NL8200987A - CRACKING CATALYST / SULFUR OXIDE ACCEPTOR MATERIALS AND METHOD FOR CRACKING HYDROCARBONS. - Google Patents

Description

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Cracking catalyst / sulfur oxide acceptor materials as well as hydrocarbon cracking process.

The invention relates to catalysts used to catalytically crack hydrocarbons and to sulfur oxide absorbing / accepting materials which can be used to control sulfur oxide emissions.

More particularly, the invention relates to the preparation and use of catalytic cracking catalysts capable of the amount of sulfur oxides (SO) emitted to the atmosphere during regeneration.

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Decrease the catalyst and very effective SO controls that can be used to reduce SO

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control emissions from a variety of working methods.

Cracking catalysts used to crack hydrocarbon raw materials become relatively inactive due to the deposition of carbonaceous deposits on the catalyst. These carbonaceous deposits are commonly called coke. When the raw materials contain organic sulfur compounds, the coke on the catalyst contains sulfur. After the cracking step, the catalyst goes to a stripping zone where steam is used to remove strippable hydrocarbons from the catalyst. The catalyst then goes to the regenerator where it is regenerated by burning the coke in an oxygen-containing gas. This converts the carbon and hydrogen in the coke into carbon monoxide, carbon dioxide and water. The sulfur in the coke is converted into oxides of sulfur, SC ^ and SO ^, i.e. SO ^.

In general, the greater the amount of sulfur in the raw material, the greater the amount of sulfur in the coke. Likewise, the greater the amount of sulfur in the coke, the greater the amount of sulfur oxides in the combustion gas leaving the regenerator. In general, the amount of SC> 2 and SO 2, that is to say SO 2, in the combustion gas is about 250 to 2500 parts per million by volume, in the amount of SC> 2 - 2 -.

The prior art has proposed several methods of removing or preventing the release of SO to the atmosphere during oxidative combustion of sulfur-containing fuels / residues. Often FCC / combustion units are equipped with conventional washers in which the SO 2 components are removed from combustion gas by absorption / reaction with SO acceptors (referred to in English as "getters"), such as calcium oxide.

In some cases, hydrocarbon feedstocks are pretreated (hydrotreated) to remove sulfur. It has also been reported that sulfur oxide emissions from FCC units (fluidized catalytic cracking units) can be controlled using a cracking catalyst in combination with a sulfur absorber or acceptor. These sulfur acceptors have also been reported to be more effective when used in the presence of oxidation catalysts. Oxidation catalysts are currently used in FCC units to oxidize CO to CO2 in the catalyst bed during the coke combustion step in the regenerator. The oxidation of CO to CO2 in the catalyst bed has many advantages. One advantage is the reduction of CO emissions. Another advantage is to avoid "afterburning", ie the oxidation of CO to CO2 outside the catalyst bed, which results in a loss of heat energy and damage to the cyclones and the flue gas exhaust pipes. The main advantage of using oxidation catalysts to oxidize CO to CO2 in the catalyst regenerator bed arises from the heat released when CO is oxidized to CO2. This heat increases the temperature of the catalyst bed and thereby increases the coke burning rate. This gives a lower residual carbon level, on regenerated catalyst (CRC). This in turn makes the regenerated catalyst more active for the cracking step. This increases the amount of beneficial products produced in the FCC integrity.

8200987 - 3 - 5 sc

Given that CO oxidation catalysts are common in many FCC units for economic reasons, SO acceptors for use in FCC units must be compatible and effective in the presence of oxidation catalysts. Furthermore, SO 2 acceptors for use in FCC units must be effective under the actual conditions found in FCC units, such as temperatures of 427 to 538 ° C and catalyst residence times of 3 to 15 seconds in the reactor reducing atmosphere, temperatures of 427 to 538 ° C in the steam atmosphere of the stripper, temperatures of 593 to 760 ° C and catalyst residence times of 5 to 15 minutes in the oxidizing atmosphere of the regenerator. Furthermore, SO accepting agents must be used

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are effective in FCC units in the presence of the materials contained in FCC-15 units, such as cracking catalysts of various compositions, oil starting materials of various compositions and the cracked products thereof, and, as previously noted, oxidation catalysts for the oxidation of CO to CO2 · 20 The following US patents describe the use of cracking catalysts containing various sulfur and carbon monoxide emission control agents.

3,542,670 3,699,037 25 3,835,031 4,071,436 4,115,249 4,115,250 4,115,251 30 4,137,151 4,151,119 4,152,298 4,153,534 4,153,535 „35 4,166,787 4,182,693 8200987 - 4 - 4,187,199 4,200,520 4,206,039 4,206,085 5 4,221,677 4,238,317.

As shown in the above literature sites, organic sulfur present during the regeneration of the cracking catalyst is eventually oxidized to sulfur trioxide (SO 2) which reacts with an acceptor to form a stable sulfate which is retained in the catalyst inventory of the FCC- unit. Regenerated catalyst containing the sulfate compound is recycled to the cracking zone where the catalyst is mixed with oil and steam dispersant to effect the cracking reaction and conversion of the oil to useful products (gasoline, light olefins, etc.).

When the sulfate-containing catalyst is exposed to the reducing and hydrolyzing conditions present during the cracking step and subsequent hydrolysing conditions present in the steam stripper, the sulfate is reduced and hydrolyzed to form hydrogen sulfide (H 2 S) and the acceptor is restored or regenerated. The hydrogen sulfide is recovered as a component of the cracked product stream. The acceptor is returned to the regenerator to repeat the process. By using catalysts containing appropriate acceptors, it is reported that the amount of sulfur oxides emitted from the regenerator can be significantly reduced.

However, it has been found that attempts to produce SO control cracking catalysts that can consistently achieve significant sulfur oxide emission reductions over long periods have generally been unsuccessful.

Accordingly, an object of the present invention is to provide a cracking catalyst material which effectively and economically reduces the sulfur oxides emission from FCC units.

Another object is to provide a sulfur oxide acceptor capable of removing sulfur oxides over a long period of time when subjected to multiple acceptance / regeneration cycles.

A further object is to provide SO control additive which can be added to the catalyst inventory of an FCC unit in amount necessary to reduce sulfur oxide regeneration flue gas emissions to an acceptable level.

Another object is to provide highly effective sulfur oxide acceptors that can be advantageously combined with conventional cracking catalyst materials or used to control SO 2 emissions from a variety of processes.

These and other objects will become apparent to those skilled in the art from the following detailed description, specific examples, and the drawing, which are graphical representations of the data illustrating the SO index as a function of the La 2 O 2 content. of SOx acceptors according to the invention.

Generally speaking, the invention relates to catalytic cracking catalyst materials comprising an alumina, lanthanum oxide-SO acceptor. Further

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The invention includes an improved SO acceptor comprising an alumina (Al2O3) -3 ^ street, coated with lanthanum oxide (Ι ^ Ο ^) in amounts containing an approximately theoretical mono-layer of La 2 O 3 molecules. provide the surface of the alumina substrate. These acceptor agents can be effectively combined with or incorporated into particulate catalyst materials used for hydrocarbon catalytic cracking, or alternatively, the acceptor agents can be used in any combustion process that generates SO 2 components which must be selectively removed from the combustion products.

More specifically, it has been found that a particularly effective S0 absorber / acceptor is suitable for use with GE.

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8200987

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Use in catalytic cracking catalysts can be obtained by combining the soluble lanthanum salt solution with a porous alumina substrate in amounts which will distribute a layer of lanthanum oxide 5 about 1 molecule thick on the surface of the alumina substrate.

In practice, Applicant has found that the desired result is achieved with about 5 to 50 wt% La 2 ^ 3 combined with an alumina substrate having a specific surface area of about 45 to 450 2 10 m / g; preferably about 12 to 30 wt% La 2 O 2 combined with an alumina substrate having a specific surface area of about 110 to 270 m / g, and even more preferably about 20 wt 2 La 2 O 2 combined with an alumina substrate having ^ 2 a specific surface area of about 180 m / g.

Suitable alumina substrates are available from many commercial sources and include the alumina hydrates, such as alpha alumina monohydrate, alpha alumina trihydrate, beta alumina monohydrate and beta alumina trihydrate. Also considered most suitable are the fired versions of the above alumina hydrates. These include gamma alumina, chi alumina, eta alumina, kappa alumina, delta alumina, theta alumina, alpha alumina and mixtures thereof.

The lanthanum oxide component applied to the aluminum oxide surface can be obtained in the form of a commercially available lanthanum salt, such as lanthanum nitrate or chloride or sulfate, or alternatively a mixed rare earth salt containing other rare earth salts. 30 elements such as Nd, Ce, Pr and Sm are used. The rare earth component of a typical commercially available mixed rare earth salt solution comprising lanthanum has the following approximate composition, expressed as oxides: 60 Zi ^ O ^, 20 Z ^ 0 ^, 14 Z CeO2 .5 Z Pr ^ O ^ and 1 Z 35 ^ m2 ^ 3 'et Za ^ it is clear that in the case of using a mixed rare earth salt source, the amount used is 8200987 - 7 - i mixed rare earth salts should be sufficient to provide the desired level of La2 O2 on the alumina substrate.

Preferably, the amount of lanthanum oxide used in the preparation of the new SO acceptor is that amount which will provide a mono-layer of lanthanum oxide molecules over the surface of the alumina substrate.

In the event that the amount of lanthanum oxide as indicated above is significantly exceeded, ie a multilayer or mass of lanthanum oxide is formed, the effectiveness of the SO acceptor is adversely affected. On the other hand,

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if insufficient lanthanum oxide is used, the acceptor's effectiveness is less than could be.

Although the exact mechanism is not fully understood, it is believed that the active spoil is a La 2 O molecule fixed on the alumina surface in a kind of surface complex of I 2 Og and A 2 O Og. This. surface complex from LagOg to AlgOg is very reactive when combined with sulfur oxides to form a thermally stable solid sulfate or sulfate type compound. Furthermore, this thermally stable solid sulfate or sulfate type compound can be easily reduced-hydrolysed to provide volatile hydrogen sulfide and to restore or regenerate the original complex from 10 Og to Al Og.

The hydrogen sulfide can be recovered as a component of the product stream. The recovered or regenerated acceptor can be returned to repeat the absorption and regeneration steps.

To prepare the new S0 acceptors of the invention, the alumina substrate is uniformly and thoroughly mixed with an amount of lanthanum salt solution which will provide the desired even dispersion of lanthanum oxide on the surface. Often the soluble lanthanum salt, preferably lanthanum nitrate, is dissolved in water to provide a desired volume of solution giving the desired concentration of the lanthanum salt. The aluminum oxide substrate is then impregnated as evenly as possible with the lanthanum salt solution to provide the desired amount of lanthanum on the alumina. The impregnated alumina is then calcined at a temperature sufficient to decompose the lanthanum salt and evenly fix the resulting lanthanum oxide on the alumina surface. Although it is possible to use firing temperatures up to about 816 ° C, firing temperatures of the order of 538 ° C have been found to be satisfactory.

In a preferred embodiment of the invention, the aluminum oxide substrate to be impregnated is in the form of microspheroidal particles, with about 90% of the particles having diameters in the fluidizable size range from 20 to 149 µm. The acceptor obtained using these microspheroidal particles can advantageously be physically mixed with FCC catalysts in amounts ranging from about 0.5 to 60% by weight of the total material.

In another preferred embodiment of the invention, the alumina substrate to be impregnated is in the form of particles having an average particle size of less than 20 microns in diameter and preferably less than 10 microns in diameter. The finished acceptor obtained using these fine particles can be incorporated into a cracking catalyst material during the formation of the catalyst particles.

Typically, the lanthanum-impregnated alumina is added to an aqueous slurry of catalyst components prior to formation, i.e., spray drying in the case of FCC catalysts.

In another embodiment of the invention, the alumina substrate to be impregnated is in the form of particles with a diameter of 1 mm or more. The finished acceptor obtained using these particles can be used in either a fixed bed or moving bed configuration to reduce SO emissions from a variety of process

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sen.

8200987 \ - 9 -

Thus, it is seen that the present acceptor may be used as a separate additive which is added to the catalyst in the form of a separate particulate component, or the acceptor may be combined with the catalyst during its preparation to form catalyst particles. containing the acceptor agent in the form of an integral component. Furthermore, the acceptor can be used by itself to reduce SOx emissions from a variety of processes.

Cracking catalysts which can advantageously be combined with the SO acceptor of the invention are commercially available materials and often include crystalline zeolites mixed with inorganic oxide binders and clay. Often these catalysts comprise about 5 to 50 weight percent crystalline aluminosilicate zeolite in combination with a silica, silicon dioxide alumina or alumina hydrogel or sol binder and optionally about 10 to 80 weight percent clay. Zeolites commonly used in the preparation of cracking catalysts are stabilized Y-type zeolites, the preparation of which is described in U.S. Pat. Nos. 3,293,192, 3,375,065, 3,402,996, 3,449,070 and 3,595,611. The preparation of catalyst materials that can be used in the practice of the present invention are typically described in U.S. Pat. Nos. 3,957,689, 3,867,308, 3,912,611 and Canadian Patent 967,136.

In a preferred embodiment of the invention, the cracking catalyst acceptor material will be used in combination with a noble metal oxidation catalyst, such as platinum and / or palladium.

In another preferred embodiment of the invention, the SO acceptor is combined with a cracking catalyst containing an aluminum oxide sol, ie, aluminum chlorine hydroxide solution, bonded zeolite / clay 8200987-10 material as described in Canadian Patent 967,136, with a particulate platinum-containing oxidation catalyst, to provide a material containing 0.5 to 60 wt.% acceptor, 40 to 99 wt.% cracking catalyst, and 1 to 5 parts per million platinum.

In another preferred embodiment of the invention, the SO acceptor is combined with a zeolite cracking catalyst which has a substantially silica-free matrix. These catalysts are obtained using the procedure described in Canadian Patent 967,136 by mixing the following materials together: 5 to 50 wt% zeolite, 10 to 80 wt% aluminum hydrate (dry basis) and 5 to 40 wt% aluminum chlorohydroxydesol (Α ^ Ο ^) and water. The mixture was spray dried to obtain a finely divided catalyst composite and then fired at a temperature of about 538 ° C. The SO acceptor can be incorporated as a component in the spray dried suspension instead of a portion of the alumina hydrate or the SO acceptor can be physically mixed with the catalyst in an amount of about 0.5 to 60 wt. %.

As indicated above, the acceptor can be used in the form of a separate particulate additive that is physically mixed with a particulate catalyst or the acceptor can be incorporated into the catalyst particle by mixing the additive with the catalyst components prior to molding of the catalyst. In addition, it is possible to use the acceptor in any combustion / reaction process where it is desirable to collect or remove sulfur oxides from a product gas stream. Typically, the SO acceptor can be used in a fluidized coal combustion process to remove SO formed during the combustion of the coal.

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The SO 2 acceptor can then be removed from the combustion / reaction zone either periodically or continuously to restore or regenerate the acceptor by subjecting it to reduction hydrolysis in the presence of hydrogen or carbon monoxide-hydrogen reducing gas mixtures (i.e., syn gas) and ELO. Using this technique, the SO component of the combustion products is selectively removed in the form of a stable sulfate, and the sulfate is then reduced-hydrolysed to release and restore or regenerate the acceptor. It can be recovered using conventional adsorption techniques.

Having described the bases of the present invention, the following examples are presented to illustrate specific embodiments thereof. Example I

A solution of lanthanum nitrate was prepared by mixing 79.7 g of lanthanum nitrate, LaiNO 2 g. Dissolve 6 ^ 0 in a sufficient amount of water to provide 100 ml of solution. 10 ml of this solution contains 3.0 g lanthanum, expressed as lanthanum oxide, ^ ^ O ^ ·

Example II

36.8 g (27 g on a dry basis) of a commercial alpha alumina monohydrate with an average particle size of 67 microns, with 96 wt% of the particles being in the size range of 20 to 149 microns, were impregnated with 30 ml of the solution described in Example I. The impregnated alumina was heated to 538 ° C and held at 538 ° C for 30 minutes. The resulting I ^ O ^ / A ^ O ^ sample contained 10 wt% I ^ O ^.

Example III

alpha alumina monohydrate of the type described in Example II was fired in air for 30 hours at 482 ° C. 27 g of this fired alumina was impregnated with 10 ml of the solution described in Example I. The impregnated sample was heated to 538 ° C and held at 538 ° C for 30 minutes. The resulting I ^ O ^ / A ^ Oym sample contained 10 wt% lanthanum oxide, La ^ O ^ ·

Example IV

The procedure of Example III was repeated except that the alumina hydrate was fired for 1 hour at 677 ° C prior to impregnation with lanthanum nitrate solution.

Example V

The procedure of Example III was repeated except that the alumina hydrate was fired at 899 ° C for 1 hour prior to impregnation with lanthanum nitrate solution.

Example VI

The procedure of Example III was repeated except that the alumina hydrate was fired at 1010 ° C for 1 hour before impregnation with lanthanum nitrate solution.

Example VII

The procedure of Example III was repeated except that the alumina hydrate was fired at 1066 ° C prior to impregnation with lanthanum nitrate solution.

Example VIII

Aluminum oxide hydrate of the type described in Example II was fired in air for 1 hour at 677 ° C. 5 ml of the solution described in Example I was mixed with 5 ml of water to give 10 ml of a solution with a lanthanum concentration of 1.50 g of lanthanum, expressed as 25 La2 ° 3 ^ 8.5 van of the fired alumina was impregnated with the 30 ml solution. The impregnated sample was heated to 538 ° C and held at 538 ° C for 30 minutes.

The resulting Al2O-1110 ^ ter contained 5 wt% I ^ O ^.

Example IX

Aluminum oxide hydrate of the type described in Example II was fired in air for 1 hour at 677 ° C. 24 g of this fired aluminum oxide was impregnated with 10 ml of the solution described in Example I. The impregnated sample was heated to 538 ° C and held at 538 ° C for 30 minutes. After it was allowed to cool to room temperature, the impregnated and fired sample was given a second impregnation with 10 ml of the solution described in Example 1. After this second impregnation, the sample was heated to 538 ° C and held at 538 ° C for 30 minutes.

The resulting I ^ OG / A ^ O ^ sample contained 20 wt% I ^ O ^.

5 Example X

A solution of lanthanum nitrate was prepared by dissolving 99.8 g of LaCNO 2 .sub.2 O in water to give 100 ml of the solution. 8 ml solution contains 3.0 g lanthanum, expressed as -

Example XI

Aluminum oxide hydrate was fired in air for 1 hour at 677 ° C as in Example IX. 21 g of this fired alumina was impregnated with 8 ml of the solution described in Example X. The impregnated sample 15 was heated to 538 ° C and held at 538 ° C for 30 minutes. After being allowed to cool to room temperature, the impregnated and fired sample was given a second impregnation with 8 ml of the solution described in Example X. After this second impregnation, the sample was heated to 538 ° C and held at 538 ° C for 30 minutes. After it was allowed to cool to room temperature, this twice-impregnated and fired sample was given a third impregnation with 8 ml of the solution described in Example X. After this third impregnation, the sample was again heated to 538 ° C and held at 538 ° C for 30 minutes. The resulting / A ^ O ^ sample contained 30 wt% La ^ O ^ ·

Example XII

The procedure of Example XI was repeated, except that 18.0 g of fired alumina was used, and after the third impregnation and firing the sample was given a fourth impregnation and firing at 538 ° C. The resulting I ^ O ^ / A ^ O ^ sample contained 40% by weight.

Example XIII

A solution of mixed rare earth nitrates was prepared by mixing 153.1 g of a commercial mixed rare earth nitrate solution with water to provide 100 ml. 8 ml of the solution contained 3.0 g of mixed rare earths, expressed as the oxides. The rare earth component of this solution, expressed by weight as oxides, has the following composition: 60% I ^ O ^, 20% 5 ^ 20 ^, 14% 0εθ2 »5% Pr ^ Ojj and 1% Sn ^ O ^ .

Example XIV

The procedure of Example IX was repeated, except that the impregnations were carried out with 8 ml of the solution described in Example XIII. The resulting sample contained 20 wt% mixed rare earth oxides. 60% of these rare earth oxides were lanthanum oxide, so that the resulting sample contained 12 wt% I 2 O 2. Example XV

The procedure of Example XI was repeated except that the impregnations were performed with 8 ml of the solution described in Example XIII. The resulting sample contained 30% by weight of mixed rare earth oxides, 60% of which was lanthanum oxide. The resulting sample contained 18 wt% I / Oy 20 Example XVI

A solution of mixed rare earth nitrates was prepared by mixing 152.8 g of a commercial mixed rare earth nitrate solution with water to give 100 ml. 10 ml of solution contains 3.75 g of mixed rare earth, expressed as the oxides. The rare earth component of this solution, expressed as oxides, has the following composition: 60% I ^ O ^, 20% ^ 20 ^, 14% CeO2, 5% Pr ^ Ojj and 1% Sn ^ O ^ ·

Example XVII

The procedure of Example IX was repeated except that the impregnations were performed with 10 ml of the solution described in Example XVI. The resulting sample contained 25% by weight of mixed rare earth oxides. 60% of these rare earth oxides were lanthanum oxide so that the resulting sample contained 15% by weight.

Example XVIII

8200987 -15--

Fine alpha alumina monohydrate was fired in air for 1 hour at 677 ° C. This fired alumina had an average particle size of 15 to 20 microns. 2000 g (dry basis) of this fired aluminum-5 oxide was mixed with a solution containing 592 g of La (NO ^) 3.6 ^ 0 dissolved in 1400 ml of water in a mechanical mixer.

The solution was added at a rate of 100 ml per minute to this alumina. The impregnated alumina was removed from the mixer, heated to 538 ° C and held at 538 ° C for 10 minutes. The sample contained 10 wt% La 2 O 2 and had an average particle size of less than 10 micrometers.

Example XIX

Alpha alumina monohydrate was fired in air for 1 hour at 677 ° C to obtain a product with an average particle size of 15 to 20 µm diameter. 2000 g (dry basis) of this calcined alumina was mixed with a solution of 670 g of LaiNO ^ 6 ^ 6H ^ 0 dissolved in 1400 ml of water in a mixer. The solution was added at a rate of 100 ml per minute.

The impregnated alumina was removed from the mixer, heated to 538 ° C and held at 538 ° C for 30 minutes.

This impregnated and fired alumina was returned to the blender and given a second impregnation with 670 g of LaiNO 6 .6 ^ 0 in 1200 ml of water added at a rate of 100 ml per minute. The impregnated material was heated to 538 ° C and held at 538 ° C for 30 minutes. The finished material contained 20 wt% l <a2 ^ 3 and had an average particle size of less than 10 µm.

30 Example XX

The finished SO acceptor of Example XVIII was incorporated within the particle of an alumina-bonded cracking catalyst. The catalyst was prepared by mixing the following materials together: The S0x acceptor of Example XVIII, a rare earth ion-exchanged crystal line of Y-type aluminosilicate, clay, aluminum chlorohydroxide-8200987-16 (approximated formula Al ^ GlCOH) and water. The mixture was spray dried and then fired at 538 ° C for 2 hours. The ratio of the starting materials was such that the finished catalyst contained 20% SO acceptor of Example XVIII, 12% 5 rare earth ion-exchanged crystalline Y-type aluminosilicate, 54% clay and 14% aluminum oxide. The finished catalyst had an average particle size of 116 microns, with 65% by weight of the particles in the size range of 20 to 149 microns.

10 Example XXI

The procedure of Example XX was repeated except that the SO acceptor of Example XIX was used.

In this example, the finished catalyst had an average particle size of 77 microns with 87 wt% of the particles falling in the size range of 20 to 149 microns.

Example XXII

An alumina sol-bonded cracking-20 catalyst was prepared by mixing the following materials together: a rare earth ion-exchanged crystalline Y-type aluminosilicate (CREY), clay, aluminum chlorohydroxydesol (approximated formula A ^ CliOH).) and water. The mixture was spray dried and then fired at 538 ° C for 2 hours.

The ratio of the starting materials was such that the finished catalyst contained 12% of a rare earth ion-exchanged crystalline Y-type aluminosilicate, 78% clay and 10% aluminum oxide.

The finished catalyst had an average particle size of 71 microns with 97 wt% of the particles falling in the size range of 20 to 149 microns.

29.89 g (dry base) of this aluminum oxide-bonded cracking catalyst was thoroughly mixed with 0.1110 g (dry base) of an oxidation catalyst containing 810 35 ppm platinum on a gamma alumina support with a particle size in the fluidisable range includes.

8200987 ___ ........: - - 17 -

Example XXIII

26.89 g (dry base) of the cracking catalyst described in Example XXII was intimately mixed with 0.1110 g (dry base) of the oxidation catalyst, also described in Example XXII. 3.00 g (dry basis) of a commercial alpha alumina monohydrate was added to this mixture and mixed intimately.

Example XXIV

26.89 g (dry base) of the cracking catalyst described in Example 10 XXII was intimately mixed with 0.1110 g (dry base) of the oxidation catalyst, also described in Example XXII. 3.00 g (dry basis) of the Ι ^ Οβ / Α ^ Ο ^ material prepared in Example II was added to this mixture and mixed intimately.

15 Examples XXV to XXXVI

The procedure of Example XXIV was repeated except that the third component to be mixed was the material prepared in Example III. Likewise, the procedure was repeated with the exception that the third component was the material prepared in Examples IV, V, VI, VII, VIII, IX, XI, XII, XIV, XV, and XVII, respectively.

Example XXXVII

29.89 g (dry base) of the finished catalyst of Example XX was intimately mixed with 0.1110 g of (dry base) of the oxidation catalyst described in Example XXII.

Example XXXVIII

29.89 g (dry base) of the finished catalyst of Example XXI was intimately mixed with 0.1110 g (dry base) of the oxidation catalyst described in Example XXII.

Example XXXIX

A laboratory scale catalytic cracking unit was used to test the catalyst materials for their ability to reduce emissions of SQx (SO2 + SO2) from the regenerator.

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Before testing the laboratory unit, the catalysts or catalyst mixtures were steam deactivated with 100% steam at 104 kPa at 732 ° C for 8 hours. This steam deactivation simulates the deactivation that takes place in a commercial catalytic cracking unit. The ability of a catalyst or catalyst mixture to reduce SO emissions in the laboratory test setup after this steam deactivation will be a measure of its ability to reduce SO emissions in commercial units. In contrast, the ability of a fresh or non-deactivated catalyst or catalyst mixture to reduce SO emissions in laboratory tests is not indicative of predicting the ability of the catalyst or catalyst mixture to produce SO 2 emissions in commercial units. because the catalyst or catalyst mixture in the commercial unit is deactivated soon after being brought into the commercial unit and can become intimately active in reducing SO emissions.

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In the laboratory unit, a gas-low sulfur oil was cracked over the catalyst or catalyst mixture at a temperature of 527 ° C. Regeneration of the catalyst or catalyst mixture, i.e. the coke combustion step, was performed with air at 677 ° C. The air used for the coke combustion step contained 2000 ppm SO2 * This is equivalent to the amount of SO2 that would be formed in the regenerator if a high sulfur gas oil had been used for the cracking step.

The regenerated catalyst or catalyst mixture was then subjected to the cracking step and the steam stripping step to release the SO 2 captured in the regenerator in the form of S.

The regeneration and cracking step and steam stripping step were repeated. During this second cycle, a portion of the catalyst or catalyst mixture was removed after the regeneration step and another portion of the catalyst or catalyst mixture was removed after the 8200987 f-19 cracking step and the steam stripping step.

An SO index that measures x the SOx captured in the regenerator and released into the reactor and the stripper was defined as; 5 Γ7 \ / \ Ί SO index = / wt% sulfur \ / wt% sulfur \ / content of the \ / content of the \ catalyst or the »/ catalyst or the \

Catalyst 1- J Catalyst x100

10 mixture after the 1 mixture after the regeneration \ cracking and \ step. steam stripping An example calculation for the catalyst mixture described in Example XXXI and tabulated in Table A is given below.

SO index * / “(0.167) - (0.097) J 1000 = 70

It should be noted that the SO index

a

20 is a measure of the amount of SO2 captured in the regenerator and released into the reactor and stripper. A catalyst or catalyst mixture that traps SO in the regenerator but this

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not released into the reactor and stripper would have an SO index of zero. Such a catalyst or catalyst mixture 25 would quickly become saturated, probably after one or two cycles, and lose its effectiveness in reducing SO emissions.

For long-term effectiveness, a catalyst or catalyst mixture must not only capture S0 in the regenerator, but be able to release it into the reactor and stripper and thereby restore its ability to repeat the process.

The greater the Davison SO2 index, the greater the long-term effectiveness of the catalyst or catalyst mixture in reducing SO emissions

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from the regenerator. As mentioned above, a 8200987 means - 20 -

Davison S0x index of zero that the catalyst is not effective, in the long run, for the reduction of SOx emissions from the regenerator. At the other extreme, a Davison SO index of 100 means close to 100% effectiveness over the long term

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5 mine, when reducing S0 emissions from the regenerator.

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The catalyst mixtures described in

examples XXII, XXIII, XXVI, XXXI, XXXII, XXXIII, XXXIV

and XXXV were tested for their ability to reduce SO 2 emissions according to the procedure described above. The SO indicia are given in Table A. A graphical representation of the data in Table A (except for the catalyst mixture described in Example XXII) is given in the drawing, where the SOx index is plotted against the percentage I ^ O ^ in the SOx acceptor in the mixture. The curve drawn in the drawing indicates that the maximum SO index is obtained when the S0x acceptor contains about 20% 10 ^.

More generally, the data in Table A show that the maximum in the 30χ index is obtained at I ^ O ^ concentrations at Al „0o greater than 12% and less than 30% (Example-2 3 i 20 den XXXII and XXXIV).

Table A

Catalyst mixture S0x ~ index described in example _ XXII 10 25 XXIII 18 XXVI 42 XXXIV 58 XXXV 70 XXXI 69 30 XXXII 56 XXXIII 44

Example XL

The catalyst mixtures described in Examples XXXVII and XXXVIII were tested for their ability to reduce SOx emissions according to the procedure described in Example XXXIX. The SO indices obtained are given in

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8200987 - 21 - Table B.

Table B

Catalyst mixture SO2 index described in Example 5 XXXVII 46 XXXVIII 58

Example XLI

The catalyst mixtures in Examples XXIV to XXIX were tested for their ability to reduce SO emissions according to the procedure described in Example XXXIX.

The Davison SO indices obtained are given in Table C.

The data in Table C show the effect of firing the alumina hydrate prior to impregnation with a solution of LaCNOp ^ .61 ^ 0. In Example XXIV, the alumina hydrate was not fired prior to impregnation. In Examples XXV to XXIX, the alumina hydrate was fired at temperatures ranging from 482 to 1066 ° C.

Table C

20 Effect of firing alumina prior to impregnation.

Catalyst mixture S0 __ index described in example _ XXIV 32 25 XXV 35 XXVI 42 XXVII 35 XXVIII 29 XXIX 36 30

Example XLII

The cracking catalyst used in this example is a commercially available cracking catalyst containing 17 wt% of a rare earth ion-exchanged crystalline Y-type aluminosilicate (KEY), 63 wt% clay and 20 wt% silicon dioxide. aluminum oxide sol binder.

8200987 - 22 - 29.89 g (dry base) of this cracking catalyst was intimately mixed with 0.1110 g (dry base) of an oxidation catalyst impregnated with 810 ppm platinum on a gamma alumina support with a particle size 5 in the fluidisable range includes.

Example XLIII

26.89 g (dry basis) of the cracking catalyst described in Example XLII was intimately mixed with 0.1110 g (dry base) of the oxidation catalyst, also described in Example XLII. 3.00 g (dry basis) of a commercial alpha alumina monohydrate was added to this mixture and mixed intimately.

Example XLIV

26.89 g (dry base) of the cracking catalyst described in Example XLII was intimately mixed with 0.1110 g (dry base) of the oxidation catalyst, also described in Example XLII. 3.00 g (dry basis) of the La2 O2 / Al2 O2 material prepared in Example IX was added to this mixture and mixed intimately.

20 Example XLV

The catalyst mixtures described in Examples XLII, XLIII and XLIV were tested for their ability to reduce SO 2 emissions according to the procedure described in Example XXXIX. The SO indices obtained are analyzed in Table D.

The results show that the silica-alumina sol-cracking catalyst gave an SO index of zero (Example XLII). The use of aluminum oxide as an SO acceptor gave an SO index of 5 (Example XLIII).

The use of a La202 / Al2O2-SOx acceptor according to the invention gave an SO index of 50 (example XLIV), which represents a significant improvement over the use of aluminum oxide.

35 8200987-23 -

Table D

Catalyst mixture SO2 index described in example ___ XL II 0 5 XLIII 5 XLIV 50

Example XLVI

27.00 g (dry basis) of the cracking catalyst described in Example XXII was intimately mixed with 3.00 g (dry basis) of the 3ja203 ^^ 2 ^ 3 ~ mater ^ aa · * '* prepared in Example IX. catalyst mixture was tested for its ability to reduce S0 emissions according to the

X

procedure described in example XXXIX. The SO-15 index obtained had a value of 48. This can be compared to an SO-SO index of 69 obtained for the catalyst mixture described in Example XXXI which contains an oxidation catalyst. This shows that the SO acceptor of the invention operates without the presence of an oxidation catalyst. It also shows that the presence of an oxidation catalyst increases the ability of the acceptor to reduce SO emissions.

25 8200987

Claims (43)

Catalyst material, characterized in that it comprises the following components: (a) a hydrocarbon cracking catalyst 5 and (b) a sulfur oxide acceptor comprising an alumina substrate coated with lanthanum oxide. 2. Material according to claim 1, characterized in that the aluminum oxide substrate contains 5 to 50% by weight of lanthanum oxide. Material according to claim 1, characterized in that the aluminum oxide has a specific surface area of about 45 to 450 m / g. 4. The material according to claim 1, characterized in that the aluminum oxide has a specific surface area of about 110 to 270 m / g and contains about 12 to 30% by weight of lanthanum oxide. 5. Material according to claim 1, characterized in that the aluminum oxide is coated with substantially a mono-layer of lanthanum oxide. Material according to claim 1, characterized in that the alumina substrate is an alumina hydrate. 7. Material according to claim 1, characterized in that the alumina substrate is fired. Material according to claim 1, characterized in that the alumina substrate coated with lanthanum oxide is fired. 9. The material of claim 1, characterized in that the cracking catalyst comprises a crystalline zeolite mixed with an inorganic oxide matrix. The material according to claim 1, characterized in that the lanthanum oxide is incorporated with a mixture of rare earth oxides. The material according to claim 8, characterized in that the zeolite is selected from the group consisting of hydrogen and / or rare earth exchanged zeolite of type X or Y, ZSM zeolites and mixtures thereof . Material according to claim 1, 5, characterized in that the cracking catalyst comprises a crystalline zeolite mixed with a matrix containing clay and / or alumina hydrate and dried alumina sol. The material according to claim 1, characterized in that the catalyst material comprises about 0.1 to 100 parts per million of a noble metal as an oxidation catalyst. 14. Material according to claim 13, characterized in that the oxidation catalyst is added to the catalyst material as precious metal impregnated on a particulate inorganic oxide. Material according to claim 13 or 14, characterized in that the oxidation catalyst is selected from the group consisting of platinum, palladium and mixtures thereof. Material according to claim 1, characterized in that the lanthanum oxide is distributed on the surface of the aluminum oxide in combination with an oxidation catalyst selected from the group consisting of platinum, palladium and mixtures thereof. Material according to claim 1, characterized in that particles of the acceptor agent are physically mixed with particles of the catalyst. 18. The material according to claim 1, characterized in that the acceptor agent is included in the particles of the catalyst. The material according to claim 1, characterized in that the catalyst material contains about 0.5 to 60% by weight of the sulfur oxide acceptor, 20. Sulfur oxide acceptor medium material 35, characterized in that it comprises the aluminum oxide and lanthanum oxide which is distributed essentially as a monolayer on the surface of the aluminum oxide. 21. Sulfur oxide acceptor material, characterized in that it comprises about 5 to 50% by weight of lanthanum oxide uniformly distributed on the surface of an aluminum oxide having a specific surface area of at least 45 m / g. Acceptor according to claim 21, characterized in that the aluminum oxide has a specific surface area 2 of about 110 to 270 m / g and contains about 12 to 30% by weight of lanthanum oxide. Acceptor according to claim 21, characterized in that the lanthanum oxide is incorporated with a mixture of rare earth oxides. Acceptor according to claim 21, characterized in that the lanthanum oxide is distributed on the surface of the aluminum oxide as a mono-layer. The material of claim 20, characterized in that it is formed into microspheroidal particles, with about 90% of the particles being in the diameter range of 20 to 105 microns. The material according to claim 20, characterized in that it is formed in particles, with about 90% of the particles being in the diameter range of 0.5 to 20 µm. 27. Material according to claim 20, characterized in that it is formed in particles with a diameter of more than 1 mm. The material according to claim 20, characterized in that it comprises an oxidation catalyst. 29. The material of claim 20, characterized in that it comprises a noble metal oxidation catalyst. The material according to claim 29, characterized in that the oxidation catalyst is included in amounts from about 0.1 to 1000 parts per million by weight of the material. 35 3J. Material according to claim 30, characterized in that the oxidation catalyst is selected from the 8200987-27 group consisting of platinum, palladium and mixtures thereof. 32. A material according to claim 29, characterized in that the oxidation catalyst is added to the material as platinum and / or palladium impregnated on a particulate inorganic oxide. 33. A material according to claim 20, characterized in that the lanthanum oxide is distributed on the surface of the aluminum oxide in combination with an oxidation catalyst selected from the group consisting of platinum, palladium and mixtures thereof. 34. A method for controlling SO 2 emissions, characterized in that (a) in a reaction zone an acetal agent as defined in claim 18 is incorporated to combine with the sulfur oxides in said zone and (b) in step (a) restores or regenerates obtained sulfur-containing acceptor agent. A method according to claim 34, characterized in that an oxidation catalyst is present in said zone. A process according to claim 34, characterized in that the aceeptor is repaired or regenerated by reduction and / or hydrolysis in the presence of a reducing gas and / or steam. 37. A method according to claim 34, characterized in that the recovered or regenerated acceptor is returned to the reaction zone. 38. Process for cracking hydrocarbon starting materials containing organic sulfur compounds, characterized in that 30 (a) hydrocarbon starting materials containing organic sulfur compounds are reacted with catalyst material according to claim 1 under catalytic cracking conditions to obtain a cracked product stream. and a catalyst material combined with sulfur-containing coke; (b) passing the catalyst material to a steam stripping zone to remove the strippable hydrocarbons from the catalyst material; (c) conveying the stripped catalyst material to a regeneration zone in which the sulfur coke is oxidized to carbon monoxide, carbon dioxide, water and sulfur oxides, and said sulfur oxides combine with the acceptor agent component of the catalyst material to form a thermally stable sulfate or compound of the sulfate type; and (d) returning the regenerated catalyst material obtained in step (c) to the reaction step (a) and the steam stripping step (b) in which the sulfate-containing accepting agent is reduced and hydrolyzed to provide volatile hydrogen sulfide which is recovered as component 15 of the cracked product stream and to restore or regenerate the acceptor agent, which is recycled back into the process. 39. Process according to claim 38, characterized in that the catalyst has the composition according to claim 11. A method according to claim 38, characterized in that the acceptor agent is included in the form of a particulate additive. 41. A process according to claim 40, characterized in that an oxidation catalyst is incorporated in amounts required to obtain a desired level of carbon monoxide and / or sulfur oxide oxidation. 42. Process according to claim 41, characterized in that the oxidation catalyst is selected from the group consisting of platinum, palladium and mixtures thereof. The process according to claim 42, characterized in that the oxidation catalyst is added in amounts ranging from about 0.01 to 1000 parts per million by weight of precious metal. 44. Process according to claim 38, 82 0 0 9 8 7 r1 - - - 29 - characterized in that the H 2 S is recovered from the cracked gas stream. 45. Methods and articles essentially as described in the description and / or the examples. 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