CN114477228A - SAPO-34 molecular sieve, and preparation method and application thereof - Google Patents

SAPO-34 molecular sieve, and preparation method and application thereof Download PDF

Info

Publication number
CN114477228A
CN114477228A CN202011264569.0A CN202011264569A CN114477228A CN 114477228 A CN114477228 A CN 114477228A CN 202011264569 A CN202011264569 A CN 202011264569A CN 114477228 A CN114477228 A CN 114477228A
Authority
CN
China
Prior art keywords
molecular sieve
sapo
acid
source
aluminum
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.)
Granted
Application number
CN202011264569.0A
Other languages
Chinese (zh)
Other versions
CN114477228B (en
Inventor
郭磊
朱伟平
邢爱华
郭智慧
李飞
袁德林
刘华
张冰
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.)
China Energy Investment Corp Ltd
National Institute of Clean and Low Carbon Energy
Original Assignee
China Energy Investment Corp Ltd
National Institute of Clean and Low Carbon Energy
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 China Energy Investment Corp Ltd, National Institute of Clean and Low Carbon Energy filed Critical China Energy Investment Corp Ltd
Priority to CN202011264569.0A priority Critical patent/CN114477228B/en
Publication of CN114477228A publication Critical patent/CN114477228A/en
Application granted granted Critical
Publication of CN114477228B publication Critical patent/CN114477228B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B39/00—Compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites; Their preparation; After-treatment, e.g. ion-exchange or dealumination
    • C01B39/54—Phosphates, e.g. APO or SAPO compounds
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J29/00—Catalysts comprising molecular sieves
    • B01J29/82—Phosphates
    • B01J29/84—Aluminophosphates containing other elements, e.g. metals, boron
    • B01J29/85—Silicoaluminophosphates (SAPO compounds)
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B37/00—Compounds having molecular sieve properties but not having base-exchange properties
    • C01B37/06—Aluminophosphates containing other elements, e.g. metals, boron
    • C01B37/08—Silicoaluminophosphates (SAPO compounds), e.g. CoSAPO
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C1/00—Preparation of hydrocarbons from one or more compounds, none of them being a hydrocarbon
    • C07C1/20—Preparation of hydrocarbons from one or more compounds, none of them being a hydrocarbon starting from organic compounds containing only oxygen atoms as heteroatoms
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2002/00—Crystal-structural characteristics
    • C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
    • C01P2002/72—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by d-values or two theta-values, e.g. as X-ray diagram
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/01—Particle morphology depicted by an image
    • C01P2004/03—Particle morphology depicted by an image obtained by SEM
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/30—Particle morphology extending in three dimensions
    • C01P2004/32—Spheres
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/60—Particles characterised by their size
    • C01P2004/61—Micrometer sized, i.e. from 1-100 micrometer
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2006/00—Physical properties of inorganic compounds
    • C01P2006/12—Surface area
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2006/00—Physical properties of inorganic compounds
    • C01P2006/14—Pore volume
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00—Technologies relating to chemical industry
    • Y02P20/50—Improvements relating to the production of bulk chemicals
    • Y02P20/52—Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts

Abstract

The invention relates to the field of catalysts for preparing olefin from methanol, and discloses a SAPO-34 molecular sieve, and a preparation method and application thereof. The method comprises the following steps: mixing an aluminum source, a phosphorus source, a silicon source, a template agent, water and an auxiliary agent, carrying out crystallization reaction, and drying and roasting the obtained solid product, wherein the auxiliary agent is heteropoly acid and/or heteropoly acid metal salt. The obtained SAPO-34 molecular sieve can effectively shorten the diffusion of product molecules in a crystal pore channel and inhibit the generation of carbon deposition, and has excellent catalytic performance when used for the reaction of preparing olefin from methanol, long service life of the catalyst and good selectivity of ethylene and propylene.

Description

SAPO-34 molecular sieve, and preparation method and application thereof
Technical Field
The invention relates to the field of catalysts for preparing olefin from methanol, in particular to a preparation method of an SAPO-34 molecular sieve, the SAPO-34 molecular sieve prepared by the method and application of the SAPO-34 molecular sieve in preparing olefin from methanol.
Background
Silicoaluminophosphate (SAPO-n) molecular sieves were a new type of molecular sieve developed by united states combined carbides (UCC) in 1984. Because SAPO-34 has a medium-strength acid center, a unique pore structure, abundant micropores and a larger specific surface area, the SAPO-34 molecular sieve has wide application in the fields of catalysis, automobile exhaust purification, membrane separation and functional materials, and particularly shows high activity and selectivity in the catalysis of methanol-to-olefin (MTO), and thus, as a catalyst, the SAPO-34 molecular sieve has been successfully applied to the MTO process. However, the SAPO-34 molecular sieve belongs to an eight-membered ring small pore molecular sieve, and is very easy to be deactivated by carbon deposition in the methanol conversion process, so that the improvement of the selectivity of the catalyst and the prolongation of the service life of the catalyst are important points in the research and development of the SAPO-34 molecular sieve.
At present, the grain size of SAPO-34 molecular sieve used industrially is generally micron-sized, but the micron-sized molecular sieve has the defects of overlarge internal diffusion resistance, insufficient catalytic activity and the like. The nano SAPO-34 molecular sieve has extremely small crystal grains, so that the external surface area is obviously increased, the pore canals in the crystal are shortened, the exposed pore openings are increased, the diffusion of reactants and products is facilitated, the reaction activity and the product selectivity are improved, the reaction depth is effectively inhibited, and the carbon deposition amount is reduced.
CN107055563A discloses a nano needle-shaped SAPO-34 molecular sieve and its preparation and application, adopting a gel deflocculation hydrothermal synthesis method, adding excessive HF solution into gel obtained by mixing, heating and stirring an aluminum source, a phosphorus source, a silicon source, deionized water and a template agent, deflocculating the gel into a solution, and then carrying out hydrothermal crystallization, wherein the prepared nano needle-shaped SAPO-34 molecular sieve has a small diameter of about 20-50nm, but the size of the SAPO-34 molecular sieve is too small to be separated in industrial production, and fluorine ions have strong corrosivity and toxicity, thereby limiting the application of the method in industry.
CN104229829A discloses a method for preparing small-grained SAPO-34 molecular sieves, which promotes the synthesis of small-grained SAPO-34 molecular sieves by adding defect-structure seeds. Although the small-crystal SAPO-34 molecular sieve synthesized by the method can improve the yield and the anti-coking performance of the diene, the catalytic life is short (30-50min), and the method has more synthesis steps and is too complex, thereby being not beneficial to realizing large-scale production.
CN103011188A discloses a spherical or flaky nano SAPO-34 molecular sieve and a synthesis method thereof, the method adopts microwave heating, and by controlling the microwave synthesis conditions, although the nano spherical or flaky SAPO-34 molecular sieve can be obtained, the grain size of the spherical nano SAPO-34 molecular sieve is below 30nm, the thickness of the flaky nano SAPO-34 molecular sieve is below 70nm, the grain size is small, the separation is difficult in industrial production, and the microwave synthesis method is not mature enough in industry, the synthesis cost is high, and the large-scale application in industrial production is difficult.
Disclosure of Invention
The invention aims to overcome the problems of difficult separation of a nano SAPO-34 molecular sieve, low product selectivity, easy carbon deposition generation and short catalytic life in the reaction of preparing olefin from methanol in the prior art, and provides the SAPO-34 molecular sieve and a preparation method and application thereof, wherein the SAPO-34 molecular sieve has a micron spherical structure formed by tightly and alternately stacking a plurality of nano cubic SAPO-34 molecular sieve grains.
In order to achieve the above object, a first aspect of the present invention provides a method for preparing a SAPO-34 molecular sieve, comprising: mixing an aluminum source, a phosphorus source, a silicon source, a template agent, water and an auxiliary agent, carrying out crystallization reaction, and drying and roasting the obtained solid product, wherein the auxiliary agent is heteropoly acid and/or heteropoly acid metal salt.
In a second aspect, the invention provides a SAPO-34 molecular sieve prepared by the method as described above.
In a third aspect, the invention provides an application of the SAPO-34 molecular sieve in the preparation of olefins from methanol.
Through the technical scheme, the invention has the following advantages:
(1) the SAPO-34 molecular sieve can effectively shorten the diffusion of product molecules in a crystal pore canal and inhibit the generation of carbon deposition, has excellent catalytic performance when used for the reaction of preparing olefin from methanol, and has long service life and good selectivity of ethylene and propylene;
(2) the SAPO-34 molecular sieve has a micron spherical structure formed by tightly and alternately stacking a plurality of nano cubic crystal grains, not only can retain the advantages of the nano crystal grains in the aspect of reducing internal diffusion, but also can utilize the advantage of larger size of the aggregated micron spherical structure, so that the molecular sieve product is easy to separate, and the production cost of the molecular sieve is effectively reduced;
(3) the method provided by the invention uses heteropoly acid and/or metal heteropoly acid salt as an auxiliary agent, and as heteropoly acid (salt) anions have larger volume, higher symmetry and lower charge density and consist of a plurality of transition metal particles which are easy to transmit electrons, the heteropoly acid (salt) anions can effectively interact with Si/Al/P in the mixed gel synthesized by the molecular sieve, thereby influencing and even changing the microstructure of the final molecular sieve and being beneficial to forming a micro-spherical structure formed by tightly and alternately stacking a plurality of nano-cubic crystal grains.
Drawings
FIG. 1 is an X-ray diffraction (XRD) pattern of a SAPO-34 molecular sieve;
FIG. 2 is a Scanning Electron Microscope (SEM) image of the SAPO-34 molecular sieve prepared in example 1, at a magnification of 40K;
FIG. 3 is a Scanning Electron Microscope (SEM) image of a SAPO-34 molecular sieve prepared as in example 1, at a magnification of 5K;
FIG. 4 is a Scanning Electron Microscope (SEM) image of the SAPO-34 molecular sieve prepared in example 2, at a magnification of 40K;
FIG. 5 is a Scanning Electron Microscope (SEM) image of a SAPO-34 molecular sieve prepared according to comparative example 1, at a magnification of 5K;
FIG. 6 is a Scanning Electron Microscope (SEM) image of SAPO-34 molecular sieve prepared according to comparative example 2, at 40K magnification.
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.
The invention provides a preparation method of a SAPO-34 molecular sieve, which is characterized by comprising the following steps: mixing an aluminum source, a phosphorus source, a silicon source, a template agent, water and an auxiliary agent, carrying out crystallization reaction, and drying and roasting the obtained solid product, wherein the auxiliary agent is heteropoly acid and/or heteropoly acid metal salt.
In some embodiments of the invention, the heteropolyacid is selected from one or more of silicotungstic acid, phosphotungstic acid, silicomolybdic acid and phosphomolybdic acid, preferably is silicotungstic acid and/or phosphotungstic acid, more preferably is phosphotungstic acid.
In some embodiments of the invention, the metal heteropolyacid salt is selected from Co1.5PW12O40、Ni1.5PW12O40、Zn1.5PW12O40、Co1.5PW18O62、Ni1.5PW18O62、Co1.5PMo12O40、Ni1.5PMo12O40、Zn1.5PMo12O40、Co1.5PMo18O62Preferably Co, preferably1.5PW12O40、Ni1.5PW12O40And Zn1.5PW12O40More preferably Co1.5PW12O40And/or Ni1.5PW12O40。
The heteropoly acid and the metal heteropoly acid salt can be prepared by using a commercial product or a conventional method, and the specific preparation method is well known by the technical personnel in the field, can be carried out by referring to the prior art, and is not described again. In the invention, heteropoly acid and/or metal heteropoly acid salt is used as an auxiliary agent, and as heteropoly acid (salt) anions have larger volume, higher symmetry and lower charge density and consist of a plurality of transition metal particles which are easy to transmit electrons, the heteropoly acid (salt) anions can effectively interact with Si/Al/P in mixed gel synthesized by a molecular sieve, thereby influencing and even changing the micro-morphology of the final molecular sieve, being beneficial to forming a micro-spherical structure formed by tightly and alternately stacking a plurality of nano-cubic crystal grains, effectively shortening the diffusion of product molecules in crystal pore channels and inhibiting the generation of carbon deposition.
In some embodiments of the invention, SAPO-5, AlPO are prevented for the synthesis of a pure phase SAPO-34 molecular sieve4-34, preferably said aluminium source is Al2O3In terms of P, the phosphorus source is2O5The silicon source is SiO2The aluminum source, the phosphorus source, the silicon source, the template agent, the water and the auxiliary agent are in a molar ratio of 1: (0.7-3): (0.05-0.7): (1-6): (5-150): (0.0025-0.5).
In some embodiments of the present invention, preferably, the aluminum source is Al2O3In terms of P, the phosphorus source is2O5The silicon source is SiO2The aluminum source, the phosphorus source, the silicon source, the template agent, the water and the auxiliary agent are in a molar ratio of 1: (0.8-2): (0.1-0.6): (1.5-5): (10-120): (0.005-0.1).
In some embodiments of the present invention, the aluminum source, the phosphorous source, and the silicon source may be materials commonly used in the art for preparing SAPO-34 molecular sieves.
In some embodiments of the present invention, for better dissolution in the gel, interaction with the auxiliary agent preferably, the aluminum source is selected from one or more of pseudoboehmite, aluminum sol and aluminum isopropoxide, more preferably, the aluminum source is selected from pseudoboehmite and/or aluminum isopropoxide.
In some embodiments of the invention, for better dissolution in the gel, interaction with the adjuvant preferably the source of phosphorus is selected from one or more of phosphoric acid, phosphorous acid, phosphate salts and diammonium phosphate, more preferably the source of phosphorus is selected from phosphoric acid and/or phosphorous acid.
In some embodiments of the present invention, for better dissolution in the gel, interaction with the adjuvant preferably the silicon source is selected from one or more of silica sol, ethyl orthosilicate, active silica and aminopropyltrimethoxysilane, more preferably the silicon source is selected from silica sol and/or ethyl orthosilicate.
In some embodiments of the present invention, preferably, the template is selected from one or more of tetraethylammonium hydroxide, diisopropylamine, morpholine, triethylamine, diethylamine, N-diisopropylethylamine, cyclohexylamine, and N-butylamine, and in order to obtain a SAPO-34 molecular sieve with a smaller particle size and a better spherical structure, preferably, the template is tetraethylammonium hydroxide and/or triethylamine.
In some embodiments of the present invention, preferably, the water is deionized water.
In some embodiments of the present invention, in order to improve the sphericity of the SAPO-34 molecular sieve and its catalytic performance in MTO reaction and avoid the formation of heterogeneous phase, preferably, the mixing process comprises: dissolving heteropoly acid in water to obtain a solution, and adding the solution, an aluminum source, a silicon source and a phosphorus source into a template agent in sequence. The above process fully ensures the dissolution of the heteropoly acid, and simultaneously utilizes the acid-base reaction of the heteropoly acid and the alkaline template agent, which is more beneficial to the interaction of the heteropoly acid and the Al/Si/P source, thereby improving the sphericity of the SAPO-34 molecular sieve.
In some embodiments of the present invention, preferably, the crystallization reaction is performed in a closed system, for example, a closed reaction vessel containing a polytetrafluoroethylene lining.
In some embodiments of the present invention, preferably, the crystallization reaction is performed at a temperature of 180 ℃ and a temperature of 210 ℃ for 12-96 h. The pressure of the crystallization reaction may be the autogenous pressure of the system.
In some embodiments of the present invention, more preferably, the crystallization reaction is performed at a temperature of 190 ℃ to 200 ℃ for 24 to 48 hours.
In some embodiments of the present invention, it is further preferred that after the crystallization reaction is finished, the product of the crystallization reaction is subjected to solid-liquid separation, and the obtained solid product is washed before being dried. The solid-liquid separation method may be a solid-liquid separation method commonly used in the art, and for example, centrifugal separation may be employed; the washing can be carried out for multiple times, and the used washing liquid can be deionized water.
In the present invention, the drying conditions may be those commonly used in the art as long as the solid product can be dried.
In some embodiments of the invention, it is preferred that the temperature of the drying is 80 to 160 ℃, preferably 90 to 150 ℃; the time is 6-36h, preferably 12-24 h.
In some embodiments of the present invention, the calcination is primarily intended to remove materials, such as templating agents, remaining in the channels of the molecular sieve during the synthesis of the SAPO-34 molecular sieve. The calcination is generally carried out in an air atmosphere.
In some embodiments of the present invention, it is preferable that the calcination temperature is 500-.
In some embodiments of the present invention, it is more preferable that the calcination temperature is 550-.
In a second aspect, the invention provides a SAPO-34 molecular sieve prepared by the method as described above. The SAPO-34 molecular sieve has a spherical structure with the diameter of 1-2 mu m, which is formed by tightly staggered packing of cubic crystal grains with the grain diameter of 50-200 nm. As mentioned above, the SAPO-34 molecular sieve of the invention has a micro-spherical structure formed by a plurality of nano-cubic crystal grains which are closely staggered and stacked, as shown in the SEM electron microscope observation and electron microscope photographs of FIGS. 2 to 4.
In some embodiments of the present invention, it is preferred that the total specific surface area of the SAPO-34 molecular sieve is 600-700m2Per g, preferably 650-698m2(ii)/g, more preferably 672-698m2/g。
In some embodiments of the present invention, it is preferred that the SAPO-34 molecular sieve have a micropore specific surface area of 510-650m2(iv)/g, preferably 550-620m2(iv)/g, more preferably 598-2/g。
In some embodiments of the present invention, it is preferred that the total pore volume of the SAPO-34 molecular sieve be 0.3-0.4cm3In g, preferably from 0.35 to 0.38cm3Per g, more preferably 0.36 to 0.38cm3/g。
In some embodiments of the present invention, it is preferred that the SAPO-34 molecular sieve have a micropore volume of 0.22 to 0.25cm3In g, preferably from 0.23 to 0.25cm3Per g, more preferably 0.23 to 0.24cm3/g。
In a third aspect, the invention provides an application of the SAPO-34 molecular sieve in the preparation of olefins from methanol.
The evaluation of the reaction for producing olefins from methanol can be carried out on a laboratory apparatus. The device can comprise a public gas, a pressure reducing valve, a feeding and discharging pipeline, a material mass flow meter, a feeding pump, a fixed bed reaction tube and the like. The reaction conditions of the methanol-to-olefin are normal pressure and the temperature is 400-600 ℃.
The evaluation process comprises the following steps: tabletting and screening the SAPO-34 molecular sieve to obtain 20-40-mesh particles, and filling the particles into a fixed bed reactor; first, N at 14mL/min2Activating under atmosphere at 500 deg.C, and adding methanol and N2(the mass fraction of the methanol is 80%) is fed into a reactor for the reaction of preparing the olefin from the methanol, wherein N is2The flow rate is 14mL/min, the normal pressure, the reaction temperature is 400 ℃ and 600 ℃, and the WHSV (weight hourly space velocity) is 3.5h-1。
The reaction product was analyzed with a model 7890B gas chromatograph, made by Agilent, equipped with HP-PLOT Al2O3KCl column (50m × 0.53mm × 15 μm) (for separating C1-C6 hydrocarbons), HP-PLOT Q column (30m × 320 μm × 20 μm) (for separating alcohols and ethers), Hayesep Q column and X molecular sieve column (for separating CO and CO)2、H2、N2Equal permanent gas), 2 FID detectors and 1 TCD detector.
The conversion rate of methanol and the selectivity of low-carbon olefin are used as evaluation indexes of the performance of the molecular sieve catalyst. Conversion of methanol (X), product selectivity (S)iBased on the carbon-based selectivity in terms of moles of carbon) are calculated from the following equations, respectively:
Figure BDA0002775700620000081
Figure BDA0002775700620000082
wherein, the conversion rate of X-methanol; s-product selectivity; i-the species entering the reactor; o-species of the production reactor; cxHy-olefins (x-number of carbon atoms of the hydrocarbon species, y-number of hydrogen atoms of the hydrocarbon species); m-corresponding substance CxHyThe number of carbon atoms of (a); n-the number of moles of the corresponding substance; MeOH-methanol; DME-dimethyl ether.
The present invention will be described in detail below by way of examples. In the following examples and comparative examples, the starting materials used were commercially available.
X-ray diffraction analysis (XRD) of the SAPO-34 molecular sieve so prepared by means of an X-ray diffractometer, model D/max-2600/pc, available from Rigaku;
the morphology of the prepared SAPO-34 molecular sieve is measured by SEM measurement and observation. The model of the SEM scanning electron microscope is Nova Nano SEM 450, the accelerating voltage is 20kV to 30kV, the resolution limit is about 1.2nm, and the magnification is 25 to 200K times;
pore structure of SAPO-34 molecular sieve is passed through low-temperature N2Physical adsorption characterization assay, the instrument is a Micromeritics ASAP 2020 adsorption apparatus (USA). Measuring dead volume of sample tube by using He as inert gas and nitrogen as adsorbentThe sample pore structure properties were measured. The specific surface area was calculated by the BET formula, and the specific surface area and volume of micropores were calculated by the t-plot method.
Example 1
Dissolving 1.50g phosphotungstic acid in 16.52g deionized water, dripping into 61.05g tetraethylammonium hydroxide, stirring at room temperature for 1 hour, adding 8.00g pseudo-boehmite, stirring uniformly, and adding silica Sol (SiO)2 Content 30 wt%) 6.20g, stirring for 1 hour, adding 11.95g of phosphoric acid (concentration 85 wt%) dropwise, stirring for 2 hours, charging the solution into a reaction kettle with polytetrafluoroethylene lining, and performing hydrothermal crystallization at 200 ℃ for 36 hours. And (3) centrifugally washing, filtering and drying the obtained product by deionized water, roasting the product for 6 hours at 650 ℃ in an air atmosphere to obtain the SAPO-34 molecular sieve, performing X-ray diffraction analysis, wherein an XRD spectrogram is shown as figure 1, performing SEM electron microscope observation, wherein the microstructure is shown as figures 2 and 3, and the SAPO-34 molecular sieve is of a spherical structure formed by tightly and alternately stacking nanocube grains and has the diameter of 1 mu m. The molecular sieve obtained is designated as S1.
Example 2
2.00g of Co1.5PW12O40Dissolving in 12.00g deionized water, adding dropwise into 61.05g tetraethylammonium hydroxide, stirring at room temperature for 1 hr, adding 8.00g pseudoboehmite, stirring well, and adding silica Sol (SiO)2 Content 30 wt%) 6.20g, stirring for 1 hour, adding dropwise 11.95g of phosphoric acid (concentration 85 wt%), stirring for 2 hours, charging the solution into a reaction kettle with polytetrafluoroethylene lining, and performing hydrothermal crystallization at 190 ℃ for 48 hours. And (3) centrifugally washing, filtering and drying the obtained product by deionized water, roasting the product for 6 hours at 650 ℃ in an air atmosphere to obtain the SAPO-34 molecular sieve, performing X-ray diffraction analysis, wherein an XRD spectrogram is shown in figure 1, performing SEM electron microscope observation, wherein the microstructure is shown in figure 4, and the SAPO-34 molecular sieve is of a spherical structure formed by tightly staggered nano cubic crystal grains and has the diameter of 2 microns. The molecular sieve obtained is designated as S2.
Example 3
4.00g of Ni1.5PW12O40Dissolved in 35.62g of deionized water and added dropwise to 58.50g of tetraethyl hydrogenAdding ammonium oxide, stirring at room temperature for 1 hr, adding aluminum isopropoxide 5.00g, stirring, and adding silica Sol (SiO)2 Content 30 wt%) 2.94g, stirring for 1 hour, adding 8.46g of phosphoric acid (concentration 85 wt%) dropwise, stirring for 2 hours, charging the solution into a reaction kettle with polytetrafluoroethylene lining, and performing hydrothermal crystallization at 200 ℃ for 24 hours. And (3) centrifugally washing, filtering and drying the obtained product by deionized water, roasting the product for 6 hours at 650 ℃ in an air atmosphere to obtain the SAPO-34 molecular sieve, and performing X-ray diffraction analysis, wherein an XRD spectrogram is shown in figure 1, SEM electron microscope observation is performed, the microstructure of the SAPO-34 molecular sieve is similar to that of figure 2, and the SAPO-34 molecular sieve has a spherical structure formed by tightly staggered and stacked nanocube grains, and the diameter of the SAPO-34 molecular sieve is 2 microns. The molecular sieve obtained is designated as S3.
Example 4
3.00g of Ni1.5PW12O40Dissolving in 18.75g of deionized water, dropwise adding into morpholine, stirring at room temperature for 1 hour, adding 5.00g of aluminum isopropoxide, stirring uniformly, adding 2.80g of tetraethoxysilane, stirring for 1 hour, dropwise adding 6.76g of phosphoric acid (the concentration is 85 wt%), stirring for 2 hours, then filling the solution into a reaction kettle with a polytetrafluoroethylene lining, and performing hydrothermal crystallization at 200 ℃ for 48 hours. And (3) centrifugally washing, filtering and drying the obtained product by deionized water, roasting the product for 6 hours at 650 ℃ in an air atmosphere to obtain the SAPO-34 molecular sieve, and performing X-ray diffraction analysis, wherein an XRD spectrogram is shown in figure 1, SEM electron microscope observation is performed, the microstructure of the SAPO-34 molecular sieve is similar to that of figure 2, and the SAPO-34 molecular sieve has a spherical structure formed by tightly staggered and stacked nanocube grains, and the diameter of the SAPO-34 molecular sieve is 1.5 mu m. The molecular sieve obtained is designated as S4.
Example 5
Dissolving 5.85g phosphotungstic acid in 16.52g deionized water, dripping into 61.05g tetraethylammonium hydroxide, adding 12.33g triethylamine, stirring at room temperature for 1 hour, adding 8.00g pseudo-boehmite, stirring uniformly, adding silica Sol (SiO)2 Content 30 wt%) 6.50g, stirring for 1 hour, adding dropwise 11.95g of phosphoric acid (concentration 85 wt%), stirring for 2 hours, charging the solution into a reaction kettle with polytetrafluoroethylene lining, and performing hydrothermal crystallization at 180 ℃ for 48 hours. The resulting product is deionizedAnd (2) after water centrifugal washing, filtering and drying, roasting for 6 hours at 650 ℃ in an air atmosphere to obtain the SAPO-34 molecular sieve, and performing X-ray diffraction analysis, wherein an XRD spectrogram is shown in figure 1, SEM electron microscope observation is performed, the microstructure is similar to that in figure 2, the SAPO-34 molecular sieve has a spherical structure formed by tightly staggered nano cubic crystal grains, and the diameter is 1 mu m. The molecular sieve obtained is designated as S5.
Comparative example 1
10.00g of pseudo-boehmite, 14.88g of phosphoric acid (85 wt% in concentration) and 47.23g of deionized water were mixed and stirred, and after stirring for 1 hour, silica Sol (SiO) was added dropwise2Content of 30 wt%) 7.71g, adding 19.65g of template triethylamine after stirring uniformly, continuing stirring for 1h, and aging for 2h at room temperature. The molar ratio of each component in the obtained mixture is as follows: 3.0TEA:0.6SiO2:1.0Al2O3:1.0P2O5:50H2And O. And (2) putting the gel into a reaction kettle with a polytetrafluoroethylene lining, carrying out hydrothermal crystallization at 200 ℃ for 48 hours, carrying out centrifugal washing on the obtained product by deionized water, filtering, drying, roasting at 550 ℃ for 8 hours in an air atmosphere to obtain the SAPO-34 molecular sieve, carrying out X-ray diffraction analysis, carrying out SEM electron microscope observation, wherein the microstructure is shown in figure 5, the SAPO-34 molecular sieve has a cubic morphology, and the size of cubic grains is 8-11 microns. The molecular sieve obtained is designated as D1.
Comparative example 2
Adding 8.00g of pseudo-boehmite into 61.05g of tetraethylammonium hydroxide, stirring uniformly, and adding silica Sol (SiO)2 Content 30 wt%) 6.20g, stirring for 1 hour, adding dropwise 11.95g of phosphoric acid (concentration 85 wt%), stirring for 2 hours, charging the solution into a reaction kettle with polytetrafluoroethylene lining, and performing hydrothermal crystallization at 200 ℃ for 24 hours. And (3) centrifugally washing, filtering and drying the obtained product by deionized water, roasting the product for 6 hours at 650 ℃ in an air atmosphere to obtain the SAPO-34 molecular sieve, and performing X-ray diffraction analysis, wherein an XRD spectrogram is shown in figure 1, SEM electron microscope observation is performed, the microstructure is shown in figure 6, the SAPO-34 molecular sieve has a cubic morphology, and the size of cubic crystal grains is 500nm-1 mu m. The molecular sieve obtained is designated as D2.
Test example 1
The results of nitrogen physisorption tests carried out on S1-S5 and D1 and D2 are shown in Table 1.
TABLE 1
Figure BDA0002775700620000121
Test example 2
The reaction evaluations of methanol to olefins were carried out for each of S1 to S5, D1 and D2 using a fixed bed catalytic reaction evaluation apparatus. The evaluation process was as follows, and the evaluation results are shown in Table 2.
Weighing 0.8 g of molecular sieve, filling the molecular sieve into a fixed bed reactor, introducing nitrogen at 500 ℃ for activation for 0.5h, cooling to 450 ℃, mixing a raw material methanol solution after passing through a flow metering pump under the carrying of carrier gas-nitrogen, feeding the mixture into a preheating furnace, vaporizing the mixture into gas in the preheating furnace, and feeding the gas into the reactor for reaction, wherein the nitrogen flow rate is 14mL/min, and the methanol space velocity is 3.50h-1。
TABLE 2
Figure BDA0002775700620000131
Note:1service life: the time for which the conversion rate of methanol is more than or equal to 99 percent;
2product selectivity: analysis of the products obtained at the highest selectivity of the ethylene + propylene products at 100% conversion of methanol.
As can be seen from the results of the examples, the comparative examples and tables 1 and 2, the SAPO-34 molecular sieve of the invention has a micron spherical structure formed by closely staggered packing a plurality of nano-cubic grains, and the specific surface area is obviously improved compared with the conventionally synthesized cubic SAPO-34 molecular sieve. The SAPO-34 molecular sieve can effectively shorten the diffusion of product molecules in a crystal pore channel and inhibit the generation of carbon deposit, and has excellent catalytic performance when used for the reaction of preparing olefin from methanol, long service life of the catalyst and good selectivity of ethylene and propylene.
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 various technical features being combined 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 (10)

1. A method for preparing SAPO-34 molecular sieve, which is characterized by comprising the following steps: mixing an aluminum source, a phosphorus source, a silicon source, a template agent, water and an auxiliary agent, carrying out crystallization reaction, and drying and roasting the obtained solid product, wherein the auxiliary agent is heteropoly acid and/or heteropoly acid metal salt.
2. The method of claim 2 wherein the aluminum source is Al2O3In terms of P, the phosphorus source is2O5The silicon source is SiO2The aluminum source, the phosphorus source, the silicon source, the template agent, the water and the auxiliary agent are in a molar ratio of 1: (0.7-3): (0.05-0.7): (1-6): (5-150): (0.0025-0.5), preferably 1: (0.8-2): (0.1-0.6): (1.5-5): (10-120): (0.005-0.1).
3. The production method according to claim 1 or 2, wherein the heteropolyacid is selected from one or more of silicotungstic acid, phosphotungstic acid, silicomolybdic acid and phosphomolybdic acid, preferably silicotungstic acid and/or phosphotungstic acid, more preferably phosphotungstic acid;
preferably, the metal heteropolyacid salt is selected from Co1.5PW12O40、Ni1.5PW12O40、Zn1.5PW12O40、Co1.5PW18O62、Ni1.5PW18O62、Co1.5PMo12O40、Ni1.5PMo12O40、Zn1.5PMo12O40、Co1.5PMo18O62Preferably Co, preferably1.5PW12O40、Ni1.5PW12O40And Zn1.5PW12O40More preferably Co1.5PW12O40And/or Ni1.5PW12O40。
4. The production method according to any one of claims 1 to 3, wherein the aluminum source is selected from one or more of pseudoboehmite, aluminum sol and aluminum isopropoxide, preferably pseudoboehmite and/or aluminum isopropoxide;
the phosphorus source is selected from one or more of phosphoric acid, phosphorous acid, phosphate and diammonium hydrogen phosphate, and is preferably phosphoric acid and/or phosphorous acid;
the silicon source is selected from one or more of silica sol, tetraethoxysilane, active silicon dioxide and aminopropyl trimethoxy silane, and the silica sol and/or tetraethoxysilane are preferred.
5. The production method according to any one of claims 1 to 4, wherein the template is selected from one or more of tetraethylammonium hydroxide, diisopropylamine, morpholine, triethylamine, diethylamine, N-diisopropylethylamine, cyclohexylamine, and N-butylamine, preferably tetraethylammonium hydroxide and/or triethylamine.
6. The production method according to any one of claims 1 to 5, wherein the mixing process comprises: dissolving heteropoly acid in water to obtain a solution, and adding the solution, an aluminum source, a silicon source and a phosphorus source into a template agent in sequence.
7. The method according to any one of claims 1-6, wherein the temperature of the crystallization reaction is 180-210 ℃, and the time of the crystallization reaction is 12-96 h;
preferably, the temperature of the crystallization reaction is 190-;
preferably, the drying temperature is 80-160 ℃, preferably 90-150 ℃; the drying time is 6-36h, preferably 12-24 h;
preferably, the roasting temperature is 500-700 ℃, preferably 550-650 ℃; the roasting time is 4-12h, preferably 5-10 h.
8. A SAPO-34 molecular sieve prepared by the method of any one of claims 1 to 7.
9. The SAPO-34 molecular sieve of claim 8, wherein the SAPO-34 molecular sieve has a spherical structure with a diameter of 1-2 μm formed by close packing of cubic grains with a particle size of 50-200 nm;
preferably, the total specific surface area of the SAPO-34 molecular sieve is 600-700m2Per g, preferably 650-698m2(ii)/g, more preferably 672-698m2/g；
Preferably, the specific surface area of the micropores of the SAPO-34 molecular sieve is 510-650m2(iv)/g, preferably 550-620m2(iv)/g, more preferably 598-2/g；
Preferably, the total pore volume of the SAPO-34 molecular sieve is 0.3-0.4cm3In g, preferably from 0.35 to 0.38cm3Per g, more preferably 0.36 to 0.38cm3/g；
Preferably, the micropore volume of the SAPO-34 molecular sieve is 0.22-0.25cm3In g, preferably from 0.23 to 0.25cm3Per g, more preferably 0.23 to 0.24cm3/g。
10. Use of the SAPO-34 molecular sieve of claim 8 or 9 in the preparation of olefins from methanol.
CN202011264569.0A 2020-11-12 2020-11-12 SAPO-34 molecular sieve, and preparation method and application thereof Active CN114477228B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202011264569.0A CN114477228B (en) 2020-11-12 2020-11-12 SAPO-34 molecular sieve, and preparation method and application thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202011264569.0A CN114477228B (en) 2020-11-12 2020-11-12 SAPO-34 molecular sieve, and preparation method and application thereof

Publications (2)

Publication Number Publication Date
CN114477228A true CN114477228A (en) 2022-05-13
CN114477228B CN114477228B (en) 2023-07-07

Family

ID=81491457

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202011264569.0A Active CN114477228B (en) 2020-11-12 2020-11-12 SAPO-34 molecular sieve, and preparation method and application thereof

Country Status (1)

Country Link
CN (1) CN114477228B (en)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009155178A (en) * 2007-12-27 2009-07-16 Hiroshima Univ Fine particle composite, method of manufacturing the same and catalyst containing the same
CN102836741A (en) * 2012-09-03 2012-12-26 吉林大学 SAPO-34 (Silicoaluminophosphate-34) molecular sieve catalyst and application thereof to preparation of low-carbon olefin from methanol
CN106732762A (en) * 2015-11-19 2017-05-31 中国石油天然气股份有限公司 A kind of metal-modified SAPO-34 molecular sieves and preparation method and application

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009155178A (en) * 2007-12-27 2009-07-16 Hiroshima Univ Fine particle composite, method of manufacturing the same and catalyst containing the same
CN102836741A (en) * 2012-09-03 2012-12-26 吉林大学 SAPO-34 (Silicoaluminophosphate-34) molecular sieve catalyst and application thereof to preparation of low-carbon olefin from methanol
CN106732762A (en) * 2015-11-19 2017-05-31 中国石油天然气股份有限公司 A kind of metal-modified SAPO-34 molecular sieves and preparation method and application

Also Published As

Publication number Publication date
CN114477228B (en) 2023-07-07

Similar Documents

Publication Publication Date Title
CN111320186B (en) SAPO-34 molecular sieve, and preparation method and application thereof
CN111068760B (en) Fast controllable preparation method of SSZ-13 zeolite and catalyst for preparing olefin from H-SSZ-13 zeolite and methanol
CN102633279B (en) Aluminum silicophosphate molecular sieve with macro-porous structure and preparation method thereof
CN101125665A (en) Method for preparing SAPO-34 molecular sieve by liquid phase crystallization method
CN104828842B (en) A kind of preparation method of the composite molecular screen of SAPO 5 and 34 symbiosis of SAPO
CN106582804A (en) Hierarchical porous SAPO-34/kaolin composite material and preparation method thereof
CN109201109B (en) Catalyst for preparing olefin from methanol and preparation method thereof
CN112794338A (en) ZSM-5 molecular sieve and preparation method and application thereof
CN103058208B (en) Preparation method of SAPO-56 molecular sieve
CN106032282A (en) Preparation method and applications of mordenite having mesopores and micropores
CN101633509B (en) Method for modifying silica alumina phosphate molecular sieve
CN106694032A (en) CHA-RHO type composite molecular sieve as well as preparation method and application thereof
CN105731484A (en) Synthetic method of meso-microporous SAPO-34 molecular sieve
CN106276964B (en) A kind of transgranular phosphorous ZSM-5 molecular sieve and preparation method thereof
CN114477228A (en) SAPO-34 molecular sieve, and preparation method and application thereof
CN112456511B (en) SAPO-34 molecular sieve, and preparation method and application thereof
CN109796028B (en) Method for preparing silicoaluminophosphate molecular sieve, silicoaluminophosphate molecular sieve and method for preparing olefin from methanol
CN113731481B (en) Catalyst composition for preparing low-carbon olefin by converting synthesis gas and preparation method and application thereof
CN106799257A (en) A kind of alkane isomerization catalyst and preparation method thereof
CN106542547B (en) A kind of preparation method of the SAPO-34 molecular sieve of high activity low silicon content
CN110357124B (en) Multi-stage pore SAPO-34/SAPO-18 interphase phase-growing molecular sieve and preparation method and application thereof
CN111285382A (en) Method for preparing metal modified nano-crystalline SAPO-34 molecular sieve, product and application thereof
CN109336132B (en) Laminated crystal form SAPO-18 molecular sieve, and synthesis method and application thereof
CN104923294B (en) Composite molecular sieve for preparing olefin from methanol, preparation method and application
CN111018645A (en) Method for preparing low-carbon olefin by using oxygen-containing compound

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
CB03 Change of inventor or designer information
CB03 Change of inventor or designer information

Inventor after: Guo Lei

Inventor after: Zhu Weiping

Inventor after: Xing Aihua

Inventor after: Guo Zhihui

Inventor after: Li Fei

Inventor after: Yuan Delin

Inventor after: Liu Hua

Inventor before: Guo Lei

Inventor before: Zhu Weiping

Inventor before: Xing Aihua

Inventor before: Guo Zhihui

Inventor before: Li Fei

Inventor before: Yuan Delin

Inventor before: Liu Hua

Inventor before: Zhang Bing

GR01 Patent grant
GR01 Patent grant