KR20020010143A - Zeolite bound catalyst containing at least three different zeolites, use for hydrocarbon conversion - Google Patents

Abstract

The present invention relates to zeolite bonded zeolite catalysts which do not contain significant amounts of non-zeolitic binders and which can be adapted to optimize catalyst performance, and methods of converting hydrocarbons using said zeolite bonded zeolite catalysts. Zeolite bonded zeolite catalysts include core crystals containing a first crystal of a first zeolite and an optional second crystal of a second zeolite having a different composition, structure, or both than the first zeolite; And a binder crystal containing a third crystal of the third zeolite and a fourth crystal of the fourth zeolite having a composition, structure, or both different from that of the third zeolite. If the core crystal does not contain the second crystal of the second zeolite, the binder crystal must contain the fourth crystal of the fourth zeolite. Zeolite-bound zeolites have use in hydrocarbon conversion processes such as catalysis cracking, alkylation, disproportionation of toluene, isomerization and transalkylation.

Description

ZEOLITE BOUND CATALYST CONTAINING AT LEAST THREE DIFFERENT ZEOLITES, USE FOR HYDROCARBON CONVERSION}

Crystalline microporous molecular sieves (both natural and synthetic) have been demonstrated to have catalytic properties for various types of hydrocarbon conversion processes. Crystalline microporous molecular sieves have also been used as adsorbents and catalyst carriers for various types of hydrocarbon conversion processes and other applications. These molecular sieves are regular porous crystalline materials with a defined crystalline structure as measured by x-ray diffraction, in which there are a number of small cavities, which can be connected to each other by even smaller channels or voids. The size of these channels or pores is such that the adsorption of molecules of a particular size is allowed while rejecting larger molecules. The interstitial spaces or channels formed by the crystalline network are composed of molecular sieves such as crystalline silicates, aluminosilicates, crystalline silicoalumino phosphates and crystalline aluminophosphates as molecular sieves in the separation process and in a wide variety of hydrocarbon conversion processes. It can be used as a catalyst and a catalyst support.

Within the pores of crystalline molecular sieves, hydrocarbon conversion reactions such as isomerization of paraffins, isomerization of olefin backbones or double bonds, disproportionation reactions, alkylation reactions and alkylation reactions of aromatic compounds, It is governed by the binding force granted. Reactant selectivity problems arise when the fraction of the feedstock is too large to enter the pores and fail to react, while product selectivity problems arise when some of the product cannot leave the channel or subsequently does not react. The product distribution can also be altered by transition state selectivity, because no specific reaction can occur because the reaction transition state is so large that it cannot form in the pores. Also, if the size of the molecules is close to the size of the pore system, the selectivity problem can also result from structural constraints on diffusion. Non-selective reactions at the surface of the molecular sieve, for example such reactions at the surface acidic sites of the molecular sieve, are generally undesirable because the shape-selective constraints imparted to the reactions occurring in the channels of the molecular sieve Because it does not apply to.

Zeolites are crystalline microporous molecular sieves composed of lattice silica and optionally alumina combined with exchangeable cations (eg alkali metal or alkaline earth metal ions). The term “zeolite” includes materials containing silica and optionally alumina, but it is recognized that portions of silica and alumina may be substituted in whole or in part with different oxides. For example, germanium oxide, titanium oxide, tin oxide, phosphorous oxide, and mixtures thereof may replace a portion of silica. Boron oxide, iron oxide, gallium oxide, indium oxide and mixtures thereof can replace a portion of alumina. Accordingly, the terms "zeolite", "zeolites" and "zeolite material" as used herein refer to materials containing silicon atoms and optionally aluminum atoms in their crystal lattice structure, as well as suitable substitution elements for such silicon and aluminum. Also included are materials such as gallosilicates, borosilicates, silicoaluminophosphate (SAPO) and aluminophosphate (ALPO). As used herein, the term "aluminosilicate zeolite" refers to a zeolite material that essentially includes silicon atoms and aluminum atoms in its crystal lattice structure.

In certain hydrocarbon conversion processes it is sometimes desirable to adapt the catalyst used in this process to maximize its performance in a particular hydrocarbon conversion process. For example, it is sometimes desirable for the catalyst used in the hydrocarbon conversion process to be a multifunctional catalyst, for example a trifunctional catalyst or a bifunctional catalyst. Bifunctional catalysts include two separate catalysts, for example two zeolites of different composition or structure, leading to separate reactions. The reaction products may be separate or two catalysts may be used together to transport the reaction product of one catalyst to the catalyst site of the second catalyst and react thereon. In addition, one of the advantages of using zeolite catalysts is that the catalysts are morphologically selective, and non-selective reactions at the zeolite surface are generally undesirable, so that the catalysts used in the hydrocarbon conversion process are inadequate molecules present in the feed stream. Having the ability to prevent or at least reduce inappropriate reactions that may occur at the surface of the zeolite catalyst by selectively screening molecules in the feed stream based on their size or shape to prevent them from entering the zeolite catalyst phase and reacting with the catalyst. It is sometimes desirable. In addition, the performance of the zeolite catalyst can sometimes be maximized when the catalyst selectively selects the desired molecule based on its size or shape to prevent the molecule from leaving the catalyst phase of the catalyst.

Hydrocarbon conversions using catalysts containing two different zeolites have been proposed in the past. For example, US Pat. No. 5,536,687 includes a hydrocracking process using a catalyst containing a catalyst of zeolite beta and zeolite Y bound by an amorphous binder material such as alumina.

Although zeolite crystal | crystallization has a favorable adsorption performance, since the fixed bed which has zeolite powder is difficult to operate, its practical use is largely limited. Thus, prior to using the crystals in commercial processes, it is common to impart mechanical strength to the zeolite crystals by forming zeolite aggregates such as pills, spheres or extrudates. The extrudate can be formed by extruding zeolite crystals in the presence of a non-zeolitic binder and drying and firing the resulting extrudate. The binder material used is resistant to temperature and other conditions, for example mechanical wear that can occur in various hydrocarbon conversion processes. In general, zeolites are required to be resistant to mechanical abrasion, i.e. the formation of fines, which are small particles, for example particles having a size smaller than 20 μm. Examples of suitable binders are amorphous materials such as alumina, silica, titania and various forms of clay.

Such bound zeolite aggregates have much better mechanical strength than zeolite powders, but when the bound zeolites are used in catalysis conversion processes, the catalytic performance, e.g. activity, selectivity, activity retention, or a combination thereof, is amorphous. May decrease due to the binder. For example, the binder is typically present in an amount up to about 60% by weight of the bound catalyst, so the amorphous binder weakens the adsorptive properties of the zeolite aggregates. In addition, bound zeolites are prepared by extruding or otherwise molding the zeolite with an amorphous binder, and then drying and firing the extrudate, so that the amorphous binder penetrates the pores of the zeolite or otherwise approaches and blocks the pores of the zeolite. Or slow the mass transfer rate into and out of the pores of the zeolite, thereby reducing the efficiency of the zeolite when used in hydrocarbon conversion processes and other applications. In addition, when bound zeolites are used in catalysis conversion processes, amorphous binders may affect the chemical reactions occurring in the zeolites, and they may also catalyze inadequate reactions resulting in the formation of inadequate products. have. Thus, the catalysts used in the hydrocarbon conversion process preferably do not contain such binders in deleterious amounts.

The present invention provides a zeolite coupled zeolite catalyst for use in a hydrocarbon conversion process that can be adapted to overcome or at least mitigate the above problems and to optimize performance.

Summary of the Invention

The present invention relates to zeolite-bound zeolite catalysts that can be adapted to optimize performance in hydrocarbon conversion reactions. This zeolite-bound zeolite catalyst comprises a core crystal comprising a first crystal of a first zeolite and optionally a second crystal of a second zeolite having a composition or structure different from that of the first zeolite, and a third of third zeolite A binder crystal comprising a fourth crystal of a fourth zeolite having a crystal and optionally a composition or structure different from that of the third zeolite. If the core crystals of the zeolite-bound zeolite catalyst do not comprise a second crystal of the second zeolite other than the first crystal of the first zeolite, the binder crystal may comprise a fourth crystal of the fourth zeolite in addition to the third crystal of the third zeolite will be. The zeolite bonded zeolite catalyst of the present invention may comprise both a second crystal of the second zeolite and a fourth crystal of the fourth zeolite. The structure and / or composition of the zeolites is generally adapted to provide a zeolite bonded zeolite catalyst with improved performance. For example, zeolite-bound zeolite catalysts can be modified to prevent multifunctionally modified and / or inadequate molecules from entering the catalyst of the zeolite-bound zeolite catalysts.

In another embodiment, the present invention provides a process for converting a hydrocarbon feed using a zeolite coupled zeolite catalyst. Examples of such methods include reactions in which the catalytic activity plays an important role in reaction selectivity along with the zeolite structure, for example catalysis decomposition reactions, alkylation reactions, dealkylation reactions, disproportionation reactions and transalkylation reactions. The method can also be used particularly in hydrocarbon conversion processes where the carbon-containing compound is changed to a different carbon-containing compound. Examples of such methods include dehydrogenation methods, hydrogenolysis methods, isomerization methods, dewaxing methods, oligomerization methods, and modification methods.

The present invention relates to zeolite-bound zeolite catalysts that can be adapted to optimize performance, and the use of such zeolite-bound zeolite catalysts in hydrocarbon conversion processes.

1 shows an electron micrograph of the catalyst prepared in Example 1 below.

Figure 2 shows an electron micrograph of the catalyst prepared in Example 2 below.

FIG. 3 is a graph showing the reaction rate of the zeolite bonded zeolite catalyst of the present invention and two catalysts other than the catalyst of the present invention as a function of temperature ⁻¹ .

In a preferred embodiment of the present invention, the core crystals of the zeolite-bound zeolite catalyst are of a first crystal of the first zeolite and of a second zeolite having a different composition or different structural form than the first zeolite or both of which are different in composition and structure. And a second crystal, wherein the binder will comprise a third crystal of the third zeolite. The composition and / or structure of the first zeolite may be the same or different than the composition and / or structure of the third zeolite.

In another preferred embodiment, the core crystals of the zeolite bonded zeolite catalyst comprise a first crystal of the first zeolite and the binder has a different composition or different structure than the third crystal of the third zeolite and the third zeolite Or fourth crystals of the fourth zeolite, both in composition and in structure. The composition and / or structure of the first zeolite may be the same or different than the composition and / or structure of the third zeolite.

When the second zeolite, the fourth zeolite or both are present in the zeolite bonded zeolite catalyst of the invention, several advantages can be obtained. For example, the presence of the zeolites can maximize catalyst performance in certain hydrocarbon conversion processes. For example, in a catalytic cracking reaction, the core crystals of the zeolite-bound zeolite catalyst are more than two types of zeolites having different structures, i.e. the first zeolite and the first zeolite, which may have a large or medium pore size. Agents that may have a smaller pore size (which may have a medium pore size or a smaller pore size if the first zeolite has a large pore size, and a smaller pore size if the first zeolite has a medium pore size) 2 zeolites can be included, as a result of which the desired product can be obtained in an improved amount.

When all four zeolites are present in the zeolite-bound zeolite catalyst, these zeolite-bound zeolite catalysts may each have four zeolites having different compositions or different structural forms, or different compositions and structures. Such zeolite bonded zeolite catalysts may also comprise, in addition to the first zeolite, the second zeolite, the third zeolite and the fourth zeolite, additional zeolites having a different composition or different structural form or different composition and structure, Such zeolites may be present in the core crystals, the binder crystals, or both.

In addition to zeolite-bound zeolite catalysts with multifunctional performance, zeolite binder crystals may provide a means for controlling inappropriate reactions occurring on or near the outer surface of the core crystals and / or may provide voids in the core crystals. It can affect the mass transfer of hydrocarbon molecules through. Alternatively, the binder crystal may optionally have catalytic activity and / or act as a catalyst carrier and / or selectively prevent inappropriate molecules from entering or leaving the pores of the first and second zeolites. have.

While not wishing to limit the invention to any theory of operation, one of the advantages of the zeolite-bound zeolite catalysts of the present invention is obtained by zeolite binder crystals that control the accessibility of reactants to acidic sites in the outer surface of the core crystals. I think I lose. Since the acidic sites present on the outer surface of the zeolite catalyst are not shape-selective, these acidic sites can have a detrimental effect on reactants entering the pores of the zeolite and products exiting the pores of the zeolite. In this regard, since the acidity and structure of the binder can be carefully selected, the binder typically does not have significant adverse effects on the reactants exiting the zeolite pores of the core crystals that can react in the bound zeolite catalysts. This can have a beneficial effect on the reactants exiting the pores. Moreover, because zeolite binders are not amorphous and instead are molecular sieves, hydrocarbons may have increased access to the pores of the core crystals during the hydrocarbon conversion process. Notwithstanding the proposed theory, zeolite-bound zeolite catalysts have one or more improved properties disclosed herein when used in catalysis processes.

The zeolite bonded zeolite catalysts of the invention generally do not contain significant amounts of non-zeolitic binders. Preferably, the zeolite bonded zeolite catalyst contains less than 10% by weight, more preferably less than 5% by weight, of non-zeolitic binder, most preferably substantially non-zeolitic binder, based on the weight of the catalyst. It does not contain. Preferably, the binder crystals bond to the core crystals by forming a matrix or crosslinked structure that adheres to the surface of the core crystals to fix the core crystals together.

The terms "acidity", "low acidity", "medium acidity" and "high acidity" as applied to zeolites are known to those skilled in the art. The acidic properties of zeolites are known. However, with regard to the present invention, there is a clear difference between acid strength and acid site density. The acidic site of the zeolite may be Bronsted acid or Lewis acid. The density of the acidic sites and the number of acidic sites are important in determining the acidity of the zeolite. Factors directly affecting acidic strength include (i) the chemical composition of the zeolite skeleton, i.e. the relative concentration and morphology of tetrahedral atoms, (ii) the concentration of cations outside the skeleton and the species outside the skeleton, (iii) Local structure, such as pore size and location within or near the surface of the zeolite, and (iv) pretreatment conditions and the presence of co-adsorbed molecules. However, provided that such acidity is limited to the loss of acidic sites for pure SiO ₂ compositions, the amount of acidity relates to the degree of amorphous substituents provided. The terms "acidity", "low acidity" and "high acidity" as used herein refer to the concentration of an acidic site, regardless of the strength of the acidic site that can be measured by ammonia absorption.

Zeolites suitable for use in the zeolite bonded zeolite catalysts of the invention include naturally occurring or synthesized crystalline zeolites. Examples of such zeolites include large pore zeolites, medium pore size zeolites and small pore zeolites. Such zeolites are described in "Atlas of Zeolite Structure Types", eds. WH Meier, DH Olson and Ch. Baerlocher, Elsevier, Fourth Edition, 1996. Large pore zeolites generally have a pore size of at least about 7 mm 3 and include LTL, VFI, MAZ, MEI, FAU, EMT, OFF, ^* BEA and MOR structured zeolites (according to the zeolite nomenclature of the IUPAC committee). Examples of large pore zeolites are mazite, opretite, zeolite L, VPI-5, zeolite Y, zeolite X, omega, beta, ZSM-3, ZSM-4, ZSM-18, ZSM-20, MCM-9, MCM-41, MCM-41S, MCM-48 and SAPO-37. Medium pore size zeolites generally have a pore size of about 5 kPa to about 7 kPa and include, for example, MFI, MEL, MTW, EUO, MTT, HEU, FER, MFS and TON structured zeolites (according to the zeolite nomenclature of the IUPAC Commission). It includes. Examples of medium pore size zeolites are ZSM-5, ZSM-12, ZSM-22, ZSM-23, ZSM-34, ZSM-35, ZSM-38, ZSM-48, ZSM-50, ZSM-57, MCM-22 , MCM-36, MCM-49, MCM-56, MCM-68, Silicalite and Silicalite 2. Small pore size zeolites have pore sizes of about 3 mm 3 to about 5.0 mm 3 and include, for example, CHA, ERI, KFI, LEV and LTA structured zeolites (according to the zeolite nomenclature of the IUPAC committee). Examples of small pore zeolites are ZK-4, SAPO-34, SAPO-35, ZK-14, SAPO-42, ZK-21, ZK-22, ZK-5, ZK-20, Zeolite A, Erionite, Tea Bazaite, zeolite T, gmmellinate, ALPO-17 and clinoptiolite.

The first, second, third and fourth zeolites used in the zeolite bonded zeolite catalysts preferably comprise a composition having the following molar relationship:

X ₂ O ₃ : (n) YO ₂

Where

X is a trivalent element such as titanium, boron, aluminum, iron and / or gallium,

Y is a tetravalent element such as silicon, tin and / or germanium,

n is a value of 2 or more, which value depends on the particular form of the zeolite and the trivalent elements present in the zeolite.

If the first, second, third or fourth zeolite has a median pore size, the zeolite preferably comprises a composition having the following molar relationship:

X ₂ O ₃ : (n) YO ₂

Where

X is a trivalent element such as aluminum and / or gallium,

Y is a tetravalent element such as silicon, tin and / or germanium,

n is a value greater than 10, which value depends on the particular form of the zeolite and the trivalent elements present in the zeolite. When the zeolite has an MFI structure, n is preferably greater than 20.

As is known to those skilled in the art, the acidity of zeolites can be reduced using many techniques, such as dealumination and steaming. The acidity of the zeolite also depends on the form of the zeolite, such as the different forms of the zeolite, such as the hydrogen form having the maximum acidity and the sodium form having a lower acidity than the acid form. Thus, the molar ratios of silica and alumina and silica and galls disclosed herein include zeolites having the disclosed molar ratios as well as zeolites having no molar ratios disclosed but having equivalent catalytic activity.

If the first, second, third or fourth zeolite is a gallosilicate median pore size zeolite, the zeolite preferably comprises a composition having the following molar relationship:

Ga ₂ O ₃ : ySiO ₂

Where

y is about 24 to about 500.

The zeolite backbone may contain only gallium and silicon atoms or may also contain a combination of gallium, aluminum and silicon. If the first or second zeolite is an MFI structured gallosilicate zeolite, the zeolite in the binder is preferably a medium pore size zeolite having a silica to gallium molar ratio of greater than 100. Zeolites in the binder may also have high silica to gallium molar ratios, for example greater than 200, 500, 1000, and the like.

When the first zeolite used in the zeolite bonded zeolite catalyst and the second zeolite, if present, is an aluminosilicate zeolite, the silica to alumina molar ratio generally depends on the structural type of the zeolite and the particular hydrocarbon process in which the catalyst system is used, Therefore, it is not limited to any particular ratio. Generally, however, depending on the structure of the zeolite, the zeolite has a molar ratio of silica to alumina of at least 2: 1 and in some cases a molar ratio of 4: 1 to about 7: 1. For many zeolites, especially medium pore size zeolites, the silica to alumina molar ratio is about 10: 1 to about 1,000: 1. When the catalyst is used in acid catalysis reactions such as decomposition reactions, preparation of paraxylene and benzene by disproportionation of toluene, alkylation of benzene, etc., the at least one zeolite will be acidic, preferably of medium pore size zeolites For example, it will have a high silica to alumina mole ratio of 20: 1 to about 200: 1. If the catalyst is used in a process in which no acid catalysis reaction is required, for example in the modification of naphtha, the first zeolite and the second zeolite, if present, will preferably exhibit reduced acidic activity.

The composition and structure of the first zeolite and the second zeolite will depend on the particular hydrocarbon process in which the zeolite catalyst is used. For example, when naphtha is used to modify the aromatics, the structure is preferably LTL (eg zeolite L) and the silica to alumina ratio is 4: 1 to about 7: 1. When the catalyst is used for the preparation of paraxylene and benzene by isomerization of xylene or disproportionation of toluene, the first zeolite and the second zeolite (optionally present) will preferably have a medium pore size zeolite . When zeolite bonded zeolite catalysts are used in the decomposition reaction of paraffins, the preferred pore size and structure type will depend on the size of the molecule to be degraded and the desired product.

As used herein, the term "average particle diameter" refers to the mathematical mean of the diameter distribution of a crystal, based on volume.

The average particle diameter of the core crystals may vary and will typically be about 0.1 to about 15 μm. In some applications, the average particle diameter will preferably be about 1 to about 6 μm. For different applications, such as hydrocarbon decomposition reactions, the preferred average particle diameter will be about 0.1 to about 3.0 μm. When the core crystal comprises the first crystal of the first zeolite and the second crystal of the second zeolite, the average particle diameter of the first crystal is often at least twice as large as the average particle diameter of the second crystal. In addition, when both crystals are present, the amount of the second crystal may vary and may even be in small amounts (eg, less than 5% by weight based on the weight of the first and second crystals).

The composition and structure of the third zeolite and, if present, the fourth zeolite will depend on the intended use of the zeolite-bound zeolite catalyst. For example, when the zeolite bonded zeolite catalyst contains core crystals of the first zeolite and the second zeolite, and the third zeolite binder crystal and is used as a catalyst for isomerization reaction of xylene / dealkylation reaction of ethylbenzene Dealkylation of benzene can take place on the catalyst of the first zeolite, the first zeolite can be selected such that the isomerization reaction of xylene occurs mainly on the catalyst of the second zeolite, and the binder zeolite is the first zeolite and the second zeolite It is chosen so as to reduce the acidity of the surface. When zeolite-bound zeolite catalysts are used in decomposition reactions, the zeolites can have acidic activity and the structure type of each zeolite can be chosen to allow larger molecules through its channel, where their pore sizes Larger molecules are applied to the decomposition reaction into smaller products. After the larger molecules have been decomposed, the decomposed molecules can be introduced into the pores of the smaller pore size zeolite, where they are further decomposed, isomerized, or oligomerized, depending on the desired product. Will be applied to. Zeolite-bound zeolite catalysts can be adapted to select feed components into which the zeolites of the binder crystals are introduced into the pores of the zeolite core crystals, or to select product components exiting the channels of the zeolite core crystals. For example, when a zeolite-bound zeolite catalyst comprises a binder zeolite (eg, third and optionally fourth zeolite) of suitable pore size, it selects and classifies molecules based on their size and shape, thereby By acting to prevent the introduction or release of inappropriate molecules onto the catalyst of the zeolite core crystals as described above.

If the third or fourth zeolite is an aluminosilicate zeolite, the silica to alumina molar ratio will typically depend on the structure type of the zeolite and the particular hydrocarbon process in which the catalyst is used and thus is not limited to any particular ratio. In general, however, depending on the structure of the zeolite, the ratio of silica to alumina will be at least 2: 1. If the aluminosilicate zeolite is a medium pore size zeolite and low acidity is desired, the binder zeolite preferably has a silica to alumina mole ratio greater than the silica to alumina mole ratio of the first zeolite, and more preferably greater than 200: 1. In addition, the binder zeolite may have a higher silica to alumina molar ratio (eg, 300: 1, 500: 1, 1,000: 1, etc.). The binder zeolite may be Silicalite (ie, the zeolite is an MFI structure substantially free of alumina) and / or silicalite 2 (ie, the MEL structure is free of zeolite substantially free of alumina and mixtures thereof). The pore size of the binder zeolite will preferably be a pore size that does not reversely limit the access of the desired molecule of the hydrocarbon feed stream onto the catalyst of the zeolite to which the zeolite is bound. For example, if the material of the feed stream to be converted by the zeolite core crystals has a size of 5 to 6.8 kPa, the binder zeolite will be a larger pore zeolite or a medium pore size zeolite.

Although binder crystals are typically present in zeolite bonded zeolite catalysts in an amount of about 10 to about 60 weight percent based on the weight of the catalyst, the amount of binder crystals will typically depend on the hydrocarbon process in which the catalyst is used. More preferably, the amount of binder crystal present is about 20 to about 50 weight percent. If the binder crystal comprises a third crystal of the third zeolite and a fourth crystal of the fourth zeolite, the average particle diameter of the third crystal may be smaller or larger than the average particle diameter of the fourth crystal.

If both the third and fourth crystals are present in the zeolite bonded zeolite catalyst, the amount of the fourth crystal present may vary and may be in small amounts (eg, less than 20% by weight based on the weight of the third and fourth crystals). Can be.

Binder crystals typically have a smaller size than core crystals. The binder crystals have an average particle diameter of less than 1 μm, preferably from about 0.1 to 0.5 μm. In addition to maximizing catalyst performance in conjunction with the core crystals, the binder crystals will preferably intergrown to form overgrowth or partial overgrowth on the first zeolite. If a second zeolite is present, the binder crystal will form an overgrowth in this zeolite. If the binder crystals comprise crystals of two zeolites having different compositions, structure types, or both, each average particle diameter may be the same or different, ie larger or smaller. Often, the coating will impart friction resistance.

The amount of second zeolite and / or fourth zeolite present in the zeolite-bound zeolite catalyst will generally depend on the particular process, and typically the zeolite-bound zeolite catalyst will contain from about 1.0% to about 70% by weight based on the weight of the catalyst. It will be a quantity.

Zeolite bonded zeolite catalysts can be prepared using a three step process. The first step involves the synthesis of zeolite core crystals. Processes for making such zeolites are known to those skilled in the art. For example, MFI structured zeolites can be prepared using the methods described in PCT International Publication No. 98/16469, which is incorporated herein by reference. If the core crystals contain a first zeolite crystal and a second zeolite crystal, the zeolite can be prepared separately or the zeolite can be prepared by converting the synthesis mixture under conditions favorable to form two separate zeolites. For example, MFI and MEL structured zeolites can be prepared in the same zeolite synthesis mixture.

Next, the silica-binder zeolite is prepared by mixing a mixture containing core crystals, silica gel or sol, water and optionally extrusion aids, until a homogeneous composition is produced in the form of an extrudable paste. The silica binder used to prepare the silica bound zeolite aggregates is preferably a silica sol and may contain various amounts of trivalent metal oxides such as alumina. The amount of zeolite in the extrudate dried at this stage will preferably be from about 40 to 90% by weight, more preferably from about 50 to 80% by weight, with the remainder being primarily, for example, from about 20 to 50% by weight. Will be silica.

The resulting paste is then cast (eg extruded) and cut into small strands (eg 2 mm diameter extrudate), dried at 100-150 ° C. for 4-12 hours and then at a temperature of about 400-550 ° C. Calcin in air for about 1 to about 10 hours.

Optionally, the silica-bonded aggregates can be made into very small particles having use in fluidic processes such as catalysis decomposition reactions. The process mixes the silica containing matrix solution with the core crystal zeolite to form an aqueous solution of zeolite and silica binder, which is then spray dried to form small flowable silica-bonded aggregate particles. Methods of making such aggregate particles are known to those skilled in the art. An example of such a method is described in Scherzer, Octane-Enhancing Zeolitic FCC Catalysts, Julius Scherzer, Marcel Dekker, Inc. New York, 1990. The flowable silica bound aggregated particles, such as the silica bound extrudate described above, are then subjected to the final steps described below to convert the silica binder into a second zeolite.

The final step in the three-step catalyst preparation process is the conversion of silica present in the silica bound zeolite to binder zeolite. The binder crystal binds the core crystals to each other. Thus, zeolite core crystals are fixed to each other without the use of significant amounts of non-zeolitic binders.

To prepare zeolite-bound zeolites, it is preferred to first age the silica-bound aggregates in a suitable aqueous solution at elevated temperature. Next, the temperature at which the contents and aggregates of the solution are aged is selected to allow the amorphous silica binder to be converted to one or more zeolites. Newly formed zeolites, which may include one or more zeolites, are produced as crystals. Crystals may grow on and / or attach to the core crystals and may be produced in the form of newly shaped crystals that are generally much smaller than the initial crystals, for example, up to a micrometer in size. These newly formed crystals can be grown and connected to each other.

The characteristics of the zeolite formed in the secondary synthesis conversion reaction from silica to zeolite may vary depending on the action of the secondary synthesis solution composition and the conditions of synthesis aging. The secondary synthetic solution is preferably an ionic aqueous solution containing sufficient source of hydroxy ions to convert the silica to the desired zeolite, which may be two or more individual zeolites. However, it is important that the aging solution is a composition such that the silica present in the bound zeolite extrudate does not dissolve into the extrudate. In some cases, it may be desirable to dissolve some of the zeolite crystals to form one or more zeolites having different compositions, structure types, or both. Sometimes it may be undesirable to dissolve zeolite crystals.

The zeolite present in the zeolite bonded zeolite catalyst replaces at least a portion of the original metal present in the zeolite with a metal of Groups IB to VIII of the periodic table, such as a different cation such as nickel, copper, zinc, calcium or a rare earth metal, or In addition, ion exchange reactions known in the art can be further carried out to provide zeolites in more acidic form by exchanging alkali metals with intermediate ammonium and then calcining the ammonium form to give an acidic hydrogen form. Acidic forms can be readily prepared by ion exchange reactions with a suitable acidic reagent such as ammonium nitrate. The zeolite may then be calcined at a temperature of 400-550 ° C. for 10-45 hours to remove ammonia and form an acidic hydrogen form. Particularly preferred cations are cations that make the catalyst catalytically active, especially for hydrocarbon conversion processes. Such cations include hydrogen, rare earth metals, and metals of groups IIA, IIIA, IVA, IB, IIB, IIIB, IVB, and VIII of the Periodic Table. Preferred metals include Group VIII metals (ie Pt, Pd, Ir, Rh, Os, Ru, Ni, Co and Fe), Group IVA metals (ie Sn and Pb), Group VB metals (ie Sb and Bi). ) And Group VIIB metals (ie, Mn, Tc and Re). Precious metals (ie, Pt, Pd, Ir, Rh, Os and Ru) are more preferred in some cases.

Zeolite-bound zeolite catalysts of the invention can be used in the processing of hydrocarbon feedstocks. The hydrocarbon feedstock may be any carbon-containing fluid that contains carbon compounds and is derived from a number of different sources, such as natural petroleum fractions, recycled petroleum fractions, tar sands, and generally susceptible to zeolite-based catalysis. Can be. Depending on the type of processing of the hydrocarbon feed, the feed may or may not contain metal. In addition, the feed may be high or low in nitrogen or sulfur impurities.

The conversion of the hydrocarbon feed can take place in any convenient manner, for example in fluid bed, mobile bed or fixed bed reactors, depending on the type of process desired.

The zeolite bonded zeolite catalysts of the present invention can be used alone or in combination with one or more catalytically active materials as catalysts or supports for various organic compounds, for example in hydrocarbon compound conversion processes. Examples of such conversion processes are described below, but are not limited to these:

(A) Catalytic cracking reaction of naphtha feed to produce light olefins. Typical reaction conditions are temperatures of about 500 to 750 ° C., subatmospheric pressures (typically about 10 atmospheres (gauge) or less) and residence times (catalyst volume feed rates) of about 10 milliseconds to about 10 seconds.

(B) Catalytic cracking of high molecular weight hydrocarbons to produce low molecular weight hydrocarbons. Typical reaction conditions for such catalysis cracking are temperatures of about 400 to about 700 ° C., pressures of about 0.1 to about 30 bar, and weight space velocity per hour of about 0.1 to about 100 hr ⁻¹ .

(C) alkylalkylation of aromatic hydrocarbons in the presence of polyalkylaromatic hydrocarbons. Typical reaction conditions include a temperature of about 200 to about 500 ° C., a pressure of about atmospheric pressure to about 200 atmospheres, a weight hourly space velocity of about 1 to about 100 hr ⁻¹ , and an aromatic hydrocarbon to poly of about 0.5 / 1 to about 16/1 Molar ratio of alkylaromatic hydrocarbons.

(D) Isomerization of aromatic (eg xylene) feedstock components. Typical reaction conditions are a temperature of about 230 to about 510 ° C., a pressure of about 0.5 to about 50 atmospheres, a weight hourly space velocity of about 0.1 to about 200 hr ⁻¹ and a mole ratio of hydrogen to hydrocarbon of about 0 to about 100.

(E) Dewaxing of hydrocarbons by selective removal of straight chain paraffins. Reaction conditions vary largely depending on the feed used and the desired pour point. Typical reaction conditions are a temperature of about 200 to 450 ° C., a pressure of about 3,000 psig or less and a liquid space velocity per hour of 0.1 to 20.

(F) Alkylating reactions of aromatic hydrocarbons such as benzene and alkylbenzenes in the presence of alkylating agents such as olefins, formaldehyde, alkyl halides and alcohols having 1 to about 20 carbon atoms. Typical reaction conditions include a temperature of about 100 to about 500 ° C., a pressure of about atmospheric pressure to about 200 atmospheres, a weight hourly space velocity of about 1 to about 100 hr ⁻¹ and an aromatic hydrocarbon to alkylating agent of about 1/1 to about 20/1. It is a molar ratio.

(G) Alkylation of aromatic hydrocarbons such as benzene with long chain olefins, such as C ₁₄ olefins. Typical reaction conditions include a temperature of about 50 to about 200 ° C., a pressure of about atmospheric pressure to about 200 atmospheres, a weight hourly space velocity of about 2 to about 2000 hr ⁻¹ and an aromatic hydrocarbon to olefin of about 1/1 to about 20/1. It is a molar ratio. The product resulting from the reaction is a long chain alkyl aromatic compound and has special use as a synthetic detergent when subsequently sulfonated.

(H) Alkylation of aromatic hydrocarbons with light olefins to obtain short chain alkyl aromatic compounds. For example, alkylation of benzene with propylene yields cumene. Typical reaction conditions include a temperature of about 10 to about 200 ° C., a pressure of about 1 to about 30 atmospheres and a weight hourly space velocity (WHSV) of aromatic hydrocarbons of 1 to about 50 hours ⁻¹ .

(I) Hydrolysis of heavy petroleum feedstocks, cyclic feedstocks and other hydrocracking feedstock feedstocks. The zeolite catalyst will contain at least one effective amount of the hydrogenation component in the form used in the hydrogenolysis catalyst.

(J) Alkylation with a fuel gas containing short chain olefins (e.g. ethylene and propylene) of a reformate containing actual amounts of benzene and toluene to produce monoalkylates and dialkylates. Preferred reaction conditions include a temperature of about 100 to about 250 ° C., a pressure of about 100 to about 800 psig, a WHSV-olefin of about 0.4 to about 0.8 hours ⁻¹ , a WHSV-modifier of about 1 to about 2 hours ⁻¹ , and Optionally about 1.5 to 2.5 volume / volume of gas circulation rate of the fuel gas feed.

(K) Alkylation of aromatic hydrocarbons (eg benzene, toluene, xylene and naphthalene) with long chain olefins (eg C ₁₄ olefins) to prepare alkylated aromatic lubricating oil-based feedstocks. Typical reaction conditions include a temperature of about 160 to about 260 ° C and a pressure of about 350 to 450 psig.

(L) Alkylation of phenols with olefins or equivalent alcohols to obtain long chain alkyl phenols. Typical reaction conditions include a temperature of about 100 to about 250 ° C., a pressure of about 1 to 300 psig and a total WHSV of about 2 to about 10 hours ⁻¹ .

(M) Conversion of light paraffins to olefins and / or aromatic compounds. Typical reaction conditions include a temperature of about 425 to about 760 ° C. and a pressure of about 10 to about 2000 psig. Methods of preparing aromatic compounds from hard paraffins are described in US Pat. No. 5,258,563, which is incorporated herein by reference.

(N) Conversion of light paraffins to hydrocarbons in the gasoline, distillate and lubricating oil range. Typical reaction conditions include a temperature of about 175 to about 375 ° C. and a pressure of about 100 to about 2000 psig.

(O) Two-stage hydrolysis to improve hydrocarbon streams having an initial boiling point of at least about 200 ° C. to higher distillates and gasoline untacked products, or to add further to the fuel or compound as a feed. In the first step, the zeolite-bound zeolite comprising at least one catalyzed active material (eg Group VIII metal) and the effluent from the first step comprises at least one catalyzed active material (eg Group VIII metal) Reaction in a second step using a second zeolite catalyst (eg zeolite beta) comprising a. Typical reaction conditions include a temperature of about 315 to about 455 ° C., a pressure of about 400 to about 2500 psig, a hydrogen cycle of about 1000 to about 10,000 SCF / bbl, and an hourly liquid space velocity (LHSV) of about 0.1 to 10.

(P) Combination of hydrogenolysis / dewaxing process in the presence of a zeolite bonded zeolite catalyst comprising a metal hydride and zeolites such as zeolite beta. Typical reaction conditions include a temperature of about 350 to about 400 ° C., a pressure of about 1400 to about 1500 psig, an LHSV of about 0.4 to about 0.6 and a hydrogen cycle of about 3000 to about 5000 SCF / bbl.

(Q) Reaction of alcohols with olefins to produce mixed ethers. For example, methanol is reacted with isobutene and / or isopentene to yield methyl-tert-butyl ether (MTBE) and / or tert-amyl methyl ether (TAME). Typical conversion conditions include a temperature of about 20 to about 200 ° C., a pressure of 2 to about 200 atmospheres, a WHSV of about 0.1 to about 200 hours ⁻¹ and a molar ratio of alcohol to olefin feed of about 0.1 / 1 to about 5/1. do.

(R) Disproportionation of aromatic compounds to obtain benzene and paraxylene (e.g. disproportionation of toluene). Typical reaction conditions include a temperature of about 200 to about 760 ° C., a pressure of about atmospheric pressure to about 60 atmospheres (bar) and a WHSV of about 0.1 to about 30 hours ⁻¹ .

(S) Conversion of naphtha (eg C ₆ -C ₁₀ ) and similar mixtures to higher aromatic mixtures. Thus, straight and slightly branched chain hydrocarbons, preferably hydrocarbons having a boiling point of about 40 to about 200 ° C., have a temperature of about 400 to 600 ° C., preferably 480 to 550 ° C., atmospheric pressure to 40 bar and a pressure of 0.1 By contacting the zeolite-bound zeolite with the hydrocarbon feed at a liquid hourly space velocity (LHSV) of from 15 to 15, it can be converted to a product having substantially higher aromatic content of octane.

(T) Selective separation of hydrocarbons by adsorption of hydrocarbons. Examples of separation of hydrocarbons include separation of xylene isomers and separation of olefins from feed streams containing olefins and paraffins.

(U) oxygen to a hydrocarbon comprising an olefin and an aromatic compound under reaction conditions comprising a temperature of about 275 to about 600 ° C., a pressure of about 0.5 to about 50 atmospheres and a liquid space velocity per hour of about 0.1 to about 100 Conversion of oxygenates such as alcohols such as methanol, ethers such as dimethyl ether or mixtures thereof.

(V) Oligomerization of straight and branched chain olefins having from about 2 to about 5 carbon atoms. The oligomers, which are products of the process, are intermediate olefins to heavy olefins useful for both fuels, ie gasoline or raw materials for mixing gasoline and chemicals. The oligomerization process is generally carried out by contacting the gaseous olefin feedstock with a zeolite catalyst at a temperature of about 250 to about 800 ° C., LHSV of about 0.2 to about 50, and hydrocarbon partial pressure of about 0.1 to about 50 atmospheres. A temperature below about 250 ° C. may be used to oligomerize the feedstock when it is present in the liquid phase when in contact with the zeolite catalyst. Thus, when the olefin feedstock is in contact with the catalyst in the liquid phase, a temperature of about 10 to about 250 ° C may be used.

(W) Conversion of aliphatic C _6-12 aldehydes to C ₂ unsaturated hydrocarbons (ethylene and / or acetylene), and conversion of aldehydes to the corresponding C _6-12 alcohols, acids or esters.

In general, catalysis conversion conditions include temperatures of about 100 ° C. to about 760 ° C., pressures of about 0.1 bar to about 200 bar, and weight hourly space velocity per hour of about 0.08 hours ⁻¹ to about 2,000 hours ⁻¹ . (weight hourly space velocity).

In many hydrocarbon conversion processes, it is desirable for the binder crystals to have a lower acidity to reduce inappropriate reactions outside the core crystals, but in some processes it is desirable for the binder crystals to have a higher acidity.

A process having a special use using the zeolite bonded zeolite catalyst of the present invention is a process in which two or more reactions occur in a zeolite bonded zeolite catalyst. Each zeolite of such a catalyst will be individually adapted to promote or inhibit different reactions. Processes using such catalysts not only have the advantage of significantly increased catalyst activity, increased zeolite accessibility, and reduced possible non-selective surface acidity with zeolite-bound zeolites, but also the advantages of a modified catalyst system.

Examples and exemplary uses of zeolite bonded zeolite catalysts are shown in Table 1 below.

Examples of preferred zeolite bonded zeolite catalyst systems include:

1. A zeolite-bound zeolite catalyst comprising a core crystal of an acidic first zeolite having a decomposition reaction activity and a second zeolite having a lower acidity than the first zeolite, and a binder crystal of a third zeolite having very low or no acidic activity. Zeolite bonded zeolite catalyst systems are particularly useful for catalytic cracking reactions. Catalysts E and F in Table 1 are examples of such catalysts.

2. A binder of a core crystal comprising an acidic first zeolite having a large pore having a decomposition reaction activity and an acidic second zeolite having a medium pore size having a decomposition reaction activity, and an acidic medium pore size zeolite having a decomposition reaction activity. Zeolite bonded zeolite catalyst with crystals. Catalyst M in Table 1 is an example of such a catalyst.

3. a core crystal containing a first zeolite having moderate acidic activity and optionally containing a hydrogenated / dehydrogenated metal and a second zeolite having a higher acidic activity than the first zeolite and optionally having a hydrogenated / dehydrogenated metal, And binder crystals of the third zeolite having lower acidic activity than the first zeolite. The pore size of the zeolite will depend on the type of process in which the catalyst system is used. For example, the catalyst system can be used in a combined process of xylene isomerization / ethylbenzene dealkylation where ethylbenzene is dealkylated to form benzene and ethane and isomers of xylene isomerized in equilibrium amounts. In such a system, the first zeolite preferably has a large or medium pore size zeolite and a large crystal size, and the second zeolite also preferably has a larger or medium pore size zeolite and a smaller one so as to have a high surface acidity. It may have a crystal size. Catalysts C, D and U in Table 1 are examples of such catalysts.

4. A zeolite bonded zeolite catalyst comprising the core crystals of the first acidic zeolite and binder crystals of the third and fourth zeolites with little or no acidic activity. The pore size of the zeolite will depend on the type of process in which the catalyst is used. For example, when a catalyst is used for the production of benzene and paraxylene by disproportionation of toluene, the first zeolite preferably has a medium pore size and the third and fourth zeolites improve the performance of the first zeolite. May be selected to control the accessibility of the reactants to acidic sites on the outer surface of the first zeolite by selecting inappropriate molecules exiting or exiting the first zeolite. Catalyst A in Table 1 is an example of such a catalyst.

The zeolite bonded zeolite catalysts of the present invention are particularly useful for vapor phase disproportionation of toluene. This vapor phase disproportionation reaction comprises contacting toluene with zeolite-bound zeolite catalysts under disproportionation conditions to obtain a product mixture comprising a mixture of unreacted (unconverted) toluene, benzene and xylene. In a more preferred embodiment, the catalyst is first selected prior to use in the disproportionation process in order to increase the conversion from toluene to xylene and to maximize catalyst selectivity for paraxylene production. Methods of selecting a catalyst are known to those skilled in the art. For example, the selectivation may cause the catalyst in the reactor bed to be pyrolytic organic compound, such as toluene, at a temperature above the decomposition temperature of the compound, for example from about 480 ° C to about 650 ° C, more preferably 540 ° C. From 0 to about 2 moles per mole of organic compound, more preferably from about 0.1 to about 650 ° C., at a WHSV of about 0.1 to 20 lb of feed / catalyst pounds / hour, at a pressure of about 1 to 100 atmospheres. It can be achieved by exposure in the presence of 2 moles of hydrogen, optionally in the presence of 0 to 10 moles of nitrogen or a different inert gas per mole of organic compound. This process is carried out for a period until a sufficient amount, generally about 2% by weight, more preferably about 8 to about 40% by weight, of coke is deposited on the catalyst surface. In a preferred embodiment, this selectivity process is carried out in the presence of hydrogen to prevent the coke from actively forming on the catalyst.

In addition, selectivity of the catalyst can be achieved by treating the catalyst with a selector such as an organosilicon compound. Examples of organosilicon compounds include polysiloxanes, siloxanes, including silicones, and silanes, including disilanes and alkoxysilanes.

Silicon compounds which find particular use can be represented by the following formulas.

In the above formula,

R ₁ is hydrogen, fluorine, hydroxy, alkyl, aralkyl, alkaryl or fluoro-alkyl.

Hydrocarbon substituents generally contain 1 to 10 carbon atoms and are preferably methyl or ethyl groups. R ₂ is selected from the same group as R ₁ , n is an integer of 2 or more and generally ranges from 2 to 1000. The molecular weight of the silicon compound used is generally 80 to 20,000 and preferably 150 to 10,000. Representative examples of the silicon compound include dimethylsilicone, diethylsilicone, phenylmethylsilicone, methylhydrogensilicone, ethylhydrogensilicone, phenylhydrogensilicone, methylethylsilicone, phenylethylsilicone, diphenylsilicone, methyltrifluoropropylsilicone , Ethyltrifluoropropylsilicone, tetrachlorophenylmethyl silicone, tetrachlorophenylethyl silicone, tetrachlorophenylhydrogen silicone, tetrachlorophenylphenyl silicone, methylvinylsilicone and ethylvinylsilicon. The silicon compound need not be linear but may be cyclic, such as, for example, hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, hexaphenylcyclotrisiloxane, and octaphenylcyclotetrasiloxane. In addition, mixtures of these compounds may be used together with silicones having different functional groups.

Non-limiting examples of useful siloxanes or polysiloxanes include hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethyl cyclopentasiloxane, hexamethyldisiloxane, octamethyltrisiloxane, decamethyltetrasiloxane, hexaethylcyclotrisiloxane, octa Ethylcyclo tetrasiloxane, hexaphenylcyclotrisiloxane and octaphenylcyclo tetrasiloxane.

Useful silanes, disilanes or alkoxysilanes include organic substituted silanes having the general formula:

In the above formula,

R is a reactive group such as hydrogen, alkoxy, halogen, carboxy, amino, acetamide, trialkylsiloxy,

R ₁ , R ₂ and R ₃ are the same as R, or alkyl having 1 to 40 carbon atoms, 6 to 24 carbons in which the organic portion of alkyl contains 1 to 30 carbon atoms and which aryl groups may be further substituted Organic radicals, including dog containing alkyl or aryl carboxylic acids, and alkylaryl and arylalkyl groups containing 7 to 30 carbon atoms. Preferably, the alkyl group for the alkyl silane has 1 to 4 carbon atoms in chain length.

When using the vaporized disproportionation of toluene, the catalyst has a medium pore size zeolite of about 2 to 6 μm average particle diameter, for example MFI structured, and has a molar ratio of silica to alumina from about 20: 1 to about 200: 1, preferably a first crystal of 25: 1 to about 120: 1; For example, silicalite or silly having a median pore size zeolite of average particle diameter of less than about 0.1 μm and having, for example, MFI or MEL structure type and having a molar ratio of alumina to silica greater than about 200: 1 to about 10,000: 1. A binder comprising a callite diphosphate 3 crystal; And a second crystal of a second zeolite of medium pore size zeolite having a structure different from the first zeolite, for example, a TON structure.

Once the catalyst is selected to the desired degree, the reactor selection conditions change to disproportionation reaction conditions. The temperature at the disproportionation reaction conditions is from 400 ° C. to 550 ° C., more preferably from about 425 ° C. to about 510 ° C., and the molar ratio of hydrogen to toluene is from 0 to about 10, preferably from about 0.1 to 5, more preferably It is about 0.1 to 1, the pressure is about 1 to 100 atmospheres and the WHSV used is about 0.5 to 50.

The disproportionation process can be carried out as a batch, semicontinuous or continuous operation using a fixed or moving bed catalyst system deposited on the reactor bed. The catalyst can be regenerated after inactivation by burning the coke to the desired degree at elevated temperatures in an oxygen-containing atmosphere as is known in the art.

The zeolite-bound zeolites of the present invention are also specially catalyzed as catalysts in processes where isomerization of one or more xylene isomers in a C ₈ aromatic compound feed yields ortho-, meta-, and para-xylene in proportions close to equilibrium values. Use has been found. In particular, the xylene isomerization reaction is used in conjunction with a separation process to produce para-xylene. For example, some para-xylene in the mixed C ₈ aromatics stream can be recovered using processes known in the art, for example, crystallization, adsorption and the like. The resulting stream can then be reacted under xylene isomerization conditions to convert ortho-, meta-, and paraxylene to near equilibrium ratios. Ethylbenzene in the feed is removed from the stream or converted to benzene which is readily separated by xylene or distillation in the process. Isomers are blended with fresh feed and the mixed stream is distilled to remove heavy and light by-products from the stream. Thus, the resulting C ₈ aromatics stream is recycled to repeat the cycle.

It is important for the xylene isomerization catalyst to produce a near-equilibrium xylene mixture and it is usually desirable to convert ethylbenzene while the catalyst has little total loss of xylene. It can be seen that the zeolite bonded zeolite catalyst is particularly applicable in this respect. The acidity of the zeolite, for example the molar ratio of silica to the trivalent metal oxide (alumina, gaul, boron oxide, iron oxide, etc.) of the zeolite's central crystals, is such that the xylene isomerization reaction and ethylbenzene dealkylation minimize the undesirable side reactions. It can be chosen to balance the reactions.

The process is carried out by contacting a stream of C ₈ aromatic compounds containing one or more xylene isomers, ethylbenzene or mixtures thereof with a zeolite bonded zeolite catalyst under silane isomerization reaction / EB conversion conditions. Preferably, at least 30% of ethylbenzene is converted.

In the vapor phase, suitable isomerization conditions include a temperature in the range of 250 ° C. to 600 ° C., preferably 300 ° C. to 550 ° C., and a pressure of 0.5 to 50 atmospheres (absolute pressure), preferably 10 to 25 atmospheres (absolute pressure). The hourly weight space velocity (WHSV) is between 0.1 and 100, preferably between 0.5 and 50. Optionally, the vapor phase isomerization reaction is carried out in the presence of 3.0 to 30.0 moles of hydrogen per mole of alkylbenzene. If hydrogen is used, the metal component of the catalyst preferably comprises from 0.1% to 2.0% by weight of the hydrogenation / dehydrogenation component selected from Group VIII of the Periodic Table of the Elements, in particular platinum, palladium or nickel. By group VIII metal components are meant metals and their components such as oxides and sulfides.

The zeolite bonded zeolite catalysts of the present invention are used to produce low molecular weight olefins, such as C ₂ to C ₄ olefins, in particular ethylene and propylene, naphtha feeds such as C ₄ ⁺ naphtha feeds, in particular C ₄ It may be particularly useful as a catalyst in the cracking reaction process of a -290 ° C naphtha feed. The process is preferably carried out by contacting the naphtha feed at a pressure in the range from 500 ° C. to 750 ° C., more preferably from 550 ° C. to 675 ° C., at a pressure of up to 10 atm, but preferably from about 1 to about 3 atm. Can be.

The zeolite bonded zeolite catalysts of the present invention are useful as catalysts in alkyl group transfer reactions of polyalkylaromatic hydrocarbons. Examples of suitable polyalkylaromatic hydrocarbons include di-benzene, triethylbenzene, diethylmethylbenzene (diethyltoluene), diisopropyl-benzene, triisopropylbenzene, diisopropyltoluene, dibutylbenzene and the like. , Tri-, and tetra-alkyl aromatic hydrocarbons. Preferred polyalkylaromatic hydrocarbons are dialkyl benzenes. Particularly preferred polyalkylaromatic hydrocarbons are diisopropylbenzene and diethylbenzene.

The molar ratio of aromatic hydrocarbon to polyalkyl aromatic hydrocarbon in the course of the transalkylation will preferably be from about 0.5: 1 to about 50: 1, more preferably from about 2: 1 to about 20: 1. The reaction temperature is preferably in the temperature range of about 340 ° C. to 500 ° C., at least in part to maintain the liquid phase, and the pressure will preferably be about 50 to 1,000 psig, preferably 300 psig to 600 psig. The space velocity in weight per hour will range from about 0.1 to 10.

Zeolite catalysts bound to zeolites are applied during the aromatization reaction to convert paraffins to aromatic compounds. Examples of suitable paraffins include aliphatic hydrocarbons containing 2 to 12 carbon atoms. The hydrocarbon may be straight chain, open or cyclic, and may be saturated or unsaturated. Examples of hydrocarbons include propane, propylene, n-butane, n-butene, isobutane, isobutene, straight pentane, branched pentane, cyclic pentane, pentene, hexane and hexene.

The conditions for the aromatization reaction are temperatures of about 200 to about 700 ° C., pressures of about 0.1 to about 60 atmospheres, hourly weight space velocity (WHSV) of about 0.1 to about 400 and a molar ratio of hydrogen / hydrocarbon of about 0 to about About 20

Zeolite catalysts bound to the zeolites used in the aromatization reaction are core crystals of two medium pore size zeolites such as MFI zeolite (eg ZSM-5) and MEL zeolite (ZSM-11). Binder crystals of medium pore size, such as, and MEL structures, may be included. The catalyst preferably comprises gallium or zinc. Gallium may be incorporated into the catalyst during the synthesis of the zeolite, or may be exchanged, injected or incorporated into the zeolite after synthesis. Preferably from 0.05 to 10% by weight, most preferably from 0.1 to 2.0% by weight of gallium is combined with the zeolite catalyst bonded to the zeolite. Gallium may be combined with primary zeolite, secondary zeolite, tertiary zeolite or quaternary zeolite. Typically zinc is incorporated into the catalyst by ion exchange and will generally be present in the zeolite bound to the zeolite in the amounts detailed above for gallium.

Zeolite catalysts bound to zeolites are applied in reactions involving aromatization reactions and / or dehydrogenation reactions. These are preferably dehydrogenated cyclization reactions, and / or hydrocarbons at temperatures of 370-600 ° C., preferably 430-550 ° C., preferably 90% as alkali metal ions, in order to convert at least part of the acyclic hydrocarbons into aromatic hydrocarbons. Non-cyclic contact with a zeolite catalyst (e.g., zeolite L and core crystals of zeolite Y bonded by zeolite Y) bound to a zeolite having at least one exchangeable cation and having at least one group 8 metal having dehydrogenation activity. It is particularly useful in the course of the hydrocarbon isomerization reaction.

Example 1

Preparation of Zeolites Bound to Zeolites

The formulation of ZSM-5 and ZSM-22 extrudates bound to silica was carried out as follows:

Ingredients Used in Manufacturing Volume (g) Ingredient number ZSM-5 Crystals 12.50 One ZSM-22 Crystals 12.50 2 water 6.24 3 Silica Gel (Aerosil 300) 2.36 4 Silica Sol (Nalcoag 1034A) 24.66 5 Methocel 0.14 6 water 19.52 7

Ingredients 1-6 were mixed in a bowl of home mixer for 6 minutes. Component 7 was then added to the bowl and mixing continued for another 3 minutes. A thick extrudable paste was obtained. This paste was extruded into an extrudate with a diameter of 2 mm. The extrudate was dried at room temperature for 2 hours and then at 130 ° C. overnight. The extrudate was then calcined at 120 ° C. (heating rate 0.5 ° C./min) for 2 hours and then calcined at 490 ° C. (heating rate 1 ° C./min) for 16 hours.

Composition of extrudate bound to calcined silica:

Zeolite 70 wt% SiO ₂ binder 30 wt%

XRD analysis of the green extrudate revealed the presence of MFI and TON. A bunch of amorphous materials was observed indicating the presence of silica.

The extrudate was converted to zeolite bound to zeolite as shown in the table below:

Ingredients Used in the Formulation Volume (g) Ingredient number Silica Bonded ZSM-5 / ZSM-22 5.02 One NaOH Pellets 0.10 2 t-butylammonium bromide 0.77 3 water 6.69 4

Components 2 and 3 were dissolved in component 4 and stirred until a clear solution was obtained. In order to convert the amorphous silica to the MEL structure, the template used in particular for the conversion (ie t-butylammonium bromide) was selected. Component 1 was then added to the solution. The synthesis mixture was then placed in a stainless steel autoclave and heated at 150 ° C. for 80 hours (heating increase time was 2 hours).

_{0.50 Na 2 O / 0.96 TBABr /} 10 SiO 2/149 H 2 O

The extrudate was washed five times with 300 ml of water until the conductivity of the final wash water was less than 10 μS / cm and then dried at 120 ° C. overnight.

The resulting extrudate was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) with the following results:

XRD: Excellent crystallinity was observed and the presence of MFI structure was observed. No amorphous clusters were observed indicating the presence of unconverted silica. The presence of the MEL structure cannot be clearly demonstrated in the presence of large amounts of MFI. The amount of TON is below the lower limit of detection.

SEM: 10,000 × magnification micrograph (FIG. 1) shows the presence of newly formed elongated crystals [1 μm × 0.2 μm] and original spherical MFI core crystals (3 μm) coated with smaller sized glial crystals. .

Example 2

Preparation of Zeolite-Bound Zeolites

Silica bonded ZSM-5 and ZSM-22 extrudates prepared according to Example 1 were converted to zeolite bonded zeolites as follows.

Ingredients Used in Manufacturing Volume (g) Ingredient number Silica Bonded ZSM-5 / ZSM-22 5.00 One NaOH Pellets 0.09 2 t-butylammonium bromide 0.77 3 water 9.42 4

Components 2 and 3 were dissolved in component 4 and stirred until a clear solution was obtained. The template used for the conversion, i.e. t-butylammonium bromide, was specifically selected to convert the amorphous silica to the MEL structure. Component 1 was then added to the solution. The synthesis mixture was then placed in a stainless steel autoclave heated to 150 ° C. for 20 hours (heating time is 2 hours).

The molar composition of the synthesis mixture was 0.47 Na ₂ O / 0.95 TBABr / 10 SiO ₂ /209.5 H ₂ O.

The extrudate was washed five times with 300 ml water until the conductivity of the final wash water was less than 10 μS / cm and then dried at 120 ° C. overnight.

The resulting extrudate was determined by the following x-ray diffraction (XRD) and scanning electron microscopy (SEM):

XRD: showed good crystallinity and confirmed the presence of MFI and TON structure types. There may be small amorphous halo. The presence of the MEL structure cannot be clearly demonstrated in the presence of large amounts of MFI.

SEM: 10,000 × magnification microscope (FIG. 2) shows the presence of both initial core crystals and newly formed binder crystals. The newly formed crystals seem to overgrow the MFI core crystals but do not overgrow the TONE core crystals.

Example 3

Zeolite-bound zeolites prepared according to Example 1 were used for disproportionation of toluene.

Prior to packing into a stainless steel reactor, 1 g of zeolite-bound zeolite was mixed with 1 g of 80-100 high purity quartz sand. The catalyst was pretreated with H ₂ at 500 ° C. for 2 hours and then treated with a co-feed of toluene and hydrogen. The total pressure of the reaction was adjusted to 45 psi. Toluene feed partial pressure was 5.4 psi and H ₂ feed partial pressure was 54 psi. Toluene flow rate was 36.7 mmol / hour. The hydrogen stream was controlled with a Brooks mass flow controller and the toluene feed was pumped with a high pressure liquid pump. The experiment was performed differentially to determine the reaction rate. All products were analyzed on-line HP 6890 GC equipped with Chirasil DEX CP and DB1 columns.

Example 4

To compare zeolite coupled zeolite catalyst performance, H-ZSM-5 catalyst and H-ZSM-223 catalyst were used separately for disproportionation of toluene. The H-ZSM-5 catalyst had a silica to alumina molar ratio of 34 and consisted of crystals having a particle diameter in the range of 0.2 to 1.0 μm. H-ZSM-22 had a silica to alumina molar ratio of 63 and consisted of crystals with an average length of 1 μm. The test was carried out using the method described in Example 2, except that each catalyst was mixed with 2.5 g of 80-100 mesh high purity quartz prior to packing into a stainless steel reactor to improve feed-catalyst contact. It became.

FIG. 3 shows a comparison of three catalyst performances by comparing the reaction rates of zeolite-bound zeolite catalysts, H-ZSM-5 catalysts and H-ZSM-22 catalysts as a function of temperature- ¹ . It is apparent from FIG. 3 that the zeolite-bound zeolite catalysts exhibit about 10 times greater activity than both H-ZSM-22 and H-ZSM-5 catalysts over the entire temperature range. The reaction mechanism for toluene disproportionation has an initial hydride transfer step and the rate is most limited in this step [Y. Xiong, PG Rodewald and CD Chang "On the Mechanism of Toluene Disproportionation in a Zeolite Environment," J. Am. Chem. Soc. 117 (1995) 9427-9431. One possible explanation for the high activity of zeolite-bound zeolite catalysts is that they give high hydride delivery rates.

Claims (37)

Does not contain significant amounts of non-zeolitic binders; (a) a core crystal containing a first crystal of a first zeolite and an optional second crystal of a second zeolite having a composition, structure or both different from the structure type of the first zeolite; And (b) a binder crystal containing a third crystal of the third zeolite and an optional fourth crystal of the fourth zeolite having a composition, structure or both different from the structure type of the third zeolite; And a second crystal of the second zeolite, a fourth crystal of the fourth zeolite or both are present in the zeolite bonded zeolite catalyst. The method of claim 1, A catalyst having an average particle diameter of the binder crystal smaller than an average particle diameter of the core crystal. The method according to claim 1 or 2, A catalyst containing the second crystal of the second zeolite and not containing the fourth crystal of the fourth zeolite. The method according to claim 1 or 2, A catalyst containing a fourth crystal of said fourth zeolite and not containing a second crystal of said second zeolite. The method according to claim 1 or 2, A catalyst containing a second crystal of said second zeolite and a fourth crystal of said fourth zeolite. The method according to any one of claims 1, 2, 3 and 5, Wherein said second zeolite has a different structure and composition than said first zeolite. The method according to any one of claims 1, 2, 4 and 5, Wherein said fourth zeolite has a different structure and composition than said third zeolite. The method according to any one of claims 1, 2, 3, 5 and 6, And the second crystal has an average particle diameter smaller than the average particle diameter of the first crystal. The method according to any one of claims 1 to 8, And the binder crystal forms an overgrowth in at least a portion of the core crystal. The method according to any one of claims 1 to 9, A catalyst containing less than about 5 weight percent of a non-zeolitic binder based on the weight of the catalyst. The method according to claim 1 or 2, A catalyst containing four or more zeolites, wherein the four zeolites each have a different composition or structure. The method according to any one of claims 1 to 11, Wherein said core crystals have an average particle diameter of about 1 to about 6 μm or greater. The method according to any one of claims 1 to 12, The catalyst of the binder has an average particle diameter of 0.1 to 0.5㎛. The method according to any one of claims 1 to 13, The catalyst is a large pore zeolite or a medium pore size zeolite. The method according to any one of claims 1 to 14, The catalyst is a large pore zeolite or a medium pore size zeolite. The method according to any one of claims 1 to 15, The catalyst of which the first zeolite and the third zeolite have a structural type selected from the group consisting of MAZ, BEA, MFI, MEL, MTW, EMT, MTT, HEU, FER, TON, MWW, LTL and EUO. The method according to any one of claims 1 to 16, The catalyst of the binder has a lower acidity than the zeolite of the core. The method according to any one of claims 1 to 16, Catalyst of the binder has a higher acidity than the zeolite of the core. The method according to any one of claims 1 to 18, The catalyst was prepared by aged at high temperature a silica-bonded aggregate containing the first crystals of the first zeolite in an ionic aqueous solution containing a source of hydroxy ions sufficient to convert the silica in the aggregate to a binder zeolite. , catalyst. The method according to any one of claims 1 to 19, And the zeolite in the catalyst is gallosilicate or aluminosilicate. The method according to any one of claims 1 to 20, The catalyst further comprises a catalytically active metal. The method according to any one of claims 1 to 21, A catalyst in which the zeolite present in the catalyst has the same structure. A process for converting hydrocarbons, comprising contacting a hydrocarbon feedstream with a zeolite-bound zeolite catalyst according to any one of claims 1 to 22 under hydrocarbon conversion conditions. The method of claim 23, The hydrocarbon conversion is carried out under conditions of temperature of 100 ° C. to 760 ° C. and / or pressure of 10.1 kPag to 10.1 MPag (0.1 to 100 atm) and / or weight hourly space velocity of 0.08 hours ⁻¹ to 200 hours ⁻¹ . The method of claim 23 or 24, Hydrocarbon conversion may include hydrocarbon decomposition, isomerization of alkyl aromatic compounds, disproportionation of toluene, alkyl exchange of aromatic compounds, alkylation of aromatic compounds, modification of naphtha to aromatic compounds, paraffins and / or olefins. A process selected from the group consisting of conversion to aromatic compounds, decomposition of naphtha to lower olefins, and dewaxing of hydrocarbons. The method according to any one of claims 23 to 25, Isomerizing a hydrocarbon feed containing a stream of aromatic C ₈ comprising a xylene isomer or a mixture of xylene isomers and ethylbenzene, wherein the feed is contacted with a zeolite bonded zeolite catalyst under isomerization conversion conditions. Wherein the catalyst does not contain a significant amount of non-zeolitic binder and comprises a core crystal comprising a first crystal of the first zeolite and a second crystal of the second zeolite and a third crystal of the third zeolite A method comprising binder crystals. 27. The method of any of claims 23 to 26, The catalyst further comprises a catalyzed active metal. The method of claim 26 or 27, Wherein said first zeolite, said second zeolite and said third zeolite of said catalyst are independently selected from the group consisting of ^* BEA, MFI, MEL, MTW, EUO, MTT, FER, TON and MOR. The method of claim 23 or 24, The hydrocarbon conversion method is a decomposition reaction of a hydrocarbon compound. The method of claim 23 or 24, Said hydrocarbon conversion method is a disproportionation reaction of toluene. The method according to any one of claims 23 to 30, Wherein the zeolite present in the catalyst has a median pore size. 32. The method of claim 30 or 31 wherein Wherein said catalyst is selected. The method of claim 32, Wherein said selected catalyst contains about 2 to about 40 weight percent coke. The method of claim 32, Wherein said selected catalyst contains silicon. The method of claim 23 or 25, Wherein said hydrocarbon conversion process comprises dehydrocyclization and / or isomerization of an acyclic hydrocarbon to form an aromatic hydrocarbon. 36. The method of claim 35 wherein The catalyst further comprises at least one catalyzed active transition metal. The method of claim 36, The catalyst contains a binder crystal comprising a first crystal of the first zeolite and a second crystal of the second zeolite, and a third crystal of the third zeolite, wherein the first zeolite, the second zeolite and the third zeolite Independently selected method from the crowd consisting of ^* BEA, MFI, MEL, MTW, MWW, LTL, EUO, MTT, FER, TON and MOR respectively.