CN1288225C - FCC method incorporating crystalline microporous oxide catalysts with increased Lewis acidity - Google Patents

Abstract

Catalyst components, catalysts, and methods of making the components and catalysts are disclosed. A fluid catalytic cracking process for converting a petroleum feedstock to lower boiling products is also disclosed, wherein the feedstock is contacted with a catalyst. The catalyst component is a crystalline microporous oxide catalyst to which is effectively added a compound capable of promoting dehydrogenation and increasing lewis acidity. The catalyst component may be included in an inorganic oxide matrix material and used as a catalyst. It is preferable that a compound capable of promoting dehydrogenation and increasing lewis acidity be efficiently added to the non-framework portion of the crystalline microporous oxide.

Description

FCC method incorporating crystalline microporous oxide catalysts with increased Lewis acidity

background

The present invention relates to catalyst components, compositions, and methods of making and using compositions comprising crystalline microporous oxides containing compounds capable of promoting dehydrogenation and increasing Lewis acidity without increasing Lewis acidity. Crystalline Microporous Oxide Unit Cell Size Promoter Metal Compounds.

Crystalline microporous oxides such as zeolite materials have been used commercially in various industries for many years. These materials are particularly valuable for their fluid separation capabilities as molecular sieves and for their ability to act as catalysts.

Crystalline microporous oxides are particularly useful as catalysts capable of converting larger paraffinic molecules of hydrocarbon mixtures into smaller, more unsaturated molecules such as olefins and aromatics. Common conversion methods include fluid catalytic cracking and hydrocracking. In order to maximize this conversion process, many structural properties of the catalyst such as pore size, pore volume, Lewis and Bronsted acidity must be balanced. If the structural properties of the reforming catalyst are not properly balanced, the conversion of the hydrocarbon mixture to products will be low, the product quality will be poor, or the reforming catalyst will deactivate rapidly.

It is particularly beneficial to obtain crystalline microporous oxide catalysts with high catalytic activity by balancing the Bronsted and Lewis acidities of the framework and non-framework parts of the catalyst. The catalytic activity can be effectively optimized by balancing the composition of the framework and non-framework parts of the crystal structure. In the case of cracking catalysts, the olefin formation reactions of larger paraffin molecules can be more efficiently linked to the cleavage reactions to form small molecules in the end product.

overview

One embodiment of the invention comprises a catalyst comprising (i) a matrix material and (ii) a crystalline microporous oxide incorporated into or associated with the matrix material. Crystalline microporous oxides contain non-framework parts and have a certain unit cell size. The non-framework portion comprises a promoter metal compound incorporated only into the non-framework portion of the crystalline microporous oxide. The promoter metal compound does not substantially increase the unit cell size of the crystalline microporous oxide.

In another embodiment of the catalyst, the crystalline microporous oxide comprises Y zeolite incorporated into a matrix material. Y zeolite contains a non-framework portion with a unit cell size greater than about 24.30 Å, and includes alumina that incorporates only the non-framework portion of the crystalline microporous oxide, so that the alumina can increase the Lewis acidity without substantially increasing the crystallinity of the zeolite. cell size.

In another embodiment of the catalyst, the crystalline microporous oxide comprises a non-framework portion comprising a promoter metal compound capable of increasing Lewis acidity and incorporating only the non-framework portion of the crystalline microporous oxide , so that the promoter metal compound does not substantially increase the unit cell size of the crystalline microporous oxide.

Embodiments of the catalyst may be used in an FCC unit, isomerization unit or hydrocracker unit by contacting the catalyst with a suitable feedstock.

Another embodiment of the invention encompasses a method of making a catalyst. The method comprises (a) contacting a crystalline microporous oxide comprising a non-framework moiety and having a unit cell with a promoter precursor comprising a promoter metal capable of forming a promoter metal compound. size; and (b) heating the mixture of step (a) to 150°C to 550°C; wherein the promoter metal compound comprising said promoter metal is introduced only into the non-framework portion of the crystalline microporous oxide, and wherein The promoter metal compound does not substantially increase the unit cell size of the crystalline microporous oxide.

Another embodiment of the present invention is a method comprising the steps of: (a) contacting a crystalline microporous oxide comprising a non-framework moiety and having a cell size of , the co-catalyst precursor comprises a co-catalyst metal capable of forming a co-catalyst metal compound; (b) decomposing said co-catalyst precursor, thereby forming a co-catalyst metal compound comprising said co-catalyst metal in the form of an oxide; (c ) dispersing said promoter metal compound only into the non-framework portion of said crystalline microporous oxide; wherein the promoter metal compound does not substantially increase the unit cell size of the crystalline microporous oxide.

Another embodiment of the present invention is a process comprising the steps of: (a) calcining a zeolite comprising a non-framework portion and having a unit cell size; (b) combining the zeolite with a catalyst-forming metal compound comprising Cocatalyst precursor contact with a cocatalyst metal, wherein said cocatalyst metal is selected from the group consisting of magnesium, chromium, iron, lanthanum, gallium, manganese and aluminum, and wherein said cocatalyst precursor is selected from aluminum acetylacetonate, isopropyl Aluminum alkoxide, aluminum hexafluoroacetylacetonate, aluminum dichlorohydrol, aluminum ethoxide, tris[2,2,6,6-tetramethyl-3,5-heptanedionato]aluminum-III[ Al(TMHD) ₃ ], aluminum acetate, aluminum nitrate, aluminum propoxide, magnesium acetylacetonate, chromium acetylacetonate, iron acetylacetonate, gallium acetylacetonate, manganese acetylacetonate and lanthanide acetylacetonate; (c) step ( b) the mixture is heated to 150°C to 550°C; (d) introducing the product of step (b) into a matrix material, wherein the promoter metal compound comprising said promoter metal is introduced into only the non-framework portion of the zeolite, and wherein The promoter metal compound does not substantially increase the unit cell size of the zeolite.

Another embodiment of the present invention is a process comprising the steps of: (a) contacting the calcined crystalline microporous oxide with a promoter precursor comprising a promoter metal capable of forming a promoter metal compound, whereby The crystalline microporous oxide comprises a non-skeletal moiety and has a unit cell size; and (b) activating the promoter metal compound, wherein the promoter metal compound is incorporated only into the crystalline microporous oxide The non-skeletal part of , and wherein the promoter metal compound does not substantially increase the unit cell size of the crystalline microporous oxide.

Another embodiment of the present invention is a method comprising the steps of: (a) calcining a crystalline microporous oxide comprising non-framework moieties and having a unit cell size; (b) contacting Aluminum alkyls selected from trimethylaluminum, triethylaluminum, tri-tert-butylaluminum and triisobutylaluminum; (c) treating the product of step (b) with an oxygen-containing species to form a promoter metal compound, wherein The promoter metal compound does not substantially increase the unit cell size of the crystalline microporous oxide.

Other embodiments of the invention include products made by the methods of the invention. These products may or may not be incorporated into a matrix material, but are preferably incorporated into a matrix material and then used in a process unit.

A detailed description

The catalytic activity of crystalline microporous oxides, such as zeolites, can be enhanced by the effective introduction of promoter metal compounds that promote dehydrogenation and increase the Lewis acidity of the crystalline microporous oxide without increasing its unit cell size. Although the crystalline microporous oxide can be used alone as a catalyst, it is preferred to incorporate the crystalline microporous oxide into a matrix material, preferably an inorganic oxide. Further catalytic or non-catalytic components may also be present in the matrix material.

The crystalline microporous oxides of the present invention can be used to catalytically crack the primary products of catalytic cracking reactions into refined products, such as naphtha used as fuel and olefins used as chemical raw materials. The crystalline microporous oxide is preferably selected from the group consisting of crystalline aluminosilicate zeolites (hereinafter referred to as zeolites), tectosilicates, tetrahedral aluminophosphates (ALPOs) and tetrahedral aluminophosphosilicates (SAPOs). ). More preferably the crystalline microporous oxide is a zeolite.

Suitable zeolites include natural and synthetic zeolites. Suitable natural zeolites include gmelinite, chabazite, cyclomorphite, clinoptilolite, faujasite, heulandite, erionite, erionite, canciline, calcite, zeolite, mordenite and magnesium alkali zeolite. Suitable synthetic zeolites are X, Y, L, ZK-4, ZK-5, E, H, J, M, Q, T, Z, alpha and beta, ZSM type zeolites and omega zeolites. Faujasites are preferred, and Y zeolites and X zeolites having a unit cell size of greater than or equal to 24.30 Å, more preferably greater than or equal to about 24.40 Å, are particularly preferred. The aluminum and silicon components of zeolites can be replaced by other framework components. For example, the aluminum moiety may be replaced with boron, gallium, titanium or a trivalent metal composition heavier than aluminum. Germanium can be used to replace the silicon part.

In the finished catalyst product, the crystalline microporous oxide is preferably included in the inorganic oxide matrix material that binds the catalyst components together so that the final catalyst is sufficiently rigid to withstand interparticle and reactor wall collisions . The inorganic oxide matrix material may be made from an inorganic oxide sol or gel that is dried to "bond" the catalyst components together. Preferred inorganic oxide matrix materials comprise oxides of silicon and aluminum. The inorganic oxide matrix material may also comprise an active porous inorganic oxide catalyst component and an inert catalyst component. Preferably all components of the catalyst are held together by attachment to the inorganic oxide matrix material.

Active porous inorganic oxide catalyst components generally catalyze the formation of primary products by cracking hydrocarbon molecules that are too bulky to enter the crystalline microporous oxide. The active porous inorganic oxide catalyst component that can be incorporated into the cracking catalyst is preferably a porous inorganic oxide that cracks a relatively large amount of hydrocarbons to lower molecular weight hydrocarbons compared to an acceptable thermal blank . Low surface area silica such as quartz is one type of acceptable thermal blank. Cracking can be determined using any of a variety of ASTM tests such as the MAT (Micro Activity Test, ASTM #D3907-8). Preferable are those compounds disclosed in Greensfelder, B.S., et al., Industrial and Engineering Chemistry, pp. 2573-83, Nov. 1949. Preferred compounds are alumina, silica-alumina and silica-alumina-zirconia.

Inert catalyst components generally add density, strength and act as a protective heat reservoir. The cracking activity of the inert catalyst components which may be incorporated into the cracking catalysts of the present invention is preferably not significantly greater than that of an acceptable thermal blank. Kaolin and other clays as well as alpha-alumina, titania, zirconia, quartz and silica are examples of suitable inert components.

Preferably a discontinuous alumina phase is incorporated into the inorganic oxide matrix material. Aluminum hydroxides can be used - gamma-alumina, boehmite, diaspore and transitional aluminas such as alpha-alumina, beta-alumina, gamma-alumina, delta-alumina, epsilon-alumina Aluminum, kappa-alumina, rho-alumina. Preferred aluminas are aluminum trihydroxides such as gibbsite, bayerite, nordstrandite or doyelite.

In one embodiment of the invention, the crystalline microporous oxide catalyst component includes a compound that promotes dehydrogenation and increases Lewis acidity, referred to herein as a promoter metal compound. The distribution of the promoter metal compound within the crystalline microporous oxide does not result in any substantial increase in the unit cell size of the crystalline microporous oxide, and the unit cell sizes of the crystalline microporous oxide material are substantially the same.

The promoter metal compound is preferably in a chemical state effective to promote the dehydrogenation of paraffinic and naphthenic compounds in the hydrocarbon feed stream to form olefinic compounds. For example, aluminum oxide (Al ₂ O ₃ ) contains a suitable promoter metal (aluminum). Aluminum oxide is in such an effective chemical state.

A crystalline microporous oxide includes a framework part and a non-framework part. The Lewis acidity of crystalline microporous oxides is increased without increasing the unit cell size by increasing the number of effective metal cation sites in the non-framework portion of the crystalline microporous oxides. Typically, when species are introduced into the framework part of the material, the unit cell size will increase. When the promoter metal compound of the present invention is incorporated into the crystalline microporous oxide material of the present invention, the unit cell dimensions remain substantially the same. Therefore, it is preferred to incorporate the promoter species only into the non-framework portion of the crystalline microporous oxide material. See W.O.Haag, "Catalysis Using Zeolites - Science and Technology", Zeolites and Related Microporous Materials, edited by J.Weitkamp, H.G.Karge, H.Pfeifer and W.Holderich, Vol.84, Elsevier Science B.V., 1994, where pp. 1375-1394 discusses the relationship of Lewis acid sites, which is hereby incorporated by reference. Herein, metal cations refer to metal ions or metal ions plus oxide ions.

One embodiment of the invention is a method of preparing an active catalytic component. Other embodiments are the active catalytic components prepared by this method and the final catalyst products including the matrix material.

One embodiment of the method of the present invention comprises contacting, by mixing or other suitable means, the crystalline microporous oxide with a promoter precursor capable of forming a promoter metal compound. In this context, mixing means combining the components without necessarily requiring any mechanical agitation. Contacting the co-catalyst precursor with the crystalline microporous oxide causes the co-catalyst precursor to disperse into the non-framework portion of the crystalline microporous oxide. The promoter metal compound is then preferably activated by decomposition of the promoter precursor, resulting in a residual organic moiety and the promoter metal compound adsorbed or dispersed into the non-framework portion of the microporous oxide. In order to increase the effective number of metal cation non-framework acid sites, the cocatalyst metal compound is adsorbed onto the crystalline microporous oxide through a liquid phase or gas phase reaction such as gas phase transfer.

The period of contact of the promoter precursor with the crystalline microporous oxide is sufficient to retain 40 to 60 percent by weight, preferably about 50 percent by weight, of the promoter metal oxide resulting from the decomposition of the promoter precursor in the crystalline microporous oxide . The degree of retention was determined by measuring the weight of the crystalline microporous oxide/co-catalyst precursor mixture during the activation/heating step. The crystalline microporous oxide and co-catalyst precursor are mixed in a weight ratio of crystalline microporous oxide:co-catalyst precursor of 100:15 to 100:200, preferably 100:15 to 100:100. For example, in _one embodiment where the zeolite is contacted with aluminum acetylacetonate, the aluminum acetylacetonate produces about 15.7% _Al2O3 as a result of decomposition/reaction. Assuming that after decomposition/reaction about 55% by weight of the _AlO from aluminum acetylacetonate is dispersed to the _non -framework part of the zeolite and retained by the zeolite, in order for 15 _grams of _AlO to be dispersed on 100 grams of the zeolite ( Add 15% Al ₂ O ₃ ), 100 grams of zeolite should be mixed with about 175 grams of aluminum acetylacetonate:

15 g Al ₂ O ₃ /(0.157 Al ₂ O ₃ /aluminum acetylacetonate×0.55 (percentage decomposed)))=173.4 g aluminum acetylacetonate.

Residual organic moieties are removed by combusting the organic moieties by contacting them with a suitable oxygen-containing gas. Other suitable methods known in the art may also be used.

The promoter metal compound is preferably a polyvalent metal compound. Preferred polyvalent metal compounds are compounds containing divalent or trivalent metals, preferably selected from magnesium, chromium, iron, lanthanum, gallium, manganese and aluminium.

Preferably the cocatalyst precursor is stable in the gas phase and preferably has a boiling point of less than about 550°C, more preferably less than about 500°C. Examples of preferred cocatalyst precursors include, but are not limited to, aluminum acetylacetonate, aluminum isopropoxide, aluminum hexafluoroacetylacetonate, aluminum dichlorodihydrate, aluminum ethoxide, tris[2,2,6,6-tetramethyl- 3,5-Heptanedionato]aluminum-III [Al(TMHD) ₃ ], aluminum alkyls such as trimethylaluminum, triethylaluminum and triisobutylaluminum, aluminum acetate, aluminum nitrate, aluminum propoxide , gallium acetylacetonate, manganese acetylacetonate, magnesium acetylacetonate, chromium acetylacetonate, iron acetylacetonate and lanthanide acetylacetonate.

In a specific embodiment, the crystalline microporous oxide is preferably calcined by methods known in the art and then contacted with a cocatalyst precursor including, but not limited to, aluminum acetylacetonate, Aluminum isopropoxide, aluminum hexafluoroacetylacetonate, aluminum dichlorodihydrate, aluminum ethoxide, tris[2,2,6,6-tetramethyl-3,5-heptanedionato]aluminum-III[Al( TMHD) ₃ ], aluminum acetate, aluminum nitrate, aluminum propionate, magnesium acetylacetonate, chromium acetylacetonate, iron acetylacetonate, manganese acetylacetonate, gallium acetylacetonate and lanthanide acetylacetonate, which upon activation form promoter metals compound.

The promoter metal compound is activated by heating the crystalline microporous oxide/promoter precursor mixture to about 150°C to about 550°C. The heating step decomposes the co-catalyst precursor into residual organic moieties and co-catalyst metal compounds capable of dispersing into the non-framework portion of the crystalline microporous oxide. The resulting activated crystalline microporous oxide catalyst component can then be mixed with a suitable matrix material and used as a catalyst. In this embodiment, preferred co-catalyst precursors include In one embodiment, the crystalline microporous oxide is a zeolite, preferably Y zeolite, the co-catalyst precursor is aluminum acetylacetonate, an alumina co-catalyst to form alumina metal compound.

In another specific embodiment, the crystalline microporous oxide is preferably calcined by methods known in the art and then contacted with a cocatalyst precursor comprising an aluminum alkyl. Suitable aluminum alkyls include, but are not limited to, trimethylaluminum, triethylaluminum, tri-tert-butylaluminum, triisobutylaluminum. In this embodiment, the promoter metal compound is activated by contacting the crystalline microporous oxide/promoter precursor mixture with an oxygen-containing species. Suitable oxygen-containing species include, but are not limited to, air, oxygen, water, and alcohols such as methanol, ethanol, isopropanol, and butanol. The oxygen-containing species reacts with the aluminum alkyl, thereby activating the promoter metal compound by forming alumina and residual organic moieties. The reaction step decomposes the co-catalyst precursor into co-catalyst metal compounds which can be dispersed within the non-framework portion of the crystalline microporous oxide and into the residual organic moiety which, if desired, can be removed as described above. The resulting activated crystalline microporous oxide catalyst component can then be mixed with a suitable matrix material and used as a catalyst. Preferably the promoter metal comprises aluminum and the crystalline microporous oxide comprises zeolite.

Adding the product obtained by the process of the preceding paragraph, comprising a crystalline microporous oxide material and a promoter metal compound incorporated into a non-framework portion of the crystalline microporous oxide material, to an inorganic oxide matrix material as described above To form the catalyst, it is preferred to form fresh, uncontaminated catalyst. The catalyst is then transferred to process equipment for appropriate application as described below.

Although other catalyst components and materials can be incorporated into the catalyst, the matrix material can make up the balance of the finished catalyst composition. Preferably the matrix material comprises from about 40% to about 90% by weight of the catalyst, more preferably from about 50% to about 80% by weight of the catalyst, based on the total weight of the catalyst. It is also within the scope of this invention to incorporate other types of microporous oxides, clays, and carbon monoxide oxidation promoters into the catalyst. The catalyst of the present invention is preferably freshly prepared when delivered to the cracking process, that is, the catalyst is substantially free of metals that could contaminate the catalyst during catalytic cracking. Said metals include, but are not limited to, nickel, vanadium, sodium and iron.

The catalysts of the present invention are useful in a variety of petroleum and chemical processes, especially those in which the dehydrogenation of paraffins is desired. For example, they can be used to catalyze reactions in fluid catalytic cracking, hydrocracking and isomerization. The promoter metal compound is adsorbed onto the crystalline microporous oxide portion of the catalyst in a manner capable of promoting the dehydrogenation of paraffins and naphthenes. The larger paraffins are preferably converted to olefins as a result of contacting the paraffins with the crystalline microporous oxide. The olefins are then preferably converted to smaller paraffin molecules, olefin molecules and aromatic compound molecules at the desired ratio for the fuel product.

Fluid catalytic cracking is used to convert high boiling petroleum oils into more valuable lower boiling products, including gasoline and middle distillates such as kerosene, aviation kerosene and heating oil. Common feeds to catalytic cracking units have relatively high boiling points and include resids by themselves, or mixtures of resids with other high boiling fractions. The most commonly used feed is gas oil, which generally has an initial boiling point above about 230°C, more typically above about 350°C, and an end point of up to about 620°C. Commonly used gas oils include straight run (atmospheric pressure) gas oils, vacuum gas oils and coker gas oils. As one of ordinary skill in the art understands, with so many different types of compounds present in petroleum hydrocarbon fractions, it is difficult to precisely define said hydrocarbon fractions by initial boiling point. Hydrocarbon fractions in this boiling range include gas oils, heat transfer oils, residues, cycle oils, topped and whole crude oils, tar sands oils, shale oils, synthetic fuels, heavy hydrocarbon fractions from coking processes, tars , wood pitch, petroleum pitch, and hydroprocessed feedstocks derived from any of the foregoing.

Fluid catalytic cracking units typically comprise a reactor in which feedstock is contacted with hot powdered catalyst heated in a regenerator. A conveyor line connects the two vessels to remove catalyst particles back and forth. The cracking reaction is preferably carried out at a temperature of about 450°C to about 680°C, more preferably about 480°C to about 560°C, a pressure of about 5 to 60 psig, more preferably about 5 to 40 psig, a contact time (catalyst and feed Contact) is about 0.5 to 15 seconds, more preferably about 1 to 6 seconds, and the ratio of catalyst to oil is about 0.5 to 10, more preferably about 2 to 8.

During the cracking reaction, low boiling point products are formed and some hydrocarbon species and non-volatile coke are deposited on the catalyst particles. Hydrocarbon species are removed by stripping the catalyst, preferably with steam. Non-volatile coke usually consists of highly condensed aromatic hydrocarbons. As hydrocarbons and coke build up on the catalyst, the activity of the cracking catalyst and the selectivity of the catalyst to generate gasoline blends decreases. Most of the original activity of the catalyst particles can be restored by stripping to remove most of the hydrocarbon species and appropriate oxidative regeneration to remove coke. Thus, the catalyst particles are sent to a stripper and then to a regenerator.

Catalyst regeneration is accomplished by burning coke deposits on the catalyst surface with an oxygen-containing gas, such as air. The catalyst temperature during regeneration is from about 560°C to about 760°C. The regenerated catalyst particles are then sent back to the reactor via a transfer line and due to its heat is able to maintain the reactor at the temperature required for the cracking reaction. Burning coke is an exothermic reaction; therefore, no additional fuel needs to be added in conventional fluid catalytic cracking units utilizing conventional feedstocks. The feedstocks used in the practice of this invention may not deposit enough coke onto the catalyst particles to deposit sufficient coke on the catalyst particles, primarily because of their low aromatic content and because of the relatively short contact times in the reactor or conveyor line. The desired temperature is reached in the regenerator. Therefore, it may be necessary to use additional fuel to provide a higher temperature within the regenerator so that the heat of the catalyst particles returning to the reactor is sufficient to sustain the cracking reaction. Non-limiting examples of suitable supplemental fuels include _C2 gas from the catalytic cracking process itself, natural gas and flare oil. _C2 gas is preferred.

Isomerization is another process in which the catalysts of the present invention can be used. Hydrocarbons which may be isomerized by the process of the present invention include paraffinic and olefinic hydrocarbons generally containing 4-20, preferably 4-12, more preferably about 4-6 carbon atoms, and aromatic compounds such as xylene. A preferred feed consists of paraffins typified by butane, pentane, hexane, heptane, and the like. Isomerization conditions include: a temperature of about 80°C to about 350°C, preferably about 100°C to 260°C; a pressure of about 0 to 1000 psig, preferably about 0 to 300 psig; a liquid hourly space velocity of about 0.1 to 20, preferably about 0.1 to 2; The hydrogen gas rate is about 1000 to 5000, preferably about 1500 to 2500 in standard cubic feet per barrel. The operating temperature and catalyst activity are correlated with space velocity to give reasonable rapid processing of the feedstock at a catalyst deactivation rate that ensures maximum continuous on-time of the catalyst during regeneration.

The catalysts of the present invention can also be used in hydrocracking treatments. Hydrocracking increases the overall refining yield of premium gasoline blending components. Hydrocracking is able to take a relatively low quality gas oil feed (which would otherwise be incorporated into distillate fuel) and convert it in the presence of hydrogen and an appropriate catalyst in a fixed bed reactor. Typically the feedstock is mixed with hydrogen, heated to about 140°C to 400°C, pressurized to about 1200 to 3500 psi, and then fed to a first stage reactor where about 40 to 50% by weight of the feedstock is reacted to remove Compounds of nitrogen and sulfur that inhibit cracking reactions and reduce product quality. The stream exiting the first stage reactor is cooled, liquefied and passed through a separator where butanes and light gases are withdrawn. The bottoms fraction is sent to a second stage reactor and cracked at higher temperature and pressure where additional gasoline blending components and hydrocracked products are produced.

A further understanding of the invention may be obtained by reference to the following examples which illustrate embodiments of the invention.

Example 1

A standard MAT test (e.g. Microactivity Test, ASTM #D3907-8) was performed on three separate commercially available crystalline microporous oxides: USY (Z14USY from W.R. Grace, Davison Division, or LZY 82 from UOP or LZY 84), LZ-210 (available from Katalystiks, Inc.) and calcined rare earth exchanged Y (CREY, available from W.R. Grace, Davison Division). Prior to performing the MAT test, the crystalline microporous oxide was mixed with a matrix material (Ludox, ex DuPont) and steamed at 1400<0>F for 16 hours to generate the cracking catalyst.

Each catalyst tested contained 20% by weight zeolite and 80% by weight matrix material. The results are shown in Table 1 below.

Table 1 MAT results USY LZ-210 CREY Conversion (% by weight, 400°F-) H ₂ (% by weight) C (% by weight) Surface area (m ² /g) Pore volume (cm ³ /g) Unit cell size (A) 42.50.01131.4802000.43924.21 47.70.01861.8911890.02324.24 64.10.00641.7601300.25424.51

Example 2

According to A.Dyer, An Introduction to Zeolite Molecular Sieves, chapter 6, "zeolite used as an ion exchanger", John Wiley & Sons, 1998 described in the method of cation exchange in zeolite, the embodiment 1 Crystalline Microporous Oxides for Metal Ion Exchange, this section is hereby incorporated by reference. After ion exchange of the crystalline microporous oxide, it was mixed with matrix material and steamed as described in Example 1, and then subjected to a standard MAT test. The results are shown in Table 2.

Table 2 MAT results USY+Al ₂ O ₃ LZ-210+Al ₂ O ₃ CREY+Al ₂ O ₃ Conversion (% by weight, 400°F-) H ₂ (% by weight) C (% by weight) Surface area (m ² /g) Pore volume (cm ³ /g) Unit cell size (A) 29.80.00471.1191940.34624.25 38.50.00551.7371720.31424.22 51.10.00561.5161610.31824.36

The results show that: compared with the non-exchanged crystalline microporous oxide of Example 1, the metal ion-exchanged crystalline microporous oxide significantly reduces the conversion rate of the product. This suggests that the metal ion exchange step causes a loss of available metal cation sites in the non-framework portion of the crystalline microporous oxides, as the balance between Bronsted and Lewis sites is not conducive to the desired activity.

Example 3

Standard MAT tests were performed on three separate commercially available crystalline microporous oxides: rare earth exchanged CREY (RECREY) prepared by exchanging a portion of the CREY of Example 1 with a solution of rare earth ions by Dyer's method; Hydrogen-calcined rare earth-exchanged Y (HCREY) obtained ^by exchanging about 4% by weight Na of CREY with NH ₄ ⁺ ; and according to R. Szostak, "Modified Zeolite" (Chapter 5), Introduction to ZeoliteScience and Practice, Vol.58, H.Van Bekkum, EM Flanigan and JC Jansen, edited, Elsevier, ₁₉₉₁ , references 6-13, the ultrastable calcined rare earth exchanged Y( USCREY). Before carrying out the MAT test, the zeolite was mixed with a matrix material (10% by weight zeolite; 30% by weight SiO ₂ , which was IMSIL-A-8 from Unimin Specialty Minerals, Inc.; 60% by weight SiO ₂ -Al ₂ O ₃ , Prepared from _a gel obtained from WR Grace, Davison Division which when dried and washed gave 25% by weight _Al2O3 , _SiO2 - _Al2O3 ) mixed to form the cracking catalyst _. The results are shown in Table 3.

table 3 MAT results RECREY HCREY USCREY Conversion (% by weight, 430°F-) C (% by weight) 650°F + product (% by weight) surface area (m ² /g) unit cell size (A) 45.31.3432.410124.49 50.11.3927.412924.45 44.01.3332.7113-

Example 4

In a separate vessel, each of the crystalline microporous oxides of Example 3 was mixed with aluminum acetylacetonate (the ratio of zeolite to aluminum acetylacetonate was close to 1:1.4, and the decomposition temperature of aluminum acetylacetonate was slightly above 320° C.). Each container was placed in an oven and heated to 150°C for 1 hour, then the oven was purged with nitrogen in an amount sufficient to flush out potentially flammable decomposition products of acetylacetone decomposition. After purging, the oven was heated to 500°C for 1 hour and then cooled. The oven was then heated at 500°C for 2 hours in air. Based on the weight of the product, it can be calculated that about 45% by weight of the alumina expected to be available from the amount of aluminum acetylacetonate remains within the zeolite as a result of the addition process. The zeolite with added alumina was then prepared as a catalyst as described in Example 3 and then tested under standard MAT conditions. The results are shown in Table 4.

Table 4 MAT results RECREY+Al ₂ O ₃ HCREY+Al ₂ O ₃ USCREY+Al ₂ O ₃ Conversion (% by weight, 430-) 55.2 58.2 60.8 C (% by weight) 650  + product (% by weight) surface area (m ² /g) unit cell size (A) 1.6322.6118- 1.5719.38124.43 1.6517.414324.46

The results show that: compared with the crystalline microporous oxide without adding metal in Example 3, the crystalline microporous oxide containing the added metal compound that can promote dehydrogenation and Lewis acidity has a significantly higher conversion rate of gasoline products . This indicates that the addition of a metal compound increases the number of available metal cation sites in the non-framework portion of the crystalline microporous oxide. In other words, the addition of metal compounds leads to a significant increase in Lewis acid sites. This is also shown in Table 5 below by direct determination of the number of acidic sites per gram of catalyst.

If, after steaming as described in Example 3, pyridine is adsorbed onto the catalyst and then heated to 250°C under vacuum to desorb any pyridine from the weaker acid at the non-acidic site, infrared spectroscopy can be used to determine the adsorption of pyridinium ions. The relative amount of pyridine to the Bronsted acidic site, and the amount of pyridine adsorbed to the strong Lewis acidic site as a coordination. When the infrared spectroscopic analysis was performed on the desorbed catalysts, the following band intensities of adsorbed pyridine could be observed on the three catalysts.

In Table 5 there are three different materials: 1) RECREY, a rare earth exchanged zeolite of FAU structure type. This is the starting material for the last two samples in the table. 2) RECREY + Added Alumina-I, which is a sample of RECREY added alumina, effectively added alumina, by the method taught herein. 3) RECREY+Alumina-II added, which is a sample in which alumina was added to RECREY in a way that the addition of alumina was not effective in increasing the Lewis acid.

The method taught by R.J.Gorte et al [Journal of Catalysis 148, 213-223, (1994), and references therein] and G.L. Price et al [Journal of Catalysis 148, 228-236, (1994)] was used to quantitatively determine Total acidity, characterized as the amount of strong acid sites (strong enough to decompose n-propylamine into propylene and ammonia upon thermal desorption) and weak acid sites (the acidity retains the amine due to its interaction with n-propylamine at 50 °C, but when the temperature will desorb n-propylamine when raised). The assay allows the simultaneous determination of Bronsted and Lewis acid sites. The determination of acidity is expressed in milliequivalents per gram of substance (1 millimole of amine is calculated as reacting with 1 millimole of acid site).

table 5 Al ₂ O ₃ added by RECREY Al ₂ O ₃ added by RECREY+ RECREY+ Total Al ₂ O ₃ (weight%) strong acidity, MEQV/G weak acidity, MEQV/G total acidity, MEQV/G 19.70.462.643.10 30.50.382.993.37 27.00.402.592.99

Table 5 shows that weak acidity increases with total acidity only when alumina is effectively added (I). Another example (II) shows that simply increasing the amount of alumina does not necessarily increase acidity.

As described in Example 3, each zeolite sample as described above was used to prepare catalysts, and then these composite catalysts were treated with steam under the same conditions as described in Example 3 to deactivate them.

A portion of each catalyst sample was then pressed into a thin disk. Each disc was weighed and its diameter and thickness determined. Each disk is then placed in a vacuum chamber and heated to remove any water or other adsorbed gases. It was then cooled to 50°C and briefly contacted with pyridine vapor. The sample is then kept in vacuum for several hours and its infrared spectrum is determined, especially between 1400 cm ⁻¹ and 1600 cm ⁻¹ . The sample was then heated to 250°C and maintained for several hours, and its infrared spectrum was measured again. This elevated temperature and high vacuum removed all physisorbed pyridine.

The infrared spectrum between 1400 cm ^-1 and 1600 cm ^-1 was measured on the material before pyridine adsorption and was subtracted from the spectrum of the sample containing pyridine. The obtained spectrum is due to the interaction of pyridine with the acid sites of the catalyst.

In this spectral region, the peak at 1540 cm ⁻¹ to 1550 cm ⁻¹ is attributed to pyridine coordinated to the proton from the Bronsted acid site. The peak between 1440 cm ⁻¹ and 1460 cm ⁻¹ is attributed to pyridine where the electron pair on nitrogen interacts with the electron accepting site (Lewis acid) of the solid. Within this spectral region 1440 cm ^-1 to 1660 cm ^-1 , other bands between 1480 cm ^-1 and 1500 cm ^-1 are the result of band combinations of pyridine adsorbed to Bronsted and Lewis sites.

Table 6 lists the observed band intensities due to the presence of Bronsted and Lewis sites on the catalysts treated with steam for composite catalysts made with the zeolites shown in Table 5.

Table 6 Reason for band intensity: (absolute unit/gram) RECREYI RECREY+ADAII RECREY+ADA Bronsted bit Lewis acidic site 2255 33104 3360

These results indicate that the effective addition of this metal compound does increase the Lewis acidity of the active catalyst.

Now that the invention has been fully described, it should be understood by those skilled in the art that it can be practiced within the broad parameters defined by the claims.

Claims (17)

1, a kind of fluid catalystic cracking method, this method comprises:

Under the fluid catalystic cracking condition raw material is contacted with freshly prepd catalyzer, this freshly prepd catalyzer comprises:

(i) substrate material

The crystalline microporous oxide of (ii) introducing substrate material or combining with described substrate material, described crystalline microporous oxide comprises non-skeleton part and has certain unit cell dimension, described non-skeleton portion branch comprises the promoter metal compounds of the non-skeleton part of only introducing crystalline microporous oxide, and wherein promoter metal compounds can not increase the unit cell dimension of crystalline microporous oxide in fact.

2, the described method of claim 1, wherein promoter metal compounds is a polyvalent metal compounds.

3, the described method of claim 1, wherein promoter metal compounds is an aluminum compound.

4, the described method of claim 1, wherein crystalline microporous oxide is a zeolite.

5, the described method of claim 4, wherein crystalline microporous oxide is X or Y zeolite.

6, the described method of claim 5, wherein crystalline microporous oxide is the Y zeolite that unit cell dimension is equal to or greater than 24.30 .

7, the described method of claim 5, wherein crystalline microporous oxide is the Y zeolite that unit cell dimension is equal to or greater than 24.40 .

8, the described method of claim 1, wherein said crystalline microporous oxide is selected from zeolite, tectosilicate, tetrahedral aluminophosphates and tetrahedral silicoaluminophosphates.

9, the described method of claim 1, wherein said crystalline microporous oxide is a zeolite, and wherein said promoter metal compounds is an aluminum oxide.

10, the described method of claim 1, wherein said promoter metal compounds is a metal oxide, the metal of wherein said metal oxide is selected from magnesium, chromium, iron, lanthanum, gallium, manganese and aluminium.

11, a kind of fluid catalystic cracking method, this method comprises:

Under the fluid catalystic cracking condition raw material is contacted with freshly prepd catalyzer, this freshly prepd catalyzer comprises:

(i) substrate material

(ii) introduce the Y zeolite of described substrate material, described Y zeolite comprises non-skeleton part and has unit cell dimension greater than about 24.30 , described non-skeleton portion branch comprises the aluminum oxide of the non-skeleton part of only introducing crystalline microporous oxide, and wherein aluminum oxide has increased lewis acidity and do not increased the unit cell dimension of zeolite in fact.

12, a kind of fluid catalystic cracking method, this method comprises:

Under the fluid catalystic cracking condition raw material is contacted with freshly prepd catalyzer, this freshly prepd catalyzer comprises:

(i) substrate material

(ii) introduce the crystalline microporous oxide of described substrate material, described crystalline microporous oxide comprises non-skeleton part and has certain unit cell dimension, described non-skeleton portion branch comprises can increase lewis acidity, only introduce the promoter metal compounds of the non-skeleton part of crystalline microporous oxide, and wherein promoter metal compounds does not increase the unit cell dimension of crystalline microporous oxide in fact.

13, the described method of claim 12, wherein said crystalline microporous oxide is selected from zeolite, tectosilicate, tetrahedral aluminophosphates and tetrahedral silicoaluminophosphates.

14, the described method of claim 12, wherein said crystalline microporous oxide is a zeolite, and wherein said promoter metal compounds is an aluminum oxide.

15, the described method of claim 12, wherein said promoter metal compounds is a metal oxide, the metal of wherein said metal oxide is selected from magnesium, chromium, iron, lanthanum, gallium, manganese and aluminium.

16, the described method of claim 14, its mesolite is the Y zeolite that unit cell dimension is equal to or greater than 24.30 .

17, the described method of claim 14, its mesolite is the Y zeolite that unit cell dimension is equal to or greater than 24.40 .