Composite solid acid catalyst, its preparation method and application

Abstract

The application relates to the field of catalysts, and discloses a composite solid acid catalyst as well as a preparation method and application thereof. The composite solid acid catalyst contains a silicon-aluminum molecular sieve, a first metal active component, sulfate ions and a second metal active component; the first metal active component is selected from at least one of non-noble metal elements in groups IVB, VB, VIB, VIIB and VIII; the second metal active component is selected from at least one of noble metal elements; wherein the proportion of the amount of super strong acid with H0<-12 in the total amount of H0<-3 in the catalyst is more than 20%. The composite solid acid catalyst is suitable for treating complex hydrocarbon raw materials, is applied to reactions such as aromatic hydrocarbon isomerization, dismutation and alkyl transfer, dealkylation or hydrocracking, and has the advantages of high reaction activity and high product selectivity.

Description

Technical Field

[0001] This invention relates to the field of catalysts, specifically to a composite solid acid catalyst, its preparation method, and its application. Background Technology

[0002] Molecular sieve materials, due to their tunable pore size and acidity, are widely used in petrochemical hydrocarbon conversion processes, such as hydrocracking, isomerization, alkylation, and aromatics conversion, all of which utilize acidic molecular sieve materials as the main active component. However, the number of strong acid centers and the acid strength of molecular sieve materials are often lower than those of liquid acids, resulting in uneven acid strength distribution and low conversion rates in reactions with high activation energies. Furthermore, due to the confining effect of the pores in molecular sieves, their application in certain macromolecular materials and liquid-phase reactions presents challenges such as high material diffusion resistance and low conversion efficiency.

[0003] Besides molecular sieve materials, solid superacid catalysts have also been a research hotspot in recent years. Commonly used solid superacid catalysts include sulfurized ZrO2, TiO2, Fe2O3, MoO3 / ZrO3, and WO3 / ZrO2 composite metal oxides. Solid superacid catalysts have higher acid strength than molecular sieve catalysts and exhibit good low-temperature activity and selectivity for hydrocarbon conversion reactions such as dealkylation and isomerization. However, existing solid superacid catalysts generally suffer from low specific surface area.

[0004] CN108328624B discloses a modified Beta molecular sieve, its preparation method, and its application. The modified Beta molecular sieve is obtained by loading zirconium sulfate onto a hydrogen-type β molecular sieve that has been modified by steam. This method overcomes the shortcomings of traditional ion exchange resins, such as difficulty in regeneration, easy loss of active components in heteropoly acid and solid superacid catalysts, and low activity and selectivity of currently reported β molecular sieves, HY molecular sieves, and mordenite catalysts.

[0005] CN103055912A discloses a solid superacid bifunctional catalyst and its preparation method. The catalyst is obtained by loading a hydrogenation / dehydrogenation metal component onto a metal oxide loaded with nitrate, and can be used for isomerization reactions of straight-chain alkane.

[0006] CN103041843A discloses an isomerization catalyst composition and its application, comprising: modified mordenite obtained by supporting rare earth oxides on mordenite, a binder consisting of a mixture of sulfur-containing compounds and inorganic oxides, a re-loaded noble metal element from group VIII, and a metal additive. The catalyst is used in the isomerization process of C4-C12 alkanes to produce high-octane gasoline components.

[0007] CN101890355A discloses a solid superacid catalyst and its preparation method. The active component is sulfate, and the support is zirconium oxide and aluminum oxide. The support is prepared by mixing zirconium hydroxide and aluminum hydroxide dry gel prepared by the supersol micelle method and then molding. The prepared catalyst has large pore volume and high porosity, and is suitable for processing reactions containing macromolecules.

[0008] CN101209423A discloses a method for preparing a superacid molecular sieve catalyst, which involves mixing a solution of one or more modified components selected from elements of the IIIA, IVA, IIIB, IVB, La series, and Ac series with a suspension of molecular sieve, aging, filtering, drying, and calcining to obtain a molecular sieve catalyst with superacidity, which can be applied to alkylation reaction processes.

[0009] With the diversification of raw materials and the trend of integrated oil and chemical production in the petrochemical industry, the staged processing and utilization of complex hydrocarbon molecules is an important development direction for refining technology. In the conversion of complex materials such as hydrocarbons, diffusion of molecules of different sizes and reaction processes with different activation energies are involved, placing varying requirements on the pore system and acid center strength of catalysts. Therefore, the synthesis of composite solid acid catalysts with suitable acid gradient distribution and complex pore systems is of great significance for the efficient conversion of complex raw materials. Summary of the Invention

[0010] The purpose of this invention is to overcome the problems of existing solid acid catalysts being unsuitable for handling complex raw materials and complex reaction processes, and to provide a composite solid acid catalyst, its preparation method, and its applications. The composite solid acid catalyst of this invention is suitable for handling complex hydrocarbon raw materials and can be applied to reactions such as aromatic isomerization, disproportionation and alkyl transfer, dealkylation, or hydrocracking, exhibiting advantages of high reactivity and high product selectivity.

[0011] To achieve the above objectives, the present invention provides a composite solid acid catalyst, wherein the catalyst comprises a silica-alumina molecular sieve, a first metal active component, sulfate ions, and a second metal active component; the first metal active component is selected from at least one of group IIIA, IVB, VB, VIB, VIIB, and VIII non-noble metal elements; and the second metal active component is selected from at least one noble metal element.

[0012] In the catalyst, the proportion of superacids with H0<-12 to acids with H0<-3 is more than 20%.

[0013] Preferably, the proportion of superacids with H0 < -12 to acids with H0 < -3 in the catalyst is 25-70%, more preferably 30-60%.

[0014] A second aspect of this invention provides a method for preparing a composite solid acid catalyst, the method comprising the following steps:

[0015] (a) A silicon source, an aluminum source, a template agent, an alkali source and water are mixed to obtain a mixture, and then crystallized to obtain a partial crystallization mother liquor;

[0016] (b) Reacting the partially crystallized mother liquor with the first metal active component compound;

[0017] (c) In the presence of a solvent, the powder obtained in step (b) is kneaded and shaped with an optional adhesive solvent and pore-forming agent, and then pre-calcined to obtain a catalyst blank.

[0018] (d) Loading a catalyst preform with a compound containing sulfate and a compound of a second metal active component to obtain a composite solid acid catalyst;

[0019] The first metal active component is selected from at least one of the non-noble metal elements of groups IIIA, IVB, VB, VIB, VIIB and VIII; the second metal active component is selected from at least one of the noble metal elements.

[0020] The third aspect of this invention provides the application of the composite solid acid catalyst described in the first aspect or the composite solid acid catalyst prepared by the preparation method described in the second aspect in aromatic hydrocarbon conversion, hydrocarbon cracking or isomerization reactions.

[0021] The beneficial effects of the present invention through the above technical solution include:

[0022] The composite solid acid catalyst of this invention employs a combination of silica-alumina molecular sieves, a first metal active component, sulfate ions, and a second metal active component, and exhibits a specific acidity distribution. Preferably, the catalyst possesses a composite pore structure of micropores and mesopores. These characteristics make this composite solid acid catalyst suitable for processing complex hydrocarbon feedstocks and applicable to reactions such as aromatic isomerization, disproportionation and alkyl transfer, dealkylation, or hydrocracking, offering advantages such as high reactivity and high product selectivity. Detailed Implementation

[0023] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0024] The first aspect of the present invention provides a composite solid acid catalyst, the catalyst comprising a silica-alumina molecular sieve, a first metal active component, sulfate ions, and a second metal active component; the first metal active component is selected from at least one non-noble metal element of Groups IIIA, IVB, VB, VIB, VIIB, and VIII; the second metal active component is selected from at least one noble metal element.

[0025] In the catalyst, the proportion of superacids with H0<-12 to acids with H0<-3 is more than 20%.

[0026] According to the present invention, preferably, the proportion of superacids with H0 < -12 to acids with H0 < -3 in the catalyst is 25-70%, more preferably 30-60%.

[0027] The amount of superacid at H0 < -12 in the composite solid acid catalyst of this invention was determined by an indicator method. The specific procedure was as follows: the catalyst to be tested was dispersed in a series of benzene solutions with different amounts of n-butylamine. After ultrasonic dispersion to reach dispersion equilibrium, the indicator m-nitrotoluene was added to the system. The change in the absorption peak of the indicator was monitored using a UV-Vis spectrophotometer to determine the amount of n-butylamine Q1 corresponding to the superacid site at H0 < -12 in the sample. The determination was performed using a PerkinElmer Lambda 35 UV-Vis spectrophotometer with a scanning interval of 3 cm. -1 The scanning range is 300-700cm. -1 .

[0028] The amount of acid with H0 < -3 in the composite solid acid catalyst of the present invention is determined by the indicator method. The specific operation process is as follows: the catalyst to be tested is dispersed in a series of benzene solutions with different amounts of n-butylamine. After ultrasonic dispersion, the dispersion equilibrium is reached. The indicator dicinnamyl acetone is added to the system. The amount of n-butylamine between the indicator color change and no color change is taken as the amount of n-butylamine Q2 corresponding to the acid site with H0 < -3 in the sample.

[0029] In this invention, the ratio of the amount of superacid with H0<-12 to the amount of acid with H0<-3 in the catalyst is calculated as Q1 / Q2.

[0030] According to the present invention, preferably, based on the total weight of the catalyst, the content of the silica-alumina molecular sieve is 20-70% by weight, preferably 25-60% by weight; the content of the first metal active component is 15-45% by weight, preferably 20-40% by weight; the content of sulfate ions is 0.1-10% by weight, preferably 0.5-8% by weight; and the content of the second metal active component is 0.01-0.5% by weight, preferably 0.05-0.3% by weight.

[0031] The total content of each component in the composite solid acid catalyst of the present invention is 100%.

[0032] The content of each component in the composite solid acid catalyst of the present invention is calculated by combining the ICP method with the feed ratio.

[0033] According to the present invention, preferably, the micropore volume of the catalyst is 0.05-0.5 cm. 3 / g, preferably 0.1-0.4cm 3 / g; mesopore volume is 0.1-1.5cm³ 3 / g, preferably 0.2-1.2cm 3 / g.

[0034] The micropore volume and mesopore volume of each component of the composite solid acid catalyst of the present invention were measured by nitrogen adsorption-desorption method.

[0035] This invention offers a wide range of options for the aluminosilicate molecular sieve. Preferably, the aluminosilicate molecular sieve is an aluminosilicate molecular sieve with ten-membered ring channels and / or aluminosilicate molecular sieve with twelve-membered ring channels, and is preferably selected from at least one of ZSM-5, MOR, Beta, Y, MCM-22, MCM-49, and MCM-41. The aluminosilicate molecular sieve used in this invention can be commercially available or prepared using conventional methods.

[0036] The present invention has a wide range of choices for the first metal active component, which is selected from at least one of Ga, Zr, Ti, V, Cr, Mo, Co, Fe and Al.

[0037] According to the present invention, preferably, the first metal active component is selected from at least one of Zr, Ti, Fe and Al, more preferably from Al and at least one of Zr, Ti and Fe. This preferred embodiment can increase the amount of superacid in the catalyst, and the combination of Al with Zr, Ti and Fe can further increase the amount of superacid in the catalyst.

[0038] Preferably, the content ratio of Al to at least one of Zr, Ti and Fe is 0.1-2:1, more preferably 0.2-1:1.

[0039] Al in the first metal active component can function as both an active component and a binder.

[0040] The composite solid acid catalyst provided by this invention may also contain silicon dioxide, which is derived from partially crystallized, uncrystallized silicon sources from molecular sieves. This invention does not impose a particular limit on its amount; it can act as a binder in the catalyst.

[0041] When the amounts of aluminum and silicon meet the catalyst's requirements for a binder, no additional binder needs to be introduced; otherwise, an additional binder may be introduced. This invention allows for a wide range of binder content selection, which can be based on the Al content in the first metal active component and the amount of uncrystalline silicon dioxide. Those skilled in the art can make adaptive selections according to specific circumstances.

[0042] The present invention allows for a wide range of choices of the type of adhesive. Preferably, the adhesive is alumina and / or silicon dioxide.

[0043] The present invention has a wide range of choices for the second metal active component. Preferably, the second metal active component is selected from at least one of Rh, Ir, Pt and Pd.

[0044] According to the present invention, preferably, the second metal active component is Pt and / or Pd.

[0045] A second aspect of this invention provides a method for preparing a composite solid acid catalyst, the method comprising the following steps:

[0046] (a) A silicon source, an aluminum source, a template agent, an alkali source and water are mixed to obtain a mixture, and then crystallized to obtain a partial crystallization mother liquor;

[0047] (b) Reacting the partially crystallized mother liquor with the first metal active component compound;

[0048] (c) In the presence of a solvent, the powder obtained in step (b) is kneaded and shaped with an optional adhesive solvent and pore-forming agent, and then pre-calcined to obtain a catalyst blank.

[0049] (d) Loading a catalyst preform with a compound containing sulfate and a compound of a second metal active component to obtain a composite solid acid catalyst;

[0050] The first metal active component is selected from at least one of the non-noble metal elements of groups IIIA, IVB, VB, VIB, VIIB and VIII; the second metal active component is selected from at least one of the noble metal elements.

[0051] According to the present invention, preferably, the amounts of the first metal active component compound, the sulfate-containing compound, and the second metal active component compound are such that, based on the total weight of the catalyst, the content of the first metal active component compound is 15-45% by weight, the content of sulfate ions is 0.1-10% by weight, and the content of the second metal active component is 0.01-0.5% by weight.

[0052] According to the present invention, preferably, the amounts of the first metal active component compound, the sulfate-containing compound, and the second metal active component compound are such that, based on the total weight of the catalyst, the content of the first metal active component compound is 20-40% by weight, the content of sulfate ions is 0.5-8% by weight, and the content of the second metal active component is 0.05-0.3% by weight.

[0053] This invention obtains a partially crystallized mother liquor by controlling the degree of crystallization of molecular sieves, which is then used to prepare composite solid acid catalysts. This facilitates close contact between the superacid components and the molecular sieves, thereby achieving a reasonable distribution of catalyst acidity and pore structure.

[0054] According to the present invention, preferably, the relative crystallinity of the molecular sieve in the partially crystallized mother liquor is 30-90%, more preferably 40-80%. This preferred embodiment further optimizes the distribution of acidity and pore size. When the relative crystallinity is below this range, the catalyst micropore volume is small and the proportion of superacid is too high. When the relative crystallinity is above this range, the catalyst mesopore volume is small and the proportion of superacid is low.

[0055] The relative crystallinity described in this invention refers to the ratio of the crystallinity of the molecular sieve in the partially crystallized mother liquor to the crystallinity of the standard sample (100% crystallinity). It is determined by powder XRD.

[0056] In this invention, the method for preparing the standard sample is as shown in Comparative Example 1.

[0057] According to the present invention, preferably, the molar ratio of the silicon source, aluminum source, template agent, alkali source and water is 1:0.01-0.5:0.01-0.5:0.05-0.8:5-100; more preferably, it is 1:0.02-0.3:0.02-0.3:0.1-0.7:8-50, wherein the silicon source is calculated as SiO2 and the aluminum source is calculated as Al2O3.

[0058] According to the present invention, preferably, the mixing is carried out under stirring conditions. The present invention does not particularly limit the stirring speed and time; preferably, the stirring speed is 10-200 r / min.

[0059] In this invention, there is no particular limitation on the order in which the silicon source, aluminum source, template agent, alkali source, and water are added during the mixing process in step (a). The materials can be added together or separately. To enhance mixing uniformity, preferably, the alkali source and aluminum source are first dissolved in water, then the template agent is added, and finally mixed with the silicon source.

[0060] The present invention has a wide range of selection for the crystallization conditions, preferably based on the molecular sieve that can obtain the above-mentioned relative crystallinity. Preferably, the crystallization conditions in step (a) include: a temperature of 120-250℃, preferably 140-200℃; and a time of 10-80h, preferably 15-65h.

[0061] The present invention allows for a wide range of silicon sources, which can be various silicon sources conventionally used in the art. Specifically, the silicon source is an organosilicon source and / or an inorganic silicon source. Preferably, the silicon source is selected from at least one of silica sol, water glass, and silica.

[0062] The present invention allows for a wide range of aluminum sources, as long as aluminum can be provided. Preferably, the aluminum source is selected from at least one of sodium aluminate, aluminum hydroxide, alumina, aluminum sol, aluminum nitrate, and aluminum sulfate.

[0063] The present invention allows for a wide range of template agents, which can be various template agents conventionally used in the art. Preferably, the template agent is selected from at least one of tetraethylammonium bromide, tetraethylammonium hydroxide, tetrapropylammonium bromide, tetrapropylammonium hydroxide, triethylamine, and ethylamine.

[0064] The present invention allows for a wide range of alkaline sources, including various alkaline sources commonly used in the art. Preferably, the alkaline source is an organic base and / or an inorganic base, and more preferably selected from at least one of NaOH, KOH, and ammonia water.

[0065] Preferably, the mixture obtained in step (a) of this invention contains sodium ions. When the mixture does not contain sodium ions, it is preferable to also add sodium salt during the mixing process. The amount of sodium salt added is based on the requirements for molecular sieve preparation and can be a conventional choice in the art.

[0066] The reaction of the first metal active component compound with a portion of the crystallization mother liquor in this invention facilitates close contact between the molecular sieve and the amorphous metal oxide, and further facilitates the achievement of a gradient distribution of the catalyst's acidity and pore structure.

[0067] According to the present invention, preferably, the reaction conditions in step (b) include: a temperature of 60-140°C, more preferably 70-110°C; a time of 1-20 h, more preferably 2-15 h; and a pH of 8-12, more preferably 9-11. This preferred embodiment further ensures close contact between the molecular sieve and the amorphous metal oxide.

[0068] Preferably, the reaction is carried out under stirring conditions. The present invention does not impose particular limitations on the stirring speed and time, which can be appropriately selected according to specific circumstances.

[0069] Preferably, the pH of the reaction in step (b) is adjusted using an acid.

[0070] Preferably, the acid is an inorganic acid and / or an organic acid, and is preferably selected from at least one of hydrochloric acid, nitric acid and sulfuric acid.

[0071] The present invention has a wide range of choices for the first metal active component, which is selected from at least one of Ga, Zr, Ti, V, Cr, Mo, Co, Fe and Al.

[0072] According to the present invention, preferably, the first metal active component is selected from at least one of Zr, Ti, Fe and Al, more preferably from Al and at least one of Zr, Ti and Fe.

[0073] According to the present invention, preferably, the amount of the Al-containing compound and the amount of at least one compound selected from Zr, Ti and Fe are such that the content ratio of Al to at least one of Zr, Ti and Fe in the prepared composite solid acid catalyst is 0.1-2:1, preferably 0.2-1:1.

[0074] The present invention has a wide range of choices for the first metal active component compound. Preferably, the first metal active component compound is selected from at least one of Zr(NO3)4, ZrOCl2, Zr(SO4)2, Fe(NO)3, FeSO4, TiCl4, Ti(SO4)2, Al(NO3)3, Al(OH)3, and Al2(SO4)3. All of the above substances are conventional choices in the art and are commercially available.

[0075] The first metal active component compound of the present invention may or may not contain water of crystallization, and the present invention does not limit this.

[0076] Preferably, the method further includes filtering, washing, and drying the material obtained in step (b) to obtain a powder. The filtration, washing, and drying conditions can be performed under conventional conditions, which will not be elaborated further here. Preferably, the washing conditions are such that the pH of the washing solution is 7-9. Using this preferred embodiment, residual Na can be effectively removed. + Alkaline ions.

[0077] According to the present invention, preferably, the solvent is an organic solvent and / or water, more preferably water.

[0078] Al in the first metal active component can function as both an active component and a binder. Preferably, step (c) may also optionally include a binder precursor. This invention offers a wide range of options for the amount of binder precursor, which can be selected based on the Al content in the first metal active component of the prepared composite solid acid catalyst. Those skilled in the art can make adaptive selections according to specific circumstances.

[0079] Preferably, the binder precursor is boehmite and / or silica sol.

[0080] In this invention, unless otherwise specified, "optional" means containing or not containing, adding or not adding, or using or not using. Specifically, step (c) of this invention may or may not involve the addition of a glue solvent and a pore-forming agent.

[0081] When an aluminum-containing compound (which can be a binder precursor or a first metal active component compound) is added during the catalyst preparation process, step (c) preferably also includes the addition of a peptizing solvent.

[0082] The present invention allows for a wide range of choices of the adhesive solvent, including various adhesive solvents conventionally used in the art. According to the present invention, preferably, the adhesive solvent is an inorganic acid, more preferably nitric acid.

[0083] In a preferred embodiment, the adhesive solvent of the present invention is provided in the form of an aqueous solution. The present invention does not particularly limit the amount of the aqueous solution of the adhesive solvent, and it can be appropriately selected according to specific circumstances.

[0084] Preferably, the pore-forming agent is selected from at least one of styrax powder, polyethylene glycol, polystyrene, and carbon black.

[0085] The present invention does not particularly limit the molding process described in step (c), and it can be performed according to conventional molding methods in the art. For example, it can be, but is not limited to, extrusion molding, spray molding, or compression molding. Extrusion molding is preferred in the present invention, and the specific method is well known to those skilled in the art, and will not be described in detail here.

[0086] According to the present invention, preferably, the pre-calcination conditions in step (c) include: a temperature of 200-600℃, preferably 300-500℃; and a time of 1-10h, preferably 2-5h.

[0087] In a preferred embodiment, the catalyst preform of the present invention undergoes ammonia exchange before loading the sulfate-containing compound and the second metal active component. The present invention does not particularly limit the method of ammonia exchange and can refer to methods commonly used in the art.

[0088] The present invention does not impose any particular limitations on the conditions for ammonia exchange, as long as the sodium ion content in the molecular sieve is less than 0.2 wt%.

[0089] According to one specific embodiment of the present invention, the catalyst preform is exchanged with a 5 wt% ammonium nitrate aqueous solution at 90°C for 4 h, and repeated until the sodium ion content is less than 0.2 wt%.

[0090] According to a preferred embodiment of the present invention, the catalyst preform is subjected to ammonia exchange followed by filtration to obtain a solid product, which is then loaded with a sulfate-containing compound and a compound containing a second metal active component. The filtration method can be carried out under conventional conditions, and will not be described in detail here.

[0091] This invention does not impose any particular limitation on the order in which the sulfate-containing compound and the second metal active component are loaded; they can be loaded together or individually. This invention preferably employs the method of individual loading.

[0092] According to the present invention, preferably, in step (d), the catalyst preform is sequentially loaded with a compound containing sulfate and a compound of the second metal active component to obtain a composite solid acid catalyst. This preferred embodiment is more conducive to the synergistic effect between the metal active component and the acidic component.

[0093] In this invention, the method for loading the sulfate-containing compound and the second metal active component as described in step (d) is not specifically limited, and conventional methods in the art can be used. The present invention preferably employs an impregnation method. The impregnation method includes: impregnating the carrier with an impregnation solution containing the sulfate-containing compound or the second hydrogenated metal component compound, followed by optional drying. The drying method can be carried out under conventional conditions, and will not be described in detail here.

[0094] The present invention does not have any particular limitation on the impregnation method; it can be impregnated with equal volume or with excessive volume. The present invention preferably uses equal volume impregnation.

[0095] The present invention allows for a wide range of selection for the sulfate compound, as long as it contains sulfate. Preferably, the sulfate-containing compound is selected from at least one of sulfuric acid, ammonium sulfate, and ammonium bisulfate.

[0096] The present invention has a wide range of choices for the second metal active component. Preferably, the second metal active component is selected from at least one of Rh, Ir, Pt and Pd.

[0097] According to the present invention, preferably, the second metal active component is Pt and / or Pd.

[0098] The present invention has a wide range of choices for the second metal active component compound. Preferably, the second metal active component compound is selected from at least one of H2PtCl6, Pt(NH3)4Cl2, PdCl2 and Pd(NH3)4Cl2.

[0099] According to the present invention, preferably, the method further includes: performing a first calcination after loading the sulfate-containing compound in step (d).

[0100] The present invention does not particularly limit the first calcination and can be carried out with reference to methods commonly used in the art. Preferably, the conditions for the first calcination include: a temperature of 400-700℃, more preferably 500-650℃; and a time of 1-15 hours, more preferably 2-6 hours. The first calcination is generally carried out in an air atmosphere, which may include a flowing atmosphere or a stationary atmosphere.

[0101] According to the present invention, preferably, the method further includes: performing a second calcination after loading the compound with the second metal active component in step (d).

[0102] The present invention does not particularly limit the second calcination and can be carried out with reference to methods commonly used in the art. Preferably, the conditions for the second calcination include: a temperature of 300-600℃, more preferably 400-550℃; and a time of 1-8 hours, more preferably 2-4 hours. The second calcination is generally carried out in an air atmosphere, which may include a flowing atmosphere or a stationary atmosphere.

[0103] The third aspect of this invention provides the application of the composite solid acid catalyst described in the first aspect or the composite solid acid catalyst prepared by the preparation method described in the second aspect in aromatic conversion, hydrocarbon cracking or isomerization reactions, preferably in xylene isomerization, toluene disproportionation and alkyl transfer or hydrogenation cracking reactions of polycyclic aromatic hydrocarbons.

[0104] According to the present invention, preferably, the reaction conditions include: a temperature of 100-500°C, more preferably 200-400°C; a pressure of 1-8 MPa, more preferably 2-6 MPa; a hydrogen-to-hydrocarbon molar ratio of 0.1-10, more preferably 0.2-8; and a liquid feedstock weight hourly space velocity of 0.5-10 h⁻¹. -1 Preferably 1-5h -1 .

[0105] According to the present invention, preferably, the catalyst is reduced under a hydrogen atmosphere before the reaction.

[0106] Preferably, the reduction conditions include: a reduction temperature of 200-500℃, more preferably 250-450℃; a reduction time of 1-10 hours, more preferably 2-6 hours; and a gas-to-solid volume ratio of 500-2000, more preferably 800-1500.

[0107] The present invention will be described in detail below through embodiments.

[0108] In the following embodiments, the testing methods for each parameter are as described above;

[0109] The raw materials used in the following examples are all commercially available and of analytical grade.

[0110] Example 1

[0111] (1) Dissolve 15.4 g NaOH and 13.3 g sodium aluminate (41 wt% alumina, 26 wt% sodium oxide) in 312 g deionized water to obtain solution A. Add 42 g tetraethylammonium bromide to solution A to obtain solution B. Then slowly add 200 g silica sol (40 wt% SiO2 content) to solution B to obtain solution C. Stir solution C at 150 r / min for 4 h at room temperature to obtain silica-alumina gel. Add silica-alumina gel to a stainless steel high-temperature reactor and crystallize at 160 °C for 30 h to obtain a partial crystallization mother liquor containing mordenite. The relative crystallinity is calculated to be 60% based on XRD of the product.

[0112] (2) Cool down to 130℃, weigh 100g ZrOCl2·8H2O, dissolve it in water, add it to part of the crystallization mother liquor, and add H2SO4 solution to adjust the pH value to 10. After stirring for 10h, discharge the material, filter, wash until the pH of the filtrate is 7-9, and dry to obtain powder.

[0113] (3) Add an appropriate amount of dilute nitric acid aqueous solution to the powder, knead it, extrude it into strips, and then pre-calcine it at 400℃ for 4 hours to obtain the catalyst blank.

[0114] (4) The catalyst preform was exchanged with a 5 wt% ammonium nitrate aqueous solution at 90°C for 4 h, and this process was repeated until the sodium ion content was less than 0.2 wt%. The solid product was then filtered to obtain a solid product. The solid product was then impregnated with a 1 mol / L sulfuric acid solution for 1 h, dried at 120°C, and calcined at 550°C for 4 h to obtain a sulfated solid acid catalyst. The above sulfated solid acid catalyst was then impregnated with an equal volume of H2PtCl6 aqueous solution and calcined at 500°C for 3 h to obtain a composite solid acid catalyst. The specific composition of the catalyst is shown in Table 1.

[0115] Example 2

[0116] (1) 19.6 g NaOH and 7.4 g sodium aluminate (41 wt% alumina, 26 wt% sodium oxide) were dissolved in 240 g deionized water to obtain solution A. 56 g tetraethylammonium bromide was added to solution A to obtain solution B. Then, 200 g silica sol (40 wt% SiO2 content) was slowly added to solution B to obtain solution C. Solution C was stirred at 150 r / min for 4 h at room temperature to obtain a silica-alumina gel. The silica-alumina gel was added to a stainless steel high-temperature reactor and crystallized at 150 °C for 65 h to obtain a partially crystallized mother liquor product containing Beta zeolite. The relative crystallinity was calculated to be 80% based on XRD analysis of the product.

[0117] (2) Cool down to 130℃, weigh 70g of Fe(NO3)3, dissolve it in water, add it to part of the crystallization mother liquor, and add H2SO4 solution to adjust the pH value to 10. After stirring for 10h, discharge the material, filter, wash until the pH of the filtrate is 7-9, and dry to obtain powder.

[0118] (3) Add an appropriate amount of dilute nitric acid aqueous solution to the powder, knead it, extrude it into strips, and then pre-calcine it at 400℃ for 4 hours to obtain the catalyst blank.

[0119] (4) The catalyst preform was exchanged with a 5 wt% ammonium nitrate aqueous solution at 90°C for 4 h, and this process was repeated until the sodium ion content was less than 0.2 wt%. The solid product was then filtered to obtain a solid product. The solid product was then impregnated with a 1 mol / L sulfuric acid solution for 1 h, dried at 120°C, and calcined at 550°C for 4 h to obtain a sulfated solid acid catalyst. The above sulfated solid acid catalyst was then impregnated with a Pt(NH3)4Cl2 aqueous solution and calcined at 500°C for 3 h to obtain a composite solid acid catalyst. The specific composition of the catalyst is shown in Table 1.

[0120] Example 3

[0121] (1) Dissolve 7.8 g NaOH and 9.5 g sodium aluminate (41 wt% alumina, 26 wt% sodium oxide) in 360 g deionized water to obtain solution A. Add 35.5 g tetrapropylammonium bromide to solution A to obtain solution B. Then slowly add 200 g silica sol (40 wt% SiO2 content) to solution B to obtain solution C. Stir solution C at 150 r / min for 4 h at room temperature to obtain silica-alumina gel. Add the silica-alumina gel to a stainless steel high-temperature reactor and crystallize at 160 °C for 24 h to obtain a product containing ZSM-5 zeolite. The relative crystallinity of the product was calculated to be 50% based on XRD.

[0122] (2) Cool down to 130℃, weigh 180g of ZrOCl2·8H2O, dissolve it in water, add it to part of the crystallization mother liquor, and add H2SO4 solution to adjust the pH value to 10. After stirring for 10h, discharge the material, filter, wash until the pH of the filtrate is 7-9, and dry to obtain powder.

[0123] (3) Add an appropriate amount of dilute nitric acid aqueous solution to the powder, knead it, extrude it into strips, and then pre-calcine it at 400℃ for 4 hours to obtain the catalyst blank.

[0124] (4) The catalyst preform was exchanged with a 5 wt% ammonium nitrate aqueous solution at 90°C for 4 h, and this process was repeated until the sodium ion content was less than 0.2 wt%. The solid product was then filtered to obtain a solid product. The solid product was then impregnated with a 2 mol / L sulfuric acid solution for 2 h, dried at 120°C, and calcined at 550°C for 4 h to obtain a sulfated solid acid catalyst. The above sulfated solid acid catalyst was then impregnated with an equal volume of PdCl2 aqueous solution and calcined at 500°C for 3 h to obtain a composite solid acid catalyst. The specific composition of the catalyst is shown in Table 1.

[0125] Example 4

[0126] The procedure is carried out according to the method of Example 1, except that...

[0127] (2) Weigh 100g ZrOCl2·8H2O and 50g aluminum nitrate, dissolve them in water, add them to part of the crystallization mother liquor, and add H2SO4 solution to adjust the pH value to 10. After stirring for 10h, discharge the material, filter, wash until the pH of the filtrate is 7-9, and dry to obtain powder.

[0128] (3) Mix the powder with 10g of Tianqing powder, add an appropriate amount of dilute nitric acid solution, knead, extrude into strips, and then pre-calcine at 400℃ for 4h to obtain the catalyst blank.

[0129] The specific composition of the prepared composite solid acid catalyst is shown in Table 1.

[0130] Example 5

[0131] The procedure was carried out according to Example 1, except that in step (4), H2PtCl6 was dissolved in a 1 mol / L sulfuric acid solution and the solid product was impregnated for 1 hour. After drying at 120°C, the product was first calcined at 550°C for 4 hours to obtain the composite solid acid catalyst. The specific composition of the catalyst is shown in Table 1.

[0132] Comparative Example 1

[0133] (1) Dissolve 15.4 g NaOH and 13.3 g sodium aluminate (41 wt% alumina, 26 wt% sodium oxide) in 312 g deionized water to obtain solution A. Add 42 g tetraethylammonium bromide to solution A to obtain solution B. Then slowly add 200 g silica sol (40 wt% SiO2 content) to solution B to obtain solution C. Stir solution C at 150 r / min for 4 h at room temperature to obtain silica-alumina gel. Add silica-alumina gel to a stainless steel high-temperature reactor and crystallize at 180 °C for 30 h to obtain a mother liquor containing mordenite. Discharge, wash, filter, and dry to obtain powdered molecular sieve. The crystallinity of the product was calculated to be 100% based on XRD.

[0134] (2) Weigh 100g ZrOCl2·8H2O and dissolve it in water. Add molecular sieve powder and mix evenly. Add ammonia solution to adjust pH=10. Stir and age at 130℃ for 10h and then discharge the material. Filter and wash until the pH of the filtrate is 7-9 and dry to obtain powder.

[0135] (3) Mix the powder with 40g of pseudoboehmite (Al2O3 content is 70wt%), add an appropriate amount of dilute nitric acid solution, knead, extrude into strips, and calcine at 400℃ for 4h to obtain catalyst blank.

[0136] (4) The catalyst preform was exchanged with a 5 wt% ammonium nitrate aqueous solution at 90°C for 4 h, and this process was repeated until the sodium ion content was less than 0.2 wt%. The solid product was then filtered to obtain a solid product. The solid product was then impregnated with a 1 mol / L sulfuric acid solution for 1 h, dried at 120°C, and calcined at 550°C for 4 h to obtain a sulfated solid acid catalyst. The above sulfated solid acid catalyst was then impregnated with an H2PtCl6 aqueous solution and calcined a second time at 500°C for 3 h to obtain a composite solid acid catalyst. The specific composition of the catalyst is shown in Table 1.

[0137] Comparative Example 2

[0138] The method was carried out according to Example 1, except that in step (1), the molecular sieve crystallization time was 20 hours, and a partially crystallized mother liquor containing mordenite was obtained. The relative crystallinity was calculated to be 25% based on the XRD of the product. The specific composition of the catalyst is shown in Table 1.

[0139] Table 1

[0140]

[0141] Note: The content of the silicon-aluminum component is the total amount of Al2O3, binder and molecular sieve in the first metal active component.

[0142] Molecular sieve content = (Silicon-aluminum component content - Al2O3 in the first metal active component) × Relative crystallinity

[0143] Test Example 1

[0144] Weigh 5g of catalyst and load it into a fixed-bed reactor. Introduce hydrogen at a rate of 50mL / min, pressurize to 4MPa, heat to 320℃, and maintain this temperature for 3 hours. Then, introduce a toluene and mixed C9+ mixture at a rate of 10g / h. + The weight ratio is 1 / 1), of which C9 + The weight composition was as follows: non-aromatic hydrocarbons: 8%, indene: 5%, ethylbenzene: 25%, trimethylbenzene: 30%, tetramethylbenzene: 14%, dimethyl ethylbenzene: 8%, naphthalene derivatives: 5%, others: 5%. The results after 10 hours of reaction are shown in Table 2.

[0145] Table 2

[0146]

[0147] As can be seen from the results in Table 2, the composite solid acid catalyst of this invention has significantly higher conversion rates of non-aromatic hydrocarbons, aromatic hydrocarbons and naphthalene series, and significantly higher selectivity for benzene and C8 aromatic hydrocarbons when treating complex hydrocarbon feedstocks.

[0148] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A composite solid acid catalyst, characterized in that, The catalyst contains a silica-alumina molecular sieve, a first metal active component, sulfate ions, and a second metal active component; the first metal active component is selected from at least one of the non-noble metal elements of Groups IIIA, IVB, VB, VIB, VIIB, and VIII; the second metal active component is selected from at least one of the noble metal elements. In the catalyst, the proportion of superacids with H0 < -12 to acids with H0 < -3 is 25-60%. The catalyst has a micropore volume of 0.05-0.5 cm. 3 / g, mesopore volume is 0.1-1.5cm³ 3 / g; Based on the total weight of the catalyst, the content of silica-alumina molecular sieve is 20-70% by weight, the content of the first metal active component is 15-45% by weight, the content of sulfate ions is 0.1-10% by weight, and the content of the second metal active component is 0.01-0.5% by weight.

2. The catalyst according to claim 1, wherein, The proportion of superacids with H0<-12 in the catalyst is 30-60% of the proportion of acids with H0<-3.

3. The catalyst according to claim 1, wherein, The catalyst has a micropore volume of 0.1-0.4 cm. 3 / g; mesopore volume is 0.2-1.2cm³ 3 / g.

4. The catalyst according to any one of claims 1-3, wherein, The silica-aluminum molecular sieve is a silica-aluminum molecular sieve with ten-membered ring channels and / or a silica-aluminum molecular sieve with twelve-membered ring channels.

5. The catalyst according to claim 4, wherein, The silicon-aluminum molecules are selected from at least one of ZSM-5, MOR, Beta, Y, MCM-22, MCM-49, and MCM-41.

6. The catalyst according to any one of claims 1-3, wherein, The first metal active component is selected from at least one of Zr, Ti, Fe and Al.

7. The catalyst according to claim 6, wherein, The first metal active component is selected from at least one of Al, Zr, Ti and Fe.

8. The catalyst according to any one of claims 1-3, wherein, The second metal active component is Pt and / or Pd.

9. A method for preparing the composite solid acid catalyst according to claim 1, the method comprising the following steps: (a) A mixture of silicon source, aluminum source, template agent, alkali source and water is obtained, and then crystallized to obtain a partial crystallization mother liquor; (b) Reacting the partially crystallized mother liquor with the first metal active component compound; (c) In the presence of a solvent, the powder obtained in step (b) is kneaded together with an optional adhesive solvent and pore-forming agent, and pre-calcined to obtain a catalyst preform; (d) Loading a catalyst preform with a compound containing sulfate and a compound with a second metal active component yields a composite solid acid catalyst; The first metal active component is selected from at least one of the non-noble metal elements of groups IIIA, IVB, VB, VIB, VIIB and VIII; the second metal active component is selected from at least one of the noble metal elements.

10. The method according to claim 9, wherein, The relative crystallinity of the molecular sieve in the partially crystallized mother liquor is 30-90%.

11. The method according to claim 10, wherein, The relative crystallinity of the molecular sieve in the partially crystallized mother liquor is 40-80%.

12. The method according to claim 9, wherein, The molar ratio of the silicon source, aluminum source, template agent, alkali source and water is 1:0.01-0.5:0.01-0.5:0.05-0.8:5-100, wherein the silicon source is calculated as SiO2 and the aluminum source is calculated as Al2O3.

13. The method according to claim 12, wherein, The molar ratio of the silicon source, aluminum source, template agent, alkali source and water is 1:0.02-0.3:0.02-0.3:0.1-0.7:8-50, wherein the silicon source is calculated as SiO2 and the aluminum source is calculated as Al2O3.

14. The method according to claim 9, wherein, The crystallization conditions in step (a) include: a temperature of 120-250°C and a time of 10-80 h.

15. The method according to claim 14, wherein, The crystallization conditions in step (a) include: a temperature of 140-200℃ and a time of 15-65h.

16. The method according to claim 9, wherein, The silicon source is selected from at least one of silica sol, water glass and silica. The aluminum source is selected from at least one of aluminum hydroxide, aluminum oxide, aluminum sol, aluminum nitrate, and aluminum sulfate; The template agent is selected from at least one of tetraethylammonium bromide, tetraethylammonium hydroxide, tetrapropylammonium bromide, tetrapropylammonium hydroxide, triethylamine, and ethylamine; The alkali source is an organic alkali and / or an inorganic alkali.

17. The method according to claim 16, wherein, The alkali source is selected from at least one of NaOH, KOH and ammonia water.

18. The method according to claim 9, wherein, The amounts of the first metal active component compound, the sulfate-containing compound, and the second metal active component compound are such that, based on the total weight of the catalyst, the content of the first metal active component compound is 15-45% by weight, the content of sulfate ions is 0.1-10% by weight, and the content of the second metal active component is 0.01-0.5% by weight.

19. The method according to claim 18, wherein, The amounts of the first metal active component compound, the sulfate-containing compound, and the second metal active component compound are such that, based on the total weight of the catalyst, the content of the first metal active component compound is 20-40% by weight, the content of sulfate ions is 0.5-8% by weight, and the content of the second metal active component is 0.05-0.3% by weight.

20. The method according to claim 9, wherein, The reaction conditions in step (b) include: temperature of 60-140℃; time of 1-20h; and pH of 8-12.

21. The method according to claim 20, wherein, The reaction conditions in step (b) include: a temperature of 70-110°C; a time of 2-15 h; and a pH of 9-11.

22. The method according to claim 9, wherein, The first metal active component is selected from at least one of Zr, Ti, Fe and Al.

23. The method according to claim 22, wherein, The first metal active component is selected from at least one of Al, Zr, Ti and Fe.

24. The method according to claim 22, wherein, The first metal active component compound is a soluble salt of the first metal active component.

25. The method according to claim 24, wherein, The first metal active component compound is selected from at least one of Zr(NO3)4, ZrOCl2, Zr(SO4)2, Fe(NO)3, FeSO4, TiCl4, Ti(SO4)2, Al(NO3)3, Al(OH)3 and Al2(SO4)3.

26. The method according to any one of claims 9-25, wherein, The pre-calcination conditions in step (c) include: a temperature of 200-600℃ and a time of 1-10h.

27. The method according to claim 26, wherein, The pre-calcination conditions in step (c) include: a temperature of 300-500℃ and a time of 2-5 hours.

28. The method according to any one of claims 9-25, wherein, The sulfate-containing compound is selected from at least one of sulfuric acid, ammonium sulfate, and ammonium bisulfate.

29. The method according to any one of claims 9-25, wherein, The second metal active component is Pt and / or Pd.

30. The method according to claim 29, wherein, The compound of the second metal active component is selected from at least one of H2PtCl6, Pt(NH3)4Cl2, PdCl2 and Pd(NH3)4Cl2.

31. The method according to any one of claims 9-25, wherein, In step (d), the catalyst preform is sequentially loaded with a compound containing sulfate and a compound of the second metal active component to obtain a composite solid acid catalyst.

32. The method according to claim 31, wherein, The method further includes: performing a first calcination after loading the sulfate-containing compound in step (d); The conditions for the first roasting include: a temperature of 400-700℃ and a time of 1-15h.

33. The method according to claim 32, wherein, The conditions for the first roasting include: a temperature of 500-650℃ and a time of 2-6 hours.

34. The method according to any one of claims 9-25, wherein, The method further includes: performing a second calcination after loading the compound with the second metal active component in step (d); The conditions for the second roasting include: a temperature of 300-600℃ and a time of 1-8 hours.

35. The method according to claim 34, wherein, The conditions for the second roasting include: a temperature of 400-550℃ and a time of 2-4 hours.

36. The application of a composite solid acid catalyst according to any one of claims 1-8 or a composite solid acid catalyst prepared by any one of claims 9-35 in aromatic conversion, hydrocarbon cracking or isomerization reactions.

37. The application according to claim 36, wherein, Application of the composite solid acid catalyst in xylene isomerization, toluene disproportionation and alkyl transfer or hydrogenation cracking of polycyclic aromatic hydrocarbons.

38. The application according to claim 36, wherein, The reaction conditions include: temperature of 100-500℃; pressure of 1-7 MPa; hydrogen-to-hydrogen molar ratio of 0.1-10; and liquid feedstock weight hourly space velocity of 0.5-10 h⁻¹. -1 .

39. The application according to claim 38, wherein, The reaction conditions include: a temperature of 200-400℃; a pressure of 2-6 MPa; a hydrogen-to-hydrocarbon molar ratio of 0.2-8; and a liquid feedstock weight hourly space velocity of 1-5 h⁻¹. -1 .

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