WO2021098078A1 - 一种组合型催化剂及其制备方法和二氧化碳加氢耦合甲苯烷基化制二甲苯的方法 - Google Patents

一种组合型催化剂及其制备方法和二氧化碳加氢耦合甲苯烷基化制二甲苯的方法 Download PDF

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WO2021098078A1
WO2021098078A1 PCT/CN2020/077412 CN2020077412W WO2021098078A1 WO 2021098078 A1 WO2021098078 A1 WO 2021098078A1 CN 2020077412 W CN2020077412 W CN 2020077412W WO 2021098078 A1 WO2021098078 A1 WO 2021098078A1
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carbon dioxide
molecular sieve
toluene
present
combined catalyst
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French (fr)
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袁友珠
左佳昌
段新平
叶林敏
梁雪莲
林海强
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厦门大学
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    • 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
    • B01J29/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
    • B01J29/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
    • B01J29/40—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of the pentasil type, e.g. types ZSM-5, ZSM-8 or ZSM-11, as exemplified by patent documents US3702886, GB1334243 and US3709979, respectively
    • B01J29/405—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of the pentasil type, e.g. types ZSM-5, ZSM-8 or ZSM-11, as exemplified by patent documents US3702886, GB1334243 and US3709979, respectively containing rare earth elements, titanium, zirconium, hafnium, zinc, cadmium, mercury, gallium, indium, thallium, tin or lead
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    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/06—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of zinc, cadmium or mercury
    • 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
    • B01J29/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
    • B01J29/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
    • B01J29/061—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof containing metallic elements added to the zeolite
    • 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
    • B01J29/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
    • B01J29/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
    • B01J29/40—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of the pentasil type, e.g. types ZSM-5, ZSM-8 or ZSM-11, as exemplified by patent documents US3702886, GB1334243 and US3709979, respectively
    • 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
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    • B01J35/19—Catalysts containing parts with different compositions
    • 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
    • B01J35/00—Catalysts, in general, characterised by their form or physical properties
    • B01J35/40—Catalysts, in general, characterised by their form or physical properties characterised by dimensions, e.g. grain size
    • B—PERFORMING OPERATIONS; TRANSPORTING
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    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/02—Impregnation, coating or precipitation
    • B01J37/03—Precipitation; Co-precipitation
    • B01J37/031—Precipitation
    • 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
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/04—Mixing
    • 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
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/08—Heat treatment
    • B01J37/082—Decomposition and pyrolysis
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
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    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/08—Heat treatment
    • B01J37/082—Decomposition and pyrolysis
    • B01J37/084—Decomposition of carbon-containing compounds into carbon
    • 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
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/16—Reducing
    • B01J37/18—Reducing with gases containing free hydrogen
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C2/00—Preparation of hydrocarbons from hydrocarbons containing a smaller number of carbon atoms
    • C07C2/86—Preparation of hydrocarbons from hydrocarbons containing a smaller number of carbon atoms by condensation between a hydrocarbon and a non-hydrocarbon
    • C07C2/862—Preparation of hydrocarbons from hydrocarbons containing a smaller number of carbon atoms by condensation between a hydrocarbon and a non-hydrocarbon the non-hydrocarbon contains only oxygen as hetero-atoms
    • 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
    • B01J2229/00—Aspects of molecular sieve catalysts not covered by B01J29/00
    • B01J2229/10—After treatment, characterised by the effect to be obtained
    • B01J2229/20—After treatment, characterised by the effect to be obtained to introduce other elements in the catalyst composition comprising the molecular sieve, but not specially in or on the molecular sieve itself
    • 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
    • B01J2229/00—Aspects of molecular sieve catalysts not covered by B01J29/00
    • B01J2229/30—After treatment, characterised by the means used
    • B01J2229/42—Addition of matrix or binder particles
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C2521/00—Catalysts comprising the elements, oxides or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium or hafnium
    • C07C2521/06—Silicon, titanium, zirconium or hafnium; Oxides or hydroxides thereof
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C2523/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group C07C2521/00
    • C07C2523/06—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group C07C2521/00 of zinc, cadmium or mercury
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C2529/00—Catalysts comprising molecular sieves
    • C07C2529/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites, pillared clays
    • C07C2529/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
    • C07C2529/40—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of the pentasil type, e.g. types ZSM-5, ZSM-8 or ZSM-11
    • 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

Definitions

  • the invention relates to the technical field of catalysts, in particular to a combined catalyst and a preparation method thereof, and a method for preparing xylene by carbon dioxide hydrogenation coupled toluene alkylation.
  • the industrial methods for preparing xylene mainly include toluene disproportionation, toluene trimethylbenzene transalkylation, and toluene methanol alkylation.
  • toluene methanol alkylation to xylene is an environmentally friendly reaction, and the theoretical by-product is only water.
  • the toluene methanol alkylation reaction is an electrophilic substitution reaction that occurs at the B acid site. It is generally believed that methanol first dehydrogenates on the molecular sieve to generate methoxy groups, and then attacks the hydrogen atoms on toluene to complete the substitution alkylation reaction. Release the acidic protons on the molecular sieve.
  • the catalyst used in the alkylation of toluene methanol to produce xylene is molecular sieve, but the molecular sieve catalyst has too many acidic sites, resulting in xylene isomerization, resulting in thermodynamic distribution of the product, and low para-xylene selectivity, which in turn leads to The separation of xylene, meta-xylene and o-xylene has higher energy consumption.
  • the purpose of the present invention is to provide a combined catalyst, which uses the catalyst provided by the present invention to prepare p-xylene, which can inhibit the xylene isomerization reaction and improve the selectivity of p-xylene in the product.
  • the present invention provides a combined catalyst, including metal oxides and molecular sieves; the metal oxides include one or more of ZnZrO x1 , ZnCrO x2 , ZnAlO x3 and CrO x4 , wherein 1 ⁇ x1 ⁇ 2, 1 ⁇ x2 ⁇ 1.5, 1 ⁇ x3 ⁇ 1.5, 1 ⁇ x4 ⁇ 1.5.
  • the molecular sieve includes one or more of ZSM-5 molecular sieve, MCM-22 molecular sieve and SAPO-34 molecular sieve.
  • the mass ratio of the metal oxide to the molecular sieve is (1-9): (1-9).
  • the present invention provides a method for preparing the combined catalyst described in the above technical solution, which includes the following steps: mixing metal oxides and molecular sieves to obtain a combined catalyst.
  • the present invention provides another preparation method of the combined catalyst described in the above technical solution, which includes the following steps: first mixing a metal salt solution and a molecular sieve to obtain a dispersion;
  • the precipitate is calcined to obtain a combined catalyst.
  • the invention also provides a method for preparing xylene from carbon dioxide hydrogenation coupled toluene alkylation, which comprises the following steps:
  • the active catalyst is mixed with carbon dioxide, hydrogen and toluene, and a carbon dioxide hydrogenation coupled toluene alkylation reaction occurs to obtain xylene.
  • the gas providing the reducing atmosphere conditions is a mixed gas of hydrogen and argon or a mixed gas of hydrogen and nitrogen.
  • the activation temperature is 200-600°C, and the activation time is 0.5-12h.
  • the space velocity of the carbon dioxide is 300-6000 mL ⁇ g -1 ⁇ h -1 ; the volume ratio of carbon dioxide to hydrogen is 1: (1-8); the molar ratio of carbon dioxide to toluene is (1 ⁇ 30): 2.
  • the temperature of the carbon dioxide hydrogenation coupled toluene alkylation reaction is 300 to 460° C., and the reaction pressure is 1 to 5 MPa.
  • the present invention provides a combined catalyst, including metal oxides and molecular sieves; the metal oxides include one or more of ZnZrO x1 , ZnCrO x2 , ZnAlO x3 and CrO x4 , wherein 1 ⁇ x1 ⁇ 2, 1 ⁇ x2 ⁇ 1.5, 1 ⁇ x3 ⁇ 1.5, 1 ⁇ x4 ⁇ 1.5.
  • metal oxides are mainly used to reduce carbon dioxide to methanol
  • molecular sieves are mainly used to react toluene and methanol to produce xylene.
  • the catalyst provided by the present invention is used to prepare xylene. Carbon dioxide and hydrogen can be used as raw materials to replace methanol.
  • the present invention also provides a method for preparing xylene by hydrogenation of carbon dioxide coupled with toluene alkylation.
  • the present invention uses carbon dioxide and hydrogen to replace conventional methanol, generates methanol by hydrogenation of carbon dioxide, and then undergoes an alkylation reaction with toluene.
  • Alkylation reaction consumes methanol and improves the conversion rate of carbon dioxide hydrogenation reaction.
  • Alkylation reaction “takes on demand” methanol generated from carbon dioxide hydrogenation reaction, which prevents methanol-to-olefin reaction from excessively high methanol concentration, which is beneficial to increase
  • the yield of xylene can slow down the deactivation of the catalyst by carbon deposition.
  • Figure 1 is a schematic diagram of the instrument used to evaluate and analyze the performance of the combined catalyst; where 1 is a steel cylinder, 2 is a pressure reducing valve, 3 is a three-way valve, 4 is a pressure regulating valve, 5 is a pressure gauge, 6 is a temperature controller, and 7 Indicates a high-pressure injection pump, 8 represents a steel tube, 9 represents a quartz reaction tube, 10 represents a heating furnace, and 11 represents a condenser;
  • FIG. 2 is a graph showing the 100-hour stability test result of the combined catalyst prepared in Example 4.
  • FIG. 2 is a graph showing the 100-hour stability test result of the combined catalyst prepared in Example 4.
  • the present invention provides a combined catalyst, including metal oxides and molecular sieves; the metal oxides include one or more of ZnZrO x1 , ZnCrO x2 , ZnAlO x3 and CrO x4 , wherein 1 ⁇ x1 ⁇ 2, 1 ⁇ x2 ⁇ 1.5, 1 ⁇ x3 ⁇ 1.5, 1 ⁇ x4 ⁇ 1.5.
  • the combined catalyst provided by the present invention includes metal oxides, and the metal oxides include one or more of ZnZrO x1 , ZnCrO x2 , ZnAlO x3 and CrO x4 , wherein 1 ⁇ x1 ⁇ 2, 1 ⁇ x2 ⁇ 1.5, 1 ⁇ x3 ⁇ 1.5, 1 ⁇ x4 ⁇ 1.5.
  • the metal oxide is preferably prepared by a co-precipitation method; the method for preparing the metal oxide by the co-precipitation method is specifically preferably: mixing the corresponding metal salt and the precipitating agent to cause a co-precipitation reaction to obtain a precipitate ⁇ ; The precipitate is washed and calcined sequentially to obtain a metal oxide.
  • the metal salt is preferably one or more of metal nitrate, metal acetate and metal sulfate;
  • the precipitating agent is preferably ammonia, ammonium carbonate, sodium hydroxide, potassium hydroxide, and carbonic acid.
  • the calcination is preferably performed in an air atmosphere, the temperature of the calcination is preferably 400 to 700° C., and the time of the calcination is preferably 2 to 12 hours.
  • the combined catalyst provided by the present invention also includes a molecular sieve, and the molecular sieve preferably includes one or more of ZSM-5 molecular sieve, MCM-22 molecular sieve and SAPO-34 molecular sieve, more preferably H-ZSM-5 molecular sieve.
  • the molecular sieve is preferably a modified molecular sieve, more preferably a tetraethylorthosilicate modified molecular sieve.
  • the method for preparing the modified molecular sieve is specifically preferably: mixing the molecular sieve with tetraethylorthosilicate, immersing, and calcining to obtain the modified molecular sieve.
  • the mass ratio of the molecular sieve to tetraethylorthosilicate is preferably 1:(0.5-2), more preferably 1:1.
  • the mixing is preferably carried out in a solvent, and the mass ratio of the molecular sieve to the solvent is preferably (1 to 5):1, more preferably 2.5:1; the solvent is preferably hexane, pentane, Heptane, octane, N,N-dimethylformamide or N,N-dimethylacetamide.
  • the immersion time is preferably 1-24h, more preferably 4h;
  • the calcination temperature is preferably 400-700°C, the calcination time is preferably 1-12h, and the calcination is preferably contained It is carried out in an oxygen atmosphere, and the gas providing the oxygen-containing atmosphere is preferably air, oxygen, a mixed gas of nitrogen and oxygen, a mixed gas of argon and oxygen, or a mixed gas of helium and oxygen.
  • the above modification step can be repeated multiple times, usually 1 to 8 times.
  • the invention carries out siloxane modification on the molecular sieve skeleton, which can cover the acid sites on the outer surface, weaken the xylene isomerization reaction, and is beneficial to improve the selectivity of p-xylene in the product.
  • the mass ratio of the metal oxide to the molecular sieve is preferably (1-9): (1-9), more preferably 1: (1-9).
  • the invention can effectively improve the selectivity of xylene by adjusting the mass ratio of the metal oxide and the molecular sieve, and inhibit the reverse water gas shift reaction.
  • the present invention provides a method for preparing the combined catalyst described in the above technical solution, which includes the following steps: mixing metal oxides and molecular sieves to obtain a combined catalyst.
  • the mixing method preferably includes grinding, ball milling, immersion, precipitation deposition, solvothermal, co-precipitation or molten salt mixing, more preferably grinding or ball milling.
  • the metal oxide and the molecular sieve are fully contacted by mixing, and the mass transfer effect is improved.
  • the obtained mixture material is preferably granulated and sieved to obtain a combined catalyst.
  • the present invention also provides another preparation method of the combined catalyst, which includes the following steps: first mixing the metal salt solution and the molecular sieve to obtain a dispersion;
  • the precipitate is calcined to obtain a combined catalyst.
  • the metal salt solution and the molecular sieve are first mixed to obtain a dispersion liquid.
  • the metal salt solution is preferably one or more of metal nitrate solution, metal acetate solution and metal sulfate solution, and more preferably a mixed solution of zinc nitrate and zirconium nitrate.
  • the solvent of the metal salt solution is water.
  • the concentration of the metal salt solution is preferably 0.010 to 0.200 g/mL, more preferably 0.065 g/mL.
  • the in-situ precipitation method is preferably used.
  • the mass ratio of the metal salt to the molecular sieve in the metal salt solution is preferably (25-35): (65-75), more preferably 28:72.
  • the present invention has no particular limitation on the specific manner of the first mixing, and it is advisable to uniformly disperse the molecular sieve in the metal salt solution.
  • the present invention performs a second mixing of the dispersion liquid and the precipitating agent to cause a precipitation reaction to obtain a precipitate.
  • the precipitating agent is preferably one or more of ammonia, ammonium carbonate, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate and potassium bicarbonate; the precipitating agent is preferably It is mixed with the dispersion in the form of an aqueous solution.
  • the aqueous precipitant solution is preferably an aqueous ammonium carbonate solution; the concentration of the aqueous precipitant solution is preferably 0.02-0.04 g/mL, more preferably 0.031 g/mL.
  • the mass ratio of the precipitation agent to the molecular sieve is preferably (10-20): (80-90), more preferably 15:85.
  • the temperature of the second mixing is preferably 60 to 80°C, more preferably 70°C; the specific manner of the second mixing is preferably: dropwise adding the aqueous precipitant solution to the dispersion
  • the rate of the dropping is preferably 1 to 5 mL/min, more preferably 3 mL/min.
  • the temperature of the precipitation reaction is preferably 60 to 80°C, more preferably 70°C; the time of the precipitation reaction is preferably 1 to 3 hours, more preferably 2 hours; the time of the precipitation reaction is based on the Start timing after adding precipitant.
  • the metal salt reacts with the precipitant to precipitate on the surface of the molecular sieve in situ, which simplifies the preparation process while ensuring full contact between the metal oxide and the molecular sieve.
  • the solid-liquid separation method is preferably centrifugation.
  • the washing detergent is deionized water, distilled water or ultrapure water.
  • the amount of detergent used for each wash is preferably 3 to 5 times the volume of the original mixed solution, and the number of washing and solid-liquid separation is preferably 3 to 5 times. .
  • the present invention calcines the precipitate to obtain a combined catalyst.
  • the calcination is preferably carried out in an air atmosphere, the temperature of the calcination is preferably 400 to 700° C., and the time of the calcination is preferably 2 to 12 hours.
  • the present invention preferably drying the precipitate, the drying temperature is preferably 80-120°C, more preferably 105°C, and the drying time is preferably 8-16h.
  • the present invention preferably granulates and sieves the calcined product to obtain a combined catalyst.
  • the particle size of the combined catalyst is preferably 40-60 mesh.
  • the invention can eliminate the influence of the internal diffusion rate on the intrinsic performance of the catalyst.
  • the invention also provides a method for preparing xylene from carbon dioxide hydrogenation coupled toluene alkylation, which comprises the following steps:
  • the active catalyst is mixed with carbon dioxide, hydrogen and toluene, and a carbon dioxide hydrogenation coupled toluene alkylation reaction occurs to obtain xylene.
  • the combined catalyst is placed in a reducing atmosphere for activation to obtain an active catalyst.
  • the reducing gas that provides the reducing atmosphere conditions is preferably a mixed gas of hydrogen and argon or a mixed gas of hydrogen and nitrogen; when the reducing gas is a mixed gas of hydrogen and argon, the The volume ratio of hydrogen and argon is preferably 5:95; when the reducing gas is a mixed gas of hydrogen and nitrogen, the volume ratio of hydrogen and nitrogen is preferably 5:95.
  • the activation temperature is preferably 200-600°C, more preferably 450°C; the activation time is preferably 0.5-12h, more preferably 2h.
  • the function of the activation is to make the catalyst in a working state as soon as possible, and to improve the catalytic reaction ability of hydrogen, carbon dioxide and toluene.
  • the present invention mixes the active catalyst with carbon dioxide, hydrogen, and toluene to cause carbon dioxide hydrogenation coupled toluene alkylation reaction to obtain xylene.
  • the space velocity of the carbon dioxide is preferably 300 to 6000 mL ⁇ g -1 ⁇ h -1 , more preferably 3000 mL ⁇ g -1 ⁇ h -1 ;
  • the volume ratio of the carbon dioxide to hydrogen is preferably 1: (1-8), more preferably 1:3;
  • the molar ratio of carbon dioxide to toluene is preferably (1-30):2, more preferably 16:2.
  • the space velocity of the introduction of carbon dioxide is preferably 300 to 6000 mL ⁇ g -1 ⁇ h -1 , more preferably 3000 mL ⁇ g -1 ⁇ h -1 ;
  • the space velocity of the introduction of hydrogen is preferably 900 ⁇ 18000mL ⁇ g -1 ⁇ h -1, more preferably 9000mL ⁇ g -1 ⁇ h -1;
  • the toluene is preferably passed in gaseous form, into a gaseous space velocity of toluene is preferably from 25 ⁇ 500mL ⁇ g - 1 ⁇ h -1 , more preferably 250 mL ⁇ g -1 ⁇ h -1 .
  • the toluene is preferably introduced by a bubbling method or a high-pressure injection pump; when the toluene is introduced by a bubbling method, the reaction pressure and the temperature of the bubbling tank can be adjusted, which can be calculated by the Antoine equation Toluene injection volume fraction; when using a high-pressure injection pump to introduce toluene, the injection rate can be directly set.
  • a purge tank to pass toluene at 90°C.
  • the active catalyst is preferably mixed with quartz sand.
  • the particle size of the quartz sand is preferably 40-60 mesh.
  • the mass ratio of sand is preferably 1:(1-8), more preferably 1:4.
  • the function of mixing the active catalyst and the quartz sand in the present invention is to eliminate the influence of the reaction heat effect on the catalytic reaction.
  • the temperature of the carbon dioxide hydrogenation coupled toluene alkylation reaction is preferably 300 to 460°C, more preferably 360°C; the reaction pressure is preferably 1 to 5 MPa, more preferably 3 MPa.
  • the carbon dioxide hydrogenation coupled toluene alkylation reaction includes the carbon dioxide hydrogenation to methanol reaction and the methanol toluene alkylation reaction; the reaction formula of the carbon dioxide hydrogenation to methanol reaction is:
  • H-ZSM-5 molecular sieve (the ratio of silicon to aluminum is 85, purchased from Nankai University Catalyst Factory), add 2.44mL of tetraethylorthosilicate and 1.0mL of hexane, stir well, immerse for 4h, at 110°C Dry under the conditions, then calcined in the air at 550°C for 4h, repeat the above steps twice to obtain modified H-ZSM-5 molecular sieve;
  • ZnZrO 1.7 and the modified H-ZSM-5 molecular sieve are ground and mixed uniformly at a mass ratio of 1:1, granulated and sieved to obtain a combined catalyst with a particle size of 40-60 mesh.
  • ZnZrO 1.7 and modified H-ZSM-5 molecular sieve were ground and mixed uniformly at a mass ratio of 1:9, granulated and sieved to obtain a combined catalyst with a particle size of 40-60 mesh; among them, the modified H-ZSM-5 molecular sieve
  • the preparation method is the same as in Example 2.
  • ZnZrO 1.7 and modified H-ZSM-5 molecular sieve were ground and mixed uniformly at a mass ratio of 1:9, granulated and sieved to obtain a combined catalyst with a particle size of 40-60 mesh; among them, the modified H-ZSM-5 molecular sieve
  • the preparation method is basically the same as that of Example 2, except that the modification step is changed from repeating twice to repeating four times.
  • a high-pressure continuous fixed-bed reactor was used to evaluate the performance of the catalyst, and gas chromatography was used to analyze the product components.
  • the schematic diagram of the instrument is shown in Figure 1. Take 0.2g of the combined catalyst provided in Examples 1 to 5, and mix it with 0.8g of 40-60 mesh quartz sand, and first reduce it in a hydrogen-nitrogen mixture at 450°C for 2h to obtain an active catalyst; among them, hydrogen accounts for hydrogen -The volume fraction of the nitrogen mixture is 5%;
  • the active catalyst is placed in a quartz reaction tube, and carbon dioxide, hydrogen, toluene and nitrogen are introduced at a space velocity of 12000 mL ⁇ g -1 ⁇ h -1 (the volume fraction of nitrogen is 1-10%, which is used as an internal standard)
  • the mixture of gas in which the molar ratio of hydrogen to carbon dioxide is 3:1, the molar ratio of carbon dioxide to gaseous toluene is 12:1, and the gaseous toluene is sampled using a stripping tank at 90°C, and at 360°C and a pressure of 3.0MPa , Reaction for 15h; all pipelines of the instrument use heating insulation design, the temperature of the pipeline before the reaction is greater than the temperature of the bubbling tank; the reaction product enters the equipped flame ionization detector (FID) and thermal conductivity detector (TCD) after being split.
  • On-line analysis is performed in gas chromatography (GC), the conversion of carbon dioxide and the selectivity of reaction products are calculated using the C-based normalization method, and
  • Example 2 Only the 0.18g modified H-ZSM-5 molecular sieve prepared in Example 2 was used as a catalyst, and the reaction was carried out in a method similar to the application example. The only difference from the application example is that the carbon dioxide and hydrogen introduced are changed to The test results of nitrogen, carbon dioxide conversion rate and reaction product selectivity are shown in Table 1.
  • the modified H-ZSM-5 molecular sieve can improve the selectivity of p-xylene (PX); by adjusting the ratio of metal oxide and molecular sieve, the xylene selectivity can be effectively improved, and the reverse water gas shift can be inhibited ( RWGS) reaction; from the comparison of Example 4 and Example 2, it can be seen that by adjusting the modification process of molecular sieve, the selectivity of PX can be further improved; combined with the experimental results of the comparative example, it can be seen that under the reaction conditions of the comparative example, toluene is in the molecular sieve The above disproportionation reaction rate is quite slow, the conversion rate of toluene is only 0.5%, and in the presence of carbon dioxide and hydrogen, the toluene alkylation reaction occurs preferentially, which shows that the xylene in Examples 1 to 5 is basically all Toluene, carbon dioxide and hydrogen are generated through alkylation reaction, instead of toluene disproportionation reaction
  • FIG. 2 The 100-hour stability test result of the combined catalyst prepared in Example 4 is shown in Figure 2, where A in Figure 2 is the distribution diagram of the catalytic reaction product (excluding CO), and B in Figure 2 is the o-dioxane in xylene. Distribution map of toluene, m-xylene and p-xylene. It can be seen from Figure 2 that the conversion of toluene and the selectivity of PX in xylene were maintained at 11% and 70%, respectively. The xylene selectivity (excluding CO) decreased from 82% at the initial level to 63% after 30h. And tends to be stable, and the selectivity of 4-ethyltoluene, which also has a high added value, has risen from 11% to 23%.
  • 4-ethyltoluene is formed by PX and further side-chain alkylation. This shows that the combined catalyst provided by the present invention has stable activity and PX selectivity, gaseous alkane selectivity is less than 1.5%, and the product always contains most of the high value-added aromatic components.

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Abstract

本发明涉及催化剂技术领域，具体涉及一种组合型催化剂及其制备方法和二氧化碳加氢耦合甲苯烷基化制二甲苯的方法。本发明提供的组合型催化剂，包括金属氧化物和分子筛。在本发明中，金属氧化物主要用于还原二氧化碳为甲醇，分子筛主要用于使甲苯和甲醇反应生成二甲苯，采用本发明提供的催化剂制备二甲苯，能够以二氧化碳和氢气为原料替代甲醇，相比于传统的甲苯甲醇烷基化法，能够避免因甲醇/甲苯投料比不当引起的甲醇制烯烃副反应，提高二甲苯的生产效率；同时可以抑制二甲苯的异构反应，提高产物中对二甲苯的选择性。

Description

一种组合型催化剂及其制备方法和二氧化碳加氢耦合甲苯烷基化制二甲苯的方法
本申请要求于2019年11月21日提交中国专利局、申请号为CN201911149539.2、发明名称为“一种组合型催化剂及其制备方法和二氧化碳加氢耦合甲苯烷基化制二甲苯的方法”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本发明涉及催化剂技术领域，具体涉及一种组合型催化剂及其制备方法和二氧化碳加氢耦合甲苯烷基化制二甲苯的方法。
背景技术
目前，工业上制备二甲苯的方法主要有甲苯歧化法、甲苯三甲苯烷基转移法和甲苯甲醇烷基化法，其中甲苯甲醇烷基化制二甲苯属于环境友好型反应，理论副产物只有水；甲苯甲醇烷基化反应是发生在B酸位点的亲电取代反应，通常认为甲醇先在分子筛上脱氢生成甲氧基，而后进攻甲苯上的氢原子，完成取代烷基化反应，同时将分子筛上的酸性质子释放。
通常，甲苯甲醇烷基化制二甲苯使用的催化剂为分子筛，但分子筛催化剂酸性位过多，导致二甲苯异构，使得产物呈热力学分布，对二甲苯的选择性较低，进而导致产物中对二甲苯、间二甲苯和邻二甲苯的分离能耗较高。
发明内容
本发明的目的在于提供一种组合型催化剂，采用本发明提供的催化剂制备对二甲苯，能够抑制二甲苯的异构反应，提高产物中对二甲苯的选择性。
为了实现上述发明目的，本发明提供以下技术方案：
本发明提供了一种组合型催化剂，包括金属氧化物和分子筛；所述金属氧化物包括ZnZrO x1、ZnCrO x2、ZnAlO x3和CrO x4中的一种或几种，其中1＜x1＜2，1＜x2＜1.5，1＜x3＜1.5，1＜x4＜1.5。
优选地，所述分子筛包括ZSM-5分子筛、MCM-22分子筛和SAPO-34 分子筛中的一种或几种。
优选地，所述金属氧化物和分子筛的质量比为(1～9)：(1～9)。
本发明提供了上述技术方案所述组合型催化剂的制备方法，包括以下步骤：将金属氧化物和分子筛进行混合，得到组合型催化剂。
本发明提供了上述技术方案所述组合型催化剂的另一种制备方法，包括以下步骤：将金属盐溶液和分子筛进行第一混合，得到分散液；
将所述分散液和沉淀剂进行第二混合，发生沉淀反应，得到沉淀物；
将所述沉淀物进行煅烧，得到组合型催化剂。
本发明还提供了一种二氧化碳加氢耦合甲苯烷基化制二甲苯的方法，包括以下步骤：
将上述技术方案所述组合型催化剂置于还原性气氛中，进行活化，得到活性催化剂；
将所述活性催化剂与二氧化碳、氢气和甲苯混合，发生二氧化碳加氢耦合甲苯烷基化反应，得到二甲苯。
优选地，提供所述还原性气氛条件的气体为氢气和氩气的混合气或氢气和氮气的混合气。
优选地，所述活化的温度为200～600℃，所述活化的时间为0.5～12h。
优选地，所述二氧化碳的空速为300～6000mL·g -1·h -1；所述二氧化碳与氢气的体积比为1：(1～8)；所述二氧化碳与甲苯的摩尔比为(1～30)：2。
优选地，所述二氧化碳加氢耦合甲苯烷基化反应的温度为300～460℃，反应压力为1～5MPa。
本发明提供了一种组合型催化剂，包括金属氧化物和分子筛；所述金属氧化物包括ZnZrO x1、ZnCrO x2、ZnAlO x3和CrO x4中的一种或几种，其中1＜x1＜2，1＜x2＜1.5，1＜x3＜1.5，1＜x4＜1.5。在本发明中，金属氧化物主要用于还原二氧化碳为甲醇，分子筛主要用于使甲苯和甲醇反应生成二甲苯，采用本发明提供的催化剂制备二甲苯，能够以二氧化碳和氢气为原料替代甲醇，相比于传统的甲苯甲醇烷基化法，能够避免因甲醇/甲苯投料比不当引起的甲醇制烯烃副反应，提高二甲苯的生产效率；同时可以抑制二甲苯的异构反应，提高产物中对二甲苯的选择性。
本发明还提供了一种二氧化碳加氢耦合甲苯烷基化制二甲苯的方法，本发明使用二氧化碳和氢气替代常规的甲醇，通过二氧化碳加氢制甲醇，再与甲苯发生烷基化反应，通过烷基化反应对甲醇的消耗，提高二氧化碳加氢反应的转化率，烷基化反应对二氧化碳加氢反应生成的甲醇“按需取用”，防止甲醇浓度过高发生甲醇制烯烃反应，有利于提高二甲苯的得率，并减缓催化剂积碳失活。
说明书附图
图1为用于评价分析组合型催化剂性能的仪器示意图；其中1表示钢瓶，2表示减压阀，3表示三通阀，4表示压力调节阀，5表示压力表，6表示温控仪，7表示高压进样泵，8表示钢管，9表示石英反应管，10表示加热炉，11表示冷凝器；
图2为实施例4制备的组合型催化剂100h稳定性测试结果图。
具体实施方式
下面结合实施例和附图对本发明进一步说明。
本发明提供了一种组合型催化剂，包括金属氧化物和分子筛；所述金属氧化物包括ZnZrO x1、ZnCrO x2、ZnAlO x3和CrO x4中的一种或几种，其中1＜x1＜2，1＜x2＜1.5，1＜x3＜1.5，1＜x4＜1.5。
本发明提供的组合型催化剂包括金属氧化物，所述金属氧化物包括ZnZrO x1、ZnCrO x2、ZnAlO x3和CrO x4中的一种或几种，其中1＜x1＜2，1＜x2＜1.5，1＜x3＜1.5，1＜x4＜1.5。在本发明中，所述金属氧化物优选采用共沉淀法制备得到；所述共沉淀法制备金属氧化物的方法具体优选为：将相应的金属盐和沉淀剂混合，发生共沉淀反应，得到沉淀物；将所述沉淀物依次进行洗涤和煅烧，得到金属氧化物。在本发明中，所述金属盐优选为硝酸金属盐、醋酸金属盐和硫酸金属盐中的一种或几种；所述沉淀剂优选为氨水、碳酸铵、氢氧化钠、氢氧化钾、碳酸钠、碳酸钾、碳酸氢钠和碳酸氢钾中的一种或多种；所述洗涤的次数优选为1～5次，所述洗涤用洗涤剂优选为去离子水和/或超纯水；所述煅烧优选在空气气氛中进行，所述煅烧的温度优选为400～700℃，所述煅烧的时间优选为2～12h。
本发明提供的组合型催化剂还包括分子筛，所述分子筛优选包括ZSM-5分子筛、MCM-22分子筛和SAPO-34分子筛中的一种或几种，更 优选为H-ZSM-5分子筛。在本发明中，所述分子筛优选为改性分子筛，更优选采用正硅酸四乙酯改性分子筛。
在本发明中，所述改性分子筛的制备方法具体优选为：将分子筛与正硅酸四乙酯混合，浸渍后，煅烧，得到改性分子筛。在本发明中，所述分子筛与正硅酸四乙酯的质量比优选为1：(0.5～2)，更优选为1：1。在本发明中，所述混合优选在溶剂中进行，所述分子筛与溶剂的质量比优选为(1～5)：1，更优选为2.5：1；所述溶剂优选为己烷、戊烷、庚烷、辛烷、N,N-二甲基甲酰胺或N,N-二甲基乙酰胺。在本发明中，所述浸渍的时间优选为1～24h，更优选为4h；所述煅烧的温度优选为400～700℃，所述煅烧的时间优选为1～12h，所述煅烧优选在含氧气氛中进行，提供所述含氧气氛的气体优选为空气、氧气、氮氧混合气、氩氧混合气或氦氧混合气。
在本发明中，为了保证分子筛外表面骨架酸性位被充分覆盖，可对上述改性步骤进行多次重复，通常1～8次为宜。本发明对分子筛骨架进行硅氧烷化改性，能够覆盖外表面酸性位，减弱二甲苯异构化反应，有利于提高产物中对二甲苯的选择性。
在本发明中，所述金属氧化物和分子筛的质量比优选为(1～9)：(1～9)，更优选为1：(1～9)。本发明通过调节金属氧化物和分子筛的质量比能够有效提高二甲苯的选择性，并抑制逆水煤气变换反应。
本发明提供了上述技术方案所述组合型催化剂的制备方法，包括以下步骤：将金属氧化物和分子筛进行混合，得到组合型催化剂。
在本发明中，所述混合的方式优选包括研磨、球磨、浸渍、沉淀沉积、溶剂热、共沉淀或熔盐混合，更优选为研磨或球磨。本发明通过混合使金属氧化物和分子筛充分接触，提高传质效果，在制备二甲苯时，可通过反应中间物种的迁移和转化实现二氧化碳加氢制甲醇与甲醇甲苯烷基化反应的耦合。
本发明在所述混合结束后，优选将所得混合物料进行造粒、过筛，得到组合型催化剂。
本发明还提供了所述组合型催化剂的另一种制备方法，包括以下步骤：将金属盐溶液和分子筛进行第一混合，得到分散液；
将所述分散液和沉淀剂进行第二混合，发生沉淀反应，得到沉淀物；
将所述沉淀物进行煅烧，得到组合型催化剂。
本发明将金属盐溶液和分子筛进行第一混合，得到分散液。在本发明中，所述金属盐溶液优选为金属硝酸盐溶液、金属醋酸盐溶液和金属硫酸盐溶液中的一种或几种，更优选为硝酸锌和硝酸锆的混合溶液。在本发明中，所述金属盐溶液的溶剂为水。在本发明中，所述金属盐溶液的浓度优选为0.010～0.200g/mL，更优选为0.065g/mL。在本发明的具体实施例中，当所述金属氧化物为ZnZrO x1(1＜x1＜2)时，优选采用该原位沉淀法。
在本发明中，所述金属盐溶液中的金属盐和分子筛的质量比优选为(25～35)：(65～75)，更优选为28：72。
在本发明中，所述分子筛的具体种类以及改性分子筛的制备方法同前文所述，这里不再赘述。
本发明对所述第一混合的具体方式没有特殊的限定，将分子筛均匀分散在所述金属盐溶液中为宜。
得到分散液后，本发明将所述分散液和沉淀剂进行第二混合，发生沉淀反应，得到沉淀物。在本发明中，所述沉淀剂优选为氨、碳酸铵、氢氧化钠、氢氧化钾、碳酸钠、碳酸钾、碳酸氢钠和碳酸氢钾中的一种或多种；所述沉淀剂优选以水溶液的形式与所述分散液混合，所述沉淀剂水溶液优选为碳酸铵水溶液；所述沉淀剂水溶液的浓度优选为0.02～0.04g/mL，更优选为0.031g/mL。在本发明中，所述沉淀剂和分子筛的质量比优选为(10～20)：(80～90)，更优选为15：85。在本发明中，所述第二混合的温度优选为60～80℃，更优选为70℃；所述第二混合的具体方式优选为：将所述沉淀剂水溶液滴加至所述分散液中，所述滴加的速度优选为1～5mL/min，更优选为3mL/min。
在本发明中，所述沉淀反应的温度优选为60～80℃，更优选为70℃；所述沉淀反应的时间优选为1～3h，更优选为2h；所述沉淀反应的时间以所述沉淀剂添加完毕开始计时。本发明在所述沉淀反应过程中，金属盐与沉淀剂反应原位沉淀在分子筛表面，在保证金属氧化物和分子筛充分接触的同时，简化制备工艺。
本发明优选将沉淀反应所得体系进行固液分离，得到沉淀物。在本发 明中，所述固液分离的方式优选离心。
本发明优选将离心后的沉淀物进行多次洗涤和固液分离，以去除多余离子的影响。所述洗涤的洗涤剂为去离子水、蒸馏水或超纯水，每次洗涤使用洗涤剂的量优选为原混合溶液体积的3～5倍，洗涤和固液分离的次数优选为3～5次。
得到上述经洗涤后的沉淀物后，本发明将所述沉淀物进行煅烧，得到组合型催化剂。在本发明中，所述煅烧优选在空气气氛中进行，所述煅烧的温度优选为400～700℃，所述煅烧的时间优选为2～12h。
在所述煅烧前，本发明优选将所述沉淀物进行干燥，所述干燥的温度优选为80～120℃，更优选为105℃，所述干燥的时间优选为8～16h。
在所述煅烧结束后，本发明优选将煅烧产物进行造粒、过筛，得到组合型催化剂。
在本发明中，所述组合型催化剂的粒径优选为40～60目。本发明通过造粒，能够消除内扩散速率对催化剂本征性能的影响。
本发明还提供了一种二氧化碳加氢耦合甲苯烷基化制二甲苯的方法，包括以下步骤：
将上述技术方案所述组合型催化剂置于还原性气氛中，进行活化，得到活性催化剂；
将所述活性催化剂与二氧化碳、氢气和甲苯混合，发生二氧化碳加氢耦合甲苯烷基化反应，得到二甲苯。
本发明将组合型催化剂置于还原性气氛中，进行活化，得到活性催化剂。在本发明中，提供所述还原性气氛条件的还原性气体优选为氢气和氩气的混合气或氢气和氮气的混合气；当所述还原性气体为氢气和氩气的混合气时，所述氢气和氩气的体积比优选为5:95；当所述还原性气体为氢气和氮气的混合气时，所述氢气和氮气的体积比优选为5:95。
在本发明中，所述活化的温度优选为200～600℃，更优选为450℃；所述活化的时间优选为0.5～12h，更优选为2h。在本发明中，所述活化的作用是使催化剂尽快处于工作状态，提升对氢气、二氧化碳和甲苯的催化反应能力。
得到活性催化剂后，本发明将所述活性催化剂与二氧化碳、氢气和甲 苯混合，发生二氧化碳加氢耦合甲苯烷基化反应，得到二甲苯。在本发明中，所述二氧化碳的空速优选为300～6000mL·g -1·h -1，更优选为3000mL·g -1·h -1；所述二氧化碳与氢气的体积比优选为1：(1～8)，更优选为1:3；所述二氧化碳与甲苯的摩尔比优选为(1～30)：2，更优选为16：2。
在本发明中，所述二氧化碳通入的空速优选为300～6000mL·g -1·h -1，更优选为3000mL·g -1·h -1；所述氢气通入的空速优选为900～18000mL·g -1·h -1，更优选为9000mL·g -1·h -1；所述甲苯优选以气态形式通入，气态甲苯通入的空速优选为25～500mL·g -1·h -1，更优选为250mL·g -1·h -1。在本发明中，所述甲苯优选采用鼓泡法或高压进样泵引入；当采用鼓泡法通入甲苯时，调节反应压力和鼓泡罐温度，即可通过安托因(Antoine)方程计算出甲苯进样体积分数；当采用高压进样泵通入甲苯时，直接设定进样速率即可。在本发明的具体实施例中，优选在90℃条件下使用吹脱罐通入甲苯。
本发明在将活性催化剂与二氧化碳、氢气和甲苯混合之前，优选先将活性催化剂与石英砂混合，在本发明中，所述石英砂的粒径优选为40～60目，所述活性催化剂与石英砂的质量比优选为1：(1～8)，更优选为1:4。本发明将活性催化剂与石英砂混合的作用是消除反应热效应对催化反应的影响。
在本发明中，所述二氧化碳加氢耦合甲苯烷基化反应的温度优选为300～460℃，更优选为360℃；反应压力优选为1～5MPa，更优选为3MPa。
在本发明中，所述二氧化碳加氢耦合甲苯烷基化反应包括二氧化碳加氢制甲醇反应和甲醇甲苯烷基化反应；所述二氧化碳加氢制甲醇反应的反应式为：
CO 2+3H 2→CH 3OH+H 2O；
所述甲醇甲苯烷基化反应的反应式为：
Figure PCTCN2020077412-appb-000001
下面将结合本发明中的实施例，对本发明中的技术方案进行清楚、完整地描述。显然，所描述的实施例仅仅是本发明一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本发明保护的范围。
实施例1
将ZnZrO 1.7与H-ZSM-5分子筛(硅铝比为85，购于南开大学催化剂厂)以质量比1:1研磨混合均匀，造粒并过筛，得到粒度为40～60目的组合型催化剂。
实施例2
取2.0g H-ZSM-5分子筛(硅铝比为85，购于南开大学催化剂厂)，加入2.44mL正硅酸四乙酯和1.0mL的己烷，搅拌均匀后，浸渍4h，在110℃条件下烘干，然后置于550℃的空气中煅烧4h，重复以上步骤两次，得到改性H-ZSM-5分子筛；
将ZnZrO 1.7与所述改性H-ZSM-5分子筛以质量比1:1研磨混合均匀，造粒并过筛，得到粒度为40～60目的组合型催化剂。
实施例3
将ZnZrO 1.7与改性H-ZSM-5分子筛以质量比1:9研磨混合均匀，造粒并过筛，得到粒度为40～60目组合型催化剂；其中，改性H-ZSM-5分子筛的制备方法与实施例2相同。
实施例4
将ZnZrO 1.7与改性H-ZSM-5分子筛以质量比1:9研磨混合均匀，造粒并过筛，得到粒度为40～60目的组合型催化剂；其中，改性H-ZSM-5分子筛的制备方法与实施例2基本相同，不同之处仅在于，所述改性步骤由重复两次更改为重复四次。
实施例5
将0.0164g六水合硝酸锌和0.1586g五水合硝酸锆溶解于2.7mL水中，记为溶液A，将0.0837g碳酸铵溶解于2.7mL水中并标记为溶液B；将0.45g改性分子筛(同实施例2)加入溶液A中，在70℃下边搅拌边逐滴加入溶液B；滴加速度为3mL/min；滴加完毕后持续搅拌2h，冷却至室温后离心得到沉淀物；将所述沉淀物依次进行洗涤和干燥过夜后，在500℃、空气 中煅烧3h，造粒并过筛，得到粒度为40～60目的组合型催化剂。
应用例
采用高压连续固定床反应器对催化剂性能进行评价，采用气相色谱对产物组分进行分析，仪器示意图如图1所示。分别取实施例1～5提供的组合型催化剂0.2g，与0.8g 40～60目的石英砂混合均匀，先在450℃的氢气-氮气混合气中还原2h，得到活性催化剂；其中，氢气占氢气-氮气混合气的体积分数为5％；
将所述活性催化剂置于石英反应管中，以12000mL·g -1·h -1的空速通入二氧化碳、氢气、甲苯和氮气(其中氮气的体积分数为1～10％，作为内标)的混合气，其中，氢气与二氧化碳的摩尔比为3:1，二氧化碳与气态甲苯的摩尔比为12：1，气态甲苯在90℃下使用吹脱罐进样，在360℃、3.0MPa压力下，反应15h；仪器的所有管路使用加热保温设计，反应前管路温度大于鼓泡罐温度；反应产物经分流后进入配备火焰离子化检测器(FID)和热导池检测器(TCD)的气相色谱(GC)中进行在线分析，二氧化碳转化率和反应产物选择性的计算使用C基归一化法，所得结果见表1；
对比例
仅以实施例2中制备得到的0.18g改性H-ZSM-5分子筛为催化剂，按照与应用例相似的方法进行反应，与应用例不同之处仅在于：将通入的二氧化碳和氢气更改为氮气，二氧化碳转化率和反应产物选择性的测试结果见表1。
表1 二氧化碳转化率和反应产物选择性测试结果
Figure PCTCN2020077412-appb-000002
Figure PCTCN2020077412-appb-000003
由表1可以看出，改性H-ZSM-5分子筛能够提高对二甲苯(PX)的选择性；通过调节金属氧化物和分子筛的比例可有效提高二甲苯选择性，并抑制逆水煤气变换(RWGS)反应；由实施例4与实施例2对比可知，通过调节分子筛的改性工艺，可进一步提高PX的选择性；结合对比例的实验结果可知，在对比例的反应条件下，甲苯在分子筛上的歧化反应速率相当缓慢，甲苯仅有0.5％的转化率，且在有二氧化碳和氢气存在的条件下，优先发生甲苯烷基化反应，由此说明实施例1～5中的二甲苯基本全部由甲苯与二氧化碳和氢气通过烷基化反应生成，而非甲苯岐化反应，二氧化碳和氢气为有效的烷基化试剂。
实施例4制备得到的组合型催化剂的100h稳定性测试结果如图2所示，其中，图2中的A为催化反应产物分布图(不计CO)，图2中的B为二甲苯中邻二甲苯、间二甲苯和对二甲苯的分布图。由图2可以看出，甲苯转化率和PX在二甲苯中的选择性分别稳定保持在11％和70％，二甲苯选择性(不计CO)从初始的82％，经30h后降至63％并趋于稳定，而同样具有高附加值的4-乙基甲苯选择性由11％上升至23％，4-乙基甲苯由PX再进行一步侧链烷基化而形成。由此说明，本发明提供的组合型催化剂具有稳定的活性和PX选择性，气态烷烃选择性小于1.5％，并且产物中始终含有绝大多数的高附加值芳烃组分。
以上实施例的说明只是用于帮助理解本发明的方法及其核心思想。应当指出，对于本技术领域的普通技术人员来说，在不脱离本发明原理的前提下，还可以对本发明进行若干改进和修饰，这些改进和修饰也落入本发明权利要求的保护范围内。对这些实施例的多种修改对本领域的专业技术人员来说是显而易见的，本文中所定义的一般原理可以在不脱离本发明的精神或范围的情况下在其它实施例中实现。因此，本发明将不会被限制于本文所示的这些实施例，而是要符合与本文所公开的原理和新颖特点相一致的最宽的范围。

Claims (10)

  1. 一种组合型催化剂，其特征在于，包括金属氧化物和分子筛；所述金属氧化物包括ZnZrO x1、ZnCrO x2、ZnAlO x3和CrO x4中的一种或几种，其中1＜x1＜2，1＜x2＜1.5，1＜x3＜1.5，1＜x4＜1.5。
  2. 根据权利要求1所述的组合型催化剂，其特征在于，所述分子筛包括ZSM-5分子筛、MCM-22分子筛和SAPO-34分子筛中的一种或几种。
  3. 根据权利要求1或2所述的组合型催化剂，其特征在于，所述金属氧化物和分子筛的质量比为(1～9)：(1～9)。
  4. 权利要求1～3任一项所述组合型催化剂的制备方法，其特征在于，包括以下步骤：将金属氧化物和分子筛进行混合，得到组合型催化剂。
  5. 权利要求1～3任一项所述组合型催化剂的另一种制备方法，其特征在于，包括以下步骤：将金属盐溶液和分子筛进行第一混合，得到分散液；
    将所述分散液和沉淀剂进行第二混合，发生沉淀反应，得到沉淀物；
    将所述沉淀物进行煅烧，得到组合型催化剂。
  6. 一种二氧化碳加氢耦合甲苯烷基化制二甲苯的方法，其特征在于，包括以下步骤：
    将权利要求1～3任一项所述组合型催化剂或权利要求4～5任一项所述制备方法制备的组合型催化剂置于还原性气氛中，进行活化，得到活性催化剂；
    将所述活性催化剂与二氧化碳、氢气和甲苯混合，发生二氧化碳加氢耦合甲苯烷基化反应，得到二甲苯。
  7. 根据权利要求6所述的方法，其特征在于，提供所述还原性气氛条件的气体为氢气和氩气的混合气，或氢气和氮气的混合气。
  8. 根据权利要求6或7所述的方法，其特征在于，所述活化的温度为200～600℃，所述活化的时间为0.5～12h。
  9. 根据权利要求6所述的方法，其特征在于，所述二氧化碳的空速为300～6000mL·g -1·h -1；所述二氧化碳与氢气的摩尔比为1：(1～8)；所述二氧化碳与甲苯的摩尔比为(1～30)：2。
  10. 根据权利要求6或9所述的方法，其特征在于，所述二氧化碳加氢耦合甲苯烷基化反应的温度为300～460℃，反应压力为1～5MPa。
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CN113600229B (zh) * 2021-09-13 2022-07-26 厦门大学 复合双层催化剂、二氧化碳/一氧化碳加氢耦合苯烷基化制备乙苯和/或丙苯的方法
CN115646536B (zh) * 2022-10-20 2024-04-26 中国科学院山西煤炭化学研究所 Co2加氢耦合苯/甲苯烷基化用催化剂及其制备与应用
CN115672385B (zh) * 2022-10-28 2024-02-20 济南新材料产业技术研究院 一种催化剂及其在二氧化碳加氢耦合btx生产多甲基芳烃的应用

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1355779A (zh) * 1999-05-14 2002-06-26 埃克森美孚化学专利公司 直接选择性合成对二甲苯的方法
US20180023008A1 (en) * 2014-07-24 2018-01-25 Exxonmobil Chemical Patents Inc. Production of Xylenes from Syngas
CN110743609A (zh) * 2019-11-21 2020-02-04 厦门大学 一种组合型催化剂及其制备方法和二氧化碳加氢耦合甲苯烷基化制二甲苯的方法

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103785463B (zh) * 2012-11-01 2016-07-27 中国石油化工股份有限公司 甲苯甲醇烷基化催化剂及其制备方法和应用
CN104557425A (zh) * 2013-10-28 2015-04-29 中国石油化工股份有限公司 芳烃烷基化生产对二甲苯的催化蒸馏方法
US9714386B2 (en) * 2014-07-24 2017-07-25 Exxonmobil Chemical Patents Inc. Production of xylenes from syngas
WO2017093881A1 (en) * 2015-12-04 2017-06-08 Sabic Global Technologies B.V. Alkane aromatization by oxidative dehydrogenation with co2
CN107970988B (zh) * 2016-10-24 2020-05-12 中国科学院大连化学物理研究所 一种用于合成芳烃的催化剂和其制备方法
CN107999118B (zh) * 2016-10-28 2021-08-06 中国石油化工股份有限公司 一种芳烃和合成气烷基化催化剂及其制备方法与应用
CN109420486A (zh) * 2017-08-29 2019-03-05 中国科学院大连化学物理研究所 二氧化碳加氢合成甲醇的ZnZrOx固溶体催化剂及制备和应用
CN109772436B (zh) * 2017-11-15 2022-08-05 中国科学院大连化学物理研究所 一种芳烃合成用催化剂及其制备方法

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1355779A (zh) * 1999-05-14 2002-06-26 埃克森美孚化学专利公司 直接选择性合成对二甲苯的方法
US20180023008A1 (en) * 2014-07-24 2018-01-25 Exxonmobil Chemical Patents Inc. Production of Xylenes from Syngas
CN110743609A (zh) * 2019-11-21 2020-02-04 厦门大学 一种组合型催化剂及其制备方法和二氧化碳加氢耦合甲苯烷基化制二甲苯的方法

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
LI ZELONG, QU YUANZHI, WANG JIJIE, LIU HAILONG, LI MINGRUN, MIAO SHU, LI CAN: "Highly Selective Conversion of Carbon Dioxide to Aromatics over Tandem Catalysts", JOULE, CELL PRESS, vol. 3, no. 2, 1 February 2019 (2019-02-01), pages 570 - 583, XP055814503, ISSN: 2542-4351, DOI: 10.1016/j.joule.2018.10.027 *
NI YOUMING, CHEN ZHIYANG, FU YI, LIU YONG, ZHU WENLIANG, LIU ZHONGMIN: "Selective conversion of CO2 and H2 into aromatics", NATURE COMMUNICATIONS, vol. 9, no. 1, 1 December 2018 (2018-12-01), XP055814504, DOI: 10.1038/s41467-018-05880-4 *
WANG YANG, TAN LI, TAN MINGHUI, ZHANG PEIPEI, FANG YUAN, YONEYAMA YOSHIHARU, YANG GUOHUI, TSUBAKI NORITATSU: "Rationally Designing Bifunctional Catalysts as an Efficient Strategy To Boost CO 2 Hydrogenation Producing Value-Added Aromatics", ACS CATALYSIS, AMERICAN CHEMICAL SOCIETY, US, vol. 9, no. 2, 1 February 2019 (2019-02-01), US, pages 895 - 901, XP055814508, ISSN: 2155-5435, DOI: 10.1021/acscatal.8b01344 *

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