CN110614114A - Isobutane dehydrogenation catalyst with spherical small-hole mesoporous silica gel composite as carrier and preparation method and application thereof - Google Patents

Isobutane dehydrogenation catalyst with spherical small-hole mesoporous silica gel composite as carrier and preparation method and application thereof Download PDF

Info

Publication number
CN110614114A
CN110614114A CN201810638975.5A CN201810638975A CN110614114A CN 110614114 A CN110614114 A CN 110614114A CN 201810638975 A CN201810638975 A CN 201810638975A CN 110614114 A CN110614114 A CN 110614114A
Authority
CN
China
Prior art keywords
silica gel
isobutane
dehydrogenation catalyst
ball milling
isobutane dehydrogenation
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN201810638975.5A
Other languages
Chinese (zh)
Inventor
刘红梅
亢宇
薛琳
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sinopec Beijing Research Institute of Chemical Industry
China Petroleum and Chemical Corp
China Petrochemical Corp
Original Assignee
Sinopec Beijing Research Institute of Chemical Industry
China Petrochemical Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sinopec Beijing Research Institute of Chemical Industry, China Petrochemical Corp filed Critical Sinopec Beijing Research Institute of Chemical Industry
Priority to CN201810638975.5A priority Critical patent/CN110614114A/en
Publication of CN110614114A publication Critical patent/CN110614114A/en
Pending legal-status Critical Current

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J29/00Catalysts comprising molecular sieves
    • B01J29/03Catalysts comprising molecular sieves not having base-exchange properties
    • B01J29/0308Mesoporous materials not having base exchange properties, e.g. Si-MCM-41
    • B01J29/0316Mesoporous materials not having base exchange properties, e.g. Si-MCM-41 containing iron group metals, noble metals or copper
    • B01J29/0325Noble metals
    • B01J35/51
    • B01J35/615
    • B01J35/633
    • B01J35/635
    • B01J35/638
    • B01J35/643
    • B01J35/647
    • B01J35/69
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01BNON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B39/00Compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites; Their preparation; After-treatment, e.g. ion-exchange or dealumination
    • C01B39/02Crystalline aluminosilicate zeolites; Isomorphous compounds thereof; Direct preparation thereof; Preparation thereof starting from a reaction mixture containing a crystalline zeolite of another type, or from preformed reactants; After-treatment thereof
    • C01B39/04Crystalline aluminosilicate zeolites; Isomorphous compounds thereof; Direct preparation thereof; Preparation thereof starting from a reaction mixture containing a crystalline zeolite of another type, or from preformed reactants; After-treatment thereof using at least one organic template directing agent, e.g. an ionic quaternary ammonium compound or an aminated compound
    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07CACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C5/00Preparation of hydrocarbons from hydrocarbons containing the same number of carbon atoms
    • C07C5/32Preparation of hydrocarbons from hydrocarbons containing the same number of carbon atoms by dehydrogenation with formation of free hydrogen
    • C07C5/327Formation of non-aromatic carbon-to-carbon double bonds only
    • C07C5/333Catalytic processes
    • C07C5/3335Catalytic processes with metals
    • C07C5/3337Catalytic processes with metals of the platinum group
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2229/00Aspects of molecular sieve catalysts not covered by B01J29/00
    • B01J2229/10After treatment, characterised by the effect to be obtained
    • B01J2229/18After treatment, characterised by the effect to be obtained to introduce other elements into or onto the molecular sieve itself
    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07CACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C2529/00Catalysts comprising molecular sieves
    • C07C2529/03Catalysts comprising molecular sieves not having base-exchange properties

Abstract

The invention relates to the field of catalysts, and discloses an isobutane dehydrogenation catalyst with a spherical small-hole mesoporous silica gel composite material as a carrier, and a preparation method and application thereof, wherein the method comprises the following steps: (a) preparing a spherical mesoporous molecular sieve; (b) preparing a silica gel filter cake; (c) mixing the spherical mesoporous molecular sieve filter cake with silica gel, performing first ball milling and second ball milling, and performing spray drying; (d) the carrier is subjected to thermal activation treatment, then is subjected to immersion treatment in a solution containing a Pt component precursor and a Zn component precursor, and then is subjected to solvent removal treatment, drying and roasting in sequence. The method can synthesize the isobutane dehydrogenation catalyst with high catalytic activity by utilizing the silicon source with low cost.

Description

Isobutane dehydrogenation catalyst with spherical small-hole mesoporous silica gel composite as carrier and preparation method and application thereof
Technical Field
The invention relates to the field of catalysts, in particular to an isobutane dehydrogenation catalyst with a carrier made of a small-hole mesoporous silica gel composite material, a preparation method of the isobutane dehydrogenation catalyst, the isobutane dehydrogenation catalyst prepared by the method and application of the isobutane dehydrogenation catalyst in preparation of isobutene through isobutane dehydrogenation.
Background
Isobutene is an important organic chemical raw material and is mainly used for preparing various organic raw materials and fine chemicals such as methyl tert-butyl ether, butyl rubber, methyl ethyl ketone, polyisobutylene, methyl methacrylate, isoprene, tert-butyl phenol, tert-butyl amine, 1, 4-butanediol, ABS resin and the like. The main sources of isobutene are the by-product C4 fraction from an apparatus for producing ethylene by steam cracking of naphtha, the by-product C4 fraction from a refinery Fluid Catalytic Cracking (FCC) apparatus, and the by-product tert-butyl alcohol (TAB) in the synthesis of propylene oxide by the Halcon method.
In recent years, with the development and utilization of downstream products of isobutene, the demand of isobutene is increased year by year, and the traditional isobutene production cannot meet the huge demand of the chemical industry on isobutene, so the research and development work of a new isobutene production technology becomes a hot spot of the chemical industry. Among the most competitive technologies, isobutane dehydrogenation, n-butene skeletal isomerization and isobutene production by a novel FCC unit are known. Among the methods, the research on the reaction for preparing isobutene by directly dehydrogenating isobutane is early, and the industrial production is realized. China has abundant C4 resources, but the chemical utilization rate of C4 fraction is low in China, most of isobutane is directly used as fuel, and the waste is serious. The reasonable utilization of C4 resource is an urgent task in the petrochemical research field. Therefore, the isobutene prepared by dehydrogenating isobutane has a great development prospect in China.
The catalysts for preparing isobutene by isobutane dehydrogenation mainly comprise two types: oxide catalysts and noble metal catalysts. The oxide catalyst mainly comprises Cr2O3、V2O5、Fe2O3、MoO3ZnO, etc., and a composite oxide thereof, such as V-Sb-O, V-Mo-O, Ni-V-O, V-Nb-O, Cr-Ce-O, molybdate, etc. Compared with noble metal catalysts, oxide catalysts are less expensive. However, the catalyst is easy to deposit carbon, and the catalytic activity, selectivity and stability are low. In addition, most oxide catalysts contain components with high toxicity, which is not favorable for environmental protection. The research on dehydrogenation reactions on noble metal catalysts has a long history, and noble metal catalysts have higher activity, better selectivity, and are more environmentally friendly than other metal oxide catalysts. However, the catalyst cost is high due to the expensive price of noble metals, and the performance of such catalysts has not yet reached a satisfactory level.
In order to improve the reaction performance of the catalyst for preparing isobutene by isobutane dehydrogenation, researchers have done a lot of work. Such as: the catalyst performance is improved by changing the preparation method of the catalyst (industrial catalysis, 2014, 22(2): 148-. However, the specific surface area of the currently used carrier is small, which is not beneficial to the dispersion of the active metal component on the surface of the carrier, and is also not beneficial to the diffusion of raw materials and products in the reaction process.
Therefore, how to improve the reaction performance of the isobutane dehydrogenation catalyst is a problem to be solved in the field of preparing isobutene by isobutane dehydrogenation.
Disclosure of Invention
The invention aims to overcome the defects of uneven dispersion of noble metal active components and poor catalytic activity and stability of the existing isobutane dehydrogenation catalyst, and provides an isobutane dehydrogenation catalyst with a carrier of a small-hole mesoporous silica gel composite material, a preparation method of the isobutane dehydrogenation catalyst, the isobutane dehydrogenation catalyst prepared by the method and application of the isobutane dehydrogenation catalyst in preparation of isobutene through isobutane dehydrogenation.
In order to achieve the above object, a first aspect of the present invention provides a method for preparing an isobutane dehydrogenation catalyst, the method comprising the steps of:
(a) under the condition of a solution, mixing and contacting a template agent, a nonionic surfactant, an acid agent and a silicon source to obtain a solution A, and sequentially crystallizing, washing and drying the solution A to obtain mesoporous material raw powder; and carrying out template removing agent treatment on the mesoporous material raw powder to obtain the spherical mesoporous molecular sieve; wherein the template agent is cetyl trimethyl ammonium bromide, and the nonionic surfactant is polyethylene glycol octyl phenyl ether;
(b) contacting water glass with inorganic acid, and filtering a product obtained after the contact to obtain a silica gel filter cake;
(c) mixing the spherical mesoporous molecular sieve filter cake and silica gel, performing first ball milling, mixing the obtained first ball milling slurry with water for pulping, performing second ball milling to obtain second ball milling slurry, performing spray drying on the second ball milling slurry, screening by adopting a cyclone separation technology, and removing a template agent in a screened product to obtain the spherical small-hole mesoporous silica gel composite material;
(d) the spherical small-hole mesoporous silica gel composite material carrier is subjected to thermal activation treatment, then is subjected to dipping treatment in a solution containing a Pt component precursor and a Zn component precursor, and then is subjected to solvent removal treatment, drying and roasting in sequence.
A second aspect of the invention provides an isobutane dehydrogenation catalyst prepared by the aforementioned process.
The third aspect of the invention provides an application of the isobutane dehydrogenation catalyst prepared by the method in preparing isobutene through isobutane dehydrogenation, wherein the method for preparing isobutene through isobutane dehydrogenation comprises the following steps: isobutane was subjected to a dehydrogenation reaction in the presence of a catalyst and hydrogen.
After intensive research, the inventor of the invention finds that the carrier structure (including physical structures such as specific surface area, pore volume and pore size distribution, and chemical structures such as surface acid sites and electronic properties) of the noble metal catalyst not only has important influence on the dispersion degree of active metal components, but also directly influences mass transfer and diffusion in the reaction process. Thus, the catalytic properties of heterogeneous catalysts, such as activity, selectivity and stability, depend both on the catalytic characteristics of the active component and on the characteristics of the catalyst support. In order to reduce the content of noble metal in the catalyst as much as possible and improve the activity and stability of the catalyst at the same time, the preparation process of the carrier is of great importance. Most commercially available activated alumina has too many surface hydroxyl groups and too strong acidity. When the aluminum oxide is used as a carrier to prepare the dehydrogenation catalyst, the surface of the catalyst is easy to deposit carbon in the reaction process, and the rapid inactivation is caused.
Compared with the prior art, the isobutane dehydrogenation catalyst prepared by the method provided by the invention has the following advantages:
(1) the method for preparing the isobutane dehydrogenation catalyst provided by the invention has the advantages of simple preparation process, easily controlled conditions and good product repeatability;
(2) the isobutane dehydrogenation catalyst prepared by the method provided by the invention can achieve better dehydrogenation activity, selectivity, stability and carbon deposition resistance under the condition of low loading of main active components (namely noble metals), and can effectively reduce the preparation cost of the isobutane dehydrogenation catalyst;
(3) in the isobutane dehydrogenation catalyst prepared by the method provided by the invention, the stability of a Zn center with an oxidized structure under a high-temperature reduction condition is very high, the inactivation of a single Pt component loaded on a carrier can be inhibited, carbon deposition is reduced, a strong acid center on the surface of the carrier is effectively neutralized, the surface of the carrier is free from acidity, and the dispersion degree of the Pt component is improved through a geometric effect, so that the carbon deposition risk in the reaction process of preparing isobutene by anaerobic dehydrogenation of isobutane can be remarkably reduced, the selectivity of a target product is improved, and the stability of the isobutane dehydrogenation catalyst is improved;
(4) the mesoporous molecular sieve material with the spherical shape, the larger specific surface area and the larger pore volume is synthesized by utilizing the silicon source with low cost, which is beneficial to the good dispersion of the noble metal component on the surface of the carrier, thereby ensuring that the isobutane catalyst is not easy to be inactivated due to the agglomeration of active metal particles in the reaction process;
(5) the isobutane dehydrogenation catalyst prepared by the method provided by the invention shows good catalytic performance when used for preparing isobutene by anaerobic dehydrogenation of isobutane, and has the advantages of high isobutane conversion rate, high isobutene selectivity, good catalyst stability and low carbon deposition.
Additional features and advantages of the invention will be set forth in the detailed description which follows.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:
FIG. 1 is an X-ray diffraction pattern of a spherical small-pore mesoporous silica gel composite support of example 1;
FIG. 2 is an SEM scanning electron micrograph of a spherical small-pore mesoporous silica gel composite support of example 1;
FIG. 3 is a pore size distribution diagram of the spherical small-pore mesoporous silica gel composite support of example 1;
fig. 4 is a distribution diagram of the pore size structure of the spherical small-pore mesoporous silica gel composite support of example 1.
Detailed Description
The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.
As indicated previously, a first aspect of the present invention provides a process for the preparation of an isobutane dehydrogenation catalyst, the process comprising the steps of:
(a) under the condition of a solution, mixing and contacting a template agent, a nonionic surfactant, an acid agent and a silicon source to obtain a solution A, and sequentially crystallizing, washing and drying the solution A to obtain mesoporous material raw powder; and carrying out template removing agent treatment on the mesoporous material raw powder to obtain the spherical mesoporous molecular sieve; wherein the template agent is cetyl trimethyl ammonium bromide, and the nonionic surfactant is polyethylene glycol octyl phenyl ether;
(b) contacting water glass with inorganic acid, and filtering a product obtained after the contact to obtain a silica gel filter cake;
(c) mixing the spherical mesoporous molecular sieve filter cake and silica gel, performing first ball milling, mixing the obtained first ball milling slurry with water for pulping, performing second ball milling to obtain second ball milling slurry, performing spray drying on the second ball milling slurry, screening by adopting a cyclone separation technology, and removing a template agent in a screened product to obtain the spherical small-hole mesoporous silica gel composite material;
(d) the spherical small-hole mesoporous silica gel composite material carrier is subjected to thermal activation treatment, then is subjected to dipping treatment in a solution containing a Pt component precursor and a Zn component precursor, and then is subjected to solvent removal treatment, drying and roasting in sequence.
The solution condition of the present invention may be an aqueous solution condition.
In the present invention, the acid agent may be various acidic aqueous solutions conventionally used in the art, and for example, may be at least one aqueous solution of hydrochloric acid, sulfuric acid, nitric acid and hydrobromic acid, preferably an aqueous hydrochloric acid solution.
The amount of the acid agent is not particularly limited, and may be varied within a wide range, and it is preferable that the pH value of the mixing contact is 1 to 7.
Preferably, in step (a), the conditions of the mixing contact include: the temperature is 25-60 ℃ and the time is 0.1-48 h. In order to further facilitate uniform mixing between the substances, according to a preferred embodiment of the invention, the mixing contact is carried out under stirring conditions.
In the present invention, the amounts of the templating agent, the nonionic surfactant and the silicon source may vary within a wide range, for example, the molar ratio of the templating agent, the nonionic surfactant and the silicon source is (0.1-0.6): (0.1-0.5): 1; more preferably, the molar ratio of the amounts of template, nonionic surfactant and silicon source is (0.1-0.3): (0.1-0.3): 1.
in the present invention, the silicon source may be various silicon sources conventionally used in the art, and preferably the silicon source is at least one of tetraethoxysilane, methyl orthosilicate, propyl orthosilicate, sodium orthosilicate and silica sol, and more preferably tetraethoxysilane.
Preferably, in step (a), the crystallization conditions include: the temperature is 90-180 ℃ and the time is 4-40 h. According to a preferred embodiment, the crystallization is carried out by hydrothermal crystallization.
Preferably, in step (a), the washing process may include: after filtration, repeated washing with deionized water (washing times may be 2 to 10) and suction filtration.
Preferably, in step (a), the drying manner is spray drying, which may be performed according to a conventional manner, and may be selected from at least one of pressure spray drying, centrifugal spray drying, and pneumatic spray drying. According to a preferred embodiment of the present invention, the spray drying is a centrifugal spray drying method. The spray drying may be carried out in an atomizer. The conditions of the spray drying may include: the temperature is 150-; preferably, the spray drying conditions include: the temperature is 150-250 ℃, and the rotating speed is 11000-13000 r/min.
Preferably, in step (a), the method for removing the template agent is a calcination method, and the process of treating the template agent comprises: calcining the mesoporous material raw powder for 5-40h at the temperature of 300-800 ℃.
According to the present invention, in the step (b), the conditions under which the water glass is contacted with the inorganic acid may include: the temperature can be 10-60 ℃, preferably 20-40 ℃; the time may be 1 to 5 hours, preferably 1.5 to 3 hours, and the pH value is 2 to 4. In order to further facilitate uniform mixing between the substances, the contact of the water glass with the mineral acid is preferably carried out under stirring conditions.
According to the invention, the water glass is an aqueous solution of sodium silicate conventional in the art, and its concentration may be 10 to 50% by weight, preferably 12 to 30% by weight.
According to the present invention, the inorganic acid may be one or more of sulfuric acid, nitric acid and hydrochloric acid. The inorganic acid may be used in a pure form or in the form of an aqueous solution thereof. The inorganic acid is preferably used in such an amount that the reaction system has a pH of 2 to 4 under the contact conditions of the water glass and the inorganic acid.
Preferably, in the presence of glycerol, for example, the method comprises: the water glass, the inorganic acid and the glycerol are contacted. Preferably, the weight ratio of the water glass, the inorganic acid and the glycerol can be (3-6): 1: 1. in order to further facilitate uniform mixing between the substances, the contact of the water glass, the inorganic acid and the glycerol is preferably carried out under stirring conditions.
Further, in the above-mentioned process for preparing silica gel, it is preferable to obtain a silica gel cake by filtration, which may include: after filtration, washing with distilled water was repeated (the number of washing may be 2 to 10), followed by suction filtration. Preferably, the washing during the preparation of the silica gel filter cake results in a sodium ion content of less than 0.02 wt.%.
According to the invention, in order to improve the strength of the spherical small-hole mesoporous composite material and further improve the catalytic performance of the prepared isobutane dehydrogenation catalyst, a secondary ball milling method for slurry is utilized.
According to the present invention, in the step (c), the first ball milling and the second ball milling may be performed in a ball mill in which an inner wall of a ball milling jar is preferably an agate inner liner, and a diameter of milling balls in the ball mill may be 2 to 3 mm; the number of the grinding balls can be reasonably selected according to the size of the ball milling tank, and for the ball milling tank with the size of 50-150mL, 1 grinding ball can be generally used; the material of the grinding ball can be agate, polytetrafluoroethylene and the like, and agate is preferred. The conditions of the first ball milling and the second ball milling are the same or different, and the conditions of the first ball milling and the second ball milling respectively and independently comprise: the rotation speed of the grinding ball is 200-
According to the invention, in step (c), the weight ratio of the first ball-milling slurry to the amount of water used is 1: (0.1-5), preferably 1: (0.5-3.5), the temperature for pulping by mixing the first ball milling slurry with water can be 25-60 ℃.
According to the present invention, in the step (c), the spray drying may be performed according to a conventional manner, and may be selected from at least one of a pressure spray drying method, a centrifugal spray drying method, and a pneumatic spray drying method. According to a preferred embodiment of the present invention, the spray drying is a centrifugal spray drying method. The spray drying may be carried out in an atomizer. The conditions of the spray drying may include: the temperature is 150-; preferably, the spray drying conditions include: the temperature is 150-250 ℃, and the rotating speed is 11000-13000 r/min.
According to the invention, the step of screening the second ball-milling slurry by adopting a cyclone separation technology after spray drying comprises the following steps: and carrying out spray drying on the second ball-milling slurry, and carrying out cyclone separation on the discharged gas containing the powder particles so as to collect the powder particles. Specifically, the cyclone separation technology is adopted to separate the powder particles contained in the discharged gas, the recovered powder particles fall into the powder collecting cylinder, the waste gas is delivered to the centrifugal fan from the outlet of the separator, the butterfly valve is installed at the lower part of the cyclone separator, and when the cyclone separator works, the butterfly valve is opened, and the obtained sample has uniformly distributed particle sizes.
According to the invention, the metal component loaded on the spherical small-hole mesoporous silica gel composite material can adopt an impregnation mode, the metal component enters the pore channel of the spherical small-hole mesoporous silica gel composite material by virtue of capillary pressure of the pore channel structure of the spherical small-hole mesoporous silica gel composite material, and meanwhile, the metal component can be adsorbed on the surface of the spherical small-hole mesoporous silica gel composite material until the metal component reaches adsorption balance on the surface of the spherical small-hole mesoporous silica gel composite material. Preferably, the impregnation treatment is performed after the thermal activation treatment is performed on the spherical small-pore mesoporous silica gel composite material, and the impregnation treatment can be co-impregnation treatment or step-by-step impregnation treatment. In order to save the preparation cost and simplify the experimental process, the dipping treatment is preferably co-dipping treatment; further preferably, the conditions of the co-impregnation treatment include: mixing and contacting the thermally activated spherical small-hole mesoporous silica gel composite material in a solution containing a Pt component precursor and a Zn component precursor, wherein the impregnation temperature can be 25-50 ℃, and the impregnation time can be 2-6 h.
According to the present invention, the solutions of the Pt component precursor and the Zn component precursor are not particularly limited as long as they are water-soluble, and may be conventionally selected in the art. For example, the Pt component precursor can be H2PtCl6The Zn component precursor may be Zn (NO)3)2
The concentration of the solution containing the Pt component precursor and the Zn component precursor is not particularly limited in the present invention, and may be conventionally selected in the art, for example, the concentration of the Pt component precursor may be 0.001 to 0.003mol/L, and the concentration of the Zn component precursor may be 0.015 to 0.1 mol/L.
According to the present invention, the solvent removal treatment can be carried out by a method conventional in the art, for example, a rotary evaporator can be used to remove the solvent in the system.
According to the present invention, in the step (d), the drying may be performed in a drying oven, and the firing may be performed in a muffle furnace. The conditions for the drying and firing are also not particularly limited in the present invention, and may be conventionally selected in the art, for example, the conditions for the drying may include: the temperature is 110-150 ℃ and the time is 3-6 h; the conditions for the firing may include: the temperature is 600 ℃ and 650 ℃, and the time is 5-8 h.
Preferably, in the step (d), the spherical small-pore mesoporous silica gel composite material carrier, the Pt component precursor and the Zn component precursor are used in amounts such that, in the prepared isobutane dehydrogenation catalyst, based on the total weight of the isobutane dehydrogenation catalyst, the content of the carrier is 98-99.4 wt%, the content of the Pt component calculated by the Pt element is 0.1-0.5 wt%, and the content of the Zn component calculated by the Zn element is 0.5-1.5 wt%.
In a second aspect, the present invention provides an isobutane dehydrogenation catalyst prepared by the aforementioned process.
According to the invention, the isobutane dehydrogenation catalyst comprises a carrier, and a Pt component and a Zn component which are loaded on the carrier, wherein the carrier is a composite material containing silica gel and a spherical mesoporous molecular sieve, the average particle diameter of the spherical mesoporous molecular sieve is 10-30 mu m, and the specific surface area of the spherical mesoporous molecular sieve is 100-300 m-2The pore volume is 0.5-1.5mL/g, the pore size distribution is bimodal, and the most probable pore sizes corresponding to the bimodal are 1-3nm and 20-50nm respectively; the specific surface area of the silica gel is 200-300m2Per g, pore volume of 1-2mL/g, average pore diameter of 10-30nm, and average particle diameter of 20-100 μm.
According to the invention, the carrier has a special bimodal distribution structure, so that the carrier has high catalytic activity and selectivity. The average particle diameter of the particles of the carrier is measured by a laser particle size distribution instrument, and the specific surface area, the pore volume and the most probable pore diameter are measured by a nitrogen adsorption method.
According to the invention, the structural parameters of the spherical small-hole mesoporous silica gel composite material are controlled within the range, so that the spherical small-hole mesoporous silica gel composite material is not easy to agglomerate, and the conversion rate of reaction raw materials in the reaction process of preparing propylene by isobutane dehydrogenation can be improved by using the supported catalyst prepared by the spherical small-hole mesoporous silica gel composite material as a carrier. When the specific surface area of the spherical small-hole mesoporous silica gel composite material is less than 100m2When the volume/g and/or pore volume is less than 0.5mL/g, the catalytic activity of the supported catalyst prepared by using the supported catalyst is remarkably reduced; when the specific surface area of the hollow spherical mesoporous molecular sieve silica gel composite material is more than 300m2When the volume/g and/or pore volume is greater than 1.5mL/g, it is used as a supportThe prepared supported catalyst is easy to agglomerate in the reaction process of preparing propylene by isobutane dehydrogenation, so that the conversion rate of reaction raw materials in the reaction process of preparing propylene by isobutane dehydrogenation is influenced.
According to the invention, as the secondary ball milling technology, the spray drying technology and the cyclone separation technology are adopted in the preparation process of the isobutane dehydrogenation catalyst, the prepared spherical small-hole mesoporous silica gel composite material has smaller size and uniformly distributed particle size and better fluidity.
The average particle diameter of the spherical mesoporous molecular sieve is 12-28 mu m, and the specific surface area is 120-29m2The pore volume is 0.6-1.2mL/g, the pore size distribution is bimodal, and the most probable pore sizes corresponding to the bimodal are 1.2-2.8nm and 25-48nm respectively; the specific surface area of the silica gel is 230-280m2Per g, pore volume of 1.2-1.8mL/g, average pore diameter of 12-18nm, and average particle diameter of 30-70 μm;
preferably, the content weight ratio of the spherical mesoporous molecular sieve to the silica gel is (1.2-10): 1;
preferably, the silica gel is 955 silica gel.
According to the invention, the isobutane dehydrogenation catalyst comprises a carrier, and a Pt component and a Zn component which are loaded on the carrier, wherein the Pt component is an active metal component, and the Zn component is a metal auxiliary agent.
According to the invention, based on the total weight of the isobutane dehydrogenation catalyst, the content of the carrier is 98-99.4 wt%, the content of the Pt component calculated by Pt element is 0.1-0.5 wt%, and the content of the Zn component calculated by Zn element is 0.5-1.5 wt%.
The third aspect of the invention provides an application of the isobutane dehydrogenation catalyst prepared by the method in preparing isobutene through isobutane dehydrogenation, wherein the method for preparing isobutene through isobutane dehydrogenation comprises the following steps: isobutane was subjected to a dehydrogenation reaction in the presence of a catalyst and hydrogen.
When the isobutane dehydrogenation catalyst prepared by the method provided by the invention is used for catalyzing isobutane to dehydrogenate to prepare isobutene, the conversion rate of isobutane and the selectivity of isobutene can be greatly improved.
According to the present invention, in order to increase the isobutane conversion rate and prevent the catalyst from coking, it is preferable that the molar ratio of the amount of isobutane to the amount of hydrogen is (0.5-1.5): 1.
the conditions for the dehydrogenation reaction in the present invention are not particularly limited and may be conventionally selected in the art, and for example, the conditions for the dehydrogenation reaction may include: the reaction temperature is 550-650 ℃, the reaction pressure is 0.05-0.2MPa, the reaction time is 20-40h, and the mass space velocity of isobutane is 2-5h-1
The present invention will be described in detail below by way of examples.
In the following examples and comparative examples, octyl phenyl ether of polyethylene glycol, commercially available from carbofuran, Beijing, under the trade name Triton X-100, and having the formula C34H62O11
In the following examples and comparative examples, ES955 silica gel was obtained from GRACE;
in the following examples and comparative examples, X-ray diffraction analysis was carried out on an X-ray diffractometer, model D8Advance, available from Bruker AXS, Germany; scanning electron microscopy analysis was performed on a scanning electron microscope, model XL-30, available from FEI, USA; pore structure parameter analysis was performed on an ASAP2020-M + C type adsorber, available from Micromeritics, USA, and BET method was used for the specific surface area and pore volume calculation of the sample; the particle size distribution of the sample is carried out on a Malvern laser particle sizer; the rotary evaporator is produced by German IKA company, and the model is RV10 digital; the active component loading of the isobutane dehydrogenation catalyst was measured on a wavelength dispersive X-ray fluorescence spectrometer, available from parnacco, netherlands, model No. Axios-Advanced; analysis of the reaction product composition was performed on a gas chromatograph available from Agilent under model 7890A; the drying box is produced by Shanghai-Hengchun scientific instruments Co., Ltd, and is of a type DHG-9030A; the muffle furnace is manufactured by CARBOLITE corporation, and is of a model CWF 1100; the ultrasonic generator is a KQ-300GTDV high-frequency constant-temperature numerical control ultrasonic cleaner produced by ultrasonic instruments Limited in Kunshan, the ultrasonic frequency is 80kHz, and the working voltage is 220V.
The nitrogen adsorption and desorption experiments of the samples were carried out on a full-automatic physicochemical adsorption analyzer model ASAP 2020M + C manufactured by Micromeritics, USA. The samples were degassed at 350 ℃ for 4 hours under vacuum prior to assay. The BET method is adopted to calculate the specific surface area of the sample, and the BJH model is adopted to calculate the pore volume and the average pore diameter.
The NH3-TPD experiment of the sample was carried out on an AUTOCHEM2920 full-automatic chemisorption instrument, manufactured by Micromeritics, USA. The sample was first reduced at 480 ℃ in an atmosphere of 10% H2-90% Ar for 1 hour. Then heating to 700 ℃ in He atmosphere, staying for 1 hour, cooling to 40 ℃ and adsorbing ammonia gas until saturation. After purging for 1h in He gas atmosphere, the temperature was raised from 40 ℃ to 700 ℃ at a rate of 10 ℃/min, while the ammonia desorption data was recorded using a TCD detector.
The content of each metal component in the prepared dehydrogenation catalyst is determined by calculating the raw material feeding during preparation.
The isobutane conversion was calculated as follows:
isobutane conversion rate ═ amount of isobutane consumed by reaction/initial amount of isobutane × 100%;
the isobutene selectivity was calculated as follows:
isobutene selectivity is the amount of isobutane consumed for the production of isobutene/total consumption of isobutane × 100%;
the isobutene yield was calculated as follows:
the isobutene yield is isobutane conversion × isobutene selectivity × 100%.
Example 1
This example is illustrative of an isobutane dehydrogenation catalyst and a method for preparing the same.
(1) Preparation of the support
1.5g (0.004mol) of template CTAB (cetyltrimethylammonium bromide) and 1.5ml (0.002mol) of polyethylene glycol octylphenyl ether (triton-X100) were added to a solution containing 37% by weight of hydrochloric acid (29.6g) and water (75g), and stirred at 40 ℃ until CTAB was completely dissolved; then adding 4.35g (0.02mol) of tetraethoxysilane into the solution, stirring for 15 minutes at 40 ℃, then transferring the obtained solution into a reaction kettle with a polytetrafluoroethylene lining, crystallizing for 24 hours at 120 ℃, filtering, washing for 4 times by using deionized water, and then carrying out suction filtration and drying to obtain mesoporous material raw powder; calcining the mesoporous material raw powder at 600 ℃ for 24h, and removing the template agent to obtain a spherical mesoporous molecular sieve A1;
mixing 15 wt% of water glass, 12 wt% of sulfuric acid solution and glycerol in a weight ratio of 5: 1: 1, then adjusting the pH value to 3 with sulfuric acid with the concentration of 98 weight percent, then carrying out suction filtration on the obtained reaction material, and washing the reaction material with distilled water until the content of sodium ions is 0.02 weight percent to obtain a silica gel filter cake B1.
And (3) putting 20g of the prepared filter cake A1 and 10g of the prepared filter cake B1 into a 100ml ball milling tank together, wherein the ball milling tank is made of polytetrafluoroethylene, grinding balls are made of agate, the diameter of each grinding ball is 3mm, the number of the grinding balls is 1, and the rotating speed is 400 r/min. And sealing the ball milling tank, and carrying out first ball milling in the ball milling tank at the temperature of 25 ℃ for 5 hours. The obtained first ball-milled slurry was mixed with 40g of deionized water at 25 ℃ for pulping, and then subjected to second ball milling at 25 ℃ for 5 hours. And (3) spray-drying the obtained second ball-milling slurry at the temperature of 200 ℃ at the rotating speed of 12000r/min, then screening by adopting a cyclone separation technology, calcining a screened product in a muffle furnace at the temperature of 550 ℃ for 10h, and removing F108 (template agent) to obtain 30g of the spherical small-hole mesoporous silica gel composite material C1.
(2) Preparation of isobutane dehydrogenation catalyst
Calcining 30g of the spherical micropore mesoporous silica gel composite material C1 obtained in the step (1) at 400 ℃ for 10h under the protection of nitrogen, and carrying out thermal activation treatment to remove hydroxyl and residual moisture of the spherical micropore mesoporous silica gel composite material C1.
0.080g H2PtCl6·6H2O and 0.457g Zn (NO)3)2·6H2Dissolving O in 100ml of deionized water to obtain a mixture solution, soaking 10g of the spherical small-hole mesoporous silica gel composite material C1 prepared in the step (1) in the mixture solution, soaking at 25 ℃ for 5h, and evaporating the solution in the system by using a rotary evaporatorAdding water to obtain a solid product, and drying the solid product in a drying oven at the temperature of 120 ℃ for 3 hours. And then roasting the mixture in a muffle furnace at the temperature of 600 ℃ for 6 hours to obtain the isobutane dehydrogenation catalyst Cat-1 (based on the total weight of the isobutane dehydrogenation catalyst Cat-1, the content of a Pt component in terms of Pt is 0.3 wt%, the content of a Zn component in terms of Zn is 1 wt%, and the balance is a carrier).
Characterizing the spherical small-hole mesoporous silica gel composite material C1 and an isobutane dehydrogenation catalyst Cat-1 by using an XRD, a scanning electron microscope and an ASAP2020-M + C type adsorption instrument;
fig. 1 is an X-ray diffraction pattern of the spherical small-pore mesoporous silica gel composite material C1, wherein the abscissa is 2 θ and the ordinate is intensity, and the XRD pattern of the spherical small-pore mesoporous silica gel composite material C1 has a mesoporous structure specific to the mesoporous material, as can be seen from a small-angle spectrum peak appearing in the XRD pattern;
FIG. 2 is an SEM scanning electron microscope image of the spherical small-pore mesoporous silica gel composite material C1, and it can be seen that the microscopic morphology of the spherical small-pore mesoporous silica gel composite material C1 is microspheres with a particle size of 10-30 μm, and the monodispersity is good;
FIG. 3 is a particle size distribution curve of the spherical mesoporous silica gel composite material C1, which shows that the spherical mesoporous silica gel composite material C1 has a uniform particle size distribution;
fig. 4 is a pore size distribution diagram of the spherical small-pore mesoporous silica gel composite material C1, wherein the abscissa is the pore size (unit is 0.1nm), and the ordinate is the pore volume (unit is mL/g), it can be seen from the diagram that the pore size distribution of the spherical small-pore mesoporous silica gel composite material C1 is bimodal distribution, and the most probable pore sizes corresponding to the bimodal distribution are 2.0nm and 50nm, respectively.
The pore structure parameters of the spherical mesoporous molecular sieves a1 and ES955 silica gel a are shown in table 1.
Comparative example 1
This comparative example serves to illustrate a reference isobutane dehydrogenation catalyst and a process for its preparation.
A carrier and an isobutane dehydrogenation catalyst were prepared according to the method of example 1, except that the same weight of alumina carrier was used instead of the composite material C1 containing silica gel and a spherical mesoporous molecular sieve in the preparation of the carrier, thereby preparing a carrier D1 and an isobutane dehydrogenation catalyst Cat-D-1, respectively.
Comparative example 2
A support and an isobutane dehydrogenation catalyst were prepared according to the method of example 1, except that commercially available ES955 silica gel (GRACE company) was used as the support D2 instead of the composite material C1 containing silica gel and a spherical mesoporous molecular sieve in the preparation of the support, thereby preparing a support D2 and an isobutane dehydrogenation catalyst Cat-D-2, respectively.
Comparative example 3
A carrier and an isobutane dehydrogenation catalyst were prepared according to the method of example 1, except that Zn (NO) was not added during the impregnation process for preparing the isobutane dehydrogenation type catalyst3)2·6H2O, addition of only 0.080g H2PtCl6·6H2And O, only loading a single Pt component on a composite material which is used as a carrier and contains silica gel and a spherical mesoporous molecular sieve by a co-impregnation method, thereby preparing the isobutane dehydrogenation catalyst Cat-D-3, wherein the content of the Pt component in terms of Pt element is 0.3 wt% and the rest is the carrier by taking the total weight of the isobutane dehydrogenation catalyst Cat-D-3 as a reference.
Example 2
This example is illustrative of an isobutane dehydrogenation catalyst and a method for preparing the same.
(1) Preparation of the support
0.75g (0.002mol) of template CTAB (cetyltrimethylammonium bromide) and 3ml (0.004mol) of polyethylene glycol octylphenyl ether (triton-X100) were added to a solution containing 37% by weight of hydrochloric acid (29.6g) and water (75g), and stirred at 40 ℃ until CTAB was completely dissolved; then adding 4.35g (0.02mol) of tetraethoxysilane into the solution, stirring for 15 minutes at 40 ℃, then transferring the obtained solution into a reaction kettle with a polytetrafluoroethylene lining, crystallizing for 24 hours at 100 ℃, filtering, washing for 4 times by using deionized water, and then carrying out suction filtration and drying to obtain mesoporous material raw powder; calcining the mesoporous material raw powder at 600 ℃ for 24h, and removing the template agent to obtain a spherical mesoporous molecular sieve A2;
mixing 15 wt% of water glass, 12 wt% of sulfuric acid solution and glycerol in a weight ratio of 4: 1: 1, then adjusting the pH value to 2 with sulfuric acid with the concentration of 98 weight percent, then carrying out suction filtration on the obtained reaction material, and washing the reaction material with distilled water until the content of sodium ions is 0.02 weight percent to obtain a silica gel filter cake B2.
And putting 15g of the prepared filter cake A2 and 15g of the prepared filter cake B2 into a 100ml ball milling tank together, wherein the ball milling tank is made of polytetrafluoroethylene, grinding balls are made of agate, the diameter of each grinding ball is 3mm, the number of the grinding balls is 1, and the rotating speed is 300 r/min. And sealing the ball milling tank, and carrying out first ball milling in the ball milling tank at the temperature of 25 ℃ for 5 hours. The obtained first ball-milled slurry was mixed with 15g of deionized water at 25 ℃ for pulping, and then subjected to second ball milling at 25 ℃ for 5 hours. And (3) spray-drying the obtained second ball-milling slurry at 250 ℃ at the rotating speed of 11000r/min, then screening by adopting a cyclone separation technology, calcining a screened product in a muffle furnace at 600 ℃ for 12h, and removing F108 (template agent) to obtain 35g of the spherical double-hole cubic cage-shaped mesoporous molecular sieve silica gel composite material C2.
(2) Preparation of isobutane dehydrogenation catalyst
Calcining 30g of the spherical double-hole cubic cage-shaped mesoporous molecular sieve silica gel composite material C2 obtained in the step (1) at 400 ℃ for 10h under the protection of nitrogen, and performing thermal activation treatment to remove hydroxyl and residual moisture of the spherical double-hole cubic cage-shaped mesoporous molecular sieve silica gel composite material C2.
0.080g H2PtCl6·6H2O and 0.457g Zn (NO)3)2·6H2Dissolving O in 100ml of deionized water to obtain a mixture solution, soaking 10g of the spherical double-hole cubic cage-shaped mesoporous molecular sieve silica gel composite material C2 prepared in the step (1) in the mixture solution, soaking at 25 ℃ for 5h, evaporating solvent water in a system by using a rotary evaporator to obtain a solid product, placing the solid product in a drying box at 120 ℃, drying for 3h, then placing in a muffle furnace at 600 ℃, and roasting for 6h to obtain the isobutane dehydrogenation catalyst Cat-2 (so as to obtain the isobutane dehydrogenation catalyst Cat-2The total weight of the isobutane dehydrogenation catalyst Cat-2 is taken as a reference, the content of a Pt component calculated by a Pt element is 0.3 weight percent, the content of a Zn component calculated by a Zn element is 1 weight percent, and the balance is a carrier).
Table 1 shows the pore structure parameters of the spherical double-pore cubic cage-shaped mesoporous molecular sieve silica gel composite material C1 and the isobutane dehydrogenation catalyst Cat-1.
Example 3
(1) Preparation of the support
First, a spherical mesoporous molecular sieve a1 and a silica cake B1 were prepared in the same manner as in preparation example 1.
And (3) putting 20g of the prepared filter cake A1 and 30g of the prepared filter cake B1 into a 100ml ball milling tank together, wherein the ball milling tank is made of polytetrafluoroethylene, grinding balls are made of agate, the diameter of each grinding ball is 3mm, the number of the grinding balls is 1, and the rotating speed is 550 r/min. And sealing the ball milling tank, and carrying out first ball milling in the ball milling tank at the temperature of 40 ℃ for 10 hours. The obtained first ball-milled slurry was mixed with 30g of deionized water at 25 ℃ for pulping, and then subjected to second ball milling at 25 ℃ for 5 hours. And (3) spray-drying the obtained second ball-milling slurry at 150 ℃ at the rotating speed of 13000r/min, then screening by adopting a cyclone separation technology, calcining the screened product in a muffle furnace at 450 ℃ for 7h, and removing F108 (template agent) to obtain 53g of spherical double-hole cubic cage-shaped mesoporous molecular sieve silica gel composite material C3.
(2) Preparation of isobutane removal catalyst
Calcining 30g of the spherical double-hole cubic cage-shaped mesoporous molecular sieve silica gel composite material C3 obtained in the step (1) at 400 ℃ for 10h under the protection of nitrogen, and performing thermal activation treatment to remove hydroxyl and residual moisture of the spherical double-hole cubic cage-shaped mesoporous molecular sieve silica gel composite material C3.
0.080g H2PtCl6·6H2O and 0.457g Zn (NO)3)2·6H2Dissolving O in 100ml of deionized water to obtain a mixture solution, soaking 10g of the spherical double-hole cubic cage-shaped mesoporous molecular sieve silica gel composite material C3 prepared in the step (1) in the mixture solution, soaking at 25 ℃ for 5h, and steaming out the mixture in a system by using a rotary evaporatorThe solid product is placed in a drying oven at the temperature of 120 ℃, dried for 3 hours and then placed in a muffle furnace at the temperature of 600 ℃ and roasted for 6 hours to obtain the isobutane dehydrogenation catalyst Cat-3 (the total weight of the isobutane dehydrogenation catalyst Cat-3 is taken as a reference, the content of the Pt component is 0.3 weight percent calculated by the Pt element, the content of the Zn component is 1 weight percent calculated by the Zn element, and the balance is a carrier).
Table 1 shows the pore structure parameters of the spherical double-pore cubic cage-shaped mesoporous molecular sieve silica gel composite material C3 and the isobutane dehydrogenation catalyst Cat-3.
TABLE 1
Sample (I) Specific surface area (m)2/g) Pore volume (ml/g) Most probable aperture*(nm) Particle size (. mu.m)
A1 280 1.2 2.5,45 25
A2 260 1 2.0,50 23
ES955 silica gel A 250 1.5 15 20-50
ES955 silica gel B 230 1.5 16 30-55
*: the first most probable aperture and the second most probable aperture are separated by a comma: the first most probable aperture and the second most probable aperture are arranged in the order from left to right.
As can be seen from the data of table 1, the composite material C1 containing silica gel and spherical mesoporous molecular sieve as the carrier has a reduced specific surface area and pore volume after supporting the main active Pt component and the auxiliary Zn component, which indicates that the main active Pt component and the auxiliary Zn component enter the interior of the composite material C1 containing silica gel and spherical mesoporous molecular sieve during the supporting reaction.
Experimental example 1
This example is intended to illustrate the preparation of isobutene using the isobutane dehydrogenation catalyst of the present invention
0.5g of isobutane dehydrogenation catalyst Cat-1 was loaded into a fixed bed quartz reactor, the reaction temperature was controlled at 590 ℃, the reaction pressure was 0.1MPa, and the isobutane: the molar ratio of hydrogen is 1: 1, the reaction time is 24 hours, and the mass space velocity of the isobutane is 4 hours-1. By Al2O3The reaction product separated by the S molecular sieve column directly enters an Agilent 7890A gas chromatograph equipped with a hydrogen flame detector (FID) for on-line analysis, and the obtained isobutane conversion rate and isobutene selectivity are shown in Table 2. After the reaction, the amount of carbon deposition in the isobutane dehydrogenation catalyst Cat-1 was measured using a TGA/DSC1 thermogravimetric analyzer from METTLER-TOLEDO, as shown in the table2, respectively.
Experimental examples 2 to 3
Isobutene was prepared by dehydrogenation of isobutane according to the method of experimental example 1, except that isobutane dehydrogenation catalyst Cat-2 and isobutane dehydrogenation catalyst Cat-3 were used instead of isobutane dehydrogenation catalyst Cat-1, respectively. The isobutane conversion, isobutene selectivity and carbon deposition amount of the isobutane dehydrogenation catalyst are shown in table 2.
Experimental comparative examples 1 to 3
Isobutene is prepared by isobutane dehydrogenation according to the method of the experimental example 1, except that isobutane dehydrogenation catalysts Cat-D-1 to Cat-D-3 are respectively adopted to replace the isobutane dehydrogenation catalyst Cat-1. The isobutane conversion, isobutene selectivity and carbon deposition amount of the isobutane dehydrogenation catalyst are shown in table 2.
TABLE 2
Dehydrogenation catalyst Isobutane conversion rate Selectivity to isobutene Amount of carbon deposition
Experimental example 1 Cat-1 17% 95% 1.1wt%
Experimental example 2 Cat-2 16% 94% 1.3wt%
Experimental example 3 Cat-3 15% 93% 1.2wt%
Experimental comparative example 1 Cat-D-1 12.5% 71.3% 5.3wt%
Experimental comparative example 2 Cat-D-2 17.2% 20.5% 6.2wt%
Experimental comparative example 3 Cat-D-3 24.5% 55.6% 3.1wt%
As can be seen from Table 2, when the isobutane dehydrogenation catalyst prepared by the method of the invention is used in the reaction of preparing isobutene by isobutane dehydrogenation, a higher isobutane conversion rate and isobutene selectivity can still be obtained after 24 hours of reaction, which shows that the isobutane dehydrogenation catalyst of the invention not only has better dehydrogenation activity and high selectivity, but also has excellent stability and low carbon deposition. In addition, the method for preparing the isobutane dehydrogenation catalyst provided by the invention has the advantages of simple preparation process and lower cost.
The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.

Claims (11)

1. A method for preparing an isobutane dehydrogenation catalyst, characterized in that the method comprises the following steps:
(a) under the condition of a solution, mixing and contacting a template agent, a nonionic surfactant, an acid agent and a silicon source to obtain a solution A, and sequentially crystallizing, washing and drying the solution A to obtain mesoporous material raw powder; and carrying out template removing agent treatment on the mesoporous material raw powder to obtain the spherical mesoporous molecular sieve; wherein the template agent is cetyl trimethyl ammonium bromide, and the nonionic surfactant is polyethylene glycol octyl phenyl ether;
(b) contacting water glass with inorganic acid, and filtering a product obtained after the contact to obtain a silica gel filter cake;
(c) mixing the spherical mesoporous molecular sieve filter cake and silica gel, performing first ball milling, mixing the obtained first ball milling slurry with water for pulping, performing second ball milling to obtain second ball milling slurry, performing spray drying on the second ball milling slurry, screening by adopting a cyclone separation technology, and removing a template agent in a screened product to obtain the spherical small-hole mesoporous silica gel composite material;
(d) the spherical small-hole mesoporous silica gel composite material carrier is subjected to thermal activation treatment, then is subjected to dipping treatment in a solution containing a Pt component precursor and a Zn component precursor, and then is subjected to solvent removal treatment, drying and roasting in sequence.
2. The process of claim 1, wherein in step (a), the conditions of the mixing contact comprise: the temperature is 25-60 ℃, and the time is 0.1-48 h;
preferably, the molar ratio of the template agent, the non-ionic surfactant and the silicon source is (0.1-0.6): (0.1-0.5): 1;
preferably, the crystallization conditions include: the temperature is 90-180 ℃ and the time is 4-40 h; the process of the stripper plate agent treatment comprises: calcining the mesoporous material raw powder for 5-40h at the temperature of 300-800 ℃.
3. The method of claim 1, wherein in step (b), the conditions under which the water glass is contacted with the mineral acid comprise: the temperature is 10-60 ℃, the time is 1-5 hours, and the pH value is 2-4; the inorganic acid is one or more of sulfuric acid, nitric acid and hydrochloric acid.
4. The method of claim 1, wherein, in step (c), the silica gel is formed by a method comprising: contacting water glass, inorganic acid and glycerol;
preferably, the conditions of the contacting include: the temperature is 10-60 ℃, the time is 1-5h, and the pH value is 2-4;
preferably, the inorganic acid solution is at least one aqueous solution of sulfuric acid, nitric acid and hydrochloric acid;
preferably, in the step (b), the conditions of the first ball milling and the second ball milling are the same or different, and the conditions of the first ball milling and the second ball milling each independently comprise: the rotation speed of the grinding ball is 200-;
preferably, the weight ratio of the first ball milling slurry to the amount of water is 1: (0.1-5), mixing the first ball-milling slurry with water to prepare slurry at the temperature of 25-60 ℃;
preferably, the conditions of the spray drying include: the temperature is 150-;
preferably, the screening process of the second ball-milling slurry by using the cyclone separation technology after the spray drying comprises the following steps: performing cyclone separation on the gas containing the powder particles discharged by the second ball-milling slurry after spray drying so as to collect the powder particles;
preferably, the weight ratio of the dosage of the spherical mesoporous molecular sieve filter cake to the dosage of the silica gel is 1: (0.5-1.5).
5. The method according to claim 1, wherein in the step (d), the small-pore mesoporous composite material support, the Pt component precursor and the Zn component precursor are used in amounts such that the support is contained in an amount of 98-99.4 wt%, the Pt component is contained in an amount of 0.1-0.5 wt% in terms of Pt element, and the Zn component is contained in an amount of 0.5-1.5 wt% in terms of Zn element, based on the total weight of the isobutane dehydrogenation catalyst, in the prepared isobutane dehydrogenation catalyst;
preferably, the conditions of thermal activation include: the temperature is 300-900 ℃ and the time is 7-10 h; the conditions of the impregnation treatment include: the temperature is 25-50 ℃ and the time is 2-6 h.
6. An isobutane dehydrogenation catalyst produced by the process of any one of claims 1-5.
7. An isobutane dehydrogenation catalyst according to claim 6, wherein said isobutane dehydrogenation catalyst comprises a carrier, and a Pt component and a Zn component supported on said carrier, wherein said carrier is a composite material comprising silica gel and a spherical mesoporous molecular sieve, wherein the average particle diameter of said spherical mesoporous molecular sieve is 10-30 μm, and the specific surface area is 100-300m2The pore volume is 0.5-1.5mL/g, the pore size distribution is bimodal, and the most probable pore sizes corresponding to the bimodal are 1-3nm and 20-50nm respectively; the specific surface area of the silica gel is 200-300m2Per g, pore volume of 1-2mL/g, average pore diameter of 10-30nm, and average particle diameter of 20-100 μm.
8. An isobutane dehydrogenation catalyst according to claim 7, wherein the spherical mesoporous molecular sieve has an average particle size of 12-28 μm in ratioThe surface area is 120-29m2The pore volume is 0.6-1.2mL/g, the pore size distribution is bimodal, and the most probable pore sizes corresponding to the bimodal are 1.2-2.8nm and 25-48nm respectively; the specific surface area of the silica gel is 230-280m2Per g, pore volume of 1.2-1.8mL/g, average pore diameter of 12-18nm, and average particle diameter of 30-70 μm;
preferably, the content weight ratio of the spherical mesoporous molecular sieve to the silica gel is (1.2-10): 1;
preferably, the silica gel is 955 silica gel.
9. An isobutane dehydrogenation catalyst according to claim 7, wherein the carrier is present in an amount of 98-99.4 wt%, the Pt component is present in an amount of 0.1-0.5 wt% calculated as Pt element, and the Zn component is present in an amount of 0.5-1.5 wt% calculated as Zn element, based on the total weight of the isobutane dehydrogenation catalyst.
10. Use of the isobutane dehydrogenation catalyst according to any one of claims 6 to 9 in the production of isobutene by the dehydrogenation of isobutane, wherein the method for producing isobutene by the dehydrogenation of isobutane comprises: isobutane was subjected to a dehydrogenation reaction in the presence of a catalyst and hydrogen.
11. Use according to claim 10, wherein the molar ratio of the amount of isobutane to the amount of hydrogen is (0.5-1.5): 1;
preferably, the dehydrogenation reaction conditions include: the reaction temperature is 550-650 ℃, the reaction pressure is 0.05-0.2MPa, the reaction time is 20-40h, and the mass space velocity of isobutane is 2-5h-1
CN201810638975.5A 2018-06-20 2018-06-20 Isobutane dehydrogenation catalyst with spherical small-hole mesoporous silica gel composite as carrier and preparation method and application thereof Pending CN110614114A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201810638975.5A CN110614114A (en) 2018-06-20 2018-06-20 Isobutane dehydrogenation catalyst with spherical small-hole mesoporous silica gel composite as carrier and preparation method and application thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201810638975.5A CN110614114A (en) 2018-06-20 2018-06-20 Isobutane dehydrogenation catalyst with spherical small-hole mesoporous silica gel composite as carrier and preparation method and application thereof

Publications (1)

Publication Number Publication Date
CN110614114A true CN110614114A (en) 2019-12-27

Family

ID=68920657

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201810638975.5A Pending CN110614114A (en) 2018-06-20 2018-06-20 Isobutane dehydrogenation catalyst with spherical small-hole mesoporous silica gel composite as carrier and preparation method and application thereof

Country Status (1)

Country Link
CN (1) CN110614114A (en)

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1070847A (en) * 1992-10-15 1993-04-14 大庆石油学院 Low-carbon chain hydrocarbon aromatization gallium, zinc, platinum modified HZSM-5 catalyst
US20060129015A1 (en) * 2004-11-12 2006-06-15 Tonkovich Anna L Process using microchannel technology for conducting alkylation or acylation reaction
CN101618336A (en) * 2009-08-03 2010-01-06 大连理工大学 Metal supported MCM-22 molecular sieve hollow sphere bifunctional catalyst preparation method and application thereof
CN105175586A (en) * 2014-06-13 2015-12-23 中国石油化工股份有限公司 Meso-porous composite material, preparation method thereof, catalyst ingredient preparation method, and polyethylene preparation method
CN105330767A (en) * 2014-06-13 2016-02-17 中国石油化工股份有限公司 Supported polyethylene catalyst ingredient and preparation method thereof, and supported polyethylene catalyst and application thereof
CN106311311A (en) * 2015-06-19 2017-01-11 中国石油化工股份有限公司 Catalyst for preparing propylene through propane dehydrogenation, preparation method of catalyst, and method for propylene through propane dehydrogenation
CN107303487A (en) * 2016-04-20 2017-10-31 中国石油化工股份有限公司 A kind of dehydrogenation and its preparation method and application
CN107837822A (en) * 2016-09-20 2018-03-27 中国石油化工股份有限公司 The preparation method of carried metallocene catalyst and its preparation method and application and methyl acrylate

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1070847A (en) * 1992-10-15 1993-04-14 大庆石油学院 Low-carbon chain hydrocarbon aromatization gallium, zinc, platinum modified HZSM-5 catalyst
US20060129015A1 (en) * 2004-11-12 2006-06-15 Tonkovich Anna L Process using microchannel technology for conducting alkylation or acylation reaction
CN101618336A (en) * 2009-08-03 2010-01-06 大连理工大学 Metal supported MCM-22 molecular sieve hollow sphere bifunctional catalyst preparation method and application thereof
CN105175586A (en) * 2014-06-13 2015-12-23 中国石油化工股份有限公司 Meso-porous composite material, preparation method thereof, catalyst ingredient preparation method, and polyethylene preparation method
CN105330767A (en) * 2014-06-13 2016-02-17 中国石油化工股份有限公司 Supported polyethylene catalyst ingredient and preparation method thereof, and supported polyethylene catalyst and application thereof
CN106311311A (en) * 2015-06-19 2017-01-11 中国石油化工股份有限公司 Catalyst for preparing propylene through propane dehydrogenation, preparation method of catalyst, and method for propylene through propane dehydrogenation
CN107303487A (en) * 2016-04-20 2017-10-31 中国石油化工股份有限公司 A kind of dehydrogenation and its preparation method and application
CN107837822A (en) * 2016-09-20 2018-03-27 中国石油化工股份有限公司 The preparation method of carried metallocene catalyst and its preparation method and application and methyl acrylate

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
胥月兵等: ""ZSM-5 分子筛在低碳烷烃脱氢中的催化应用"", 《化学进展》 *

Similar Documents

Publication Publication Date Title
CN109746033B (en) Method for preparing propane dehydrogenation catalyst, propane dehydrogenation catalyst and method for preparing propylene by propane dehydrogenation
CN109746027B (en) Method for preparing propane dehydrogenation catalyst, propane dehydrogenation catalyst and method for preparing propylene by propane dehydrogenation
CN109746032B (en) Propane dehydrogenation catalyst, preparation method thereof and method for preparing propylene by propane dehydrogenation
CN110496618B (en) Isobutane dehydrogenation catalyst, preparation method thereof and method for preparing isobutene through isobutane dehydrogenation
CN108722403B (en) A kind of method of propane dehydrogenation catalyst and preparation method thereof and preparing propylene by dehydrogenating propane
CN108722468B (en) A kind of method of propane dehydrogenation catalyst and preparation method thereof and preparing propylene by dehydrogenating propane
CN110614118A (en) Isobutane dehydrogenation catalyst with three-hole sepiolite spherical mesoporous composite material as carrier and preparation method and application thereof
CN110614108B (en) Isobutane dehydrogenation catalyst with carrier being mesoporous molecular sieve with three-dimensional cage-shaped pore channel distribution structure, preparation method and application
CN110732341A (en) Isobutane dehydrogenation catalyst with spherical aluminum-containing double mesoporous molecular sieve silica gel composite as carrier and preparation method and application thereof
CN109746028B (en) Propane dehydrogenation catalyst, preparation method thereof and method for preparing propylene by propane dehydrogenation
CN110614097A (en) Isobutane dehydrogenation catalyst with carrier being composite material containing silica gel and hexagonal mesoporous material, and preparation method and application thereof
CN110732342A (en) Isobutane dehydrogenation catalyst with chlorite composite material with three-dimensional cubic and hexagonal pore channel structure as carrier and preparation method and application thereof
CN110496635B (en) Isobutane dehydrogenation catalyst, preparation method thereof and method for preparing isobutene through isobutane dehydrogenation
CN110614107A (en) Isobutane dehydrogenation catalyst with carrier of hollow spherical mesoporous molecular sieve silica gel composite material and preparation method and application thereof
CN110614114A (en) Isobutane dehydrogenation catalyst with spherical small-hole mesoporous silica gel composite as carrier and preparation method and application thereof
CN110732343A (en) Isobutane dehydrogenation catalyst with carrier of three-hole hollow spherical mesoporous molecular sieve silica gel composite material and preparation method and application thereof
CN110813285A (en) Isobutane dehydrogenation catalyst with spherical surface-surrounded mesoporous material silica gel composite material as carrier and preparation method and application thereof
CN110614106A (en) Isobutane dehydrogenation catalyst with spherical double-mesoporous illite composite material as carrier, preparation method and application
CN110496637B (en) Isobutane dehydrogenation catalyst, preparation method thereof and method for preparing isobutene through isobutane dehydrogenation
CN110614115A (en) Isobutane dehydrogenation catalyst with spherical tri-mesoporous composite material as carrier and preparation method and application thereof
CN110496634B (en) Isobutane dehydrogenation catalyst, preparation method thereof and method for preparing isobutene through isobutane dehydrogenation
CN110496630B (en) Isobutane dehydrogenation catalyst, preparation method thereof and method for preparing isobutene through isobutane dehydrogenation
CN110614119A (en) Isobutane dehydrogenation catalyst with spherical double-hole cubic cage-shaped mesoporous molecular sieve silica gel composite material as carrier, and preparation method and application thereof
CN110496632B (en) Isobutane dehydrogenation catalyst, preparation method thereof and method for preparing isobutene through isobutane dehydrogenation
CN110614110A (en) Isobutane dehydrogenation catalyst with eggshell-shaped mesoporous material silica gel composite material as carrier, and preparation method and application thereof

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
WD01 Invention patent application deemed withdrawn after publication
WD01 Invention patent application deemed withdrawn after publication

Application publication date: 20191227