Method for preparing methyl-ethylbenzene by converting synthesis gas and coupling ethylbenzene

Abstract

The invention discloses a method for preparing methyl-ethylbenzene through conversion and coupling of synthesis gas and ethylbenzene, and the preparation method comprises the following steps: contacting a raw material containing synthesis gas and ethylbenzene with a combined catalyst, and carrying out a reaction to obtain an aromatic hydrocarbon product containing methyl-ethylbenzene, the synthesis gas comprises hydrogen and carbon monoxide; wherein the combined catalyst comprises a first component and a second component; the first component is an oxide with synthesis gas conversion activity, and the second component is a zeolite molecular sieve with acidic sites; the oxide accounts for 10-90% of the mass fraction of the combined catalyst; and the zeolite molecular sieve accounts for 10-90% of the mass fraction of the combined catalyst. The catalyst is prepared by combining an oxide material with synthesis gas conversion capability and a modified zeolite molecular sieve material through a proper method, so that the preparation of high-selectivity methyl-ethylbenzene is realized.

Description

Technical Field

[0001] The present application relates to a method for synthesizing ethylbenzene by coupling syngas conversion to prepare methyl ethylbenzene, belonging to the technical field of aromatic hydrocarbon preparation. Background Art

[0002] Methyl ethylbenzene is a raw material for the production of methylstyrene. As a low-toxicity and low-volatility monomer, methylstyrene can be widely used in the production of a variety of high-value industrial polymers, such as polymethylstyrene, unsaturated polyester, reinforcing fibers, alkyl coatings, etc., showing superior properties beyond polymers based on common monomers such as styrene. However, its current production capacity is still low, and its large-scale application awaits further upgrading of the upstream and downstream industries.

[0003] In addition to a small amount from the separation of reformed C9 aromatics, most of the production of methyl ethylbenzene is obtained by the alkylation reaction of toluene with ethylating reagents such as ethanol or ethylene in the presence of a catalyst. The typical products are three isomers of methyl ethylbenzene in thermodynamic equilibrium composition and a small amount of other aromatic products (CN104557375A)(CN102503762A)(CN105367373A)(CN105536862A). The main problems are the dependence on high-value ethanol or ethylene as raw materials and the high energy consumption for the separation of isomer products.

[0004] Using syngas mainly composed of carbon monoxide and hydrogen obtained from various sources such as coal, natural gas, and biomass as raw materials, high-value aromatic hydrocarbon products can be obtained. Traditional schemes can obtain a relatively high proportion of aromatic hydrocarbon products by combining the modified Fischer-Tropsch (FT) route with zeolite molecular sieves. Methanol intermediates can also be obtained through oxide catalysts and then aromatic hydrocarbon products can be obtained through the Methanol to Aromatics (MTA) route. However, none of the above schemes can obtain a single aromatic hydrocarbon product with high selectivity, and there are inevitable hydrogen transfer reactions, resulting in the formation of a large amount of low-value saturated alkanes, reducing the carbon utilization rate of the reaction. Summary of the Invention

[0005] The technical problem to be solved by the present application is to provide a method for synthesizing methyl ethylbenzene by coupling syngas conversion with ethylbenzene alkylation using a combined catalyst, opening up a reaction route without using ethanol or ethylene as raw materials, and at the same time overcoming the problem that it is difficult to obtain a single high-value aromatic hydrocarbon product with high selectivity in syngas conversion.

[0006] In one aspect of the present application, a method for highly selectively preparing methyl ethylbenzene in the coupling reaction of syngas conversion and ethylbenzene alkylation using a combined catalyst is provided. A combined catalyst obtained by combining two or more active component materials in a certain combination is used, and carbon monoxide, hydrogen, and ethylbenzene vapor are co-fed to obtain an aromatic hydrocarbon product containing methyl ethylbenzene.

[0007] The method includes:

[0008] Contacting a raw material containing syngas and ethylbenzene with a combined catalyst to carry out a reaction to obtain an aromatic hydrocarbon product containing methyl ethylbenzene;

[0009] The syngas is a mixed gas of hydrogen and carbon monoxide;

[0010] Wherein, the combined catalyst is reduced in a hydrogen atmosphere;

[0011] The combined catalyst includes a first component and a second component;

[0012] The first component is an oxide having syngas conversion activity, and the second component is a zeolite molecular sieve having acidic sites;

[0013] The mass fraction of the oxide in the combined catalyst is 10% - 90%;

[0014] The mass fraction of the zeolite molecular sieve in the combined catalyst is 10% - 90%.

[0015] Optionally, the mass fraction of the first component in the combined catalyst independently selects any value from 10%, 30%, 50%, 70%, 90%, 100% or any range value between any two of the above;

[0016] Optionally, the mass fraction of the second component in the combined catalyst independently selects any value from 10%, 30%, 50%, 70%, 90%, 100% or any range value between any two of the above;

[0017] Optionally, the temperature of the reaction is 200 - 600 °C.

[0018] Optionally, the temperature of the reaction is 300 - 500 °C.

[0019] Optionally, the temperature of the reaction independently selects any value from 200 °C, 300 °C, 320 °C, 340 °C, 360 °C, 380 °C, 400 °C, 420 °C, 440 °C, 460 °C, 480 °C, 500 °C, 600 °C or any range value between any two of the above;

[0020] Optionally, the pressure of the reaction is 0.5 - 10 MPa.

[0021] Optionally, the pressure of the reaction is 1 - 4 MPa.

[0022] Optionally, the pressure of the reaction is independently selected from any value among 0.5 MPa, 1 MPa, 2 MPa, 3 MPa, 4 MPa, 6 MPa, 8 MPa, 10 MPa or any range value between any two of the above.

[0023] Optionally, in the mixed gas, the volume ratio of carbon monoxide to hydrogen is 12:1 to 1:12.

[0024] Optionally, the volume ratio of carbon monoxide to hydrogen is 1:1 to 1:6.

[0025] Optionally, the volume ratio of carbon monoxide to hydrogen is 1:3.

[0026] Optionally, the volume ratio of carbon monoxide to hydrogen is independently selected from any value among 12:1, 6:1, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:12 or any range value between any two of the above.

[0027] Optionally, the syngas further includes an inert gas;

[0028] The inert gas is selected from at least one of nitrogen and argon.

[0029] Optionally, the inert gas is argon.

[0030] Optionally, the space velocity of the syngas is 600 - 48000 mL g -1 h -1 。

[0031] Optionally, the space velocity of the syngas is 6000 - 24000 mL g -1 h -1 。

[0032] Optionally, the space velocity of the syngas is independently selected from 600 mL g -1 h -1 、6000 mL g -1 h -1 、12000 mL g -1 h -1 、18000 mL g -1 h -1 、24000 mL g -1 h -1 、30000 mL g -1 h -1 、36000 mL g -1 h -1 、42000 mL g -1 h -1 、48000 mL g -1 h-1 Any range value between them.

[0033] Optionally, the mass hourly space velocity of the ethylbenzene is 0.1 - 10 h -1 .

[0034] Optionally, the mass hourly space velocity of the ethylbenzene is 1 - 4 h -1 .

[0035] Optionally, the mass hourly space velocity of the ethylbenzene is independently selected from any value of 0.1 h -1 , 1 h -1 , 2 h -1 , 3 h -1 , 4 h -1 , 6 h -1 , 8 h -1 , 10 h -1 or any range value between any two of the above.

[0036] As a specific embodiment, carbon monoxide, hydrogen and ethylbenzene vapor are co-fed and contacted with a catalyst bed for reaction to obtain an aromatic hydrocarbon product containing methyl ethylbenzene. The carbon monoxide-hydrogen mixed gas can be diluted with a certain proportion of inert gas, and the inert gas can be selected but not limited to nitrogen and argon, and preferably argon.

[0037] Optionally, the combined catalyst used in this application can be diluted or not diluted with an inert material such as quartz sand.

[0038] Optionally, the pressure of the hydrogen atmosphere is 0.1 - 10.0 MPa.

[0039] Optionally, the pressure of the hydrogen atmosphere is independently selected from any value of 0.1 MPa, 1 MPa, 2 MPa, 3 MPa, 4 MPa, 5 MPa, 6 MPa, 8 MPa, 10 MPa or any range value between any two of the above.

[0040] Optionally, the reduction temperature is 300 - 600 °C.

[0041] Optionally, the reduction temperature is independently selected from any value of 300 °C, 400 °C, 500 °C, 600 °C or any range value between any two of the above.

[0042] Optionally, the reduction time is 0.5 - 8 h.

[0043] Optionally, the reduction time is 1 - 3 h.

[0044] Optionally, the reduction time is independently selected from any value of 0.5 h, 1 h, 2 h, 3 h, 4 h, 6 h, 8 h or any range value between any two of the above.

[0045] Optionally, the first component and the second component are combined by at least one of powder mechanical grinding and particle physical mixing.

[0046] Optionally, the powder mechanical grinding includes:

[0047] Grinding the oxide powder and the zeolite molecular sieve powder for 1 to 30 minutes; extruding the obtained powder under 5 to 30 MPa; crushing, and screening out particles with a size of 10 to 80 meshes; mixing evenly.

[0048] Optionally, the grinding time is 5 to 10 minutes.

[0049] Optionally, the extrusion pressure is 15 to 20 MPa.

[0050] Optionally, the particle size of the screening is 20 to 60 meshes.

[0051] Optionally, the particle physical mixing includes:

[0052] Extruding the oxide powder and the zeolite molecular sieve powder respectively under 5 to 30 MPa; crushing, and screening out particles with a size of 10 to 80 meshes; mixing the two kinds of particles evenly according to the designed ratio.

[0053] Optionally, the extrusion pressure is 15 to 20 MPa.

[0054] Optionally, the particle size of the screening is 20 to 60 meshes.

[0055] This application uses a combined catalyst obtained by combining two or more active component materials in a certain combination manner.

[0056] Optionally, the first component is selected from at least one of oxides of elements in IIIA, IIB, IVB, and VIB.

[0057] Optionally, the first component is selected from at least one of oxides of Zn, Zr, Al, Cr, Ga, and In.

[0058] Optionally, the first component further includes a carrier, and the oxide is loaded on the carrier;

[0059] The carrier is selected from at least one of silica and alumina.

[0060] Optionally, the preparation of the oxide used in this application can be realized by one or several of impregnation method, sol-gel method, precipitation method, template method, and mechanical mixing method, and includes the following steps:

[0061] a. Impregnation method: Using a commercially purchased or pre-prepared oxide material as a carrier, mixing it evenly with a solution prepared from soluble salts of another metal or multiple metals, and removing the solvent by evaporation or other means;

[0062] Sol-gel method: Mixing soluble salts of one or more metals with specific organic ligands, adjusting parameters such as pH and temperature to form a sol, removing part of the solvent by evaporation or other means, and forming a dry gel at a higher temperature;

[0063] Precipitation method: Preparing a solution from soluble salts of one or more metals, using an alkaline reagent as a precipitant to adjust the pH to precipitate the oxide, with an optional pH range of 5 - 10, preferably 6 - 8; solid-liquid separation is carried out by filtration, centrifugation, etc., and the solid is washed to remove excess ions;

[0064] Template method: Mixing a solution prepared from soluble salts of one or more metals with templates such as activated carbon and silica sol to form a suspension, adjusting the pH to precipitate the metal or evaporating the solvent;

[0065] Mechanical mixing method: Mechanically mixing soluble salts of one or more metals in solid form with an inert carrier by ball milling or other means;

[0066] b. Drying: Temperature 40 - 150 °C, preferably 80 - 120 °C; under static air, blowing or vacuum conditions, drying for 2 - 24 h, preferably 8 - 12 h;

[0067] c. Calcination: Temperature 200 - 800 °C, preferably 200 - 600 °C; in static air, calcining for 2 - 12 h, preferably 4 - 8 h.

[0068] Optionally, the second component mainly consists of silicon, aluminum, and oxygen, and is selected from at least one of H-Y zeolite, H-MCM-22 zeolite, H-ZSM-5 zeolite, H-MOR zeolite, and H-Beta zeolite;

[0069] Optionally, the second component is H-ZSM-5 zeolite;

[0070] Optionally, the silicon-aluminum atomic ratio of the zeolite molecular sieve is 1 - 500.

[0071] Optionally, the silicon-aluminum atomic ratio of the zeolite molecular sieve is 10 - 200.

[0072] Optionally, the silicon-aluminum atomic ratio of the zeolite molecular sieve is 30 - 50.

[0073] Optionally, the silicon-aluminum atomic ratio of the zeolite molecular sieve is independently selected from any value among 1, 10, 30, 40, 50, 100, 150, 200, 300, 400, 500 or any range value between any two of the above.

[0074] Optionally, the zeolite molecular sieve may be modified by a suitable method.

[0075] Optionally, the zeolite molecular sieve is modified by at least one of loading metals and their oxides, non-metals and their oxides, etching, and hydrothermal treatment.

[0076] Optionally, the zeolite molecular sieve is modified by loading non-metal and its oxide.

[0077] Optionally, the zeolite molecular sieve is modified by loading a modifier;

[0078] The modifier is selected from at least one of Zn, Ga, Mg, Mn, Mo, P, and Si.

[0079] Optionally, the modifier is Si.

[0080] Optionally, the mass fraction of the modifier in the zeolite molecular sieve is 0.1% to 20%.

[0081] Optionally, the mass fraction of the modifier in the zeolite molecular sieve is 1% to 10%.

[0082] Optionally, the mass fraction of the modifier in the zeolite molecular sieve is independently selected from any value among 0.1%, 1%, 2%, 4%, 6%, 8%, 10%, 15%, 20% or any range of values ​​between any two of the above points.

[0083] Optionally, the modification method of the zeolite molecular sieve can be achieved by one or more of an impregnation method, a solid phase grinding method, and a chemical deposition method:

[0084] a. Impregnation method: a pre-prepared zeolite molecular sieve material is used as a carrier, a solution prepared with one or more element precursors is mixed with it evenly, and the solvent is removed by evaporation or the like;

[0085] Solid phase grinding method: Precursors of one or more elements and zeolite molecular sieve materials are mechanically mixed by ball milling or other methods;

[0086] Chemical deposition method: disperse the precursor compound containing one or more elements and the zeolite molecular sieve material in a specific solvent, and try to remove the solvent;

[0087] b. Drying: temperature 40 to 150 ° C, preferably 80 to 120 ° C; under still air, blast or vacuum conditions, drying for 2 to 24 hours, preferably 8 to 12 hours;

[0088] c. Calcination: temperature 200-800°C, preferably 200-600°C; calcination in still air for 2-12h, preferably 4-8h.

[0089] The process adopted in this application is such that the product stream enters a gas-liquid separation device to obtain a liquid-phase product stream mainly composed of aromatic hydrocarbon products, and the non-condensable gas stream is vented or can be recycled after purification and separation.

[0090] The beneficial effects that this application can produce include:

[0091] (1) The catalyst used in this invention is composed of an oxide material with syngas conversion performance and a modified zeolite molecular sieve material combined by an appropriate method, realizing the preparation of high-selectivity ethylmethylbenzene. This invention adopts a reaction route without using ethanol or ethylene as raw materials, and at the same time overcomes the problem that it is difficult to obtain a single high-value aromatic hydrocarbon product with high selectivity in syngas conversion, achieving a single-pass conversion rate of carbon monoxide of 20%, the conversion rate of ethylbenzene can reach 30%, and the total selectivity of ethylmethylbenzene in the liquid-phase product can reach up to 84% at most, among which the proportion of the para-isomer can reach 76%.

[0092] (2) This application provides an efficient method for obtaining ethylmethylbenzene products with a higher yield through the coupling of syngas conversion and ethylbenzene alkylation, overcomes the dependence on the petroleum route and high-value raw materials such as alcohols and olefins, avoids the complex operations and separation processes of multi-step synthesis to a certain extent, and broadens the catalytic synthesis route for converting syngas into high-value aromatic hydrocarbon products. BRIEF DESCRIPTION OF THE DRAWINGS

[0093] Figure 1 This is the evaluation stability result of this application for 50 hours. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0094] The following describes this application in detail with reference to the embodiments, but this application is not limited to these embodiments.

[0095] Unless otherwise specified, the raw materials in the embodiments of this application are all purchased through commercial channels.

[0096] In the embodiments of this application, the conversion rates of CO and ethylbenzene, the 2 selectivity of CO and the selectivity of aromatic hydrocarbon products in the liquid-phase product are calculated as follows:

[0097]

[0098]

[0099]

[0100] According to an embodiment of the present application, a combined catalyst is obtained by combining two or more active component materials in a certain combination manner. The first key component is an oxide material having syngas conversion activity, accounting for 10% to 90% of the mass of the combined catalyst. The second key component is a zeolite molecular sieve material having acidic sites, accounting for 10% to 90% of the mass of the combined catalyst. Preferably, the mass fraction of the oxide is 30% to 60%, and the mass fraction of the zeolite molecular sieve is preferably 30% to 60%.

[0101] The first key component used in the present application is an oxide material having syngas conversion activity, including one or more of oxides of elements in Group IIIA, IIB, IVB, and VIB, preferably oxides of one or more elements in Zn, Zr, Al, Cr, Ga, and In, and more preferably an oxide containing two elements of metal Zn and Zr.

[0102] The preparation of the oxide used in the present application can be achieved by one or more of impregnation method, sol-gel method, precipitation method, template method, and mechanical mixing method, preferably the sol-gel method; a soluble salt of metal Zn and Zr and a specific organic ligand are mixed, and parameters such as pH and temperature are adjusted to form a sol. Part of the solvent is removed by evaporation or the like, and a dry gel is formed at a higher temperature. After calcination, the oxide material is obtained; the metal salt in the present application is preferably one or both of nitrate and acetate, and more preferably nitrate; the organic ligand in the present invention is preferably citric acid; the evaporation temperature is preferably 40 to 120 °C; the temperature for forming the dry gel is preferably 120 to 240 °C; the calcination temperature is preferably 400 to 600 °C, and the time is preferably 4 to 12 h.

[0103] The second key component used in the present application is a zeolite molecular sieve material having acidic sites, mainly composed of silicon, aluminum, and oxygen, including one or more of H-Y molecular sieve, H-MCM-22 molecular sieve, H-ZSM-5 molecular sieve, H-MOR molecular sieve, and H-Beta molecular sieve, preferably H-ZSM-5 molecular sieve; the silicon-aluminum atomic ratio of the molecular sieve can be 1 to 500, preferably 10 to 200, and more preferably 30 to 50.

[0104] The zeolite material used in the present application can be modified by one or more of methods such as loading metals and their oxides, non-metals and their oxides, etching, and hydrothermal treatment, preferably modification with metals and their oxides.

[0105] The modification of the zeolite material used in this application can use one or several of the elements such as Zn, Ga, Mg, Mn, Mo, P, Si, etc.; preferably silicon is used as the modifier, and the added mass fraction can be between 0.1% and 20%, preferably between 1% and 10%. The modification method can be achieved by one or several of the impregnation method, solid-phase grinding method, and chemical deposition method. The preferred modification method is the impregnation method: using a pre-prepared zeolite molecular sieve material as the carrier, mixing it evenly with the organosilicon precursor tetraethyl orthosilicate, removing the solvent by evaporation or other means, and obtaining the modified zeolite molecular sieve material through drying and calcination; the drying temperature is 40 - 150°C, preferably 80 - 120°C, the drying time is 2 - 24h, preferably 8 - 12h; the calcination temperature is 200 - 800°C, preferably 200 - 600°C, and the calcination time is 2 - 12h, preferably 4 - 8h.

[0106] The two key components used in this application can be combined by means such as powder mechanical grinding and particle physical mixing. Preferably, powder mechanical grinding is used: mixing the oxide material and the zeolite molecular sieve material powder evenly in an agate mortar, grinding for 1 - 30 min, preferably 5 - 10 min; extruding the obtained powder under 5 - 30 MPa, preferably 15 - 20 MPa; crushing, and screening out particles with a mesh size of 10 - 80 meshes, preferably 20 - 60 meshes.

[0107] The combined catalyst used in this application can be diluted or not diluted with inert materials such as quartz sand, preferably diluted; under a pressure of 0.1 - 10.0 MPa and in a hydrogen atmosphere, at a temperature of 300 - 600°C, reduce for 0.5 - 8 h, preferably 1 - 3 h.

[0108] This application uses carbon monoxide, hydrogen, and ethylbenzene vapor to co-feed, contact and react with the catalyst bed layer to obtain an aromatic hydrocarbon product containing methyl ethylbenzene.

[0109] The reaction temperature used in this application can be 200 - 600°C, preferably 300 - 500°C; the reaction pressure is 0.5 - 10 MPa, preferably 1 - 4 MPa; the ratio of carbon monoxide to hydrogen can be 1:1 - 1:6, preferably 1:3; it can be diluted with a certain proportion of inert gas, and the inert gas can be selected but not limited to nitrogen and argon, preferably argon; the space velocity is 600 - 48000 mL g -1 h -1 ,preferably 6000 - 24000 mL g -1 h -1 ; the mass space velocity of ethylbenzene is 0.1 - 10 h -1 ,preferably 1 - 4 h -1 .

[0110] The specific embodiments of the present invention are specifically described below through specific examples. The described examples are only partial embodiments of the present invention, and all other embodiments obtained by modifying and changing the specific embodiments based on the spirit of the present invention fall within the protection scope of the present invention.

[0111] Example 1

[0112] Catalyst preparation:

[0113] 7.28 g of zirconium nitrate pentahydrate, 0.08 g of zinc nitrate hexahydrate and 8.28 g of citric acid monohydrate were dissolved in 50 mL of ultrapure water, and the solvent was continuously stirred and evaporated at 90 °C. The obtained sol was heat-treated at 180 °C to obtain a xerogel, and calcined at 500 °C for 10 h to obtain the required oxide material.

[0114] 1 g of H-ZSM-5 zeolite molecular sieve was mixed with 20 mL of cyclohexane solution containing 0.5 mL of tetraethyl orthosilicate, stirred at 60 °C for 4 h, the solvent was evaporated to dryness at 80 °C, dried at 120 °C for 12 h, and calcined at 500 °C for 4 h. The above operations were repeated 2 times to obtain the modified zeolite molecular sieve.

[0115] Equal masses of the oxide and the modified H-ZSM-5 zeolite molecular sieve with a silicon-aluminum atomic ratio of 50 were mixed evenly, ground for 15 min, extruded at 15 MPa, crushed, and 250 mg of particles with a mesh size of 40 - 60 were screened out for standby.

[0116] Performance evaluation:

[0117] The shaped catalyst was diluted with quartz sand at a mass ratio of 1:5, filled into the constant temperature section of the stainless steel tube of the fixed bed reactor, pretreated at 500 °C for 2 h in a hydrogen atmosphere with a pressure of 0.1 MPa, the reaction temperature was 320 °C, the pressure was 3 MPa, the volume ratio of carbon monoxide: hydrogen: argon was 32:64:4, and the space velocity was 12000 mL g -1 h -1 The mass space velocity of ethylbenzene was 1 h -1 .

[0118] For easy comparison, the reaction results are summarized in Table 1.

[0119] Example 2

[0120] Catalyst preparation:

[0121] 7.28 g of zirconium nitrate pentahydrate, 0.08 g of zinc nitrate hexahydrate and 8.28 g of citric acid monohydrate were dissolved in 50 mL of ultrapure water, and the solvent was continuously stirred and evaporated at 90 °C. The obtained sol was heat-treated at 180 °C to obtain a xerogel, and calcined at 500 °C for 10 h to obtain the required oxide material.

[0122] 1 g of H-ZSM-5 zeolite molecular sieve was mixed with 20 mL of cyclohexane solution containing 0.5 mL of tetraethyl orthosilicate, stirred at 60 °C for 4 h, the solvent was evaporated at 80 °C, dried at 120 °C for 12 h, calcined at 500 °C for 4 h, and the above operations were repeated twice to obtain the modified zeolite molecular sieve.

[0123] Equal masses of the oxide and H-ZSM-5 zeolite molecular sieve with a silica-alumina atomic ratio of 50 were mixed evenly, ground for 15 min, extruded at 15 MPa, crushed, and 250 mg of particles with a mesh size of 40 - 60 were sieved out for standby.

[0124] Performance evaluation:

[0125] The shaped catalyst was diluted with quartz sand at a mass ratio of 1:5, filled into the isothermal section of the stainless steel tube of the fixed-bed reactor, pretreated at 500 °C for 2 h in a hydrogen atmosphere with a pressure of 0.1 MPa, the reaction temperature was 340 °C, the pressure was 3 MPa, the volume ratio of carbon monoxide:hydrogen:argon was 32:64:4, and the space velocity was 12000 mL g -1 h -1 , and the mass hourly space velocity of ethylbenzene was 1 h -1 .

[0126] For easy comparison, the reaction results are summarized in Table 1.

[0127] Example 3

[0128] Catalyst preparation:

[0129] 7.28 g of zirconium nitrate pentahydrate, 0.08 g of zinc nitrate hexahydrate and 8.28 g of citric acid monohydrate were dissolved in 50 mL of ultrapure water, and the solvent was continuously stirred and evaporated at 90 °C. The obtained sol was heat-treated at 180 °C to obtain a dry gel, and calcined at 500 °C for 10 h to obtain the required oxide material.

[0130] 1 g of H-ZSM-5 zeolite molecular sieve was mixed with 20 mL of cyclohexane solution containing 0.5 mL of tetraethyl orthosilicate, stirred at 60 °C for 4 h, the solvent was evaporated at 80 °C, dried at 120 °C for 12 h, calcined at 500 °C for 4 h, and the above operations were repeated twice to obtain the modified zeolite molecular sieve.

[0131] Equal masses of the oxide and H-ZSM-5 zeolite molecular sieve with a silica-alumina atomic ratio of 50 were mixed evenly, ground for 15 min, extruded at 15 MPa, crushed, and 250 mg of particles with a mesh size of 40 - 60 were sieved out for standby.

[0132] Performance evaluation:

[0133] The shaped catalyst was diluted with quartz sand at a mass ratio of 1:5, filled into the isothermal section of the stainless steel tube of the fixed-bed reactor, pretreated at 500 °C for 2 h in a hydrogen atmosphere with a pressure of 0.1 MPa, the reaction temperature was 360 °C, the pressure was 3 MPa, the volume ratio of carbon monoxide:hydrogen:argon was 32:64:4, and the space velocity was 12000 mL g -1 h -1 , and the mass hourly space velocity of ethylbenzene was 1 h -1 .

[0134] For easy comparison, the reaction results are summarized in Table 1.

[0135] Example 4

[0136] Catalyst preparation:

[0137] 7.28 g of zirconium nitrate pentahydrate, 0.08 g of zinc nitrate hexahydrate and 8.28 g of citric acid monohydrate were dissolved in 50 mL of ultrapure water, and the solvent was continuously stirred and evaporated at 90 °C. The obtained sol was heat-treated at 180 °C to obtain a dry gel, and calcined at 500 °C for 10 h to obtain the required oxide material.

[0138] 1 g of H-ZSM-5 zeolite molecular sieve was mixed with 20 mL of cyclohexane solution containing 0.5 mL of tetraethyl orthosilicate, stirred at 60 °C for 4 h, the solvent was evaporated to dryness at 80 °C, dried at 120 °C for 12 h, and calcined at 500 °C for 4 h. The above operations were repeated 2 times to obtain the modified zeolite molecular sieve.

[0139] Equal masses of the oxide and H-ZSM-5 zeolite molecular sieve with a silicon-aluminum atomic ratio of 50 were mixed evenly, ground for 15 min, extruded at 15 MPa, crushed, and 250 mg of particles with a mesh size of 40 - 60 were screened out for standby.

[0140] Performance evaluation:

[0141] The shaped catalyst was diluted with quartz sand at a mass ratio of 1:5, filled into the isothermal section of the stainless steel tube of the fixed-bed reactor, pretreated at 500 °C for 2 h in a hydrogen atmosphere with a pressure of 0.1 MPa, the reaction temperature was 380 °C, the pressure was 3 MPa, the volume ratio of carbon monoxide:hydrogen:argon was 32:64:4, and the space velocity was 12000 mL g -1 h -1 , and the mass hourly space velocity of ethylbenzene was 1 h -1 .

[0142] For easy comparison, the reaction results are summarized in Table 1.

[0143] Example 5

[0144] Catalyst preparation:

[0145] 7.28 g of zirconium nitrate pentahydrate, 0.08 g of zinc nitrate hexahydrate and 8.28 g of citric acid monohydrate were dissolved in 50 mL of ultrapure water. The solvent was continuously stirred and evaporated at 90 °C. The obtained sol was heat-treated at 180 °C to obtain a xerogel, and calcined at 500 °C for 10 h to obtain the required oxide material.

[0146] 1 g of H-ZSM-5 zeolite molecular sieve was mixed with 20 mL of cyclohexane solution containing 0.5 mL of tetraethyl orthosilicate, stirred at 60 °C for 4 h, the solvent was evaporated to dryness at 80 °C, dried at 120 °C for 12 h, and calcined at 500 °C for 4 h. The above operations were repeated 2 times to obtain the modified zeolite molecular sieve.

[0147] Equal masses of the oxide and H-ZSM-5 zeolite molecular sieve with a silicon-aluminum atomic ratio of 50 were mixed evenly, ground for 15 min, extruded at 15 MPa, crushed, and 250 mg of particles with a mesh size of 40 - 60 were sieved out for standby.

[0148] Performance evaluation:

[0149] The shaped catalyst was diluted with quartz sand at a mass ratio of 1:5, filled into the isothermal section of the stainless steel tube of the fixed bed reactor, pretreated at 500 °C for 2 h in a hydrogen atmosphere with a pressure of 0.1 MPa, the reaction temperature was 400 °C, the pressure was 3 MPa, the volume ratio of carbon monoxide: hydrogen: argon was 32:64:4, and the space velocity was 12000 mL g -1 h -1 , and the mass hourly space velocity of ethylbenzene was 1 h -1 .

[0150] For easy comparison, the reaction results are summarized in Table 1.

[0151] Example 6

[0152] Catalyst preparation:

[0153] 7.28 g of zirconium nitrate pentahydrate, 0.08 g of zinc nitrate hexahydrate and 8.28 g of citric acid monohydrate were dissolved in 50 mL of ultrapure water. The solvent was continuously stirred and evaporated at 90 °C. The obtained sol was heat-treated at 180 °C to obtain a xerogel, and calcined at 500 °C for 10 h to obtain the required oxide material.

[0154] 1 g of H-ZSM-5 zeolite molecular sieve was mixed with 20 mL of cyclohexane solution containing 0.5 mL of tetraethyl orthosilicate, stirred at 60 °C for 4 h, the solvent was evaporated to dryness at 80 °C, dried at 120 °C for 12 h, and calcined at 500 °C for 4 h. The above operations were repeated 2 times to obtain the modified zeolite molecular sieve.

[0155] An equal mass of the oxide and the H-ZSM-5 zeolite molecular sieve with a silica-alumina atomic ratio of 50 were mixed evenly, ground for 15 min, extruded under 15 MPa, crushed, and 250 mg of particles with a mesh size of 40 - 60 were sieved out for standby.

[0156] Performance evaluation:

[0157] The shaped catalyst was diluted with quartz sand at a mass ratio of 1:5, filled into the isothermal section of the stainless-steel tube of the fixed-bed reactor, pretreated at 500 °C for 2 h under a hydrogen atmosphere with a pressure of 0.1 MPa, the reaction temperature was 360 °C, the pressure was 0.5 MPa, the volume ratio of carbon monoxide:hydrogen:argon was 32:64:4, and the space velocity was 12000 mL g -1 h -1 , and the mass space velocity of ethylbenzene was 1 h -1 .

[0158] For the convenience of comparison, the reaction results are summarized in Table 1.

[0159] Example 7

[0160] Catalyst preparation:

[0161] 7.28 g of zirconium nitrate pentahydrate, 0.08 g of zinc nitrate hexahydrate, and 8.28 g of citric acid monohydrate were dissolved in 50 mL of ultrapure water, and the solvent was continuously stirred and evaporated at 90 °C. The obtained sol was heat-treated at 180 °C to obtain a xerogel, and calcined at 500 °C for 10 h to obtain the required oxide material.

[0162] 1 g of H-ZSM-5 zeolite molecular sieve was mixed with 20 mL of cyclohexane solution containing 0.5 mL of tetraethyl orthosilicate, stirred at 60 °C for 4 h, the solvent was evaporated to dryness at 80 °C, dried at 120 °C for 12 h, and calcined at 500 °C for 4 h. The above operations were repeated 2 times to obtain the modified zeolite molecular sieve.

[0163] An equal mass of the oxide and the H-ZSM-5 zeolite molecular sieve with a silica-alumina atomic ratio of 50 were mixed evenly, ground for 15 min, extruded under 15 MPa, crushed, and 250 mg of particles with a mesh size of 40 - 60 were sieved out for standby.

[0164] Performance evaluation:

[0165] The shaped catalyst was diluted with quartz sand at a mass ratio of 1:5, filled into the isothermal section of the stainless-steel tube of the fixed-bed reactor, pretreated at 500 °C for 2 h under a hydrogen atmosphere with a pressure of 0.1 MPa, the reaction temperature was 360 °C, the pressure was 1.0 MPa, the volume ratio of carbon monoxide:hydrogen:argon was 32:64:4, and the space velocity was 12000 mL g -1 h -1 , and the mass space velocity of ethylbenzene was 1 h -1 .

[0166] For easy comparison, the reaction results are summarized in Table 1.

[0167] Example 8

[0168] Catalyst preparation:

[0169] Dissolve 7.28 g of zirconium nitrate pentahydrate, 0.08 g of zinc nitrate hexahydrate and 8.28 g of citric acid monohydrate in 50 mL of ultrapure water. Continuously stir and evaporate the solvent at 90 °C. The obtained sol is heat-treated at 180 °C to obtain a xerogel, and calcined at 500 °C for 10 h to obtain the required oxide material.

[0170] Mix 1 g of H-ZSM-5 zeolite molecular sieve with 20 mL of cyclohexane solution containing 0.5 mL of tetraethyl orthosilicate, stir at 60 °C for 4 h, evaporate the solvent at 80 °C, dry at 120 °C for 12 h, and calcine at 500 °C for 4 h. Repeat the above operations 2 times to obtain the modified zeolite molecular sieve.

[0171] Take equal masses of the oxide and H-ZSM-5 zeolite molecular sieve with a silicon-aluminum atomic ratio of 50, mix them evenly, grind for 15 min, extrude at 15 MPa, crush, and screen out 250 mg of particles with a mesh size of 40 - 60 for standby.

[0172] Performance evaluation:

[0173] The shaped catalyst is diluted with quartz sand at a mass ratio of 1:5, filled into the isothermal section of the stainless steel tube of the fixed-bed reactor, pretreated at 500 °C for 2 h in a hydrogen atmosphere with a pressure of 0.1 MPa, the reaction temperature is 360 °C, the pressure is 2.0 MPa, the volume ratio of carbon monoxide: hydrogen: argon is 32:64:4, and the space velocity is 12000 mL g -1 h -1 , and the mass space velocity of ethylbenzene is 1 h -1 .

[0174] For easy comparison, the reaction results are summarized in Table 1.

[0175] Example 9

[0176] Catalyst preparation:

[0177] Dissolve 7.28 g of zirconium nitrate pentahydrate, 0.08 g of zinc nitrate hexahydrate and 8.28 g of citric acid monohydrate in 50 mL of ultrapure water. Continuously stir and evaporate the solvent at 90 °C. The obtained sol is heat-treated at 180 °C to obtain a xerogel, and calcined at 500 °C for 10 h to obtain the required oxide material.

[0178] 1 g of H-ZSM-5 zeolite molecular sieve was mixed with 20 mL of cyclohexane solution containing 0.5 mL of tetraethyl orthosilicate, stirred at 60 °C for 4 h, the solvent was evaporated at 80 °C, dried at 120 °C for 12 h, calcined at 500 °C for 4 h, and the above operations were repeated 2 times to obtain the modified zeolite molecular sieve.

[0179] Equal masses of the oxide and H-ZSM-5 zeolite molecular sieve with a silicon-aluminum atomic ratio of 50 were mixed evenly, ground for 15 min, extruded at 15 MPa, crushed, and 250 mg of particles with a mesh size of 40 - 60 were screened out for standby.

[0180] Performance evaluation:

[0181] The shaped catalyst was diluted with quartz sand at a mass ratio of 1:5, filled into the isothermal section of the stainless steel tube of the fixed-bed reactor, pretreated at 500 °C for 2 h in a hydrogen atmosphere with a pressure of 0.1 MPa, the reaction temperature was 360 °C, the pressure was 3 MPa, the volume ratio of carbon monoxide:hydrogen:argon was 32:64:4, and the space velocity was 6000 mL g -1 h -1 , and the mass hourly space velocity of ethylbenzene was 1 h -1 .

[0182] For easy comparison, the reaction results are summarized in Table 1.

[0183] Example 10

[0184] Catalyst preparation:

[0185] 7.28 g of zirconium nitrate pentahydrate, 0.08 g of zinc nitrate hexahydrate and 8.28 g of citric acid monohydrate were dissolved in 50 mL of ultrapure water, and the solvent was continuously stirred and evaporated at 90 °C. The obtained sol was heat-treated at 180 °C to obtain a dry gel, and calcined at 500 °C for 10 h to obtain the required oxide material.

[0186] 1 g of H-ZSM-5 zeolite molecular sieve was mixed with 20 mL of cyclohexane solution containing 0.5 mL of tetraethyl orthosilicate, stirred at 60 °C for 4 h, the solvent was evaporated at 80 °C, dried at 120 °C for 12 h, calcined at 500 °C for 4 h, and the above operations were repeated 2 times to obtain the modified zeolite molecular sieve.

[0187] Equal masses of the oxide and H-ZSM-5 zeolite molecular sieve with a silicon-aluminum atomic ratio of 50 were mixed evenly, ground for 15 min, extruded at 15 MPa, crushed, and 250 mg of particles with a mesh size of 40 - 60 were screened out for standby.

[0188] Performance evaluation:

[0189] The shaped catalyst was diluted with quartz sand at a mass ratio of 1:5, filled into the isothermal section of the stainless steel tube of the fixed-bed reactor, pretreated at 500 °C for 2 h in a hydrogen atmosphere with a pressure of 0.1 MPa, the reaction temperature was 360 °C, the pressure was 3 MPa, the volume ratio of carbon monoxide: hydrogen: argon was 32:64:4, and the space velocity was 18000 mL g -1 h -1 , and the mass space velocity of ethylbenzene was 1 h -1 .

[0190] For the convenience of comparison, the reaction results are summarized in Table 1.

[0191] Comparative Example 1

[0192] Catalyst preparation:

[0193] 7.28 g of zirconium nitrate pentahydrate, 0.08 g of zinc nitrate hexahydrate and 8.28 g of citric acid monohydrate were dissolved in 50 mL of ultrapure water, the solvent was continuously stirred and evaporated at 90 °C, the obtained sol was heat-treated at 180 °C to obtain a dry gel, and calcined at 500 °C for 10 h to obtain the required oxide material.

[0194] 1 g of H-ZSM-5 zeolite molecular sieve was mixed with 20 mL of cyclohexane solution containing 0.5 mL of tetraethyl orthosilicate, stirred at 60 °C for 4 h, the solvent was evaporated to dryness at 80 °C, dried at 120 °C for 12 h, and calcined at 500 °C for 4 h. The above operations were repeated 2 times to obtain the modified zeolite molecular sieve.

[0195] Equal masses of the oxide and H-ZSM-5 zeolite molecular sieve with a silicon-aluminum atomic ratio of 50 were mixed evenly, ground for 15 min, extruded at 15 MPa, crushed, and 250 mg of 40-60 mesh particles were screened out for standby.

[0196] Performance evaluation:

[0197] The shaped catalyst was diluted with quartz sand at a mass ratio of 1:5, filled into the isothermal section of the stainless steel tube of the fixed-bed reactor, pretreated at 500 °C for 2 h in a hydrogen atmosphere with a pressure of 0.1 MPa, the reaction temperature was 360 °C, the pressure was 3 MPa, the volume ratio of carbon monoxide: hydrogen: argon was 32:64:4, and the space velocity was 12000 mL g -1 h -1 .

[0198] For the convenience of comparison, the reaction results are summarized in Table 1.

[0199] Table 1

[0200]

[0201]

[0202] From the results in Table 1, it can be seen from the results of Examples 1-5 that with the increase of reaction temperature, the CO conversion rate continues to increase, up to 15.9%, and the product selectivity first increases and then decreases; from the results of Examples 6-8, it can be seen that with the increase of reaction pressure, the conversion rate and product selectivity increase simultaneously; from Examples 9-10, the increase in space velocity leads to a decrease in conversion rate, but the product selectivity can be improved. The comparative example shows that the target product methyl ethylbenzene accounts for a very low proportion when ethylbenzene is not involved, proving that the co-feed of ethylbenzene is a necessary condition for the formation of methyl ethylbenzene.

[0203] Test Case

[0204] The catalyst obtained in Example 1 was subjected to a 50-hour stability test under the following conditions: reaction temperature 360°C, pressure 3 MPa, carbon monoxide: hydrogen: argon volume ratio 32:64:4, space velocity 12000 mL g -1 h -1 .

[0205] Test results see Figure 1 ,Depend on Figure 1 It can be seen that the activity and selectivity of the catalyst fluctuated only within a small range during 50 h, and no obvious deactivation occurred, which proves its good stability and potential application value.

[0206] The above are only a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A method for preparing styrene by coupling the conversion of syngas with ethylbenzene, characterized in that, the method comprises: contacting a raw material containing syngas and ethylbenzene with a combined catalyst to carry out a reaction to obtain an aromatic hydrocarbon product containing styrene; the syngas is a mixed gas of hydrogen and carbon monoxide; wherein, the combined catalyst is reduced in a hydrogen atmosphere; the combined catalyst comprises a first component and a second component; the first component is an oxide having syngas conversion activity, and the second component is a zeolite molecular sieve having acidic sites; the mass fraction of the oxide in the combined catalyst is 10% to 90%; the mass fraction of the zeolite molecular sieve in the combined catalyst is 10% to 90%.

2. The method according to claim 1, characterized in that, the temperature of the reaction is 200 to 600 °C, preferably 300 to 500 °C; the pressure of the reaction is 0.5 to 10 MPa, preferably 1 to 4 MPa; preferably, in the mixed gas, the volume ratio of carbon monoxide to hydrogen is 12:1 to 1:12; preferably, the volume ratio of carbon monoxide to hydrogen is 1:1 to 1:6; preferably, the syngas further comprises an inert gas; the inert gas is selected from at least one of nitrogen and argon; Preferably, the space velocity of the syngas is 600 - 48000 mL g -1 h -1 , preferably 6000 - 24000 mL g -1 h -1 ; Preferably, the mass hourly space velocity of ethylbenzene is 0.1 to 10 h -1 , preferably 1 to 4 h -1 .

3. The method according to claim 1, characterized in that, the pressure of the hydrogen atmosphere is 0.1 to 10.0 MPa; the temperature of the reduction is 300 to 600 °C; the time of the reduction is 0.5 to 8 h, preferably 1 to 3 h.

4. The method according to claim 1, characterized in that, the first component and the second component are combined by at least one of powder mechanical grinding and particle physical mixing.

5. The method according to claim 4, characterized in that, the powder mechanical grinding includes: grinding the oxide powder and the zeolite molecular sieve powder for 1 to 30 min, preferably 5 to 10 min; extruding the obtained powder at 5 to 30 MPa, preferably 15 to 20 MPa; crushing, screening out particles of 10 to 80 mesh, preferably 20 to 60 mesh; and mixing evenly.

6. The method according to claim 4, characterized in that, the particle physical mixing includes: extruding the oxide powder and the zeolite molecular sieve powder respectively at 5 to 30 MPa, preferably 15 to 20 MPa; crushing, screening out particles of 10 to 80 mesh, preferably 20 to 60 mesh; and mixing evenly.

7. The method according to claim 1, characterized in that, the first component is selected from at least one of oxides of elements of IIIA, IIB, IVB, and VIB; preferably, the first component is selected from at least one of oxides of Zn, Zr, Al, Cr, Ga, and In; preferably, the first component further comprises a carrier, and the oxide is supported on the carrier; the carrier is selected from at least one of silica and alumina.

8. The method according to claim 1, characterized in that, the second component is selected from at least one of H-Y molecular sieve, H-MCM-22 molecular sieve, H-ZSM-5 molecular sieve, H-MOR molecular sieve, and H-Beta molecular sieve; Preferably, the second component is H-ZSM-5 molecular sieve; Preferably, the silicon-aluminum atomic ratio of the zeolite molecular sieve is 1 to 500, preferably 10 to 200, and more preferably 30 to 50.

9. According to the method described in claim 1, it is characterized in that the zeolite molecular sieve is modified by at least one of the methods of loading metals and their oxides, non-metals and their oxides, etching, and hydrothermal treatment; Preferably, the zeolite molecular sieve is modified by loading non-metals and their oxides.

10. According to the method described in claim 1, it is characterized in that: the zeolite molecular sieve is modified by loading a modifier; the modifier is selected from at least one of Zn, Ga, Mg, Mn, Mo, P, and Si; Preferably, the modifier is Si; Preferably, the mass fraction of the modifier in the zeolite molecular sieve is 0.1% to 20%; Preferably, the mass fraction of the modifier in the zeolite molecular sieve is 1% to 10%.

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