A system and method for producing aromatics from carbon dioxide using renewable energy

Abstract

The application discloses a kind of renewable energy driven carbon dioxide hydrogenation production aromatic hydrocarbon system and method, belong to clean energy utilization and carbon capture utilization technical field;The system includes renewable energy power generation device, renewable energy storage device, carbon dioxide capture device, electrolytic water hydrogen production device, moving bed reaction device and product separation device;Wherein, moving bed reaction device includes multiple moving bed reactors and dehydrator, carbon dioxide hydrogenation reaction is carried out in multiple steps, after every moving bed reactor is entered dehydrator and is treated, dehydration can improve carbon dioxide conversion rate;The application carries out carbon dioxide hydrogenation reaction under the driving of renewable energy, can produce chemical aromatic hydrocarbon, can reduce the content of CO2 in air, solve greenhouse effect and other environmental problems.

Description

Technical Field

[0001] This invention relates to the field of clean energy utilization and carbon capture and utilization technology, specifically to a system and method for producing aromatics from carbon dioxide via renewable energy-driven hydrogenation. Background Technology

[0002] Fossil fuels (coal, oil, and natural gas) have provided enormous economic benefits to human society. However, in recent decades, the large-scale combustion of fossil fuels has led to a continuous increase in CO2 emissions, causing serious environmental problems such as global warming. Therefore, researching CO2 capture and catalytic conversion technologies to utilize CO2 resources is an effective way to solve the greenhouse effect, replace fossil fuels, and generate chemicals with higher economic value. This is of great significance to the sustainable development of the world's energy and ecological environment.

[0003] Renewable energy sources include solar, wind, and tidal energy, which are clean, green, and low-carbon energy sources. These energy sources are renewable in nature, inexhaustible, and do not pose a threat to the environment. Therefore, they are an inevitable choice for sustainable development strategies.

[0004] Aromatics, as an important class of bulk chemicals, are mainly used in the production of polymers such as nylon, phenolic resins, polyester fibers, and benzene derivatives. Traditional methods for producing aromatics primarily involve naphtha catalytic reforming. Utilizing clean energy to produce hydrogen for the direct conversion of CO2 into aromatics is an effective means to alleviate excessive consumption of petroleum resources, reduce the over-reliance on fossil resources in aromatics production, and decrease CO2 emissions. It has significant strategic and economic implications.

[0005] In the prior art, Chinese patent document CN113620798A discloses a system and method for synthesizing formic acid by hydrogenation of carbon dioxide driven by renewable energy. The system includes a carbon dioxide capture device, a hydrogen production device, a formic acid synthesis device, and a renewable energy power generation device. Through the coordinated action of the various devices, the system can directly utilize carbon dioxide in the air and the excess electricity from the renewable energy power generation device to synthesize high-energy formic acid. This reduces the serious waste of renewable energy during off-peak hours, solves the problem of renewable energy curtailment, and reduces the content of the greenhouse gas carbon dioxide in the air. However, the system is complex to operate, has high equipment investment costs, and does not involve CO2 conversion rate, so it does not have broad economic applicability. Combining renewable energy utilization with greenhouse gas treatment, and producing aromatics through carbon dioxide hydrogenation reaction, can solve environmental problems such as the greenhouse effect while producing aromatics. This approach is rarely reported in the prior art. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a system and method for producing aromatics by hydrogenating carbon dioxide using renewable energy. This system utilizes carbon dioxide captured from the air as a carbon source and hydrogen produced by water electrolysis as a hydrogen source, thus solving environmental problems such as the greenhouse effect. Furthermore, the entire device is powered entirely by non-fossil energy sources, achieving zero carbon emissions. In addition, the carbon dioxide hydrogenation reaction of this invention, through the combination of multiple moving bed reactors and dehydrators, greatly improves the conversion rate of carbon dioxide and the yield of aromatics.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a renewable energy-driven system for producing aromatics by carbon dioxide hydrogenation, comprising: a renewable energy power generation device, a renewable energy storage device, a carbon dioxide capture device, a water electrolysis hydrogen production device, a moving bed reactor, and a product separation device; wherein, carbon dioxide captured by the carbon dioxide capture device and hydrogen produced by the water electrolysis hydrogen production device undergo a carbon dioxide hydrogenation reaction in the moving bed reactor, and the product after the reaction enters the product separation device for separation; the renewable energy power generation device and the renewable energy storage device provide electrical energy for the carbon dioxide capture device, the water electrolysis hydrogen production device, the moving bed reactor, and the product separation device.

[0009] As a further preferred embodiment of the technical solution of the present invention, the moving bed reactor includes multiple moving bed reactors and dewatering devices arranged alternately from top to bottom. Each moving bed reactor and dewatering device is provided with an inlet and an outlet, wherein the outlet of the moving bed reactor is connected to the inlet of the dewatering device, and then connected to the inlet of the next moving bed reactor through the outlet of the dewatering device.

[0010] As a further preferred embodiment of the technical solution of the present invention, the number of moving bed reactors is greater than or equal to 2; more preferably, the number of moving bed reactors is 2 to 8; it can be understood that the number of dewatering devices can be flexibly adjusted according to the number of moving bed reactors and the dewatering situation.

[0011] As a further preferred embodiment of the technical solution of the present invention, the moving bed reactor further includes an upper hopper, a catalyst delivery pipe, and an elevator. The catalyst delivery pipe is used to transport the catalyst from the reaction zone of the previous moving bed reactor to the reaction zone of the next moving bed reactor. The bottom outlet of the upper hopper is connected to the reaction zone of the first moving bed reactor through the top catalyst delivery pipe, and the inlet of the elevator is connected to the reaction zone of the last moving bed reactor through the bottom catalyst delivery pipe.

[0012] As a further preferred embodiment of the technical solution of the present invention, the system further includes a raw material mixing tank and a raw material preheating furnace, used for mixing and preheating carbon dioxide and hydrogen, respectively; the system further includes a carbon dioxide storage tank and a hydrogen storage tank, used for storing carbon dioxide and hydrogen, respectively; wherein, a carbon dioxide capture device is connected in series with the carbon dioxide storage tank and then connected to the inlet of the raw material mixing tank, and an electrolysis hydrogen production device is connected in series with the hydrogen storage tank and then connected to the inlet of the raw material mixing tank; the outlet of the raw material mixing tank is sequentially connected to the raw material preheating furnace, the moving bed reactor, and the product separation device; the product separation device has an outlet connected to the raw material mixing tank, the moving bed reactor, and the electrolysis hydrogen production device, respectively.

[0013] Secondly, the present invention provides a method for producing aromatics by carbon dioxide hydrogenation driven by renewable energy using the above-mentioned system. Specifically, carbon dioxide captured by a carbon dioxide capture device is used as a carbon source, and hydrogen produced by water electrolysis is used as a hydrogen source. Aromatics are produced by carbon dioxide hydrogenation reaction driven by renewable energy. In this method, after the carbon dioxide hydrogenation reaction is carried out in a moving bed reactor, the product is dehydrated and then enters the next moving bed reactor.

[0014] As a further preferred embodiment of the technical solution of the present invention, the dehydrating agent used in the dehydration treatment is a type A molecular sieve, and the dehydration treatment temperature is 100-300℃.

[0015] As a further preferred embodiment of the technical solution of the present invention, the volume percentage of carbon dioxide to hydrogen in the carbon dioxide hydrogenation reaction feedstock is 1:20 to 20:1; and the volume hourly space velocity (VHSV) of the carbon dioxide and hydrogen mixture is 100 to 10000 h⁻¹. -1 .

[0016] As a further preferred embodiment of the technical solution of the present invention, the reaction temperature of carbon dioxide hydrogenation is 200-550℃ and the reaction pressure is 0-10MPa.

[0017] As a further preferred embodiment of the technical solution of the present invention, the carbon dioxide hydrogenation reaction uses a small ball catalyst with a diameter of 1.0 to 2.5 mm. The small ball catalyst comprises 10 to 80 wt% nano-metal oxide and 20 to 90 wt% modified ZSM-5 molecular sieve. The nano-metal oxide and modified ZSM-5 molecular sieve are obtained by calcination after treatment with a silane coupling agent.

[0018] As a further preferred embodiment of the technical solution of the present invention, the nano-metal oxide includes component A and component B, wherein component A is selected from any three of iron oxide, cobalt oxide, molybdenum oxide, nickel oxide and copper oxide, and component B is selected from any one of zirconium oxide, potassium oxide and calcium oxide; wherein component B accounts for 1 to 10% of the weight percentage of the nano-metal oxide.

[0019] As a further preferred embodiment of the technical solution of the present invention, the modified ZSM-5 molecular sieve includes component a, component b and ZSM-5 molecular sieve, wherein component a is selected from any one of lanthanum oxide and cerium oxide, and component b is selected from any one of potassium oxide and magnesium oxide; wherein component a accounts for 0.1% to 5% of the weight percentage of the modified ZSM-5 molecular sieve, and component b accounts for 0.1% to 3% of the weight percentage of the modified ZSM-5 molecular sieve.

[0020] As a further preferred embodiment of the technical solution of the present invention, the silane coupling agent is KH560 and / or KH570.

[0021] As a further preferred embodiment of the technical solution of the present invention, the preparation method of the microsphere catalyst is as follows:

[0022] S1. Dissolve the first metal salt in deionized water, then add sucrose and polyethylene glycol, stir to obtain a sol, dry and calcine the sol to obtain nano-metal oxide;

[0023] S2. Dissolve the second metal salt in deionized water to obtain a second metal salt solution, age the ZSM-5 molecular sieve, then impregnate the ZSM-5 molecular sieve with the second metal salt solution, let it stand, dry it, and calcine it to obtain the modified ZSM-5 molecular sieve.

[0024] S3. Disperse nano-metal oxides and modified ZSM-5 molecular sieves in deionized water, add ethanol and silane coupling agent, stir thoroughly to obtain a slurry, dry and calcine the slurry, then grind the calcined catalyst, and finally use a binder to roll the ground catalyst into balls to obtain the small ball catalyst.

[0025] As a further preferred embodiment of the technical solution of the present invention, in step S1, the first metal salt is one or more of the nitrates of Fe, Co, Mo, Ni, Cu, Zr, K, and Ca, and the weight ratio of the first metal salt to deionized water is 15-40:100; in step S2, the second metal salt is one or more of the nitrates of La, Ce, K, and Mg, and the weight ratio of the second metal salt to deionized water is 10-30:100.

[0026] As a further preferred embodiment of the technical solution of the present invention, in step S1, the stirring conditions are stirring at 40-95°C for 5-15 hours, the drying conditions are drying at 110-120°C for 10-15 hours, and the calcination conditions are calcining at 400-600°C for 5-15 hours.

[0027] As a further preferred embodiment of the technical solution of the present invention, in step S1, the polyethylene glycol is PEG2000 and / or PEG4000; sucrose and polyethylene glycol account for 0.01-5% and 0.01-10% of the weight of the sol, respectively; more preferably, sucrose and polyethylene glycol account for 0.1-3% and 0.1-5% of the weight of the sol, respectively.

[0028] As a further preferred embodiment of the technical solution of the present invention, in step S2, the aging conditions are aging at 400-550℃ for 0.5-2 hours, the standing time is 10-15 hours, the drying conditions are drying at 100-120℃ for 8-15 hours, and the calcination conditions are calcination at 500-600℃ for 10-15 hours; the weight ratio of the second metal salt solution to the ZSM-5 molecular sieve is 5-7:10; the particle size of the ZSM-5 molecular sieve is <800nm, and the silicon-to-aluminum ratio is 15-100; more preferably, the silicon-to-aluminum ratio is 30-65.

[0029] As a further preferred embodiment of the technical solution of the present invention, in step S3, ethanol and silane coupling agent account for 0.5-3% and 1-5% of the weight of the slurry, respectively.

[0030] As a further preferred embodiment of the technical solution of the present invention, in step S3, the solid content of the slurry is 25-35 wt%.

[0031] As a further preferred embodiment of the technical solution of the present invention, in step S3, the drying conditions are drying at 100-130°C for 4-7 hours, and the calcination conditions are calcination at 400-600°C for 5-10 hours.

[0032] As a further preferred embodiment of the technical solution of the present invention, in step S3, the binder is aluminum sol and / or silica sol, the solid content of the binder is 20-40 wt%, and the binder content in the spheroidized catalyst is 5-35%.

[0033] In the above technical solution, preferably, the slurry is fully dried at 120°C and calcined at 500°C. The calcined catalyst is then ground, and the particle size of the ground catalyst is <1μm. A binder is used to roll the ground catalyst into spherical shapes to obtain spherical catalysts with a diameter of 1-2.5mm.

[0034] It is understood that the system provided by this invention can be applied to the fields of renewable energy utilization and greenhouse gas emission reduction, and this invention claims protection for its application in these fields.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] 1. The renewable energy-driven carbon dioxide hydrogenation system for producing aromatics provided by this invention can directly utilize carbon dioxide and hydrogen to synthesize aromatic chemicals. The entire system, whether directly or indirectly, is powered by renewable energy generation, achieving zero emissions. This system can both produce aromatic chemicals and reduce the content of the greenhouse gas carbon dioxide in the air, solving environmental problems such as the greenhouse effect. It is of great significance to the sustainable development of the world's energy and ecological environment.

[0037] 2. The renewable energy-driven carbon dioxide hydrogenation system for producing aromatics provided by the present invention includes a renewable energy storage device. The installation of this device can improve the stability of the entire carbon dioxide hydrogenation system and reduce the waste of renewable energy.

[0038] 3. The carbon dioxide hydrogenation reactor of the present invention, by setting up a combination of multiple moving bed reactors and dehydrators, can not only control the reaction temperature within the optimal range, but also improve the carbon dioxide conversion rate and aromatic yield by removing moisture. The entire reaction process has small fluctuations and is easy to control, with low equipment cost, thereby improving economic benefits.

[0039] 4. The hydrogenation metal oxide in the catalyst used in the carbon dioxide hydrogenation reaction of this invention is at the nanoscale, which can effectively improve the hydrogenation activity and increase the conversion rate of carbon dioxide hydrogenation; the ZSM-5 molecular sieve, after treatment and modification, has good hydrothermal stability and coke-holding capacity, giving the catalyst good selectivity and lifespan; the nano-metal oxide and modified ZSM-5 molecular sieve are modified with silane coupling agents, which, compared with simple mechanical mixing or binder mixing, have a tighter connection, higher catalytic efficiency, and can effectively reduce the formation of by-products, improve conversion rate and target product selectivity.

[0040] In summary, the system and method provided by this invention are simple to operate, economical and practical, and energy-saving and environmentally friendly. They can be widely applied to the fields of renewable energy utilization and greenhouse gas emission reduction. Attached Figure Description

[0041] Figure 1 A schematic diagram of a renewable energy-driven carbon dioxide hydrogenation system for producing aromatics, provided by the present invention.

[0042] Figure 2 This is a schematic diagram of the moving bed reactor for carbon dioxide hydrogenation reaction according to the present invention;

[0043] Among them, 101, renewable energy power generation unit; 102, renewable energy storage unit; 103, carbon dioxide capture unit; 104, water electrolysis hydrogen production unit; 105, carbon dioxide storage tank; 106, hydrogen storage tank; 107, raw material mixing tank; 108, raw material preheating furnace; 109, moving bed reactor; 110, product separation unit; 111, refining hydrogen and carbon dioxide; 112, C1 and C2 hydrocarbons; 113, liquefied petroleum gas; 114, mixed aromatics; 115, product water; 201, upper hopper; 202, raw material inlet; 203, first moving bed reactor; 204, dehydrator inlet; 205, dehydrator; 206, dehydrator outlet; 207, second moving bed reactor; 208, elevator; 209, product outlet; 210, catalyst delivery pipe. Detailed Implementation

[0044] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0045] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0046] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0047] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention in light of the specific circumstances.

[0048] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0049] Please see Figure 1 A renewable energy-driven system for producing aromatics by hydrogenating carbon dioxide includes: a renewable energy power generation unit 101, a renewable energy storage unit 102, a carbon dioxide capture unit 103, a water electrolysis hydrogen production unit 104, a moving bed reactor 109, and a product separation unit 110; wherein, the moving bed reactor 109 is used for the carbon dioxide hydrogenation reaction; the renewable energy power generation unit 101 and the renewable energy storage unit 102 provide electrical energy to the carbon dioxide capture unit 103, the water electrolysis hydrogen production unit 104, the moving bed reactor 109, and the product separation unit 110.

[0050] In the above technical solution, the moving bed reactor 109 includes multiple moving bed reactors and dewatering devices arranged alternately from top to bottom. Each moving bed reactor and dewatering device is provided with a feed inlet and a discharge outlet. The discharge outlet of the moving bed reactor is connected to the feed inlet of the dewatering device, and then connected to the feed inlet of the next moving bed reactor through the discharge outlet of the dewatering device.

[0051] Preferably, the number of moving bed reactors in the above technical solution is greater than or equal to 2; more preferably, the number of moving bed reactors is 2 to 8. In specific implementation, it can be flexibly adjusted according to actual needs, and can be set to 2, 3, 4, 5, 6, 7, or 8. It can be understood that the number of dehydrators can be flexibly adjusted according to the number of moving bed reactors and the dehydration situation. Preferably, each reactor has at least two dehydrators for switching between desorption and regeneration. Specifically, each reactor has at least two dehydrators, one for adsorption and the other for desorption when the adsorption is saturated, i.e., one is in use and the other is on standby, or two can be in use and one is on standby, etc.

[0052] Furthermore, the moving bed reactor 109 also includes an upper hopper 201, a catalyst delivery pipe 210, and an elevator 208. The catalyst delivery pipe 210 is used to transport the catalyst from the reaction zone of the previous moving bed reactor to the reaction zone of the next moving bed reactor. The bottom outlet of the upper hopper 201 is connected to the reaction zone of the first moving bed reactor through the top catalyst delivery pipe 210, and the inlet of the elevator 208 is connected to the reaction zone of the last moving bed reactor through the bottom catalyst delivery pipe 210.

[0053] Specifically, such as Figure 2 As shown, the moving bed reactor of the present invention includes multiple axial moving bed reactors. Each reactor has a reaction zone, which is a catalyst bed. The upper and lower ends of the reaction zone are screens with mesh sizes smaller than the catalyst particle size, which ensures material entry while preventing catalyst entry and exit. Carbon dioxide and hydrogen feedstocks enter the reaction zone (catalyst bed) of the first moving bed reactor 203 from the feedstock inlet 202 and come into axial contact with the catalyst to undergo a carbon dioxide hydrogenation reaction. The product after the reaction flows out of the discharge port of the moving bed reactor through the bottom screen, enters the dehydrator 205 through the dehydrator inlet 204, and flows out of the dehydrator outlet 206 to the second moving bed reactor 207 after further reaction. After further reaction, the product flows out from the product outlet 209 to the next step of processing (product separation device 110).

[0054] In the above technical solution, the catalyst enters the first moving bed reactor 203 and the second moving bed reactor 207 successively from the upper hopper 201 through the catalyst conveying pipe 210, and finally enters the elevator 208. The elevator is provided with a catalyst outlet (not shown in the figure), which can transport the catalyst to the next process for regeneration. The catalyst in the upper hopper 201 can be a regenerated catalyst, a fresh catalyst, or a combination of a regenerated catalyst and a fresh catalyst from the regenerator. Furthermore, it can be understood that in the above technical solution, the catalyst inlet and outlet are located at the top and bottom of the catalyst bed, respectively, and the number of catalyst conveying pipes between adjacent areas can be set to multiple, preferably 2 to 10.

[0055] Furthermore, the renewable energy-driven carbon dioxide hydrogenation system for producing aromatics according to the present invention also includes a raw material mixing tank 107 and a raw material preheating furnace 108, used for mixing and preheating carbon dioxide and hydrogen, respectively; the system also includes a carbon dioxide storage tank 105 and a hydrogen storage tank 106, used for storing carbon dioxide and hydrogen, respectively; specifically, a carbon dioxide capture device 103 is connected in series with the carbon dioxide storage tank 105 and then connected to the inlet of the raw material mixing tank 107, and an electrolysis water hydrogen production device 104 is connected in series with the hydrogen storage tank 106 and then connected to the inlet of the raw material mixing tank 107; the outlet of the raw material mixing tank 107 is sequentially connected to the raw material preheating furnace 108, the moving bed reactor 109, and the product separation device 110; the product separation device 110 has an outlet that is connected to the raw material mixing tank 107, the moving bed reactor 109 (not shown in the figure), and the electrolysis water hydrogen production device 104, respectively.

[0056] In the above technical solution, the renewable energy power generation device 101 can be solar power generation, wind power generation, tidal power generation or other forms of power generation, or a combination of two or more forms of power generation. In specific implementation, it can be flexibly adjusted according to actual needs and site conditions. This invention does not impose specific limitations on this.

[0057] Furthermore, the present invention includes a renewable energy storage device 102. Since renewable energy power generation may be intermittent and unstable, the renewable energy storage device can be used for energy storage and stabilization after renewable energy power generation, so as to provide a continuous and stable energy supply for the entire carbon dioxide hydrogenation system. Similarly, the renewable energy storage device 102 can be battery storage, pumped hydro storage, molten salt thermal storage, hydrogen storage, etc., or it can be a combination of two or more energy storage devices. In specific implementation, it can be flexibly adjusted according to actual needs and site conditions. The present invention does not impose specific limitations on this.

[0058] Furthermore, the present invention provides a method for producing aromatics by carbon dioxide hydrogenation driven by renewable energy using the above-mentioned system. Specifically, carbon dioxide captured by a carbon dioxide capture device is used as the carbon source, and hydrogen produced by water electrolysis is used as the hydrogen source. Aromatics are produced by carbon dioxide hydrogenation reaction driven by renewable energy. In this method, after the carbon dioxide hydrogenation reaction is carried out in a moving bed reactor, the product is dehydrated and then enters the next moving bed reactor.

[0059] Specifically, the above method includes the following steps:

[0060] The renewable energy power generation device 101 generates electricity using renewable energy, and the generated electricity is stored and used through the renewable energy storage device 102. All the energy required by the entire system comes directly or indirectly from this. The carbon dioxide collected by the carbon dioxide replenishment device 103 is released into the carbon dioxide storage tank 105. The hydrogen produced by the water electrolysis hydrogen production device 104 is stored in the hydrogen storage tank 106. The raw material carbon dioxide and raw material hydrogen are mixed in the raw material mixing tank 107 and then preheated to the reaction temperature in the raw material preheating furnace 108. After that, they enter the moving bed reactor 109 to carry out the carbon dioxide hydrogenation reaction. The reaction products enter the product separation device 110 for product separation. The separated products are recycled hydrogen and carbon dioxide 111, C1 and C2 hydrocarbon products 112, liquefied gas product 113, mixed aromatic products 114, and product water 115. The recycled hydrogen and carbon dioxide 111 can be recycled into the raw material mixing tank 107 or directly into the moving bed reactor 109 for recycling reaction. The product water 115 is recycled to the water electrolysis hydrogen production device 104 for recycling.

[0061] In the above technical solution, the renewable energy power generation and renewable energy storage devices provide the necessary electrical energy for carbon dioxide capture, water electrolysis hydrogen production, carbon dioxide hydrogenation devices and product separation devices, and the entire system is directly or indirectly driven by renewable energy.

[0062] In the above technical solutions, carbon dioxide capture can be carried out by chemical absorption, physical absorption and adsorption, or a combination of multiple adsorption methods; the carbon dioxide captured by the carbon dioxide capture device can be carbon dioxide in the air, or carbon dioxide in the exhaust gas from the combustion of fossil fuels in refineries, power plants, etc.

[0063] In the above technical solution, the method for producing hydrogen by electrolysis of water can be alkaline electrolysis of water, proton exchange membrane electrolysis of water, high-temperature solid oxide electrolysis of water, or a combination of multiple hydrogen production methods. The specific implementation can be flexibly adjusted according to actual needs and site conditions, and this invention does not impose specific limitations on this. The hydrogen obtained by electrolysis of water can be used as a hydrogen feedstock for subsequent carbon dioxide hydrogenation or for storing electrical energy.

[0064] The carbon dioxide raw material of the present invention comes entirely from the carbon dioxide replenishment device 103; the hydrogen raw material comes entirely from the water electrolysis hydrogen production device 104.

[0065] As a further preferred embodiment of the technical solution of the present invention, the volume percentage of carbon dioxide to hydrogen in the carbon dioxide hydrogenation reaction feedstock is 1:20 to 20:1. Specifically, it can be 20:1, 19:1, 18:1, 17:1, 16:1, 15:1, 14:1, 13:1, 12:1, 11:1, 10:1, 9:1, 8:1, 7:1, 6:1, 5:1, 4:1, 3:1, 2:1, 1 The ratio of carbon dioxide to hydrogen is 1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19, 1:20, or any specific value within the range of 1:20 to 20:1; preferably, the volume percentage of carbon dioxide to hydrogen is 1:2 to 1:9, for example, 1:3 or 1:5.

[0066] As a further preferred embodiment of the technical solution of the present invention, the volume hourly space velocity (VHSV) of the carbon dioxide and hydrogen mixture is 100–10000 h⁻¹. -1 Specifically, it can be 100h -1 500h -1 1000h -1 2000h -1 3000h -1 4000h -1 5000h -1 6000h -1 7000h -1 8000h -1 9000h -1 10000h -1 Or 100-10000h -1 Any specific value within the range; preferably, the volume hourly space velocity (VHSV) of the carbon dioxide and hydrogen mixture is 2000–4000 h⁻¹. -1 .

[0067] As a further preferred embodiment of the technical solution of the present invention, the reaction temperature for carbon dioxide hydrogenation is 200–550°C. Specifically, it can be any specific value within the range of 200°C, 250°C, 260°C, 270°C, 280°C, 290°C, 300°C, 310°C, 320°C, 330°C, 340°C, 350°C, 400°C, 450°C, 550°C, or 200–550°C. Preferably, the reaction temperature is 250–350°C.

[0068] As a further preferred embodiment of the technical solution of the present invention, the reaction pressure of carbon dioxide hydrogenation is 0 to 10 MPa, specifically, it can be 0 MPa, 1 MPa, 2 MPa, 3 MPa, 4 MPa, 5 MPa, 6 MPa, 7 MPa, 8 MPa, 9 MPa, 10 MPa or any specific value within the range of 0 to 10 MPa; preferably, the reaction pressure is 3 to 6 MPa.

[0069] As a further preferred embodiment of the technical solution of the present invention, the dehydrating agent used in the dehydration treatment is a type A molecular sieve, preferably one or more of type 3A molecular sieve and type 5A molecular sieve.

[0070] As a further preferred embodiment of the technical solution of the present invention, the dehydration treatment temperature is 100-300℃, specifically, it can be 100℃, 150℃, 160℃, 170℃, 180℃, 190℃, 200℃, 250℃, 300℃ or any specific value within the range of 100-300℃; preferably, the dehydration treatment temperature is 150-200℃.

[0071] In the above technical solution, in order to improve the conversion rate of the reaction and reduce the residence of non-target products in the reactor, a dehydrator is set between each moving bed reactor. The material at the reactor outlet enters the dehydrator, and after the water in the material is removed, it enters the inlet of the next reactor to continue the reaction. Since the hydrogenation of carbon dioxide is an exothermic reaction, in order to control the reaction temperature and to ensure a good dehydration effect, external heat can be extracted before entering the dehydrator, or a heat exchanger can be included in the dehydrator. There are at least two dehydrators between each reactor for switching between desorption and regeneration.

[0072] As a further preferred embodiment of the technical solution of the present invention, a small spherical catalyst with a diameter of 1.0 to 2.5 mm is used in the carbon dioxide hydrogenation reaction. Specifically, the catalyst can be any specific value within the range of 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, or 1.0 to 2.5 mm. It is understood that the particle size of the catalyst can be flexibly adjusted according to the settings of the moving bed reactor. In principle, the particle size of the catalyst is larger than the aperture of the screen at the upper and lower ends of the catalyst bed in the moving bed reactor to prevent the catalyst from entering or exiting through the screen aperture.

[0073] Specifically, the catalyst used in the carbon dioxide hydrogenation reaction of the present invention comprises 10-80 wt% nano-metal oxide and 20-90 wt% modified ZSM-5 molecular sieve, which are obtained by calcining after treatment with a silane coupling agent.

[0074] Specifically, the nano-metal oxide can account for 10 wt%, 20 wt%, 30 wt%, 40 wt%, 50 wt%, 60 wt%, 70 wt%, or 80 wt%, preferably 20–50 wt%; the modified ZSM-5 molecular sieve can account for 20 wt%, 30 wt%, 40 wt%, 50 wt%, 60 wt%, 70 wt%, 80 wt%, or 90 wt%, preferably 50–80 wt%.

[0075] Specifically, the nano-metal oxide includes component A and component B. Component A is selected from any three of iron oxide, cobalt oxide, molybdenum oxide, nickel oxide, and copper oxide, and component B is selected from any one of zirconium oxide, potassium oxide, and calcium oxide. More specifically, component A includes component 1, component 2, and component 3, which are selected from any three of iron oxide, cobalt oxide, molybdenum oxide, nickel oxide, and copper oxide, and each component accounts for 1-80% of the weight percentage of the nano-metal oxide, which can be 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, and 80%, preferably 10-70%. Component B accounts for 1-10% of the weight percentage of the nano-metal oxide, which can be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, and 10%, preferably 1-5%.

[0076] Specifically, the modified ZSM-5 molecular sieve includes component a, component b, and ZSM-5 molecular sieve. Component a is selected from any one of lanthanum oxide and cerium oxide, and component b is selected from any one of potassium oxide and magnesium oxide. Component a accounts for 0.1% to 5% of the weight of the modified ZSM-5 molecular sieve, and can be 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, or 5%, more preferably 0.5% to 3%. Component b accounts for 0.1% to 3% of the weight of the modified ZSM-5 molecular sieve, and can be 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, or 3%, more preferably 0.1% to 1.5%.

[0077] Preferably, the silane coupling agent is KH560 and / or KH570.

[0078] Preferably, the preparation method of the microsphere catalyst is as follows:

[0079] S1. Dissolve the first metal salt in deionized water, then add sucrose and polyethylene glycol, stir to obtain a sol, dry and calcine the sol to obtain nano-metal oxide;

[0080] S2. Dissolve the second metal salt in deionized water to obtain a second metal salt solution, age the ZSM-5 molecular sieve, then impregnate the ZSM-5 molecular sieve with the second metal salt solution, let it stand, dry it, and calcine it to obtain the modified ZSM-5 molecular sieve.

[0081] S3. Disperse nano-metal oxides and modified ZSM-5 molecular sieves in deionized water, add ethanol and silane coupling agent, stir thoroughly to obtain a slurry, dry and calcine the slurry, then grind the calcined catalyst, and finally use a binder to roll the ground catalyst into balls to obtain the small ball catalyst.

[0082] Specifically, in step S1, the first metal salt is one or more of the nitrates of Fe, Co, Mo, Ni, Cu, Zr, K, and Ca, and the weight ratio of the first metal salt to deionized water is 15-40:100, which can be 15:100, 20:100, 25:100, 30:100, 35:100, or 40:100; in step S2, the second metal salt is one or more of the nitrates of La, Ce, K, and Mg, and the weight ratio of the second metal salt to deionized water is 10-30:100, which can be 10:100, 15:100, 20:100, 25:100, or 30:100.

[0083] Specifically, in step S1, the stirring conditions are 40–95°C for 5–15 hours, the drying conditions are 110–120°C for 10–15 hours, and the calcination conditions are 400–600°C for 5–15 hours.

[0084] Specifically, in step S1, the polyethylene glycol is PEG2000 and / or PEG4000.

[0085] Optionally, in step S1, the sucrose is 0.01% to 5% of the weight of the sol, and can be 0.01%, 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, or 5%, preferably 0.1% to 3%.

[0086] Optionally, in step S1, the polyethylene glycol is 0.01% to 10% of the weight of the sol, and can be 0.01%, 0.05%, 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10%, preferably 0.1% to 5%.

[0087] Specifically, in step S2, the aging conditions are aging at 400-550℃ for 0.5-2 hours, the standing time is 10-15 hours, the drying conditions are drying at 100-120℃ for 8-15 hours, and the calcination conditions are calcination at 500-600℃ for 10-15 hours; the weight ratio of the second metal salt solution to ZSM-5 molecular sieve is 5-7:10.

[0088] Specifically, in step S2, the ZSM-5 molecular sieve has a particle size of <800nm ​​and a silicon-to-aluminum ratio of 15 to 100, which can be 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 80, 90, or 100, with a preferred ratio of 30 to 65.

[0089] Specifically, in step S3, ethanol accounts for 0.5% to 3% of the slurry weight, and can be 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.5%, 2%, 2.5%, or 3%.

[0090] Specifically, in step S3, the silane coupling agent accounts for 1-5% of the slurry weight, which can be 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, or 5%.

[0091] More specifically, in step S3, the solid content of the slurry is 25-35 wt%, which can be 25 wt%, 26 wt%, 27 wt%, 28 wt%, 29 wt%, 30 wt%, 31 wt%, 32 wt%, 33 wt%, 34 wt%, or 35 wt%.

[0092] Specifically, in step S3, the catalyst is dried at 100-130℃ for 4-7 hours after molding, and calcined at 400-600℃ for 5-10 hours.

[0093] Specifically, in step S3, the binder is aluminum sol and / or silica sol, and the binder solid content is 20-40 wt%, which can be any value among 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, or 20-40 wt%; the binder content in the spheroidized catalyst is 5%-35%, which can be any value among 5%, 10%, 15%, 20%, 25%, 30%, 35%, or 5-35%.

[0094] In the above technical solution, preferably, the slurry is fully dried at 120°C and calcined at 500°C. The calcined catalyst is then ground, and the particle size of the ground catalyst is <1μm. A binder is used to roll the ground catalyst into spherical shapes to obtain spherical catalysts with a diameter of 1-2.5mm.

[0095] The following further combines Figure 1 and Figure 2 The implementation principle and process of the renewable energy-driven carbon dioxide hydrogenation to aromatics production system of the present invention are described as follows:

[0096] Please see Figure 1 A renewable energy-driven system for producing aromatics by carbon dioxide hydrogenation includes: a renewable energy power generation unit 101, a renewable energy storage unit 102, a carbon dioxide capture unit 103, a water electrolysis hydrogen production unit 104, a carbon dioxide storage tank 105, a hydrogen storage tank 106, a feed mixing tank 107, a feed preheating furnace 108, a moving bed reactor 109, and a product separation unit 110; wherein, the renewable energy power generation unit 101 and the renewable energy storage unit 102 provide electricity for the entire system; the carbon dioxide capture unit... The carbon dioxide captured by device 103 is released into carbon dioxide storage tank 105, and the hydrogen produced by water electrolysis hydrogen production device 104 is stored in hydrogen storage tank 106. Both carbon dioxide storage tank 105 and hydrogen storage tank 106 are connected to raw material mixing tank 107, and then raw material mixing tank 107 is sequentially connected to raw material preheating furnace 108, moving bed reactor 109 and product separation device 110. Product separation device 110 has an outlet that is connected to raw material mixing tank 107, moving bed reactor 109 and water electrolysis hydrogen production device 104 respectively.

[0097] Specifically, the raw materials carbon dioxide and hydrogen are mixed in the raw material mixing tank 107 and then preheated to the reaction temperature in the raw material preheating furnace 108. After that, they enter the moving bed reactor 109 for carbon dioxide hydrogenation reaction. The reaction products enter the product separation device 110 for product separation. The separated products are recycled hydrogen and carbon dioxide 111, C1 and C2 hydrocarbon products 112, liquefied gas product 113, mixed aromatic products 114, and product water 115. The recycled hydrogen and carbon dioxide 111 can be recycled back into the raw material mixing tank 107 or directly into the moving bed reactor 109 for recycling reaction. Product water 115 is recycled to the water electrolysis hydrogen production device 104 for recycling.

[0098] For further details, please refer to [link / reference]. Figure 2The moving bed reactor 109 includes two moving bed reactors and a dehydrator arranged alternately from top to bottom. Each moving bed reactor and dehydrator is provided with an inlet and an outlet, respectively. The outlet of the moving bed reactor is connected to the inlet of the dehydrator, and then connected to the inlet of the next moving bed reactor via the outlet of the dehydrator. Furthermore, the moving bed reactor 109 also includes an upper hopper 201, a catalyst conveying pipe 210, and an elevator 208. The catalyst conveying pipe 210 is used to convey the catalyst from the reaction zone of the previous moving bed reactor to the reaction zone of the next moving bed reactor. The bottom outlet of the upper hopper 201 is connected to the reaction zone of the first moving bed reactor through the top catalyst conveying pipe 210, and the inlet of the elevator 208 is connected to the reaction zone of the last moving bed reactor through the bottom catalyst conveying pipe 210.

[0099] Specifically, the moving bed reactor 109 includes an upper hopper 201, a catalyst conveying pipe 210, a first moving bed reactor 203, a dehydrator 205, a second moving bed reactor 207, and an elevator 208. The catalyst enters the first moving bed reactor 203 and the second moving bed reactor 207 sequentially from the upper hopper 201 through the catalyst conveying pipe 210, and finally enters the elevator 208. Carbon dioxide and hydrogen feedstocks enter the first moving bed reactor 203 from the feedstock inlet 202 and come into contact with the catalyst bed to undergo a carbon dioxide hydrogenation reaction. The reaction products enter the dehydrator 205 for dehydration. After dehydration, the material enters the second moving bed reactor 207 for further reaction and then flows out from the product outlet 209 into the product separation device 110.

[0100] The present invention will be further explained below with reference to specific embodiments; it should be noted that, unless otherwise specified in the embodiments, the conditions shall be in accordance with conventional conditions or conditions recommended by the manufacturer; and unless the manufacturer of the reagents or instruments used is specified, they are all conventional products that can be purchased commercially.

[0101] Example 1

[0102] A method for preparing a spherical catalyst for carbon dioxide hydrogenation includes the following steps:

[0103] (1) Dissolve 4.1 kg Fe(NO3)3·9H2O, 0.2 kg Cu(NO3)2·3H2O, 3.6 kg Ni(NO3)2·6H2O, and 0.05 kg Zr(NO3)4·5H2O in 20 kg of deionized water. After stirring evenly, add 0.1 kg sucrose and 0.4 kg PEG4000. Stir at 80 °C for 10 h to obtain a sol. Dry the sol at 120 °C for 10 h and then calcine at 480 °C for 8 h to obtain nano-metal oxides.

[0104] (2) Dissolve 187g La(NO3)3·6H2O and 10g KNO3 in 500g deionized water to obtain a modified solution. Age 1kg of nano ZSM-5 molecular sieve at 450℃ for 1h, then impregnate ZSM-5 molecular sieve with the modified solution, let stand for 12h, dry at 110℃ for 8h, and then calcine at 550℃ for 12h to obtain modified ZSM-5 molecular sieve.

[0105] (3) Disperse the nano metal oxide obtained in step (1) and the modified ZSM-5 molecular sieve obtained in step (2) in 6 kg of deionized water, then add 150 g of ethanol, 100 g of KH560 and 180 g of KH570, stir thoroughly to obtain a slurry, dry the slurry at 120 °C for 8 h, and calcine it at 500 °C for 10 h, then grind the calcined catalyst. The particle size of the ground catalyst is <1 μm. Use aluminum sol (content accounts for 15% of the catalyst) to roll the ground catalyst into spheres to obtain spherical catalysts with a particle size of 1 to 2.5 mm.

[0106] Example 2

[0107] In this specific embodiment, a method for producing aromatics from carbon dioxide via renewable energy-driven hydrogenation using the catalyst prepared in Example 1 and the system of the present invention is provided, as follows:

[0108] The system generates electricity using solar power, which is stored and used in batteries. All energy required by the entire system comes directly or indirectly from this source. Carbon dioxide is captured using chemical absorption and stored in a carbon dioxide storage tank. Hydrogen produced by an alkaline water electrolysis hydrogen production unit is stored in a hydrogen storage tank. Raw carbon dioxide and raw hydrogen (volume ratio 1:3) are mixed in a raw material mixing tank and pressurized to 5 MPa before being preheated to 300°C in a raw material preheating furnace. The mixture then enters a moving bed reactor for carbon dioxide hydrogenation, with a volume hourly space velocity (VHSV) of 3000 h⁻¹. -1 The moving bed reactor includes two reactors and a dehydrator (specifically, two dehydrators, one for adsorption and one for desorption), with a dehydrator temperature of 150°C. The reaction products enter a product separation device for separation, yielding unreacted hydrogen and carbon dioxide, C1 and C2 hydrocarbon products, liquefied petroleum gas (LPG) products, mixed aromatic hydrocarbon products, and product water. The unreacted hydrogen and carbon dioxide are mixed with the raw materials to participate in a recycling reaction, and the product water is recycled to an alkaline water electrolysis hydrogen production device to participate in water electrolysis hydrogen production. The composition of the carbon dioxide hydrogenation reaction product in this embodiment is shown in Table 1.

[0109] Example 3

[0110] In this specific embodiment, a method for producing aromatics from carbon dioxide via renewable energy-driven hydrogenation using the catalyst prepared in Example 1 and the system of the present invention is provided, as follows:

[0111] The system generates electricity using wind power generation, which is then stored and utilized via molten salt thermal storage. All energy required by the entire system originates directly or indirectly from this source. Carbon dioxide is captured using physical absorption, and the captured carbon dioxide is stored in a carbon dioxide storage tank. Hydrogen produced by a proton exchange membrane hydrogen production unit is stored in a hydrogen storage tank. Raw carbon dioxide and raw hydrogen (volume ratio 1:5) are mixed in a raw material mixing tank and pressurized to 6 MPa before being preheated to 350°C in a raw material preheating furnace. The mixture then enters a moving bed reactor for carbon dioxide hydrogenation, with a volume hourly space velocity (VHSV) of 2000 h⁻¹. -1 The moving bed reactor includes three reactors and two dehydrators (specifically, each stage includes two dehydrators, one for adsorption and one for desorption), with a dehydrator temperature of 180°C. The reaction products enter the product separation system for product separation. After separation, the products are unreacted hydrogen and carbon dioxide, C1 and C2 hydrocarbon products, liquefied gas products, mixed aromatic hydrocarbon products, and product water. The unreacted hydrogen and carbon dioxide are mixed with the raw materials to participate in the recycling reaction, and the product water is recycled to the proton exchange membrane hydrogen production unit to participate in water electrolysis to produce hydrogen. The composition of the carbon dioxide hydrogenation reaction product 2 in this embodiment is shown in Table 1.

[0112] Comparative Example 1

[0113] The conditions were the same as in Example 2, except that the moving bed reactor did not include a dehydrator. As a result, the composition of the carbon dioxide hydrogenation reaction product 3 is shown in Table 1.

[0114] Comparative Example 2

[0115] The conditions were the same as in Example 2, except that the catalyst prepared in Example 1 was not used in the carbon dioxide hydrogenation reaction. The composition of the carbon dioxide hydrogenation reaction product 4 is shown in Table 1.

[0116] Table 1. Composition of Aromatic Hydrogenation Products from Examples 2-3 and Comparative Examples 1-2.

[0117] Example 2 Example 3 Comparative Example 1 Comparative Example 2 <![CDATA[CO2 conversion rate, %]]> 38.9 40.1 30.2 28.1 Product composition 1, m% Product composition 2, m% Product composition 3, m% Product composition 4, m% C1+C2 13.6 15.8 20.9 18.6 Liquefied gas 30.2 25.3 35.8 35.5 C5+ liquid yield 56.2 58.9 43.3 45.9 in benzene 15.8 23.3 18.9 16.1 Toluene 42.6 48.8 40.1 41 xylene 32.5 20 25.7 30.6 C9+ Aromatics 9.1 7.9 15.3 12.3

[0118] As shown in Table 1, compared with Comparative Examples 1 and 2, Examples 1 and 2 show a significant improvement in CO2 conversion rate and aromatic yield, demonstrating the remarkable effectiveness of the present invention.

[0119] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for producing aromatics by renewable energy-driven carbon dioxide hydrogenation, characterized in that, The system includes: a renewable energy power generation device (101), a renewable energy storage device (102), a carbon dioxide capture device (103), a water electrolysis hydrogen production device (104), a moving bed reactor (109), and a product separation device (110); wherein, the carbon dioxide captured by the carbon dioxide capture device (103) and the hydrogen produced by the water electrolysis hydrogen production device (104) undergo a carbon dioxide hydrogenation reaction in the moving bed reactor (109), and the product after the reaction enters the product separation device (110) for separation; the renewable energy power generation device (101) and the renewable energy storage device (102) provide electrical energy to the carbon dioxide capture device (103), the water electrolysis hydrogen production device (104), the moving bed reactor (109), and the product separation device (110); The method is as follows: using carbon dioxide captured by a carbon dioxide capture device as a carbon source and hydrogen produced by water electrolysis as a hydrogen source, carbon dioxide hydrogenation reaction is carried out to produce aromatics under the drive of renewable energy. In this process, after the carbon dioxide hydrogenation reaction is carried out in a moving bed reactor, the product is dehydrated and then enters the next moving bed reactor. The carbon dioxide hydrogenation reaction uses a spherical catalyst with a diameter of 1.0 to 2.5 mm. The spherical catalyst comprises 10 to 80 wt% nano-metal oxide and 20 to 90 wt% modified ZSM-5 molecular sieve. The nano-metal oxide and modified ZSM-5 molecular sieve are obtained by calcination after treatment with a silane coupling agent. The specific method for preparing the microsphere catalyst is as follows: S1. Dissolve the first metal salt in deionized water, then add sucrose and polyethylene glycol, stir to obtain a sol, dry and calcine the sol to obtain nano metal oxides; S2. Dissolve the second metal salt in deionized water to obtain a second metal salt solution, age the ZSM-5 molecular sieve, then impregnate the ZSM-5 molecular sieve with the second metal salt solution, let it stand, dry it, and calcine it to obtain the modified ZSM-5 molecular sieve. S3. Disperse nano-metal oxides and modified ZSM-5 molecular sieves in deionized water, add ethanol and silane coupling agent, stir thoroughly to obtain a slurry, dry and calcine the slurry, then grind the calcined catalyst, and finally use a binder to roll the ground catalyst into balls to obtain the small ball catalyst.

2. The method according to claim 1, characterized in that, The moving bed reactor (109) includes multiple moving bed reactors and dewaterers arranged alternately from top to bottom. Each moving bed reactor and dewaterer is provided with an inlet and an outlet. The outlet of the moving bed reactor is connected to the inlet of the dewaterer, and then connected to the inlet of the next moving bed reactor through the outlet of the dewaterer.

3. The method according to claim 2, characterized in that, The number of moving bed reactors is greater than or equal to 2.

4. The method according to claim 3, characterized in that, The moving bed reactor (109) also includes an upper hopper (201), a catalyst delivery pipe (210), and an elevator (208). The catalyst delivery pipe (210) is used to transport the catalyst from the reaction zone of the previous moving bed reactor to the reaction zone of the next moving bed reactor. The bottom outlet of the upper hopper (201) is connected to the reaction zone of the first moving bed reactor through the top catalyst delivery pipe (210), and the inlet of the elevator (208) is connected to the reaction zone of the last moving bed reactor through the bottom catalyst delivery pipe (210).

5. The method according to claim 1, characterized in that, The system also includes a raw material mixing tank (107) and a raw material preheating furnace (108), which are used for mixing and preheating carbon dioxide and hydrogen, respectively; the system also includes a carbon dioxide storage tank (105) and a hydrogen storage tank (106), which are used for storing carbon dioxide and hydrogen, respectively; wherein, a carbon dioxide capture device (103) is connected in series with the carbon dioxide storage tank (105) and then connected to the inlet of the raw material mixing tank (107), and an electrolysis hydrogen production device (104) is connected in series with the hydrogen storage tank (106) and then connected to the inlet of the raw material mixing tank (107); the outlet of the raw material mixing tank (107) is connected in sequence to the raw material preheating furnace (108), the moving bed reactor (109) and the product separation device (110); the product separation device (110) has an outlet that is connected to the raw material mixing tank (107), the moving bed reactor (109) and the electrolysis hydrogen production device (104), respectively.

6. The method according to claim 1, characterized in that, The dehydrating agent used in the dehydration process is type A molecular sieve, and the dehydration temperature is 100–300℃.

7. The method according to claim 1, characterized in that, The volume percentage of carbon dioxide to hydrogen in the feedstock for the carbon dioxide hydrogenation reaction is 1:20 to 20:1; the volume hourly space velocity (HSV) of the carbon dioxide and hydrogen mixture is 100 to 10000 h⁻¹. -1 .

8. The method according to claim 1, characterized in that, The reaction temperature for carbon dioxide hydrogenation is 200–550℃, and the reaction pressure is 0–10 MPa.

9. The method according to claim 1, characterized in that, The nano-metal oxide comprises component A and component B. Component A is selected from any three of iron oxide, cobalt oxide, molybdenum oxide, nickel oxide, and copper oxide, and component B is selected from any one of zirconium oxide, potassium oxide, and calcium oxide. Component B accounts for 1% to 10% of the weight of the nano-metal oxide.

10. The method according to claim 1, characterized in that, The modified ZSM-5 molecular sieve includes component a, component b, and ZSM-5 molecular sieve. Component a is selected from any one of lanthanum oxide and cerium oxide, and component b is selected from any one of potassium oxide and magnesium oxide. Component a accounts for 0.1% to 5% of the weight of the modified ZSM-5 molecular sieve, and component b accounts for 0.1% to 3% of the weight of the modified ZSM-5 molecular sieve.

11. The method according to claim 1, characterized in that, The silane coupling agent is KH560 and / or KH570.

12. The method according to claim 1, characterized in that, In step S1, the first metal salt is one or more of the nitrates of Fe, Co, Mo, Ni, Cu, Zr, K, and Ca, and the weight ratio of the first metal salt to deionized water is 15-40:100; in step S2, the second metal salt is one or more of the nitrates of La, Ce, K, and Mg, and the weight ratio of the second metal salt to deionized water is 10-30:

100.

13. The method according to claim 1, characterized in that, In step S1, the stirring conditions are: stirring at 40–95°C for 5–15 hours; drying conditions are: drying at 110–120°C for 10–15 hours; and calcination conditions are: calcination at 400–600°C for 5–15 hours. In step S1, the polyethylene glycol is PEG2000 and / or PEG4000. Sucrose and polyethylene glycol account for 0.01%–5% and 0.01%–10% of the weight of the sol, respectively.

14. The method according to claim 1, characterized in that, In step S2, the aging conditions are aging at 400–550℃ for 0.5–2 hours, standing time for 10–15 hours, drying conditions are drying at 100–120℃ for 8–15 hours, and calcination conditions are calcination at 500–600℃ for 10–15 hours; the weight ratio of the second metal salt solution to ZSM-5 molecular sieve is 5–7:10; the particle size of ZSM-5 molecular sieve is <800nm, and the silicon-to-aluminum ratio is 15–100.

15. The method according to claim 1, characterized in that, In step S3, ethanol and silane coupling agent account for 0.5%–3% and 1%–5% of the slurry weight, respectively; the solid content of the slurry is 25–35 wt%; in step S3, the drying conditions are drying at 100–130℃ for 4–7 h, and the calcination conditions are calcination at 400–600℃ for 5–10 h; the binder is aluminum sol and / or silica sol, and the solid content of the binder is 20–40 wt%.

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