CN110496632B - Isobutane dehydrogenation catalyst, preparation method thereof and method for preparing isobutene through isobutane dehydrogenation - Google Patents

Isobutane dehydrogenation catalyst, preparation method thereof and method for preparing isobutene through isobutane dehydrogenation Download PDF

Info

Publication number
CN110496632B
CN110496632B CN201810475363.9A CN201810475363A CN110496632B CN 110496632 B CN110496632 B CN 110496632B CN 201810475363 A CN201810475363 A CN 201810475363A CN 110496632 B CN110496632 B CN 110496632B
Authority
CN
China
Prior art keywords
isobutane
dehydrogenation catalyst
isobutane dehydrogenation
mesoporous
filter cake
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.)
Active
Application number
CN201810475363.9A
Other languages
Chinese (zh)
Other versions
CN110496632A (en
Inventor
亢宇
刘红梅
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
Original Assignee
Sinopec Beijing Research Institute of Chemical Industry
China Petroleum and Chemical 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 Petroleum and Chemical Corp filed Critical Sinopec Beijing Research Institute of Chemical Industry
Priority to CN201810475363.9A priority Critical patent/CN110496632B/en
Publication of CN110496632A publication Critical patent/CN110496632A/en
Application granted granted Critical
Publication of CN110496632B publication Critical patent/CN110496632B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

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
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00Catalysts, in general, characterised by their form or physical properties
    • B01J35/60Catalysts, in general, characterised by their form or physical properties characterised by their surface properties or porosity
    • B01J35/61Surface area
    • B01J35/615100-500 m2/g
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00Catalysts, in general, characterised by their form or physical properties
    • B01J35/60Catalysts, in general, characterised by their form or physical properties characterised by their surface properties or porosity
    • B01J35/63Pore volume
    • B01J35/6350.5-1.0 ml/g
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00Catalysts, in general, characterised by their form or physical properties
    • B01J35/60Catalysts, in general, characterised by their form or physical properties characterised by their surface properties or porosity
    • B01J35/63Pore volume
    • B01J35/638Pore volume more than 1.0 ml/g
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00Catalysts, in general, characterised by their form or physical properties
    • B01J35/60Catalysts, in general, characterised by their form or physical properties characterised by their surface properties or porosity
    • B01J35/64Pore diameter
    • B01J35/643Pore diameter less than 2 nm
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00Catalysts, in general, characterised by their form or physical properties
    • B01J35/60Catalysts, in general, characterised by their form or physical properties characterised by their surface properties or porosity
    • B01J35/64Pore diameter
    • B01J35/6472-50 nm
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00Catalysts, in general, characterised by their form or physical properties
    • B01J35/60Catalysts, in general, characterised by their form or physical properties characterised by their surface properties or porosity
    • B01J35/66Pore distribution
    • B01J35/69Pore distribution bimodal
    • 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
    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07CACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C2529/00Catalysts comprising molecular sieves
    • C07C2529/03Catalysts comprising molecular sieves not having base-exchange properties

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Dispersion Chemistry (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
  • Catalysts (AREA)

Abstract

The invention relates to the field of catalysts, and discloses a method for preparing an isobutane dehydrogenation catalyst, the isobutane dehydrogenation catalyst prepared by the method and a method for preparing isobutene by isobutane dehydrogenation. The method for preparing the isobutane dehydrogenation catalyst comprises the following steps: (a) preparing a mesoporous material filter cake; (b) providing a silica gel filter cake; (c) mixing and ball-milling the mesoporous material filter cake and the silica gel filter cake, pulping solid powder obtained after ball-milling, drying, and removing a template agent in the obtained product to obtain a spherical double-mesoporous composite material carrier; (d) the spherical double-mesoporous composite material carrier is soaked 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 obtained isobutane dehydrogenation catalyst has better dehydrogenation activity and carbon deposition resistance.

Description

Isobutane dehydrogenation catalyst, preparation method thereof and method for preparing isobutene through isobutane dehydrogenation
Technical Field
The invention relates to the field of catalysts, in particular to a method for preparing an isobutane dehydrogenation catalyst, the isobutane dehydrogenation catalyst prepared by the method and a method for preparing isobutene by 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 a method for preparing the isobutane dehydrogenation catalyst, the isobutane dehydrogenation catalyst prepared by the method and a method for preparing isobutene by isobutane dehydrogenation.
In order to accomplish the above object, an aspect of the present invention provides a method for preparing an isobutane dehydrogenation catalyst, the method comprising the steps of:
(a) in the presence of a template agent, contacting tetraethoxysilane with ammonia water, and filtering a mixture obtained after the contact to obtain a mesoporous material filter cake;
(b) contacting water glass with inorganic acid, and filtering a product obtained after the contact to obtain a silica gel filter cake;
(c) mixing and ball-milling the mesoporous material filter cake and the silica gel filter cake, pulping solid powder obtained after ball-milling with water, then carrying out spray drying, and removing the template agent in the obtained product to obtain a spherical double-mesoporous composite material carrier;
(d) and (c) dipping the spherical double-mesoporous composite material carrier obtained in the step (c) in a solution containing a Pt component precursor and a Zn component precursor, and then sequentially carrying out solvent removal treatment, drying and roasting.
A second aspect of the invention provides an isobutane dehydrogenation catalyst prepared by the aforementioned process.
The third aspect of the invention provides a method for preparing isobutene by dehydrogenating isobutane, which comprises the following steps: and (2) carrying out dehydrogenation reaction on the isobutane in the presence of a catalyst and hydrogen, wherein the catalyst is the isobutane dehydrogenation catalyst prepared by the method.
The carrier structure of the noble metal catalyst (including physical structures such as specific surface area, pore volume, pore size distribution and the like and chemical structures such as surface acid sites, electronic properties and the like) 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.
The inventor of the invention discovers, through research, that the composite material with a two-dimensional hexagonal special pore channel distribution structure is introduced as a carrier in the preparation process of the isobutane dehydrogenation catalyst, so that the carrier of the isobutane dehydrogenation catalyst can obtain the characteristics of a porous structure, a large specific surface area and a large pore volume of a mesoporous molecular sieve material, and the carrier is favorable for good dispersion of a noble metal component on the surface of the carrier, so that the prepared catalyst can achieve good dehydrogenation activity, selectivity, stability and carbon deposition resistance under the condition of low noble metal loading. In addition, 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.
And when the isobutane dehydrogenation catalyst is prepared by a spray drying method, the isobutane dehydrogenation catalyst can be recycled, and a high conversion rate of reaction raw materials can be still obtained in the recycling process.
In addition, the preparation method of the isobutane dehydrogenation catalyst adopts a co-impregnation method to replace the conventional step impregnation method, and has the advantages of simple preparation process, low preparation cost and good economy.
Additional features and advantages of the invention will be set forth in the detailed description which follows.
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 double mesoporous composite support of example 1;
FIG. 2A is an SEM scanning electron micrograph of the microstructure of the spherical double mesoporous composite support of example 1 at 50 times magnification;
FIG. 2B is an SEM scanning electron micrograph of the microscopic morphology of the spherical mesoporous dual mesoporous composite support of example 1 at a magnification of 100 times;
FIG. 3 is a pore size distribution curve of the spherical dual mesoporous composite support of example 1;
fig. 4 is a particle size distribution curve of the spherical dual mesoporous composite support of example 1.
Detailed Description
The following describes in detail specific embodiments of the present invention. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.
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 previously described, a first aspect of the present invention provides a method for preparing an isobutane dehydrogenation catalyst, the method comprising the steps of:
(a) in the presence of a template agent, contacting tetraethoxysilane with ammonia water, and filtering a mixture obtained after the contact to obtain a mesoporous material filter cake;
(b) contacting water glass with inorganic acid, and filtering a product obtained after the contact to obtain a silica gel filter cake;
(c) mixing and ball-milling the mesoporous material filter cake and the silica gel filter cake, pulping solid powder obtained after ball-milling with water, then carrying out spray drying, and removing the template agent in the obtained product to obtain a spherical double-mesoporous composite material carrier;
(d) and (c) dipping the spherical double-mesoporous composite material carrier obtained in the step (c) in a solution containing a Pt component precursor and a Zn component precursor, and then sequentially carrying out solvent removal treatment, drying and roasting.
In the formation process of the isobutane dehydrogenation catalyst, the mesoporous material filter cake is a mesoporous molecular sieve material with a two-dimensional hexagonal pore channel distribution structure.
In the process of forming the spherical double-mesoporous composite material carrier, the pore size distribution is controlled to be bimodal distribution mainly by controlling the composition of the mesoporous material filter cake and the silica gel filter cake, the spherical double-mesoporous composite material carrier is enabled to have a double-pore distribution structure, the micro-morphology of the spherical double-mesoporous composite material carrier is controlled to be spherical by controlling a forming method (namely, the mesoporous material filter cake and the silica gel filter cake are mixed and ball-milled firstly, then the obtained solid powder is slurried with water and then is spray-dried), so that the mesoporous molecular sieve material with a two-dimensional hexagonal special pore channel distribution structure and the spherical double-mesoporous composite material carrier with the advantages of the spherical carrier can be synthesized by using common and easily-obtained raw materials under simple operation conditions, and the carrier has the porous structure, the large specific surface area and the porous structure of the mesoporous molecular sieve material with a two-dimensional hexagonal pore channel distribution structure, The isobutane dehydrogenation catalyst with no acidity on the surface, good dehydrogenation activity, high selectivity, strong stability and good carbon deposition resistance can be prepared by dipping and processing the loaded Pt component and the loaded Zn component.
According to the present invention, the amount of each substance can be selected and adjusted within a wide range in the process of preparing the mesoporous material filter cake. For example, in the step (a), the tetraethoxysilane, the template agent, the ammonia in the ammonia water and the water are used in a molar ratio of 1: 0.1-1: 0.1-5: 100-200, preferably 1: 0.2-0.5: 1.5-3.5: 120-180.
According to the invention, in order to make the obtained mesoporous material filter cake have a two-dimensional hexagonal pore channel distribution structure, the type of the template agent is preferably Cetyl Trimethyl Ammonium Bromide (CTAB).
According to the invention, the conditions for contacting the ethyl orthosilicate with ammonia water may comprise: the temperature is 25-100 ℃, and the time is 10-72 hours; preferably, the conditions for contacting the tetraethoxysilane and the ammonia solution can comprise: the temperature is 30-150 ℃ and the time is 10-72 hours.
The mode of contacting the template agent, the tetraethoxysilane and the ammonia water is not particularly limited, for example, the template agent, the tetraethoxysilane and the ammonia water solution can be simultaneously mixed, or any two of the template agent, the tetraethoxysilane and the ammonia water solution can be mixed, and other components can be added and uniformly mixed. According to a preferred embodiment, the template agent and the tetraethoxysilane are added into the ammonia water solution together and mixed evenly. The contact mode is that the template agent and the tetraethoxysilane are added into an ammonia water solution and mixed evenly, the obtained mixture is placed into a water bath with the temperature of 25-100 ℃ to be stirred until the mixture is dissolved, then the temperature is kept unchanged, and the mixture is stirred and reacts for 20-40 hours.
According to the method for preparing an isobutane dehydrogenation catalyst provided by the present invention, in the step (b), the conditions for contacting the water glass 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.
In addition, in the above process for preparing the mesoporous material filter cake and the silica gel filter cake, the process for obtaining the filter cake by filtering 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 mesoporous material filter cake results in a filter cake pH of 7 and 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 present invention, in the step (c), the amount of the mesoporous material filter cake and the silica gel filter cake may be selected according to the components of the spherical double mesoporous composite material carrier to be obtained, and preferably, the silica gel filter cake may be used in an amount of 1 to 200 parts by weight, preferably 50 to 150 parts by weight, based on 100 parts by weight of the mesoporous material filter cake.
According to the invention, the specific operation method and conditions of the ball milling are based on that the structure of the mesoporous material is not damaged or basically not damaged and the silica gel enters the pore canal of the mesoporous material. One skilled in the art can select various suitable conditions to implement the present invention based on the above principles. Specifically, the ball milling is carried out in a ball mill, wherein the diameter of the milling balls in the ball mill can be 2-3 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 ball milling conditions include: the rotation speed of the grinding ball can be 300-500r/min, the temperature in the ball milling tank can be 15-100 ℃, and the ball milling time can be 0.1-100 hours.
In the invention, the specific operation method and conditions of the spray drying are preferably as follows: adding a slurry prepared from the solid powder and water into an atomizer, and rotating at a high speed to realize spray drying. Wherein the spray drying conditions may include: the temperature can be 100-300 ℃, and the rotating speed can be 10000-15000 r/min; preferably, the spray drying conditions include: the temperature is 150-250 ℃, and the rotating speed is 11000-13000 r/min; most preferably, the spray drying conditions include: the temperature is 200 ℃, and the rotating speed is 12000 r/min.
According to the invention, the method for removing the template agent is preferably a calcination method. The conditions for removing the template agent may include: the temperature is 300-600 ℃, preferably 350-550 ℃, and most preferably 500 ℃; the time is 10 to 80 hours, preferably 20 to 30 hours, most preferably 24 hours.
According to the invention, in the step (d), the metal component loaded on the spherical double-mesoporous composite material carrier can adopt an impregnation mode, the metal component enters the pore channel of the spherical double-mesoporous composite material carrier by virtue of capillary pressure of the pore channel structure of the carrier, and meanwhile, the metal component can be adsorbed on the surface of the spherical double-mesoporous composite material carrier until the metal component reaches adsorption balance on the surface of the carrier. The dipping treatment may be a co-dipping treatment or a stepwise dipping 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: the spherical double-mesoporous composite material carrier is mixed and contacted with a solution containing a Pt component precursor and a Zn component precursor, the dipping temperature can be 25-50 ℃, and the dipping time can be 2-6 h.
According to the invention, the Pt component precursor is preferably H2PtCl6The Zn component precursor is preferably 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 drying conditions 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.
According to the invention, in the step (d), the spherical dual-mesoporous 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 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%.
Preferably, the spherical dual-mesoporous 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 98.4 to 99 wt%, the content of the Pt component calculated by the Pt element is 0.2 to 0.4 wt%, and the content of the Zn component calculated by the Zn element is 0.8 to 1.2 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 isobutane dehydrogenation catalyst comprises the carrier, and the Pt component and the Zn component which are loaded on the carrier, the carrier is a spherical double-mesoporous composite material carrier, the spherical double-mesoporous composite material carrier contains a mesoporous molecular sieve material with a two-dimensional hexagonal pore channel distribution structure, the average particle size of the spherical double-mesoporous composite material carrier is 30-60 mu m, and the specific surface area of the spherical double-mesoporous composite material carrier is 200-650m2The 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 1.5-15nm and 16-50nm respectively.
According to the invention, in the isobutane dehydrogenation catalyst, a spherical double-mesoporous composite material carrier serving as a carrier has a special two-dimensional hexagonal pore channel distribution structure, the average particle size of particles is measured by adopting 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. In the present invention, the particle size refers to the particle size of the raw material particles, and is expressed by the diameter of the sphere when the raw material particles are spherical, by the side length of the cube when the raw material particles are cubic, and by the mesh size of the screen that can sieve out the raw material particles when the raw material particles are irregularly shaped.
According to the invention, the spherical double-mesoporous composite material carrier can ensure that the spherical double-mesoporous composite material carrier is not easy to agglomerate by controlling the particle size of the spherical double-mesoporous composite material carrier within the range, and the conversion rate of reaction raw materials in the reaction process of preparing isobutene by isobutane dehydrogenation can be improved by using the supported catalyst prepared by using the spherical double-mesoporous composite material carrier as the carrier. When the specific surface area of the spherical double mesoporous composite material carrier is less than 200m2When 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 spherical double mesoporous composite material carrier is more than 650m2When the volume/g and/or the pore volume is more than 1.5mL/g, the supported catalyst prepared by using the catalyst as the carrier is easy to generate in the reaction process of preparing isobutene by dehydrogenating isobutaneAgglomeration is carried out, thus influencing the conversion rate of reaction raw materials in the reaction process of preparing isobutene by isobutane dehydrogenation.
Preferably, the average particle diameter of the spherical double mesoporous composite material carrier is 35-60 μm, and the specific surface area is 200-400m2The pore volume is 0.8-1.4mL/g, the pore size distribution is bimodal, and the most probable pore sizes corresponding to the bimodal are 1.8-12nm and 18-40nm respectively.
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%.
Preferably, the content of the carrier is 98.4-99 wt%, the content of the Pt component calculated by Pt element is 0.2-0.4 wt%, and the content of the Zn component calculated by Zn element is 0.8-1.2 wt%, based on the total weight of the isobutane dehydrogenation catalyst.
Further preferably, the average particle diameter of the isobutane dehydrogenation catalyst is 30-60 μm, and the specific surface area is 180-400m2The 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 1.8-12nm and 18-40nm respectively.
According to the present invention, the spherical double mesoporous composite material support may further contain silica introduced through silica gel. The term "silica introduced through silica gel" refers to a silica component which is brought into the finally prepared spherical double-mesoporous composite material carrier by using silica gel as a preparation raw material during the preparation process of the spherical double-mesoporous composite material carrier. In the spherical dual mesoporous composite support, the content of the silica introduced through the silica gel may be 1 to 200 parts by weight, preferably 50 to 150 parts by weight, with respect to 100 parts by weight of the mesoporous molecular sieve material having a two-dimensional hexagonal pore distribution structure.
According to the invention, the mesoporous molecular sieve material with the two-dimensional hexagonal pore channel distribution structure can be prepared according to the method.
As described above, the third aspect of the present invention provides a method for producing isobutene by dehydrogenating isobutane, including: and (2) carrying out dehydrogenation reaction on the isobutane in the presence of a catalyst and hydrogen, wherein the catalyst is the isobutane dehydrogenation catalyst prepared by the method.
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 to 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, 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.
In the following experimental examples and experimental comparative examples, the conversion (%) of isobutane was equal to the amount of isobutane consumed by the reaction/initial amount of isobutane × 100%;
the selectivity (%) of isobutylene was defined as the amount of isobutane consumed for producing isobutylene/total consumption of isobutane × 100%.
Example 1
This example is illustrative of an isobutane dehydrogenation catalyst and a method for preparing the same.
(1) Preparation of spherical double-mesoporous composite material carrier
Adding hexadecyl trimethyl ammonium bromide and ethyl orthosilicate into an ammonia water solution with the concentration of 25 weight percent, wherein the adding amount of the ethyl orthosilicate is 1g, and the mol ratio of ammonia to water in the ethyl orthosilicate, the hexadecyl trimethyl ammonium bromide and the ammonia water is 1: 0.37: 2.8: 142 and stirred at 80 ℃ until dissolved, then the obtained solution is filtered and washed 4 times with deionized water, and then filtered by suction to obtain a filter cake a1 of the mesoporous molecular sieve material with a two-dimensional hexagonal pore structure.
Mixing 15 wt% water glass and 12 wt% sulfuric acid solution in a weight ratio of 5:1, reacting at 30 deg.c for 2 hr, regulating the pH to 3 with 98 wt% sulfuric acid, suction filtering the obtained reaction material, and washing with distilled water to sodium ion content of 0.02 wt% to obtain 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. Sealing the ball milling tank, and carrying out ball milling for 1 hour in the ball milling tank at the temperature of 60 ℃ to obtain 30g of solid powder; dissolving the solid powder in 30g of deionized water, and spray-drying at 200 ℃ at a rotating speed of 12000 r/min; calcining the spray-dried product in a muffle furnace at 500 ℃ for 24 hours, and removing the template agent to obtain 30g of spherical double-mesoporous composite material carrier C1 with a two-dimensional hexagonal pore channel distribution structure.
(2) Preparation of isobutane dehydrogenation catalyst
0.080g H2PtCl6·6H2O and 0.457g Zn (NO)3)2·6H2Dissolving O in 100ml deionized water to obtainAnd (2) soaking 10g of the spherical double-mesoporous composite material carrier C1 prepared in the step (1) in the mixture solution at 25 ℃ for 5h, evaporating solvent water in the system by using a rotary evaporator to obtain a solid product, and drying the solid product in a drying oven at 120 ℃ for 3 h. 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).
The spherical double mesoporous composite material carrier C1 and the isobutane dehydrogenation catalyst Cat-1 are characterized by an XRD, a scanning electron microscope and an ASAP2020-M + C type adsorption instrument.
Fig. 1 is an X-ray diffraction pattern of C1, wherein a is an XRD pattern of C1 of the spherical double mesoporous composite material carrier, the abscissa is 2 θ, and the ordinate is intensity, and the XRD pattern a of the spherical double mesoporous composite material carrier C1 has a two-dimensional hexagonal channel structure specific to the mesoporous material, as can be seen from a small-angle spectrum peak appearing in the XRD pattern;
fig. 2A is an SEM (50 times magnification) of C1, fig. 2B is an SEM of C1 (100 times magnification), and fig. 2A and 2B show that the spherical mesoporous composite material carrier C1 is a spherical material with good dispersibility and a particle size of 30 to 60 μm;
FIG. 3 is a graph of pore size distribution of C1, the abscissa is pore size, the unit is nm, it can be seen from the graph that the pore size distribution of the spherical double mesoporous composite material carrier C1 is bimodal distribution, and the most probable pore sizes corresponding to the bimodal distribution are 1.5-15nm and 16-50nm, respectively, and the pore canal distribution is uniform;
FIG. 4 is a graph of the particle size distribution of C1, the abscissa is μm, and it can be seen that the spherical mesoporous composite material carrier C1 has a uniform particle size distribution and an average particle size of 56.9 μm.
Table 1 shows the pore structure parameters of the spherical double mesoporous composite material carrier C1 and the isobutane dehydrogenation catalyst Cat-1.
TABLE 1
Sample (I) Specific surface area (m)2/g) Pore volume (ml/g) Most probable aperture*(nm) Particle size (. mu.m)
Vector C1 220 1.4 7.2,33.3 56.9
Catalyst Cat-1 207 1.2 6.3,32.1 56.9
*: 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 sequence from left to right.
As can be seen from the data of table 1, the specific surface area and the pore volume of the spherical dual mesoporous composite support are reduced after the Pt component and the Zn component are loaded, which indicates that the Pt component and the Zn component enter the interior of the spherical dual mesoporous composite support during the loading reaction.
Comparative example 1
The carrier and the 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 spherical dual mesoporous composite carrier C1 in the process of preparing the carrier, thereby preparing the carrier D1 and the 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 there was no spray-drying step in the preparation of the isobutane dehydrogenation catalyst, and a Pt component and a Zn component were supported on the support only by the impregnation method, thereby preparing the isobutane dehydrogenation catalyst Cat-D-2.
Comparative example 3
A support and an isobutane dehydrogenation catalyst were prepared according to the method of example 1, except that the catalyst used was an oxide catalyst such as ZnO, thereby obtaining an isobutane dehydrogenation catalyst Cat-D-3.
Comparative example 4
A support 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 catalyst3)2·6H2O, addition of only 0.080gH2PtCl6·6H2And O, only loading a single Pt component on the spherical double-mesoporous composite material carrier by a co-impregnation method to prepare the isobutane dehydrogenation catalyst Cat-D-4, wherein the content of the Pt component is 0.3 wt% calculated by Pt element and the balance is the carrier on the basis of the total weight of the isobutane dehydrogenation catalyst Cat-D-4).
Example 2
This example is illustrative of an isobutane dehydrogenation catalyst and a method for preparing the same.
(1) Preparation of spherical double-mesoporous composite material carrier
Adding hexadecyl trimethyl ammonium bromide and ethyl orthosilicate into an ammonia water solution with the concentration of 25 weight percent, wherein the adding amount of the ethyl orthosilicate is 1g, and the mol ratio of ammonia to water in the ethyl orthosilicate, the hexadecyl trimethyl ammonium bromide and the ammonia water is 1: 0.5: 3.2: 140 and stirred at 90 ℃ until dissolved, then the obtained solution is filtered and washed 4 times with deionized water, and then filtered by suction to obtain a filter cake a2 of the mesoporous molecular sieve material with a two-dimensional hexagonal pore structure.
Mixing 15 wt% water glass and 12 wt% sulfuric acid solution in a weight ratio of 4:1, reacting at 40 deg.c for 1.5 hr, regulating the pH value to 2 with 98 wt% sulfuric acid, suction filtering the obtained reaction material, and washing with distilled water to sodium ion content of 0.02 wt% to obtain silica gel filter cake B2.
28g of the prepared filter cake A2 and 10g of the prepared filter cake B2 are put 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. Sealing the ball milling tank, and carrying out ball milling for 0.5 hour in the ball milling tank at the temperature of 80 ℃ to obtain 38g of solid powder; dissolving the solid powder in 12g of deionized water, and spray-drying at 250 ℃ at the rotating speed of 11000 r/min; calcining the spray-dried product in a muffle furnace at 500 ℃ for 15 hours, and removing the template agent to obtain 35g of spherical double-mesoporous composite material carrier C2 with a two-dimensional hexagonal pore channel distribution structure.
(2) Preparation of isobutane dehydrogenation catalyst
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-mesoporous composite material carrier C2 prepared in the step (1) in the mixture solution for 5 hours at 25 ℃, evaporating solvent water in the system by using a rotary evaporator to obtain a solid product, and placing the solid product in a drying oven at 120 ℃ for drying 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-2 (based on the total weight of the isobutane dehydrogenation catalyst Cat-2, 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).
Table 2 shows the pore structure parameters of the spherical double mesoporous composite material carrier C2 and the isobutane dehydrogenation catalyst Cat-2.
TABLE 2
Sample (I) Specific surface area (m)2/g) Pore volume (ml/g) Most probable aperture*(nm) Particle size (. mu.m)
Vector C2 232 1.2 5.5,31.7 55
Catalyst Cat-2 211 1 4.2,30.3 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 sequence from left to right.
As can be seen from the data of table 2, the specific surface area and the pore volume of the spherical dual mesoporous composite support are reduced after the Pt component and the Zn component are loaded, which indicates that the Pt component and the Zn component enter the interior of the spherical dual mesoporous composite support during the loading reaction.
Example 3
This example is illustrative of an isobutane dehydrogenation catalyst and a method for preparing the same.
(1) Preparation of spherical double-mesoporous composite material carrier
Adding hexadecyl trimethyl ammonium bromide and ethyl orthosilicate into an ammonia water solution with the concentration of 25 weight percent, wherein the adding amount of the ethyl orthosilicate is 1g, and the mol ratio of ammonia to water in the ethyl orthosilicate, the hexadecyl trimethyl ammonium bromide and the ammonia water is 1: 0.3: 3: 150, and stirring the mixture at 90 ℃ until the mixture is dissolved, filtering the obtained solution, washing the solution for 4 times by using deionized water, and performing suction filtration to obtain a filter cake A3 of the mesoporous molecular sieve material with the two-dimensional hexagonal pore structure.
Mixing 15 wt% water glass and 12 wt% sulfuric acid solution in the weight ratio of 6:1, contacting and reacting at 20 deg.c for 3 hr, regulating the pH value to 4 with 98 wt% sulfuric acid, suction filtering the obtained reaction material, and washing with distilled water to sodium ion content of 0.02 wt% to obtain silica gel filter cake B3.
32g of the prepared filter cake A3 and 30g of the prepared filter cake B3 are put 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. Sealing the ball milling tank, and carrying out ball milling for 10 hours in the ball milling tank at the temperature of 40 ℃ to obtain 55g of solid powder; dissolving the solid powder in 30g of deionized water, and spray-drying at 150 ℃ at the rotating speed of 13000 r/min; calcining the spray-dried product in a muffle furnace at 450 ℃ for 70 hours, and removing the template agent to obtain 53g of spherical double-mesoporous composite material carrier C3 with a two-dimensional hexagonal pore channel distribution structure.
(2) Preparation of isobutane dehydrogenation catalyst
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-mesoporous composite material carrier C3 prepared in the step (1) in the mixture solution at 25 ℃ for 5h, and then performing rotary evaporationAnd (3) evaporating solvent water in the system 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 for 6 hours in a muffle furnace at the temperature of 600 ℃ to obtain the isobutane dehydrogenation catalyst Cat-3 (based on the total weight of the isobutane dehydrogenation catalyst Cat-3, 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).
Table 3 shows the pore structure parameters of the spherical double mesoporous composite material carrier C3 and the isobutane dehydrogenation catalyst Cat-3.
TABLE 3
Sample (I) Specific surface area (m)2/g) Pore volume (ml/g) Most probable aperture*(nm) Particle size (. mu.m)
Vector C3 218 1.3 7,28.5 52.5
Catalyst Cat-3 199 0.9 5.9,25.7 52.5
*: 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 sequence from left to right.
As can be seen from the data of table 3, the specific surface area and the pore volume of the spherical dual mesoporous composite support are reduced after the Pt component and the Zn component are supported, which indicates that the Pt component and the Zn component enter the interior of the spherical dual mesoporous composite support 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 was directly fed into an Agilent 7890A gas chromatograph equipped with a hydrogen flame detector (FID) for on-line analysis, and the isobutane conversion and isobutene selectivity were obtained as shown in Table 4. 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 table 4.
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 4.
Experimental comparative examples 1 to 4
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-4 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 4.
TABLE 4
Dehydrogenation catalyst Isobutane conversion rate Selectivity to isobutene Carbon deposition amount of catalyst
Experimental example 1 Cat-1 16% 87% 1.1wt%
Experimental example 2 Cat-2 15.5% 85.3% 1.1wt%
Experimental example 3 Cat-3 15.9% 86.4% 1.2wt%
Experimental comparative example 1 Cat-D-1 11.2% 70.2% 5.3wt%
Experimental comparative example 2 Cat-D-2 11.5% 62.1% 3.4wt%
Experimental comparative example 3 Cat-D-3 7% 0% 5.8wt%
Experimental comparative example 4 Cat-D-4 6.9% 45.5% 6.8wt%
As can be seen from table 4, when the isobutane dehydrogenation catalyst prepared by using the spherical dual-mesoporous composite material carrier of the present invention is used in the reaction of preparing isobutene by isobutane dehydrogenation, a higher isobutane conversion rate and isobutene selectivity can be still obtained after 24 hours of reaction, which indicates that the isobutane dehydrogenation catalyst of the present invention has not only a better catalytic performance, but also good stability and low carbon deposition amount.
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 (14)

1. A method for preparing an isobutane dehydrogenation catalyst, characterized in that the method comprises the following steps:
(a) in the presence of a template agent, contacting tetraethoxysilane with ammonia water, and filtering a mixture obtained after the contact to obtain a mesoporous material filter cake;
(b) contacting water glass with inorganic acid, and filtering a product obtained after the contact to obtain a silica gel filter cake;
(c) mixing and ball-milling the mesoporous material filter cake and the silica gel filter cake, pulping solid powder obtained after ball-milling with water, then carrying out spray drying, and removing the template agent in the obtained product to obtain a spherical double-mesoporous composite material carrier;
(d) dipping the spherical double-mesoporous composite material carrier obtained in the step (c) in a solution containing a Pt component precursor and a Zn component precursor, and then sequentially carrying out solvent removal treatment, drying and roasting;
in the step (d), the use amounts of the spherical dual-mesoporous composite material carrier, the Pt component precursor and the Zn component precursor are such that, in the prepared isobutane dehydrogenation catalyst, based on the total weight of the isobutane dehydrogenation catalyst, the content of the carrier is 98.4-99 wt%, the content of the Pt component calculated by Pt element is 0.2-0.4 wt%, and the content of the Zn component calculated by Zn element is 0.8-1.2 wt%;
wherein the average particle size of the spherical double-mesoporous composite material carrier is 30-60 mu m, and the specific surface area is 200-650m2The 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 1.5-15nm and 16-50nm respectively.
2. The method of claim 1, wherein in the step (a), the ethyl orthosilicate, the template, ammonia in ammonia water and water are used in a molar ratio of 1: 0.1-1: 0.1-5: 100-200.
3. The method of claim 2, wherein in the step (a), the ethyl orthosilicate, the template, ammonia in ammonia water and water are used in a molar ratio of 1: 0.2-0.5: 1.5-3.5: 120-180.
4. The method of claim 1, wherein, in step (a), the templating agent is cetyltrimethylammonium bromide.
5. The method of claim 4, wherein in step (a), the conditions under which the ethyl orthosilicate is contacted with the aqueous ammonia comprise: the temperature is 25-100 ℃ and the time is 10-72 hours.
6. 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.
7. The method according to claim 1, wherein, in the step (c), the silica gel cake is used in an amount of 1 to 200 parts by weight based on 100 parts by weight of the mesoporous material cake.
8. The method according to claim 7, wherein, in the step (c), the silica gel cake is used in an amount of 50 to 150 parts by weight based on 100 parts by weight of the mesoporous material cake.
9. An isobutane dehydrogenation catalyst produced by the process of any one of claims 1-8.
10. An isobutane dehydrogenation catalyst according to claim 9, wherein said isobutane dehydrogenation catalyst comprises a support and a Pt component and a Zn component supported on said support, wherein said support is a spherical double mesoporous composite support containing a mesoporous molecular sieve material having a two-dimensional hexagonal pore distribution structure.
11. Isobutane dehydrogenation catalyst according to claim 9, wherein the average particle diameter of the isobutane dehydrogenation catalyst is between 30 and 60 μm, the specific surface area is 180-400m2The 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 1.8-12nm and 18-40nm respectively.
12. A method for preparing isobutene by dehydrogenating isobutane, comprising the following steps: isobutane is subjected to a dehydrogenation reaction in the presence of a catalyst and hydrogen, characterized in that said catalyst is an isobutane dehydrogenation catalyst according to any one of claims 9-11.
13. The process according to claim 12, wherein the molar ratio of the amount of isobutane to the amount of hydrogen is between 0.5 and 1.5: 1.
14. the method of claim 13, wherein the dehydrogenation reaction conditions comprise: 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
CN201810475363.9A 2018-05-17 2018-05-17 Isobutane dehydrogenation catalyst, preparation method thereof and method for preparing isobutene through isobutane dehydrogenation Active CN110496632B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201810475363.9A CN110496632B (en) 2018-05-17 2018-05-17 Isobutane dehydrogenation catalyst, preparation method thereof and method for preparing isobutene through isobutane dehydrogenation

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201810475363.9A CN110496632B (en) 2018-05-17 2018-05-17 Isobutane dehydrogenation catalyst, preparation method thereof and method for preparing isobutene through isobutane dehydrogenation

Publications (2)

Publication Number Publication Date
CN110496632A CN110496632A (en) 2019-11-26
CN110496632B true CN110496632B (en) 2021-12-21

Family

ID=68584596

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201810475363.9A Active CN110496632B (en) 2018-05-17 2018-05-17 Isobutane dehydrogenation catalyst, preparation method thereof and method for preparing isobutene through isobutane dehydrogenation

Country Status (1)

Country Link
CN (1) CN110496632B (en)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103420769A (en) * 2012-05-16 2013-12-04 中国石油化工股份有限公司 Method for preparing low-carbon olefin from low-carbon alkane through dehydrogenation
CN104248970A (en) * 2013-06-28 2014-12-31 中国石油化工股份有限公司 Supported phosphotungstic acid catalyst, preparation method and application thereof, and preparation method of cyclohexanone glycerol ketal
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

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA2752409C (en) * 2011-09-19 2018-07-03 Nova Chemicals Corporation Membrane-supported catalysts and the process of oxidative dehydrogenation of ethane using the same

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103420769A (en) * 2012-05-16 2013-12-04 中国石油化工股份有限公司 Method for preparing low-carbon olefin from low-carbon alkane through dehydrogenation
CN104248970A (en) * 2013-06-28 2014-12-31 中国石油化工股份有限公司 Supported phosphotungstic acid catalyst, preparation method and application thereof, and preparation method of cyclohexanone glycerol ketal
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

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Zn-modified MCM-41 as support for Pt catalysts;J. Silvestre-Albero等;《Applied Catalysis A: General》;20080829;第351卷;第16-23页 *

Also Published As

Publication number Publication date
CN110496632A (en) 2019-11-26

Similar Documents

Publication Publication Date Title
CN109746032B (en) Propane dehydrogenation catalyst, preparation method thereof and method for preparing propylene by propane dehydrogenation
CN108722402B (en) A kind of method of propane dehydrogenation catalyst and preparation method thereof and preparing propylene by dehydrogenating propane
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
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
CN111085208A (en) Non-noble metal low-carbon alkane dehydrogenation catalyst with spherical double-mesoporous composite carrier and preparation method and application thereof
CN109382131B (en) The method of propane dehydrogenation catalyst and preparation method thereof and preparing propylene by dehydrogenating propane
CN110614108B (en) Isobutane dehydrogenation catalyst with carrier being mesoporous molecular sieve with three-dimensional cage-shaped pore channel distribution structure, preparation method and application
CN110496632B (en) Isobutane dehydrogenation catalyst, preparation method thereof and method for preparing isobutene through isobutane dehydrogenation
CN110732341A (en) Isobutane dehydrogenation catalyst with spherical aluminum-containing double mesoporous molecular sieve silica gel composite as carrier and preparation method and application thereof
CN110496635B (en) Isobutane dehydrogenation catalyst, preparation method thereof and method for preparing isobutene through isobutane dehydrogenation
CN110614097A (en) Isobutane dehydrogenation catalyst with carrier being composite material containing silica gel and hexagonal mesoporous material, and preparation method and application thereof
CN110496630B (en) Isobutane dehydrogenation catalyst, preparation method thereof and method for preparing isobutene through isobutane dehydrogenation
CN110813285A (en) Isobutane dehydrogenation catalyst with spherical surface-surrounded mesoporous material silica gel composite material as carrier and preparation method and application thereof
CN110496637B (en) Isobutane dehydrogenation catalyst, preparation method thereof and method for preparing isobutene through isobutane dehydrogenation
CN110614118A (en) Isobutane dehydrogenation catalyst with three-hole sepiolite spherical mesoporous composite material as carrier and preparation method and application thereof
CN110614107A (en) Isobutane dehydrogenation catalyst with carrier of hollow spherical mesoporous molecular sieve silica gel composite material and preparation method and application thereof
CN110496633B (en) Isobutane dehydrogenation catalyst, preparation method thereof and method for preparing isobutene through isobutane dehydrogenation
CN110496634B (en) Isobutane dehydrogenation catalyst, preparation method thereof and method for preparing isobutene through isobutane dehydrogenation
CN112221490A (en) Isobutane dehydrogenation catalyst with modified hexagonal mesoporous material containing Mg and/or Ti components as carrier and preparation method and application thereof
CN109382133B (en) The method of propane dehydrogenation catalyst and preparation method thereof and preparing propylene by dehydrogenating propane
CN110614106A (en) Isobutane dehydrogenation catalyst with spherical double-mesoporous illite composite material as carrier, preparation method and application
CN111085207A (en) Non-noble metal low-carbon alkane dehydrogenation catalyst with spherical three-mesoporous composite carrier and preparation method and application thereof
CN110614110A (en) Isobutane dehydrogenation catalyst with eggshell-shaped mesoporous material silica gel composite material as carrier, and preparation method and application thereof
CN110614115A (en) Isobutane dehydrogenation catalyst with spherical tri-mesoporous 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
GR01 Patent grant
GR01 Patent grant