst. A sulfur reduction in gasoline of 25% is easily achieved with many of the additives of the invention, as shown in the examples below. For the middle distillate fractions including the LCO fraction, reductions of up to 25% can also be obtained as shown in the examples below, coupled with a reduction in the content of heat resistant sulfur compounds, including the alkyl-substituted benzothiophenes and dibenzothiophenes. The degree of sulfur reduction may depend on the original organic sulfur content of the cracking feed, the greatest reductions being obtained in the feedings with higher sulfur contents. The metal content of the equilibrium catalyst in the unit can also affect the degree of desulfurization obtained, with a low metal content, especially the vanadium content, on the equilibrium catalyst favoring greater desulfurization. Desulfurization will be very effective at E-catalyst vanadium levels below 1,000 ppm although current catalysts remain effective even at much higher vanadium levels. The sulfur reduction can be effective not only to improve product quality but also to increase product yield, in cases where the refinery-cracked gasoline endpoint is limited by the sulfur content of the heavy gasoline fraction; by providing an effective and economical way of reducing the sulfur content of the heavy gasoline fraction, the gasoline endpoint can be shifted without the need to resort to expensive hydrotreating, with subsequent beneficial effect on the refinery economy. Removal of the various thiophene derivatives which are resistant to removal by hydrotreating under less severe conditions is also desirable when a subsequent hydrotreating is contemplated.

25

Example 1

Preparation of Catalyst Series 1

All samples in catalyst series 1 were prepared from a single source of spray dried material consisting of 50% USY, 21% silica sol and 29% clay. The USY had a starting cell unit size of 2.454 nm, SiO2 / Al2 O3 molar ratio of 5.46 and a total area of 810 m2g_1.

A V / USY catalyst, Catalyst A, was prepared by slurrying the above spray dried catalyst with NH 4 OH 35 at a pH of 6, followed by filtration, exchange with ammonium sulfate and washing with water. The catalyst was calcined in the presence of steam at 1300 ° F for 2 hours and impregnated with vanadyl oxalate. Steam calcination decreased the unit cell size of the zeolite and improved stability in the presence of vanadium.

101 33 S 6 - 22 -

A V / USY catalyst, Catalyst B, was prepared in the same manner as Catalyst A, except that the initial slurrying of the catalyst was carried out at a pH between 3.2 and 3.5.

The two RE + V / USY catalysts, Catalyst C and D were prepared in the same manner as Catalyst B except that after the exchange with ammonium sulfate, the catalysts were exchanged with rare earth chloride solutions and 2 and 4 wt% RE2O3, respectively. was added to the catalyst (RE means Rare 10 Earth or rare earth; edit). From the rare earth solution used, some of its Ce3 + ions were extracted, so that it contained only few Ce ions.

A Ce + V / USY catalyst, Catalyst E was prepared in the same manner as Catalyst B except that after the exchange with ammonium sulfate, the catalyst was exchanged with a solution of cerium chloride to give 5% cerium (if CeC> 2) to the catalyst to add.

To simulate deactivation of a catalyst in an FCC unit, these catalysts were then steam deactivated in a fluidized bed steam device at 770 ° C (1420 ° F) for 20 hours using 50% steam. The physical properties of the calcined and steam-deactivated catalysts are summarized in Table 1.

L l O _ 'J Ü - 23 -Table 1

Physical properties of the V, RE + V and Ce + V USY / silica sol catalysts (series 1)

V / ÜSY V / USY | re + V / | re + V / | Ce + V / cat A cat B USY USY USY

cat.C cat.D cat.E

Calcined Catalyst V Charge, Wt% 0.36 0.37 0.39 0.38 0.39 RE203 Charge, Wt% N.A. AFTER. 2.0 4.1 5.1

Ce203, wt% N.A. AFTER. 0.49 0.95 4.95

La203, wt% N.A. AFTER. 0.96 1.83 0.03

Na2O, wt% 0.30 0.24 0.42 0.21 0.19

Unit cell size, nm 2.433 2.433 2.442 2.443 2.442

Deactivated catalyst (CPS 770 ° C 20 hours)

Specific surface area, m2g'1 255 252 249 248 284

Unit cell size, nm 2.425 2.424 2.426 2.428 2.428 5

Example 2

Preparation of Catalyst Series 2

A V / USY catalyst, catalyst F was prepared using a USY zeolite with a silica to aluminum-10 trioxide ratio of 5.4 and a unit cell size of 2.435 nm. A fluidization catalyst was prepared by spray drying an aqueous slurry containing 50% by weight of the USY crystals in a silicon dioxide sol / clay matrix. The matrix contained 22 wt% silica sol and 28 wt% kaolin clay. The spray dried catalyst was exchanged with NH4 + by exchange with a solution of ammonium sulfate and then dried. Then the USY catalyst was impregnated with a solution of vanadium oxalate to the target 0.5 wt% v.

A RE + V / USY catalyst, Catalyst G, was prepared using USY zeolite with a silica to aluminum trioxide-20 ratio of 5.5 and a unit cell size of 2.454 nm. The USY was exchanged with NH4 + by exchange with a solution of ammonium sulfate. The NH4 + exchanged USY was then exchanged with rare earth cations (e.g., La3 +, Ce3 +, etc.) by exchanging a solution of mixed rare earth chlorides. In the rare earth solution used, most of its 1013966 - 24 -

Ce3 + extracted so that it contained very little Ce. The RE-exchanged USY was further washed, dried and calcined in the presence of steam in a rotary calciner at 760 ° C (1400 ° F). The steam calcination decreased the unit cell size of the zeolite to 24.40 Å and improved its stability in the presence of vanadium. The fluidization catalyst was prepared by spray drying an aqueous slurry containing 50% by weight of the RE-USY crystals in a silica sol / clay matrix. The matrix contained 22 wt% silica sol and 28 wt% kaolin clay. The spray dried catalyst was exchanged with NH / by exchange with a solution of ammonium sulfate and was then dried and calcined at 540 ° C (1000 ° F) for 2 hours. Following the calcination, the RE / USY catalyst was impregnated with a V SO4 solution.

Catalyst H was prepared using the same procedures as for Catalyst G except that a mixed REC13 solution mainly containing CeCl3 was used to exchange the USY. Catalyst H was prepared using a commercially available USY zeolite with a silica to aluminum trioxide ratio of 5.5 and a unit cell size of 2.454 nm. The USY was exchanged with NH4 + by exchanging with a solution of ammonium sulfate. The NH4 + exchanged USY was then exchanged with a CeCl3 solution containing some lanthanum. The exchanged USY was further washed, dried and calcined in the presence of steam in a rotary calciner at 760 ° C (1400 ° F). The steam calcination decreased the unit cell size of the zeolite to 2,440 nm. A fluidization catalyst was prepared by spray drying an aqueous slurry containing 50% by weight of the rare earth containing USY crystals in a silica sol / clay matrix. The matrix contained 22 wt% silica sol and 28 wt% kaolin clay. The spray dried catalyst was exchanged. with NH4 + by exchanging with a solution of ammonium sulfate and then dried and calcined at 540 ° C (1000 ° F) for 2 hours. Following the calcination, the catalyst was impregnated with a V SO4 solution. The physical properties of the calcined catalysts are summarized in Table 2.

1013986 - 25 - Table 2

Physical properties of V / USY, RE + V / USY silica sol catalyst (series 2)

~ ~ IV / USY RE + V / USY IRE + V / USY

cat.F cat.G cat.H

Calcined Catalyst 'V Charge, Wt% 0.5 0.43 0.44 RE203 Charge, Wt% N.A. 1.93 2.66

Ce02 charge, wt% N.A. 0.21 2.42

Na2O, wt% 0.13 0.16 0.20

Specific surface, m2g_1 327 345 345

Unit cell size, nm 2.4355 ^

Example 3

Preparation of Catalyst Series 3.

A V / USY catalyst, Catalyst I was prepared using a commercially available H-form USY (crystal) with a bulk silicon dioxide to aluminum trioxide ratio of 5.4 and a unit cell size of 2,435 nm. A fluidization catalyst was prepared by spray drying an aqueous slurry containing 40% by weight of the USY crystals, 25% by weight silicon dioxide, 5% by weight aluminum trioxide and 30% by weight kaolin clay. The spray dried catalyst was calcined at 540 ° C (1000 ° F) for 3 hours. The resulting H-form USY catalyst was impregnated with a vanadium oxalate solution to a target 0.4 wt% V by initial moisture impregnation. The impregnated V / USY catalyst was further calcined in air at 540 ° C (1000eF) for 3 hours. The final catalyst contained 0.39% V.

A Ce + V / USY catalyst, Catalyst J was prepared from the same spray dried H-form USY catalyst intermediate as Catalyst I. The H-form USY catalyst was impregnated with a solution of Ce (NO 3) 3 to an intended 1. 5 wt% Ce charge using an initial moisture impregnation process. The resulting Ce / USY catalyst was calcined in air at 540 ° C (1000 ° F) for 3 hours followed by steaming at 540 ° C (1000 ° F) for 3 hours. Then, the catalyst was impregnated with a vanadium oxalate solution to a target 0.4 wt% V by initial moisture impregnation. The impregnated Ce + V / USY catalyst was further calcined in air at 600 ° C (1000 ° F) for 3 hours. The final catalyst contained 1.4% Ce and 0.43% V.

Table 3 5 Physical Properties of the V and Ce + V USY / Silicon Dioxide Aluminum Trioxide Clay Catalysts (Series 3)

IV / USY Ce + V / USY

Catalyst I Catalyst J

Calcined Catalyst V Charge, Wt% 0.39 0.43

Ce charge, wt% N.A. 1.4

Specific surface, m2g "1 302 250

Alpha 130 12 UCS, nm 2.436 2.437 10 Example 4

Preparation of Catalyst Series 4

All samples in Catalyst Series 4 were prepared from a single source of spray dried material consisting of 50% USY, 21% silica sol and 29% clay. The starting USY had a mass of silica to aluminum trioxide ratio of 5.4 and a unit cell size of 2,435 nm. The spray dried catalyst was slurried with a solution of (NH2 SO1 and NH4OH at pH 6 to remove Na +, followed by washing with water and air calcining at 650 ° C (1200 ° F) for 2 hours.

A V / USY catalyst, Catalyst K was prepared using the above H-form USY catalyst. The H-form USY catalyst was impregnated with a vanadium oxalate solution to the target 0.5 wt% V by initial moisture impregnation. The impregnated V / USY catalyst was further air-calcined at 650 ° C (1200 ° F) for 2 hours. The final catalyst contained 0.53% V.

A Ce + V / USY catalyst, Catalyst L, was prepared from the above H-form USY catalyst. The H-form USY catalyst was exchanged with a solution of CeCl3 until the target 0.75 wt% Ce 30 charge. The resulting Ce / USY catalyst was air-calcined and impregnated with a vanadium oxalate solution to the target 0.5 wt% V by initial moisture impregnation. The impreg-; The ablated Ce + V / USY catalyst was further calcined in air. The final catalyst contained 0.72% Ce and 0.52% V.

A Ce + V / USY catalyst, Catalyst M, was prepared from the above H-form USY catalyst by exchanging with a solution of 5 CeCl 3 to the target 3 wt% Ce charge. The resulting Ce / USY catalyst was air-calcined and impregnated with a vanadium oxalate solution to the target 0.5 wt% V by initial moisture impregnation. The impregnated Ce + V / USY catalyst was further calcined in air. The final catalyst contained 1.5% Ce and 0.53% V.

A Ce + V / USY catalyst, Catalyst N, was prepared from the above H-form USY catalyst by an initial moisture impregnation with a solution of CeCl 3 to the intended 1.5 wt% Ce load. The resulting Ce / USY catalyst was air dried and impregnated with a vanadium oxalate solution to the target 0.5 wt% V by initial moisture impregnation. The impregnated Ce + V / USY catalyst was further calcined in air. The final catalyst contained 1.5% Ce and 0.53% V.

These catalysts were then steam deactivated to simulate catalyst deactivation in an FCC unit, in a fluidized bed steamer at 770 ° C (1420 ° F) for 20 hours using 50% steam and 50% gas. The gas stream was changed to air, N2, propylene, and N2 mixture and to N2 every 10 minutes, then returned to air to simulate the coke / -25 regeneration cycle of an FCC unit (cyclic steaming). Two sets of deactivated catalyst samples were generated: the steam deactivation cycle was terminated with firing, air (oxidation termination) for a batch of catalysts and the other terminated with propylene (reduction termination). The coke content of the "reduction termination" catalyst was less than 0.05% C. The physical properties of the calcined and steam catalysts (oxidation termination catalysts) are summarized in Table 4.

***** "Λ I i.; ^ V. -, - - 28 -Table 4

Physical properties of V and Ce + V USY / silica sol catalysts (series 4)

IV / USY Ce + V / USY Ce + V / USY [Ce + V / USY cat.K cat.L cat.M cat.N

Calcined Catalyst V Charge, Wt% 0.53 0.52 0.53 0.53

Ce charge, wt% N.A. 0.72 1.5 1.5

Na, ppm 890 1190 1190 1260

Deactivated catalyst (CPS 770 ° C, 20 hours)

Specific surface, m2g_1 237 216 208 204

Unit cell size, nm 2.425 2.423 2.425 2.425 5

Example 5

Preparation of Catalyst Series 5.

All samples in Catalyst Series 5 were prepared from a single source of spray dried material consisting of 40% USY, 30% colloidal silica sol and 30% clay. The starting H-form USY had a mass of silica to aluminum trioxide ratio of 5.4 and a unit cell size of 2,435 nm. The spray dried catalyst was air-calcined at 540 ° C (1000 ° F) for 3 hours.

A Ce / USY catalyst, Catalyst 0, was prepared using the above H-form USY catalyst. The H-form USY catalyst was impregnated with a solution of Ce (NO 3) 3 to the intended 1.5 wt% Ce charge using an initial moisture impregnation process. The resulting Ce / USY catalyst was calcined in air at 540 ° C (1000 ° F) followed by steaming at 540 ° C (1000 ° F) for 3 hours.

A Ce + V / USY catalyst, Catalyst P, was prepared from Catalyst O. The Ce / USY catalyst was impregnated with a vanadium oxalate solution to the target 0.5 wt% V by initial moisture impregnation. The impregnated Ce + V / USY catalyst was dried and calcined in air at 540 ° C (1000 ° F) for 3 hours. The final catalyst contained 1.4% Ce and 0.49% V.

A Ce + V / USY catalyst, Catalyst Q, was prepared from Catalyst 0 by exchanging with a solution of V SO4 at pH ~ 3 to 1013966-29 - the target 0.5 wt% V charge. The resulting Ce + V / USY catalyst was dried and calcined in air at 540 ° C (1000 ° F) for 3 hours. The final catalyst contained 0.9% Ce and 0.47% V. The physical properties of calcined catalysts are summarized in Table 5.

Table 5

Physical properties of the Ce and Ce + V USY / silica-clay catalysts (series 5)

| Ce / USY Ce + V / USY Ce + V / USY

cat.O cat.P cat.Q

Calcined Catalyst V Charge, Wt% N.A. 0.49 0.47

Ce charge, wt% 1.6 1.4 0.9

Na, ppm - - 940

Specific surface, m2g_1 284 281 272

Alpha - 10 14

Unit cell size, nm 2.435 2.436 2.436 10

Example 6

Preparation of RE + V / USY / silica sol catalyst.

A RE + V / USY catalyst, Catalyst R, was prepared using a NaY zeolite with a silica to aluminum trioxide ratio of 5.5 and a unit cell size of 2.465 nm. Zeolite Y was exchanged with NH4 + by exchange with a solution of ammonium sulfate. The NH / exchanged Y was then exchanged with rare earth cations (e.g. La3 +, Ce3 +, etc.) by exchanging with a solution of mixed rare earth chlorides from which most Ce3 + had been removed by extraction so that the solution contained very little cerium. The RE-exchanged Y was further washed, dried and calcined in the presence of steam at 705 ° C (1300 ° F) for 2 hours. The steam calcination decreased the unit cell size of the zeolite and improved its stability in the presence of vanadium. A fluidization catalyst was prepared by spray drying an aqueous slurry containing 50% by weight of the RE-USY crystals in a silica sol / clay matrix. The matrix contained 22 wt% silica sol and 28 wt% kaolin clay. The spray dried catalyst was exchanged with NH4 + by exchange with a solution of ammonium sulfate and then dried and calcined at 540 ° C (1000 ° F) for 1 hour. Following calcination, the RE / USY catalyst was impregnated with a vanadium oxalate solution. The physical properties of the calcined catalyst are summarized in Table 6.

5

Table 6

Physical properties of RE + V USY / silicon dioxidesol catalyst

RE + V / USY catalyst R

Calcined Catalyst V Charge, Wt% 0.43 RE2O3 Load, Wt% 1.93

CeC> 2 charge, wt% 0.21

Na2O, wt% 0.16

Specific surface, m2 / g 345

Unit cell size, A 24.58 10

Example 7

Preparation of Ce + V / USY / silica sol catalyst.

A Ce + V / USY catalyst, Catalyst S, was prepared using a NaüSY zeolite with a silica to aluminum trioxide ratio of 5.5 and a unit cell size of 2.454 nm. The USY was exchanged with NH4 + by exchanging with a solution of ammonium sulfate. The NH4 + exchanged USY was then exchanged with Ce3 + cations by exchanging with a solution of cerium chloride containing a small amount of other rare earth ions (eg La3 +, Pr, Nd, Gd, etc.). The Ce-exchanged USY was further washed, dried and calcined in the presence of steam at 705 ° C (1300 ° F) for 2 hours. Steam calcination decreased the unit cell size of the USY and improved its stability in the presence of vanadium. A fluidization catalyst was prepared by spray drying an aqueous slurry containing 50 wt% Ce / USY crystals in a silica sol / clay matrix. The matrix contained 22 wt% silica sol and 28 wt% kaolin clay. The spray dried catalyst was exchanged with NH4 + by exchange with a solution of ammonium sulfate and then dried and calcined at 540 ° C (1000 ° F) for 1 hour. Following iHi O '.' 'Ϊ́.' V | T; 'ij V. ·' v '- 31 - calcination, the Ce / USY catalyst was impregnated with a vansium sulfate solution. The physical properties of the calcined catalyst are summarized in Table 7.

5 Table 7

Physical properties of Ce + V / USY / silica catalyst.

Ce + V / USY catalyst S

Calcined Catalyst V Charge, Wt% 0.44 RE2O3 Load, Wt% 2.66

CeO 2 charge, wt% 2.42

Na2O, wt% 0.20

Specific surface, m2g_1 345

Unit cell size, 2.446 nm 10

Test method: assessment of cracking behavior.

The catalysts from Examples 1 to 7 were evaluated in FCC and the results are reported in Examples 8 to 15. The mixed catalysts (a candidate plus equilibrium 15 catalyst) were tested for gas oil cracking and selectivity by the ASTM microactivity test (MAT), which was modified from the ASTM method D-3907, using a vacuum gas oil feed (VGO). Some of the addition catalysts were evaluated in a circulation type riser tester using a vacuum gas oil or a hydrotreated feed. The compositions of the three VGO feeds and a high catalyst feed based hydrotreated feed (CFHT) used in these examples are shown in Table 8.

"I! - 7 ^ ~ - 32 -Table 8

Properties of cracking foods.

Properties of the la VGO no. 1 VGO no. 2 VGO no. 3 CFHT thing API specific weight 26.6 22.5 24.2 23.6

Aniline point, ° C 83 73 187 164 CCR, wt% 0.23 0.25 0.6 0.09

Sulfur, wt% 1.05 2.59 1.37 0.071

Nitrogen, ppm 600 860 900 1200

Basic nitrogen, ppm 310 340 290 380

Ni, ppm 0.32 - 0.2 0.2 V, ppm 0.68 - 0.1 0.2

Fe, ppm 9.15-0.3

Cu, ppm 0.05-0.0

Na, ppm 2.93 - 0.6 1.2

Sim. Dist., ° C

IBP, 181 217 192 172 50 wt%, 380 402 430 373 99.5% 610 553 556 547 5

A series of cracking conversions were obtained by varying the catalyst to oil ratio with the reaction carried out at 527 ° C (980 ° F). The series of cut-off points for the cracked products were: 10

Gasoline C5 + up to 220 ° C (125 ° F-430 ° F)

Light LCO 220 ° C to 310 ° C (430 ° F-590 ° F)

Heavy LCO 310 ° C to 370 ° C (590 ° F-700 ° F)

Light Fuel Oil (LFO) 220 ° C to 370 ° C (430 ° F-700 ° F) 15 Heavy Fuel Oil (HFO) 370 ° C + (700 ° F +)

The gasoline product of each material balance was analyzed with a sulfur GC (AED) to determine the sulfur concentration in the gasoline. To reduce the test errors in the sulfur concentration, which are linked to fluctuations in the distillation cut-off point of gasoline, the sulfur materials running from thio-1.

IV - V - 33 - Phenes to C4-thiophenes in syncrude (excluding benzothiophene and higher boiling S species) were quantitatively determined and the sum was defined as "gasoline fraction S".

To determine the sulfur content of the distillate fractions boiling above the gasoline range (Examples 14 and 15), the syncrude was subjected to atmospheric pressure distillation to separate the gasoline. The bottom fraction was then further distilled under vacuum to generate two LFO / LCO fractions (light LCO and heavy LCO) and HFO. The sulfur materials in the LCO sample were quantified using a GC equipped with a J&W 100 m DP petro column and a Sievers 355B sulfur detector. The concentration of each LCO sulfur material was based on the percentage of sulfur materials from the GC and the total sulfur content measured by the XPS method.

15

Example 8

Fluid Catalytic Crack Assessment of Series 1 Catalysts.

The catalysts of Example 1 were steam deactivated in a fluidized bed steamer at 770 ° C (1420 ° F) for 20 hours using 50% steam and 50% gas as described in Example 4 above, and ended with a burn-off in air (oxidation termination). Twenty five weight percent of the steamed addition catalyst was mixed with a very low metal equilibrium catalyst (120 ppm V and 60 ppm Ni) from an FCC unit.

The catalytic cracking performance of the catalysts was evaluated using VGO No. 1 as a cracking feed in the micromachining test. The behaviors of the catalysts are summarized in Table 9 where the product selectivity was interpolated to a constant conversion, 65 wt% conversion from feed to material of 220 ° C or less (430 ° F).

1013966 - 34 - Table 9

Catalytic cracking behavior of series 1 catalysts, VGO No. 1.

lEkat 1 + 2 5% + 25% 1 + 25% + 25% + 25%

base V / ÜSY V / ÜSY RE + V / RE + V / RE + V / case cat. A cat. B USY ÜSY USY

cat.C cat.D cat.E

MAT product yields

Conversion, wt% 65 65 65 65 65 65

Cat / Oil 3.0 3.3 3.3 2.9 3.0 2.9 _ Yield increase_ H2 Yield, wt% 0.03 +0.05 +0.05 +0.04 +0.02 +0 , 04

C1 + C2 gas, wt% 1.1 + 0.1 + 0.1 + 0 + 0.1 + 0

Total amount of C3 gas, 4.3 +0.1 +0.1 -0.1 +0 -0.2 wt. % C3 ”yield, wt% 3.7 +0.1 +0.1 +0 +0 -0.1

Total amount of C4 gas, 9.3 +0.1 +0.2 -0.1 +0 -0.3 wt. % C4 “yield, wt% 4.7 +0.3 +0.4 +0.4 +0.1 +0 C5 + petrol, wt% 47.6 -0.6 -0.4 +0.4 +0 +0.5 LFO, wt.% 29.6 +0 +0.2 +0 +0.1 +0 HFO, wt.% 5.4 +0 -0.2 +0 -0.1 +0

Coke, wt% 2.4 +0.3 +0.0 -0.2 -0.1 -0.1

Gasoline fraction S in ppm 618 377 366 369 382 352% reduction in sulfur in base 39.0 40.8 40.4 38.3 43.1 gasoline fraction 5

The catalyst to oil ratios in Table 9 show that the deactivated V / USY and Ecatalyst mixtures require a higher catalyst to oil ratio than the 100% equilibrium catalyst based on obtaining a conversion of 65% (3.3%). versus 3.0 catalyst / oil, i.e., 10% reduction in activity). This is due to lower cracking activity of V / USY catalysts over the equilibrium catalyst. In comparison, adding the RE + V / USY catalysts did not increase the catalyst to oil ratio to obtain a 65% conversion. This catalyst to oil results indicate that 1013066 - 35 - the RE + V / USY catalysts are more stable and retain their cracking activity better than the V / USY catalysts.

Compared to the equilibrium catalyst base case, addition of V / USY and RE + V / USY catalyst gave small changes in the overall product yield structure. There were slight increases in hydrogen and coke yields. Small changes in C4 gas, gasoline, light cycle oil and heavy fuel oil yields were also observed. Adding the V / USY and RE + V / USY catalysts significantly changed the S concentration in gasoline. When 25 wt% of Catalyst A or B (V / USY reference catalysts) was mixed with the equilibrium FCC catalyst, a 39.0 and 40.8% reduction in the gasoline sulfur concentration was obtained. When 25 wt% RE / USY catalysts (Catalysts C and D) were added to the equilibrium catalyst, the gasoline sulfur reduction activities were comparable to the reference catalysts (38-40%). The RE + V / USY catalyst containing predominantly cerium rare earth metal (Catalyst E) gave a gasoline sulfur reduction of 43.1%, further reducing the gasoline sulfur content by 4%, i.e. 10% improvement over the V / USY and the mixed 20 RE / USY catalysts. All catalysts had a comparable vanadium charge (0.36-0.39%).

These results show that adding rare earth elements improves the cracking activity of a V / USY catalyst. Changes in cracked product yield were minor. Among rare earth ions, cerium exhibits a unique property in that the Ce + V / USY catalyst not only exhibits higher cracking activity but also exhibits increased gasoline sulfur reducing activity under fluid catalytic cracking conditions. The rare earth RE / USY catalyst with no significant amounts of cerium has no added benefit over V / USY for the reduction of gasoline sulfur while the presence of cerium reduced the gasoline sulfur content of the V / USY or RE / USY (without significant cerium contents) catalysts .

35 Example 9

Comparison of cracking of series 2 catalysts.

The V and RE / V USY catalysts from Example 2 (Catalyst Series 2, Catalysts F, G, H) were steam deactivated at 770 ° C (1420 ° F) for various periods of time to compare the stability of the 40 catalysts. The catalysts were steamed in a 0.01 - 36 fluidized bed steamer for 2.3; 5.3; 10, 20 and 30 hours using 50% steam and 50% gas (cyclic steam termination reduction as described in Example 4 above). The specific surface retention of the deactivated catalysts is plotted in Figure 2.

The steam deactivated catalysts were tested for their gas oil cracking activity using the ASTM microactivity test (ASTM method D-3907) with vacuum gas oil No. 2 (over 2.6 wt% S). At a contact time of 30 seconds and at 545 ° C (980 ° F) reaction temperature, a weight percent conversion at 220 ° C (430 ° F) was measured with a constant catalyst to oil ratio of 4: 1. The conversions as a function of the steam deactivation time are plotted in figure 3.

The surface area retention shown in Figure 2-2 indicates that V / SSY and RE + V / USY catalysts exhibit similar surface area retention under various hydrothermal deactivation conditions, suggesting that all three catalysts have similar lattice stability. Plotting the conversion as shown in Figure 3, however, clearly indicates that RE + V / USY has greatly improved cracking efficacy retention as the severity of hydrothermal deactivation increases. In the hydrothermal deactivation, the improvement in cracking activity from the V / USY to RE + V version was 15% conversion. No clear differences were observed between the RE versions at varying amounts of cerium. These results are consistent with those of Example 8 in which RE + V / USY obtained the target conversion at a lower catalyst to oil ratio than V / USY. These conversion results indicate that the RE + V / USY catalysts are more stable and retain their cracking activity better than the V / USY catalysts. Addition of 30 rare earth ions to the USY followed by steam calcination to decrease the unit cell size of the zeolite improved catalyst stability in the presence of vanadium.

Example 10 Evaluation of Fluid Catalytic Cracking of Series 3 Catalysts.

The V and Ce + V USY catalysts from Example 3 (Catalysts I, J) were steam deactivated in a fluidized bed steamer at 770 ° C (1420 ° F) for 20 hours using 50% steam and 50% gas as described in Example 1 01 3966 - 37 - above, ending with burning in air (final oxidation). Twenty five weight percent of the steamed addition catalysts were mixed with the FCC low metal equilibrium catalyst (120 ppm V and 60 ppm Ni). The mixed catalysts were then evaluated by the MAT test as described above using VGO No. 1 feed.

The performance of the Series 3 catalysts using the VGO No. 1 feed is summarized in Table 10, in which the product selectivity was interpolated to a constant conversion, 70% by weight conversion of feed to 220 ° C (430 ° C) F) material.

\ i 1013965 - 38 - Table 10

Catalytic cracking behavior of series 3 catalysts.

Ekat base-1 + 25% V / ÜSY- 1 + 25% Ce + V / case cat. (Kata- USY cat.

lysator I) (catalyst J) MAT product yields

Conversion, wt% 70 70 70

Cat./oil 3.3 3.8 3.7 _ yield increase_ H2 yield, wt% 0.03 +0.04 +0.13

C1 + C2 gas, wt% 1.4 + 0.1 + 0.1

Total C3 gas, wt.% 5.4 +0.1 -0.1 C3 "yield, wt.% 4.5 +0.1 -0.1

Total amount of C4 gas, 10.9 +0.2 -0.2 wt. % C4 ”yield, wt% 5.2 +0.4 +0.2 iC4 yield, wt% 4.8 -0.2 -0.4 C5 + gasoline, wt% 48.9 -0.3 - 0.3 LFO, wt% 24.6 +0.5 +0.3 HFO, wt% 4.7 -0.2 -0.1

Coke, wt% 2.7 +0 +0.5

Gasoline sulfur in the fraction 529 378 235, ppm% reduction in S base 29 56 in the gasoline fraction 5

Table 10 compares the FCC behavior of V / USY and Ce + V / USY / silica-aluminum trioxide clay catalysts each mixed with an equilibrium FCC catalyst (Ekat.) After cyclic deactivation with steam (oxidation termination). Compared to the Ekat 10 base case, addition of V / SSY and Ce + V / USY catalyst only slightly changes the overall product yield structure. Yield changes in C4 gas, gasoline, light cycle oil, and heavy fuel oil are all minor. Moderate increases in hydrogen and coke yields were observed. Although the product yields are · ->. As changes were small, the V / SY and Ce + V / USY catalysts significantly changed the gasoline S concentration. When 25% by weight of Catalyst I (V / USY reference catalyst) was mixed with an equilibrium FCC catalyst, a 29% reduction in gasoline sulfur concentration was obtained. In comparison, the Ce + V / -USY catalyst (Catalyst J) reduced gasoline S by 56%. Addition of Ce to the V / USY catalyst reduced the gasoline S content by an additional 27%, i.e., 93% improvement over the V / USY reference catalyst. Both catalysts had comparable vanadium charges (0.39% vs 0.43% V). In view of the fact that Ce does not in itself have any gasoline sulfur reduction activity (see Example 11 below), these results are completely unexpected and clearly demonstrate the benefits of adding cerium.

15

Example 11

Fluid catalytic cracking evaluation of Series 4 catalysts after cyclic steaming.

The behaviors of V and Ce + V catalysts from Example 4 are summarized in this example. The Series 4 catalysts were steam deactivated as described in Example 4 above by cyclic steaming (reduction termination) then mixed with the FCC low metal equilibrium catalyst (120 ppm V and 60 ppm Ni) in the weight ratio of 25:75 and examined using VGO 25 No. 1 food. The results are summarized in Table 11.

-I '}' i '· ^ - 40 -Table 11

Catalytic cracking behavior of V versus Ce + V / USY / silica sol catalysts.

Ekat + 25% + 25% [+ 25%

basic V / USY Ce + V / USY Ce + V / USY

case cat. cat. (cat. N) (cat. K) (cat. M) MAT product yields

Conversion, wt% 65 65 65 65

Cat / Oil 3.0 3.4 3.2 3.3 Yield Increase_ H2 Yield, wt% 0.03 +0.02 +0.02 +0.02

C1 + C2 gas, wt% 1.1 +0 +0 +0.1

Total amount of C3 gas, 4.4 -0.1 -0.1 +0 wt. % C3 = yield, wt% 3.7 +0 -0.1 +0

Total amount of C4 gas, 9.5 -0.1 -0.2 -0.1 wt. % C4 = yield, wt% 4.8 +0.1 +0.1 +0.1 iC4 yield, wt% 4.1 -0.2 -0.3 -0.1 C5 + gasoline, wt% 47.4 +0.1 +0.5 +0.1 LFO, wt% 29.7 -0.2 +0 -0.1 HFO, wt% 5.3 +0.2 +0 +0, 1

Coke, wt% 2.3 +0.1 -0.1 +0

Gasoline sulfur in the fraction, 516 489 426 426 ppm% reduction in S in the base 5.2 17.4 17.4 gasoline fraction 5

Table 11 compares the FCC behaviors of V / USY and Ce + V / USY / -silicasol addition catalysts after cyclic deactivation with steam (reduction termination). Compared to the Ekat base case, adding the V / USY and Ce + V / USY catalysts gave very slight changes in the overall product yield structure. The yields of hydrogen, C4 "gas, gasoline, light cycle oil, heavy fuel oil and coke were each changed by less than 0.2% by weight. Addition of the 1013966 - 41 - V / USY and Ce + V / SY catalysts changed the S concentration in various sizes When 25% by weight of catalyst K (V / USY reference catalyst) was mixed with the equilibrium FCC catalyst, a reduction in gasoline sulfur concentration of 5.2% was obtained. USY catalysts (Catalysts M and N) respectively a 17.4% reduction in gasoline-S Adding Ce to the V / USY catalyst reduced the gasoline-S content by a further 12.3%, i.e. 237% improvement relative to the V / USY reference catalyst.

10

Example 12

Fluid catalytic cracking evaluation of Series 4 catalysts after cyclic steaming.

The behaviors of V and Ce + V catalysts of Example 4 after 15 cyclic deactivation of steam are summarized in this example. The catalysts of Example 4 were deactivated by cyclic steaming as described in Example 4 above (oxidation termination) and were then mixed with the FCC low metal equilibrium catalyst (120 ppm V and 60 ppm Ni) in a weight ratio of 25:75 . The assessment results obtained with VGO No. 1 diet are summarized in Table 12.

1013368 - 42 - Table 12

Catalytic cracking behavior of V versus Ce + V / USY / silica sol catalyst.

Ekat + 25% + 25% + 25%

basic V / USY Ce + V / ÜSY Ce + V / USY

case cat. cat. (cat. M) (cat. K) (cat. L) MAT product yields

Conversion, wt% 70 70 70 70

Cat./oil 2.8 3.7 3.6 3.4 _ yield increase_ H2 yield, wt% 0.03 +0.12 +0.13 +0.12

C1 + C2 gas, wt% 1.5 +0.2 +0.2 +0.1

Total amount of C3 gas, 5.5 +0.1 +0 -0.1 wt. % C3 = yield, wt% 4.7 +0 +0 -0.1

Total amount of C4 gas, 11.1 +0 +0 -0.2 wt. % C4 = yield, wt% 5.8 +0.1 +0.1 +0 iC4 yield, wt% 4.6 -0.1 -0.2 -0.2 C5 + gasoline, wt% 49, 4 -1.0 -0.9 -0.5 LFO, wt% 25.6 -0.1 +0 +0.2 HFO, wt% 4.4 +0.1 +0 -0.2

Coke, wt% 2.3 +0.6 +0.5 +0.5

Gasoline sulfur in fraction, 579 283 243 224 ppm% reduction in base 51.1 58.1 61.3 Gasoline sulfur in fraction 5

Table 12 compares the FCC behaviors of V / USY and Ce + V / USY / -silicasol addition catalysts after cyclic deactivation with steam (oxidation termination). Compared to the Ekat base case, addition of V / USY and Ce + V / USY catalyst gave only minor changes in the overall product yield structure. Moderate increases in hydrogen and coke yields occurred. Small changes in C4 gas yield, gasoline, light cycle oil and heavy fuel oil were also observed. Adding the V / USY and Ce + V / USY kata 1 0 1 c? The gas-S catalysts changed the gasoline-S concentration significantly. When 25 wt.% Catalyst K (V / SSY reference catalyst) was mixed with an equilibrium FCC catalyst, a reduction in gasoline-sulfur concentration of 51.1% was obtained. For comparison, the 5 Ce + V / USY catalysts (catalysts L and M) gave a decrease in gasoline S of 58.1% and 61.3%, respectively. Adding Ce to the V / USY catalyst reduced the gasoline S content by an additional 7.0-10.2%, that is, up to a 20% improvement over the V / USY reference catalyst.

The product yield data of the V / USY and Ce + V / USY catalysts indicate that the yield changes by the Ekat are due to the addition of vanadium to the USY catalyst. The product yields of V / USY catalyst are comparable to that of Ce + V / USY catalysts except for the gasoline-S content.

These results suggest that Ce increases the gasoline sulfur reduction activity of the V / USY addition catalyst with little effect on product yields.

Example 13 Evaluation of Fluid Catalytic Cracking of Series 5 Catalysts (Investigation of Promoting Effects).

Behaviors of the Ce and Ce + V catalysts of Example 5 after cyclic deactivation with steam (reduction termination) as described above are summarized in this example. The deactivated catalysts were mixed with the FCC low metal equilibrium catalyst (120 ppm V and 60 ppm Ni) in a weight ratio of 25:75. The results obtained with VGO No. 1 diet are summarized in Table 13.

] y 1 o - v v. ' - 44 - Table 13

Catalytic cracking behavior of Ce versus Ce + V / USY / silica clay catalysts.

Ekat + 25% + 25% + 25%

basic Ce / USY Ce + V / ÖSY Ce + V / USY

case cat. cat. (cat. Q) (cat. O) (cat. P) MAT product yields

Conversion, wt% 70 70 70 70

Cat./oil 3.2 3.4 3.7 3.9 Yield increase _ H2 yield, wt.% 0.04 +0 +0.07 +0.07 Οχ + C2 gas, wt.% 1.5 +0, 1 + 0.1 + 0.1

Total amount of C3 gas, 5.7 +0.1 -0.1 +0 wt. % C3 = yield, wt% 4.8 +0 +0 +0

Total amount of C4 gas, 11.5 +0 -0.3 -0.1 wt. % C4 = yield, wt.% 5.7 +0 +0.1 +0.1 iC4 yield, wt.% 4.9 +0 -0.3 -0.2 C5 + gasoline, wt.% 48.8 - 0.2 -0.2 -0.7 LFO, wt% 25.5 +0 +0.1 +0.1 HFO, wt% 4.5 +0 -0.1 -0.1

Coke, wt% 2.4 +0 +0.3 +0.6

Gasoline sulfur in the fraction, 486 487 341 351 ppm% reduction in base 0 29.8 27.7 Gasoline-S in the fraction 5

Table 13 compares the FCC behaviors of Ce / USY and Ce + V / USY / silica clay addition catalysts after cyclic deactivation with steam (reduction termination). Compared to the Ekat base case, adding the Ce / USY catalyst gave virtually no changes in the total product yields. Addition of the Ce + V / USY catalyst gave small changes in the overall product yield structure. There were moderate increases in hydrogen and coke yields at 1013966 - 45 - as well as slight changes in C4 gas, gasoline, light cycle oil and heavy fuel oil yields. The addition of the Ce / SSY catalysts did not change the gasoline-S concentration. In contrast, Ce + V / USY catalysts (Catalysts P and Q, invention) gave a gasoline S reduction of 29.8 and 27.7%, respectively. These results indicate that cerium alone does not have any activity in reducing sulfur in gasoline. Cerium has been shown to promote vanadium to enhance the effectiveness of the V / USY addition catalyst for reducing gasoline sulfur.

Example 14

Catalyst R was evaluated in a circulating riser tester (Davison Circulating Riser) in combination with a typical FCC equilibrium catalyst using VGO No. 3 feed (Table 8). Prior to evaluation, the RE + V USY catalyst was steam deactivated at 770 ° C (1420 ° F) for 20 hours using 50% steam and 50% gas. Twenty five percent steamed addition catalyst was mixed with an equilibrium catalyst (530 ppm vanadium and 330 ppm Ni) from an FCC unit.

The FCC behaviors of the catalysts are summarized in Table 14 where the product selectivity was interpolated to a constant conversion, 75 wt% conversion of feed to 220 ° C (430 ° F) material.

1013966 - 46 - Table 14

Catalytic cracking behavior of RE + V / ÜSY / silica sol catalyst.

Ekat base case + 25% RE + V / ÜSY

(cat. R)

Riser product yields

Conversion, wt% 75 75

Cat./oil 7.0 6.7 yield increase H2 yield, wt% 0.03 + 0.01

Total amount of C3 wt% 6.5 -0.1

Total amount of C4 wt% 12.1 -0.1 C5 + gasoline, wt% 49.4 -0.1 LFO, wt% 18.3 -0.1 HFO, wt% 6.7 +0.1

Coke, wt% 4.1 + 0.3

Gasoline sulfur in fraction, ppm 735 589 LCO sulfur, wt% 2.36 2.16% reduction in Base 2Ö gasoline sulfur% reduction in LCO sulfur Base 9 5

Compared to the base case, adding 25 wt% RE + V / -USY catalyst gave slight changes in the total product yield structure. There were negligible increases in H 2 and coke yields. Small changes in C4 gas, gasoline, light cycle oil and heavy fuel oil yields were also observed. Addition of the RE + V / USY catalyst significantly changed the gasoline sulfur content, a 20% reduction in gasoline sulfur concentration was obtained. In addition to the reduction in gasoline sulfur, a significant reduction in sulfur in LCO was observed, equivalent to an overall reduction of 9% sulfur in LCO.

The sulfur species in LCO are shown in Table 15 and Figure 4. The LCO contains broad ranges of benzothiophene and dibenzothiophene sulfur materials. The sulfur reductions were more pronounced for substituted benzothiophenes and substituted dibenzothiophenes such as C3 + benzothiophenes and C1 to C4 + dibenzothiophenes. The results are completely unexpected as substituted dibenzothio- 1 r · 'Λ. «4. · (I' w 'i Oo ö ^ - 47 - phenen are larger and were expected to be more difficult to crack and to remove sulfur in FCC .

Table 15 5 Sulfur specification of LCO from VGO feed no. 3.

(parts by weight sulfur in LCO) Ekat base case + 25% RE + V / USY

(cat.I)

Benzothiophene 0.04 0.04

Ci-Benzothiophenes 0.22 0.24 C2-Benzothiophenes 0.39 0.38 C3 + Benzothiophenes 0.47 0.38

Dibenzothiophene 0.10 0.09

Ci-dibenzothiophenes 0.36 0.32 C2-dibenzothiophenes 0.39 0.35 C3-dibenzothiophenes 0.24 0.22 C4 + dibenzothiophenes 0.16 0.14 __ 2.36 2.16

Example 15 Evaluation of Fluid Catalytic Cracking of Ce + V / USY / Silica Sol Catalysts.

The Ce + V / USY catalyst from Example 7 (Catalyst S) was evaluated in a 40 day fluid cracking circulating unit in combination with a typical FCC catalyst 15 using the highly hydrotreated FCC feed from Table 8 (CFHT raw material ). The base FCC equilibrium catalyst had very low levels of metal (200 ppm V and 130 ppm Ni). During the first 15 days, a 50/50 mixture of fresh FCC catalyst and the Ce + V / USY catalyst from Example 7 was added to the FCC regenerator in an amount of 1.4% of the catalyst stock per day. From the 15th to the 40th day, an 85/15 mixture of the fresh FCC catalyst and the Ce + V / USY catalyst was added to the FCC regenerator in an amount of 1.4% of the catalyst stock per day. The regenerator temperature was maintained at about 705 ° C (1300 ° F) during the evaluation. Two equilibrium catalyst samples (Ekat) were collected: the first was sampled before adding Ce + V / USY (base case) and the second on the 40th day. Based on T IJ i übG w - 48 - the Ce and V analysis, the charge of the Ce + V / USY catalyst was estimated at 12%.

FCC behaviors of the catalysts are summarized in Table 16 in which the product selectivity was interpolated to a constant conversion, 70% by weight conversion of the feed to 220 ° C (430 ° F) material.

Table 16

Catalytic cracking behavior of Ce + V / USY / silica sol catalyst.

10

Ekat base case + 12% CE + V / USY

(cat. S)

Style tube product yields

Conversion, wt% 70 70

Cat./oil 6.5 6.4 Yield increase H2 yield, wt.% 0.02 + 0.0

Total amount of C3 wt% 4.8 +0.0

Total amount C4 wt% 9.3 +0.1 C5 + gasoline, wt% 51.9 -0.2 LFO, wt% 24.0 -0.2 HFO, wt% 6.1 +0.1

Coke, wt% 2.6 + 0.1

Gasoline sulfur in fraction, ppm 100 79

Sulfur in light LCO, ppm 815 599

Sulfur in heavy LCO, bpm 1957 1687

Sulfur in HFO, ppm 2700 1700% reduction in gasoline Base 21 sulfur% reduction of sulfur in Base 27

light LCO

% reduction of sulfur in Base 14

heavy LCO

% reduction in HFO sulfur Basis 37

Wt% sulfur of the spent <0.06 <0.06 catalyst 1013966 - 49 -

Compared to the Ekat base case, addition of the Ce + V / -USY catalyst gave slight changes in the overall product yield structure. There was a negligible increase in H 2 and coke yields. Minor changes in C4 "gas, gasoline, light cycle oil and heavy fuel oil yields were also observed. Addition of the Ce + V / USY catalyst significantly changed the gasoline sulfur concentration. When 12 wt% Ce + V / US catalyst was added to the equilibrium FCC catalyst, a reduction in gasoline sulfur concentration of 21% was obtained In addition to reductions in benzene sulfur, significant reductions in sulfur in LCO and HFO were observed.

The sulfur materials in the light 'LCO fraction were analyzed with a sulfur GC. The concentration of each organosulfur class was as shown in Table 17 and Figure 5 for light LCO.

15

Table 17

Sulfur specification for light LCO from CFHT feed.

(ppm sulfur in light LCO) Ekat base case + 12% Ce + V / USY

(cat. J) C3 + thiophenes 4 1

Benzothiophene 20 14

Ci-Benzothiophenes 141 106 C2-Benzothiophenes 237 174 C3 + Benzothiophenes 295 215

Dibenzothiophene 17 .14

Ci-dibenzothiophenes 47 34 C2-dibenzothiophenes 32 25 C3-dibenzothiophenes 20 13 C4 + dibenzothiophenes 3 1

Sum 815 599 1 2 3 4 5 6 1013966 2

As shown in Figure 5, the light LCO mainly contains 3 benzothiophene sulfur materials. The sulfur reductions, equivalent to 4% total sulfur reduction in light LCO of 5-27%, were more pronounced for substituted benzothiophenes such as C 1 through C 3 + benzothiophenes. The results are completely - 50 - expected as substituted benzothiophenes are more voluminous and expected to be more difficult to crack and desulfurize in FCC.

The sulfur materials in the heavy LCO fraction were as shown in Table 18 and Figure 6. The heavy LCO mainly contains 5 dibenzothiophene sulfur materials. The sulfur reductions (14% total for heavy LCO) were more pronounced for substituted dibenzothiophenes such as C1 to C4 + dibenzothiophenes. The results are quite unexpected since substituted dibenzothiophenes are more voluminous and are expected to be more difficult to crack and desulfurize in FCC.

Table 18

Sulfur specification of heavy LCO from CFHT food.

(ppm sulfur in heavy LCO) Ekat base case + 12% Ce + V / USY

(cat. S)

Benzothiophene 0 0

Ci-Benzothiophenes 2 1 C2-Benzothiophenes 12 7 C3 + Benzothiophenes 128 86

Dibenzothiophene 65 54

Ci-dibenzothiophenes 361 312 C2-dibenzothiophenes 537 480 C3-dibenzothiophenes 475 425 C4 + dibenzothiophenes 378 322

Sum 1957 ^ 1687 15

The sulfur reduction catalyst is effective in reducing benzothiophene and dibenzothiophene sulfur materials as well as thiophene sulfur materials. Sulfur reduction mainly occurs in substituted benzothiophenes and substituted dibenzothiophenes. These results suggest that the C-S bonds in alkyl-substituted thiophenes are more reactive and more sensitive to cracking.

Reducing substituted thiophenes, substituted benzothiophenes and substituted dibenzothiophenes into sulfur was quite unexpected and will enhance the effectiveness of a subsequent LCO hydrodesulfurization process. From LCO

'1 r'i i o C.? ·>

Ij U l O o Vi, - - 51 - hydrodesulfurization process, it is known that methyl and / or alkyl substitution of benzothiophene and dibenzothiophene causes the desulfurization reactivity of the organic sulfur materials to decrease significantly and become "hard sulfur" or "heat resistant sulfur" . The LCO used here, which contained a lower amount of substituted benzo and dibenzothiophenes, will generate a diesel fuel with a lower sulfur content after a hydrodesulfurization process than the comparable LCO generated with a conventional FCC catalyst.

1013966

Claims (32)

A method for reducing the sulfur content of a catalytically cracked petroleum fraction, which method comprises catalytically cracking a high-boiling petroleum feed fraction containing organic sulfur compounds at elevated temperature in the presence of a cracking catalyst and a product sulfur reduction catalyst containing a porous molecular sieve with (i) a first metal component located within the inner pore structure of the molecular sieve and comprising vanadium in an oxidation state greater than zero and (ii) a second metal component located within the internal pore structure of. the molecular sieve and that at least one rare earth in a matrix comprising aluminum trioxide or silica-aluminum-trioxide with clay to prepare liquid cracking products with a reduced sulfur content. 15 The method of claim 1 wherein the product sulfur reduction catalyst comprises a large pore size or medium pore size zeolite as a mole screen component. The method of claim 2 wherein the large pore size zeolite comprises a faujasite zeolite. The method of claim 2 wherein the first metal component comprises 0.2 to 5 wt% vanadium. 25 The method of claim 2 wherein the second metal component comprises lanthanum alone or in combination with cerium. 6. The method of claim 2 wherein the second metal component comprises cerium. A method according to claim 1 wherein the second metal component is present in an amount of 1 to 10% by weight of the catalytic composition. The method of claim 1 wherein the product sulfur reduction catalyst comprises a USY zeolite having a UCS of 2,420 to 2,460 nm, a bulk silica: aluminum trioxide ratio of at least 5.0 as a molecular sieve component and as a first metal component vanadium in an oxidation state higher than zero and as the second metal constituent cerium alone or in combination with lanthanum. 5 The method of claim 1 wherein the sulfur reduction catalyst is a separate particulate additive catalyst. The method of claim 1 wherein the reduced sulfur liquid cracking products comprise a gasoline fraction, a cycle oil fraction and a fuel oil fraction, the cycle oil and fuel oil boiling above the gasoline fraction. 11. Fluid catalytic cracking process in which a heavy hydrocarbon feed containing organic sulfur compounds is catalytically cracked to lighter products by contacting it in a cyclic catalyst recirculation cracking process with a circulating fluidizable catalytic cracking catalyst stock consisting of particles having a size of 20 up to 100 microns, by: (i) catalytic cracking of the feed in a catalytic cracking zone operating at catalytic cracking conditions by contacting the feed with a regenerated cracking catalyst source to prepare a crack zone outflow containing cracked products and spent catalyst and containing coke and strippable hydrocarbons; (ii) discharging and separating the effluent mixture into a vapor phase rich in the cracked product and a phase rich in solids and comprising spent catalyst; (iii) removing the vapor phase as a product and fractionating the vapor to form liquid cracking products including gasoline, (iv) stripping the spent catalyst phase rich in solids to remove entrapped hydrocarbons from the catalyst (v) transferring the stripped catalyst from the stripper to a catalyst regenerator, (vi) regenerating the stripped catalyst by contacting it with oxygen-containing gas to prepare regenerated catalyst; and (vii) returning the regenerated catalyst to the cracking zone for contacting further amounts of heavy hydrocarbon feed, wherein the sulfur content of the liquid cracking products is reduced by performing the catalytic cracking in the presence of a product sulfur reduction catalyst containing a porous moiety -10 a molecular sieve comprising (i) a first metal component located within the inner pore structure of the molecular sieve and comprising vanadium in an oxidation state greater than zero, and (ii) a second metal component located within the inner pore structure of the molecular sieve and at least one rare earth in a matrix comprising aluminum trioxide or silicon dioxide aluminum trioxide with clay. The method of claim 11 wherein the cracking catalyst 20 comprises a faujasite zeolite in a matrix. 13. The method of claim 12 wherein the product sulfur reduction catalyst comprises a large pore size or medium pore size zeolite as the molecular sieve component, vanadium as the first metal component and cerium, alone or in combination with at least one other rare earth as the second metal component. 14. The method of claim 13 wherein the large pore size zeolite of the product sulfur reduction catalyst comprises a faujasite zeolite. The method of claim 11 wherein the first metal component comprises 0.2 to 5 wt% vanadium. 35 The method of claim 11 wherein the second metal component comprises lanthanum alone or in combination with cerium. A method according to claim 11, wherein the second metal component comprises cerium. The method of claim 11, wherein the second metal component is present in an amount of 1 to 10% by weight of the catalytic composition. 5 The method of claim 11 wherein the liquid cracking products comprises a reduced sulfur gasoline fraction and a reduced sulfur cycle oil fraction boiling above the gasoline fraction. 10 20. A fluidizable product sulfur reduction catalytic cracking catalyst composition for reducing the sulfur content of a catalytic cracked gasoline fraction during the catalytic cracking process, said composition comprising fluidisable particles having a size of 20 to 100 micrometers of (i) a porous molecular sieve component, (ii) a first metal component comprising vanadium in a oxidation state greater than zero contained within the inner pore structure of the porous molecular sieve component, and (iii) a second metal component consisting of a rare earth metal contained within the internal pore structure of the porous molecular sieve component, in a matrix comprising aluminum trioxide or silica-aluminum trioxide with clay. 25 The fluidizable product sulfur reduction catalytic cracking catalyst composition of claim 20 wherein the porous molecular sieve component comprises a porous hydrocarbon cracking sieve component. 30 A fluidizable product sulfur reduction catalytic cracking catalyst composition according to claim 21 wherein the porous molecular sieve component comprises zeolite USY having a UCS of 2,420 to 2,460 nm and a bulk silica: aluminum trioxide ratio of at least 5.0. A fluidizable product sulfur reduction catalytic cracking catalyst composition according to claim 22 wherein the porous molecular sieve component comprises zeolite USY with a UCS * 101 39 66 ^ 5 6 of 2,420 to 2,435 nra and a bulk silica: alumina ratio of at least 5.0 . A fluidizable product sulfur reduction catalytic cracking catalyst composition according to claim 20 comprising from 0.1 to 5 weight percent vanadium as the first metal component, based on the weight of the zeolite, of the first metal component. A fluidizable product sulfur reduction catalytic cracking catalyst composition according to claim 24 comprising as a second metal component a combination of cerium and at least one other rare earth. The fluidizable product sulfur reduction catalytic cracking catalyst composition of claim 20, which comprises cerium as a second metal component. The fluidizable product sulfur reduction catalytic cracking catalyst composition of claim 20, wherein the metal components are introduced into the zeolite as exchanged cationic materials within the zeolite pores. 28. The fluidizable product sulfur reduction catalytic cracking catalyst of claim 20, which is formulated with a matrix component as a fluid cracking catalyst additive. The fluidizable catalytic cracking product sulfur reduction catalyst of claim 20, which is formulated as an integrated fluidizable catalytic cracking / product sulfur reduction catalyst for cracking a heavy hydrocarbon feedstock to prepare liquid cracking products comprising gasoline and reducing sulfur content of the catalytic gas -35 cracked gasoline fraction during the catalytic cracking process comprising fluidisable particles having a size of 20 to 200 micrometers of a hydrocarbon cracking component comprising a zeolitic molecular sieve containing within the pore structure of the zeolite 40 (i) a first metal component comprising vanadium and «Ι0139 66 · (ii) a second metal component comprising at least one rare earth element. An integrated fluidizable catalytic cracking / product-5 sulfur reduction catalyst according to claim 29 containing from 0.1 to 5% by weight, based on the weight of the zeolite, of vanadium as the first metal component. The integrated fluidizable product sulfur reduction catalytic cracking catalyst of claim 29 wherein the second metal component contains a combination of cerium and at least one other rare earth in an amount of 1 to 5 weight percent of the catalyst. The integrated fluidizable product sulfur reduction catalytic cracking catalyst of claim 29 wherein the second metal component comprises a combination of cerium in an amount of 1 to 5% by weight of the catalyst. The integrated fluidizable product zwayel catalytic cracking reduction catalyst of claim 29 wherein the zeolitic molecular sieve comprises zeolite USY having a UCS of 2,420 to 2,460 nm and a bulk silica: aluminum trioxide ratio of at least 5.0. 25 The fluidizable product sulfur reduction catalytic cracking catalyst composition of claim 32, wherein the porous molecular sieve component comprises zeolite USY having a UCS of 2,420 to 2,435 nm and a bulk silica: aluminum trioxide ratio of at least 5.0. The fluidizable catalytic cracking sulfur reduction catalyst of claim 29, which is formulated as an integrated sulfur reduction catalytic converter with a matrix component and a faujasite zeolite as the cracking component. f013966