A system and method for efficiently converting CO2 and H2 into chemicals

Abstract

The application provides a system and method for efficiently converting CO2 and H2 into chemicals, wherein a reverse water gas shift device is arranged to make the reverse water gas shift process independent, and the generated H2O is adsorbed by water absorption particles and removed in situ in time, thereby avoiding the influence of H2O on the activity of the first metal supported catalyst and the second metal supported catalyst, promoting the forward movement of the reaction equilibrium at low temperature and high pressure, effectively improving the conversion rate of CO2, and after the reaction is completed, the CO content in the remaining gas in the reverse water gas shift device can reach 80%-99%; a heat treatment device is arranged to separately dry the water absorption particles after water absorption, thereby realizing the effective separation of H2O and CO, and the recycling of the water absorption particles, and the separate drying and dehydration temperature is low, and the energy consumption is small; a water gas shift device is arranged to hydrogenate and convert the CO from which H2O is removed, thereby efficiently and selectively preparing target chemicals. The system is simple in configuration, can utilize the existing industrial system, and effectively reduces the preparation cost.

Description

Technical Field

[0001] This invention relates to the field of chemical raw material, fuel, and solvent manufacturing technology, and in particular to a system and method for efficiently converting CO2 and H2 into chemicals. Background Technology

[0002] CO2 is a typical greenhouse gas, and its emissions are positively correlated with observed global warming. Internationally, there is a strong push to reduce the use of fossil fuels and CO2 emissions, and efforts are being made to capture CO2 from the atmosphere. Simultaneously, various green chemicals are being produced using the chemical reaction between CO2 and green hydrogen (derived from the electrolysis of water using renewable electricity), thus achieving CO2 conversion.

[0003] However, the chemical inertness of CO2 makes it much less reactive than CO hydrogenation, resulting in low conversion rates, large amounts of recycle streams, and high separation costs when using existing catalysts or reactor systems for the reaction of CO2 with green hydrogen. This runs counter to the original intention of carbon emission reduction. Summary of the Invention

[0004] To address the aforementioned problems in existing technologies, this invention provides a system and method for efficiently converting CO2 and H2 into chemicals. By separately performing a reverse water-gas shift process and removing the generated water in situ using a solid medium, the reverse water-gas shift process proceeds in the forward direction under low temperature and high pressure, promoting the conversion of CO2 to CO. The generated CO is then combined with H2 for a secondary conversion, thereby obtaining the target chemical. This achieves the goal of preparing various chemicals with high conversion rate and high selectivity using existing industrial systems.

[0005] The specific details of the invention are as follows:

[0006] In a first aspect, the present invention provides a system for efficiently converting CO2 and H2 into chemicals, the system comprising: a reverse water-gas conversion device, a heat treatment device, and a water-gas conversion device;

[0007] The reverse water gas conversion device is equipped with a first metal-supported catalyst. The first metal-supported catalyst has several axially connected channels uniformly arranged inside for the flow of CO2, H2 and water-absorbing particles. Under the action of the first metal-supported catalyst, CO2 and H2 are converted into CO and H2O. The generated H2O is adsorbed by the water-absorbing particles, thus separating CO and H2O.

[0008] The heat treatment device is used to dry water-absorbing particles;

[0009] The water-gas conversion device is filled with a second metal-supported catalyst to convert CO into hydrocarbons or oxygen-containing compounds.

[0010] A circulation loop is provided between the reverse water gas conversion device and the heat treatment device to allow the water-absorbing particles to be circulated and transported between the reverse water gas conversion device and the heat treatment device.

[0011] The reverse water gas conversion device is connected to the water gas conversion device so that the CO generated by the reverse water gas conversion device is delivered to the water gas conversion device.

[0012] Optionally, the reverse water gas conversion device is located at the top of the heat treatment device so that the water-absorbing particles, after adsorbing H2O, enter the heat treatment device under the action of gravity.

[0013] Optionally, the cross-sectional area of ​​some of the axially penetrating channels accounts for 10%-50% of the cross-sectional area of ​​the structured metal-supported catalyst.

[0014] Optionally, the reverse-flow gas conversion device further includes a mixture inlet;

[0015] The heat treatment device also includes a steam outlet;

[0016] The water-gas conversion device also includes a target chemical discharge outlet.

[0017] In a second aspect, the present invention provides a method for efficiently converting CO2 and hydrogen into chemicals, the method being applicable to the system for efficiently converting CO2 and H2 into chemicals described in the first aspect above, the method comprising:

[0018] Under the condition that the temperature inside the reverse water gas conversion device is not higher than 90℃ and the pressure is 2-15MPa, water-absorbing particles, CO2 and H2 are introduced into the reverse water gas conversion device. The water-absorbing particles, CO2 and H2 flow through the internal channel of the first metal supported catalyst, where CO2 and H2 are catalytically converted into CO and H2O, and H2O is adsorbed by the water-absorbing particles.

[0019] After absorbing water, the water-absorbing particles enter the heat treatment device under the action of gravity, where they are dried at 120-600℃, and then returned to the reverse water gas conversion device for recycling.

[0020] The pressure of the reverse water gas conversion device is controlled at 2-8 MPa and the temperature at 180-350℃. The remaining gas in the reverse water gas conversion device is introduced into the water gas conversion device, and H2 is added at the same time. Under the action of the second metal supported catalyst, the target hydrocarbons or oxygen-containing compounds are generated.

[0021] Optionally, the absorbent particles are silica gel, porous carbon, or porous carbon supported on metal salts; the loading of the metal salt is 3%-35%, and the metal salt is magnesium chloride, copper sulfate, sodium chloride, or potassium chloride.

[0022] Optionally, the molar ratio of CO2 and H2 introduced into the reverse water gas conversion device is 1:1;

[0023] The amount of water-absorbing particles introduced into the reverse-flow gas conversion device is sufficient to adsorb all the H2O generated in the reverse-flow gas conversion device.

[0024] The amount of H2 introduced into the water-gas conversion device satisfies the following proportional relationship:

[0025] The molar ratio of H2 to CO in the remaining gas in the reverse water gas conversion device is 1.5:1 to 2.5:1.

[0026] Optionally, the support for the first metal-supported catalyst is composed of carbon nanotubes, graphene, cerium oxide, silicon oxide, or aluminum oxide, and the supported metal is one or more of iron, cobalt, nickel, copper, zinc, and manganese. The loading amount is 3%-25%.

[0027] Optionally, the support for the second metal-supported catalyst is alumina, silica, or molecular sieve, and the supported metal is one or more of iron, cobalt, nickel, copper, zinc, and chromium, with a loading of 6%-50%.

[0028] Optionally, the target hydrocarbon or oxygen-containing compound is at least one of olefins, alkanes, gasoline, diesel, and C1-C5 alcohols.

[0029] Compared with the prior art, the present invention has the following advantages:

[0030] This invention provides a system and method for efficiently converting CO2 and H2 into chemicals, comprising: a reverse-flow gas conversion device, a heat treatment device, and a water-gas conversion device; the reverse-flow gas conversion device is equipped with a first metal-supported catalyst, which has several axially connected channels uniformly arranged inside for the flow of CO2, H2, and water-absorbing particles, so that CO2 and H2 are converted into CO and H2O under the action of the first metal-supported catalyst, and the generated H2O is adsorbed by the water-absorbing particles, thus separating CO and H2O; the heat treatment device is used to dry the water-absorbing particles; the water-gas conversion device is filled with a second metal-supported catalyst to convert CO into hydrocarbons or oxygen-containing compounds; a circulation loop is provided between the reverse-flow gas conversion device and the heat treatment device to circulate the water-absorbing particles between the two devices; the reverse-flow gas conversion device and the water-gas conversion device are connected so that the CO generated by the reverse-flow gas conversion device is transported to the water-gas conversion device. This invention utilizes a reverse water-gas shifter to allow the reverse water-gas shifting process to proceed independently (CO2 and H2 are converted into CO and H2O). Furthermore, the generated H2O is adsorbed by water-absorbing particles and promptly removed in situ, preventing its impact on the activity of the first and second metal-supported catalysts. This also promotes a positive shift in reaction equilibrium under low temperature and high pressure, effectively improving the CO2 conversion rate. After the reaction, the CO content in the remaining gas in the reverse water-gas shifter can reach 80%-99%. The system also includes a heat treatment device for separate drying of the water-absorbing particles, achieving effective separation of H2O and CO, and allowing for the recycling of the water-absorbing particles. This separate drying process is characterized by low temperature and low energy consumption. Finally, the system further includes a water-gas shifter for hydrogenation conversion of the CO after H2O removal, enabling efficient and highly selective preparation of the target chemical. The system is simple to configure, can utilize existing industrial systems, and effectively reduces production costs. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This diagram illustrates a system structure for efficiently converting CO2 and H2 into chemicals, as provided in an embodiment of the present invention.

[0033] Figure 2 A schematic diagram of the reverse water gas conversion device provided in an embodiment of the present invention is shown.

[0034] Figure 3 This invention provides a schematic diagram of another reverse-flow gas conversion device according to an embodiment of the invention.

[0035] Figure 4 A flowchart of a method for efficiently converting CO2 and hydrogen into chemicals according to an embodiment of the present invention is shown. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention. Furthermore, all other embodiments obtained by those skilled in the art without inventive effort are within the protection scope of the present invention.

[0037] Specific experimental steps or conditions are not specified in the embodiments; they can be performed according to the conventional experimental steps or conditions described in the prior art. Reagents and other instruments used, unless otherwise specified, are all commercially available conventional reagent products. Furthermore, the accompanying drawings are merely illustrative diagrams of the embodiments of the present invention and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore, repeated descriptions of them will be omitted. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities.

[0038] Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of this specification.

[0039] In the description of this invention, it should be understood that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0040] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0041] Compared to the CO hydrogenation process, the CO2 hydrogenation process involves an additional reverse water-gas shift process. Chemically, the reverse water-gas shift (CO2 + H2 = CO + H2O) is a high-temperature endothermic process, while the generated CO immediately reacts with water in a low-temperature exothermic process (the water-gas shift process CO + H2O = CO2 + H2). The latter is thermodynamically and kinetically more favorable, resulting in the lower efficiency of the reverse water-gas shift process.

[0042] Currently, various attempts have been made to improve catalyst activity, reduce the temperature of reverse water-gas conversion, and increase its conversion efficiency, but many technical challenges still remain.

[0043] To address the aforementioned problems, this invention provides a novel solution. First, the water generated during the reverse water-gas shift reaction is removed in situ using a solid medium. This effectively separates CO and H2O while allowing the reaction equilibrium to shift forward under low temperature and high pressure, thus significantly improving the CO2 conversion rate. Furthermore, the concept of chemical recycling is employed to dry and reuse the solid medium; and the generated CO is then combined with H2 for further conversion. Utilizing existing industrial systems, this achieves the goal of highly selectively preparing various chemicals from CO2 and H2. Specific implementation details are as follows:

[0044] In a first aspect, the present invention provides a system for efficiently converting CO2 and H2 into chemicals. Figure 1 This diagram illustrates a system structure for efficiently converting CO2 and H2 into chemicals, as provided in an embodiment of the present invention. Figure 1 As shown, the system includes: a water-gas shifter 1, a heat treatment unit 2, and a water-gas shifter 3; the water-gas shifter 1 is equipped with a first metal-supported catalyst 1-1. Figure 2 A schematic diagram of the reverse water gas conversion device provided in an embodiment of the present invention is shown, as follows: Figure 2As shown, the reverse-flow gas conversion device is equipped with a mixture distribution zone 1-1, a catalyst loading zone 1-2, and a water-absorbing particle collection zone 1-3. The catalyst loading zone 1-2 is filled with a first metal-supported catalyst, specifically a structured metal-supported catalyst. Several axially connected channels 1-4 are uniformly arranged inside the catalyst loading zone 1 for the flow of CO2, H2, and water-absorbing particles. CO2, H2, and water-absorbing particles enter the mixture distribution zone 1-1 through the mixture inlet 4 of the reverse-flow gas conversion device 1 and are evenly distributed to the axially connected channels 1-4. After contacting the catalyst in this area, they react. The gas flows axially. During the flow in the connected channels 1-4, CO2 and H2 contact and act with the first metal-supported catalyst, converting into CO and H2O. The generated H2O is adsorbed by the water-absorbing particles, thus separating CO and H2O. Because the water generated in the reverse water-gas shift reaction is removed in situ, the reaction equilibrium shifts to the right. This allows for an increase in CO2 conversion rate at a lower temperature (not higher than 90℃) by simply increasing the pressure (2-15MPa). Ultimately, after the reverse water-gas shift reaction is completed, the CO content in the remaining gas in the device can reach 80%-99%.

[0045] In some implementations... Figure 3 A schematic diagram of another reverse-flow gas conversion device provided in an embodiment of the present invention is shown, as follows: Figure 3 As shown, the reverse water gas conversion device is equipped with a mixed material distribution area 1-1, a catalyst loading area 1-2, and a water-absorbing particle collection area 1-3. The first metal-supported catalyst loaded in the catalyst loading area 1-2 is a structured metal-supported catalyst. The white area (middle) shown in the catalyst loading area 1-2 is the through channel 1-4 for CO2, H2O and water-absorbing particles (mixture). The white areas on the far left and far right are the through channels 1-5 for CO and H2O gases only. The black area is the loaded catalyst.

[0046] See also Figure 1 A circulation loop 5 is provided between the reverse-flow gas conversion device 1 and the heat treatment device 2. After absorbing H2O, the water-absorbing particles collect in the water-absorbing particle collection area 1-3, and then reach the heat treatment device 2 through the circulation loop 5. Under the action of the heat treatment device 2, the water-absorbing particles are dried. The water vapor generated during the drying process is discharged through the water vapor outlet 6. The dried water-absorbing particles are then returned to the reverse-flow gas conversion device 1 through the circulation loop 5 for continued use, thus achieving reuse. This invention removes water from the water-absorbing particles in another independent device, which is simple and has a low dehydration temperature. It reduces the energy consumption of separating water from other organic matter and does not affect the activity of the catalysts used in each reaction stage.

[0047] See also Figure 1The heat treatment device 2 is located below the reverse water gas conversion device 1. The advantage of this arrangement is that after the H2O generated by the reverse water gas conversion device 1 is adsorbed by the water-absorbing particles, the water-absorbing particles can smoothly enter the heat treatment device 2 for drying under the action of gravity, thereby reducing the energy consumption of transportation.

[0048] See also Figure 1 The reverse water gas conversion device 1 is connected to the water gas conversion device 3. The CO generated in the reverse water gas conversion device 1 is transported to the water gas conversion device 3 for further reaction. The water gas conversion device 3 is filled with a second metal supported catalyst. By supplementing the water gas conversion device 3 with a certain amount of H2, the H2 and CO are converted into hydrocarbons or oxygen-containing compounds under the action of the second metal supported catalyst. Finally, the hydrocarbons are discharged from the water gas conversion device 3 through the target chemical discharge outlet 7.

[0049] In some embodiments, the cross-sectional area of ​​several axially connected channels 1-2 accounts for 10%-50% of the cross-sectional area of ​​the first metal-supported catalyst 1-1.

[0050] Secondly, the present invention provides a method for efficiently converting CO2 and hydrogen into chemicals, applicable to the system described in the first aspect for efficiently converting CO2 and H2 into chemicals. Figure 4 A flowchart illustrating a method for efficiently converting CO2 and hydrogen into chemicals according to an embodiment of the present invention is shown, as follows: Figure 4 As shown, the method includes:

[0051] S1. Control the temperature inside the reverse water gas conversion device to be no higher than 90℃ and the pressure to be 2-15MPa. In this device, water-absorbing particles, CO2 and H2 are introduced. The water-absorbing particles, CO2 and H2 flow through the internal channel of the first metal-supported catalyst. The CO2 and H2 are catalytically converted into CO and H2O, and the H2O is adsorbed by the water-absorbing particles.

[0052] S2. After absorbing water, the water-absorbing particles enter the heat treatment device under the action of gravity, are dried at 120-600℃, and then returned to the reverse water gas conversion device for recycling.

[0053] S3. Control the pressure of the reverse water gas conversion device to 2-8 MPa and the temperature to 180-350℃, and introduce the remaining gas in the reverse water gas conversion device into the water gas conversion device, while adding hydrogen. Under the action of the second metal supported catalyst, the target hydrocarbons or oxygen-containing compounds are generated.

[0054] In practice, a mixture of water-absorbing particles, CO2, and H2 is introduced into the reverse-flow gas shifter through mixture inlet 4. The molar ratio of CO2 to H2 introduced is 1:1. The amount of water-absorbing particles introduced is sufficient to adsorb all the H2O generated in the reverse-flow gas shifter. The water-absorbing particles are selected from silica gel, porous carbon, or porous carbon supported on metal salts. If the water-absorbing particles are porous carbon supported on metal salts, the metal salt loading is 3%-35%, and the metal salt is selected from magnesium chloride, copper sulfate, sodium chloride, or potassium chloride.

[0055] In specific implementation, the amount of H2 introduced into the water-gas conversion device satisfies the following ratio: the molar ratio of H2 to the molar ratio of CO in the remaining gas in the reverse water-gas conversion device is 1.5:1 to 2.5:1.

[0056] In specific implementation, the support for the first metal-supported catalyst is composed of carbon nanotubes, graphene, cerium oxide, silicon oxide, or aluminum oxide, and the supported metal is one or more of iron, cobalt, nickel, copper, zinc, and manganese, with a loading amount of 3%-25%; the support for the second metal-supported catalyst is aluminum oxide, silicon oxide, or molecular sieve, and the supported metal is one or more of iron, cobalt, nickel, copper, zinc, and chromium, with a loading amount of 6%-50%.

[0057] In specific implementation, the target hydrocarbon or oxygen-containing compound is at least one of olefins, alkanes, gasoline, diesel, and C1-C5 alcohols.

[0058] To enable those skilled in the art to more clearly understand the present invention, the following embodiments will now be used to provide a detailed description of a system and method for efficiently converting CO2 and H2 into chemicals according to the present invention.

[0059] Example 1

[0060] The reverse water-gas conversion device 1, the heat treatment device 2, and the water-gas conversion device 3 are connected in sequence. In the reverse water-gas conversion device 1, the ratio of the cross-sectional area of ​​the water-absorbing particle channel to the catalyst loading area is 0.1:1. The reverse water-gas conversion device 1 is filled with a catalyst (3% Co-5% Cu, supported on a carrier of 50% carbon nanotubes and 42% alumina, in cylindrical form with a diameter of 3-5 mm), and the water-gas conversion device 3 is filled with a catalyst (30% Cu-20% Zn-50% Al2O3 catalyst).

[0061] Dry water-absorbing particles (3% anhydrous magnesium chloride, supported on porous carbon) are mixed with CO2 and H2 (CO2 to H2 molar ratio 1:1) and introduced into the reverse-flow gas shifter 1 through the mixture inlet 4. The reaction is carried out at a temperature <80℃ and a pressure of 15MPa. The generated water is bound or adsorbed by the water-absorbing particles. The water-absorbing particle content in the CO2 gas is 113% of the total amount of water adsorbed or bound under the corresponding reaction conditions. When the product gas reaches the outlet of the reverse-flow gas shifter 1, the CO content in the gas reaches 90%. The water-absorbing particles and gas exit the reverse-flow gas shifter 1 together. After separation, the water-absorbing particles and gas enter the heat treatment device 2 containing water solids. Carrier gas is introduced into the heat treatment device 2 through the carrier gas inlet 8, heated to 120℃ using green electricity, and maintained for 6 hours to remove the water from the water-absorbing particles. The water and carrier gas exit the heat treatment device 2 through the water vapor outlet 6. The dried particles are circulated through the circulation loop 5 to the reverse water gas conversion device 1 for reuse.

[0062] After separation from the water-absorbing particles, CO and other gases enter the water-gas shift unit 3, and hydrogen (H2 / CO = 2:1) is added at the same time. The reaction takes place on the metal-supported catalyst at 6 MPa and 180-240℃ to generate C1-C5 alcohols, of which C1 alcohols account for 90% of the alcohols.

[0063] Example 2

[0064] The reverse water-gas conversion device 1, the heat treatment device 2, and the water-gas conversion device 3 are connected in sequence. The reverse water-gas conversion device 1 adopts... Figure 2 The structure is shown. In the reverse water-gas shifter 1, the ratio of the cross-sectional area of ​​the water-absorbing particle channel to the catalyst loading area is 1:1; the reverse water-gas shifter 1 is loaded with catalyst (3% Co-15% Cu, supported on a carrier of 50% carbon nanotubes and 32% silica, in cylindrical form with a diameter of 4-5 mm), and the water-gas shifter 3 is loaded with catalyst (ZnFe2O4 catalyst).

[0065] Dry water-absorbing particles (10% anhydrous sodium chloride, 15% anhydrous potassium chloride, loaded on silica gel) are mixed with CO2 and H2 (molar ratio of CO2 to H2 is 1.05:1) and introduced into the reverse-flow gas shifter 1 through the mixture inlet 4. The reaction is carried out at a temperature of 80-85℃ and a pressure of 8MPa. The generated water is bound or adsorbed by the water-absorbing particles. The water-absorbing particle content in the CO2 gas is 118% of the total amount of water adsorbed or bound under the corresponding reaction conditions. When the product gas reaches the outlet of the reverse-flow gas shifter 1, the CO content in the gas reaches 95%. The water-absorbing particles and gas exit the reverse-flow gas shifter 1 together. After separation, the water-absorbing particles and gas enter the heat treatment device 2 containing water solids. Carrier gas is introduced into the heat treatment device 2 through the carrier gas inlet 8, and the temperature is heated to 600℃ using green heat, then maintained for 1 hour to remove the water from the water-absorbing particles. The water and carrier gas exit the heat treatment device 2 through the water vapor outlet 6. The dried particles are circulated through the circulation loop 5 to the reverse water gas conversion device 1 for reuse.

[0066] After separation from the water-absorbing particles, CO and other gases enter the water-gas conversion unit 3, and hydrogen (H2 / CO = 2:1) is introduced at the same time. The reaction takes place on the metal-supported catalyst at 3 MPa and 300-320℃ to produce C1-C2 alcohols and C2-C5 alkenes, wherein the mass ratio of alcohol to alkene is 1:2.

[0067] Example 3

[0068] The reverse water-gas conversion device 1, the heat treatment device 2, and the water-gas conversion device 3 are connected in sequence. The reverse water-gas conversion device 1 adopts... Figure 2 Structure. In the reverse water-gas shift unit 1, the ratio of the cross-sectional area of ​​the water-absorbing particle channel to the catalyst loading area is 2:1. The catalyst (1% Fe-2% Co-3% Cu, supported on a carrier of 35% graphene and 52% cerium oxide, in cylindrical form with a diameter of 4-5 mm) is loaded in the reverse water-gas shift unit 1, while the catalyst (15% Ni-85% Al2O3 catalyst) is loaded in the water-gas shift unit 3.

[0069] Dry water-absorbing particles (13% anhydrous sodium chloride, 22% anhydrous copper sulfate, supported on porous carbon) are introduced into the reverse-flow gas shifter 1 via the mixture inlet 4 with CO2 and H2 (CO2 to H2 molar ratio of 1.02:1). The reaction occurs at 75°C and 2 MPa. The generated water is bound or adsorbed by the water-absorbing particles. The water-absorbing particle content in the CO2 gas is 115% of the total amount of water adsorbed or bound under the corresponding reaction conditions. When the product gas reaches the outlet of the reverse-flow gas shifter 1, the CO content in the gas reaches 93%. The water-absorbing particles exit the reverse-flow gas shifter 1 along with the gas. After separation, the water-absorbing particles and gas enter the heat treatment device 2 containing water solids. Carrier gas is introduced into the heat treatment device 2 through the carrier gas inlet 8, heated to 450°C using green heat, and maintained for 5 hours to remove the water from the water-absorbing particles. The water and carrier gas exit the heat treatment device 2 through the water vapor outlet 6. The dried particles are circulated through the circulation loop 5 to the reverse water gas conversion device 1 for reuse.

[0070] After separation from the water-absorbing particles, CO and other gases enter the water-gas conversion unit 3, while hydrogen (H2 / CO = 1.8:1) is introduced from the inlet 10. The reaction takes place on the metal-supported catalyst at 4 MPa and 300-310℃, producing 20% ​​C1-C5 alcohols, 30% gasoline, and 50% diesel.

[0071] Example 4

[0072] The reverse water-gas conversion device 1, the heat treatment device 2, and the water-gas conversion device 3 are connected in sequence. The reverse water-gas conversion device 1 adopts... Figure 3 Structure. In the reverse water-gas shift unit 1, the ratio of the cross-sectional area of ​​the water-absorbing particle channel to the catalyst loading area is 0.5:1. The catalyst (5% Fe-20% Mn-10% Zn, supported on a 65% cerium oxide carrier, cylindrical with a diameter of 4-5 mm) is loaded in the reverse water-gas shift unit 1, and the catalyst (5% Co-5% Ni-90% Al2O3 catalyst) is loaded in the water-gas shift unit 3.

[0073] Dry water-absorbing particles (porous carbon) are mixed with CO2 and H2 (molar ratio of CO2 to H2 is 1.02:1) and introduced into the reverse-flow gas shifter 1 through the mixture inlet 4. The reaction is carried out at 75℃ and 7MPa. The generated water is bound or adsorbed by the water-absorbing particles. The water-absorbing particle content in the CO2 gas is 120% of the total amount of water adsorbed or bound under the corresponding reaction conditions. When the product gas reaches the outlet of the reverse-flow gas shifter 1, the CO content in the gas reaches 82%. The water-absorbing particles and gas exit the reverse-flow gas shifter 1 together. After separation, the water-absorbing particles and gas enter the heat treatment device 2 for water-containing solids. Carrier gas is introduced into the heat treatment device 2 through the carrier gas inlet 8, heated to 200℃ using green electricity, and maintained for 3 hours to remove the water from the water-absorbing particles. The water and carrier gas exit the heat treatment device 2 through the water vapor outlet 6. The dried particles are recycled back to the reverse-flow gas shifter 1 through the circulation loop 5 for reuse.

[0074] After separation from the water-absorbing particles, CO and other gases enter the water-gas shift unit 3, while hydrogen (H2 / CO = 2.5:1) is introduced from the inlet 10. The reaction takes place on the metal-supported catalyst at 3 MPa and 250-280℃, producing 20% ​​olefins, 30% gasoline, and 50% diesel.

[0075] Example 5

[0076] The reverse water-gas conversion device 1, the heat treatment device 2, and the water-gas conversion device 3 are connected in sequence. The reverse water-gas conversion device 1 adopts... Figure 3 Structure. In the reverse water-gas shift unit 1, the ratio of the cross-sectional area of ​​the water-absorbing particle channel to the catalyst loading area is 1.5:1; the catalyst (6% Ni, supported on a carrier of 75% carbon nanotubes and 19% silica, in cylinders with a diameter of 3-4 mm) is loaded in the reverse water-gas shift unit 1, and the catalyst (ZnCrO4-ZSM-5 catalyst) is loaded in the water-gas shift unit 3.

[0077] Dry absorbent granules (silica gel) are mixed with CO2 and H2 (molar ratio of CO2 to H2 is 1.02:1) and introduced into the reverse-flow gas shifter 1 through the mixture inlet 4. The reaction is carried out at 85℃ and 12MPa. The generated water is bound or adsorbed by the absorbent granules. The water content of the absorbent granules in the CO2 gas is 90% of the amount of water adsorbed or bound under the corresponding reaction conditions. When the product gas reaches the outlet of the reverse-flow gas shifter 1, the CO content in the gas reaches 85%. The water-absorbed granules and gas exit the reverse-flow gas shifter 1 together. After separation, the water-absorbed granules and gas enter the heat treatment device 2 for water-containing solids. Carrier gas is introduced into the heat treatment device 2 through the carrier gas inlet 8, heated to 300℃ using green electricity, and maintained for 3 hours to remove the water from the absorbent granules. The water and carrier gas exit the heat treatment device 2 through the water vapor outlet 6. The dried granules are then recycled back to the reverse-flow gas shifter 1 through the circulation loop 5 for reuse.

[0078] After separation from the water-absorbing particles, CO and other gases enter the water-gas conversion unit 3, while hydrogen (H2 / CO = 1.5:1) is introduced from the inlet 10. The reaction takes place on the metal-supported catalyst at 2 MPa and 325 °C, producing 80% olefins and 20% alkanes.

[0079] Example 6

[0080] The reverse water-gas conversion device 1, the heat treatment device 2, and the water-gas conversion device 3 are connected in sequence. The reverse water-gas conversion device 1 adopts... Figure 2 Structure. In the reverse water-gas shift unit 1, the ratio of the cross-sectional area of ​​the water-absorbing particle channel to the catalyst loading area is 0.8:1; the catalyst (15% Co, supported on a carrier of 55% graphene and 30% cerium oxide, in cylindrical form with a diameter of 3-5 mm) is loaded in the reverse water-gas shift unit 1, and the catalyst (15% Co-65% silica-20% alumina catalyst) is loaded in the water-gas shift unit 3.

[0081] Dry water-absorbing particles (30% porous carbon, 70% silica gel) are mixed with CO2 and H2 (CO2 to H2 molar ratio 1.03:1) and introduced into the reverse-flow gas shifter 1 through the mixture inlet 4. The reaction is carried out at 88℃ and 3MPa. The generated water is bound or adsorbed by the water-absorbing particles. The water-absorbing particle content in the CO2 gas is 150% of the total amount of water adsorbed or bound under the corresponding reaction conditions. When the product gas reaches the outlet of the reverse-flow gas shifter 1, the CO content in the gas reaches 85%. The water-absorbing particles and gas exit the reverse-flow gas shifter 1 together. After separation, the water-absorbing particles and gas enter the heat treatment device 2 containing water solids. Carrier gas is introduced into the heat treatment device 2 through the carrier gas inlet 8, heated to 350℃ using green electricity, and maintained for 4 hours to remove the water from the water-absorbing particles. The water and carrier gas exit the heat treatment device 2 through the water vapor outlet 6. The dried particles are circulated through the circulation loop 5 to the reverse water gas conversion device 1 for reuse.

[0082] After separation from the water-absorbing particles, CO and other gases enter the water-gas shift unit 3, while hydrogen (H2 / CO = 2.2:1) is introduced from the inlet 10. The reaction takes place on the metal-supported catalyst at 8 MPa and 290-310℃, producing 20% ​​olefins, 40% gasoline, and 40% diesel.

[0083] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0084] For the sake of simplicity, the method embodiments are described as a series of actions. However, those skilled in the art should understand that the present invention is not limited to the described order of actions, as some steps can be performed in other orders or simultaneously according to the present invention. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and components involved are not necessarily essential to the present invention.

[0085] The above provides a detailed description of a system and method for efficiently converting CO2 and H2 into chemicals. Specific examples have been used to illustrate the principles and implementation methods of the invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the invention. At the same time, those skilled in the art will recognize that, based on the ideas of the invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the invention.

Claims

1. A system for efficiently converting CO2 and H2 into chemicals, characterized in that, The system includes: a reverse water-gas conversion device, a heat treatment device, and a water-gas conversion device; The reverse water gas conversion device is equipped with a first metal-supported catalyst. The first metal-supported catalyst has several axially connected channels uniformly arranged inside for the flow of CO2, H2 and water-absorbing particles. Under the action of the first metal-supported catalyst, CO2 and H2 are converted into CO and H2O. The generated H2O is adsorbed by the water-absorbing particles, thus separating CO and H2O. The heat treatment device is used to dry the water-absorbing particles; The water-gas conversion device is filled with a second metal-supported catalyst to convert CO into hydrocarbons or oxygen-containing compounds. A circulation loop is provided between the reverse water gas conversion device and the heat treatment device to allow the water-absorbing particles to be circulated and transported between the reverse water gas conversion device and the heat treatment device. The reverse water gas conversion device is connected to the water gas conversion device so that the CO generated by the reverse water gas conversion device is delivered to the water gas conversion device.

2. The system according to claim 1, characterized in that, The reverse water gas conversion device is located at the top of the heat treatment device so that the water-absorbing particles, after adsorbing H2O, enter the heat treatment device under the action of gravity.

3. The system according to claim 1, characterized in that, The cross-sectional area of ​​several of the axially penetrating channels accounts for 10%-50% of the cross-sectional area of ​​the first metal-supported catalyst.

4. The system according to claim 1, characterized in that, The reverse-flow gas conversion device also includes a mixed feed inlet; The heat treatment device also includes a steam outlet; The water-gas conversion device also includes a target chemical discharge outlet.

5. A method for efficiently converting CO2 and hydrogen into chemicals, characterized in that, The method is applicable to the system for efficiently converting CO2 and H2 into chemicals according to any one of claims 1-4, and the method includes: Under the condition that the temperature inside the reverse water gas conversion device is not higher than 90 ℃ and the pressure is 2-15 MPa, water-absorbing particles, CO2 and H2 are introduced into the reverse water gas conversion device. The water-absorbing particles, CO2 and H2 flow through the internal channel of the first metal supported catalyst, where CO2 and H2 are catalytically converted into CO and H2O, and H2O is adsorbed by the water-absorbing particles. After absorbing water, the water-absorbing particles enter the heat treatment device under the action of gravity, where they are dried at 120-600 ℃, and then returned to the reverse water gas conversion device for recycling. The pressure of the reverse water gas conversion device is controlled at 2-8 MPa and the temperature at 180-350 ℃. The remaining gas in the reverse water gas conversion device is introduced into the water gas conversion device, and hydrogen is added at the same time. Under the action of the second metal supported catalyst, the target hydrocarbons or oxygen-containing compounds are generated.

6. The method according to claim 5, characterized in that, The absorbent particles are silica gel, porous carbon, or porous carbon supported on metal salts; the loading of the metal salts is 3%-35%, and the metal salts are magnesium chloride, copper sulfate, sodium chloride, or potassium chloride.

7. The method according to claim 5, characterized in that, The molar ratio of CO2 and H2 introduced into the reverse water gas conversion device is 1:1; The amount of water-absorbing particles introduced into the reverse-flow gas conversion device is sufficient to adsorb all the H2O generated in the reverse-flow gas conversion device; The amount of H2 introduced into the water-gas conversion device satisfies the following proportional relationship: The molar ratio of H2 to CO in the remaining gas in the reverse water gas conversion device is 1.5:1 to 2.5:

1.

8. The method according to claim 5, characterized in that, The support for the first metal-supported catalyst is composed of carbon nanotubes, graphene, cerium oxide, silicon oxide or aluminum oxide, and the supported metal is one or more of iron, cobalt, nickel, copper, zinc and manganese, with a loading amount of 3%-25%.

9. The method according to claim 5, characterized in that, The support for the second metal-supported catalyst is alumina, silica, or molecular sieve, and the supported metal is one or more of iron, cobalt, nickel, copper, zinc, and chromium, with a loading of 6%-50%.

10. The method according to claim 5, characterized in that, The target hydrocarbon or oxygen-containing compound is at least one of olefins, alkanes, gasoline, diesel, and C1-C5 alcohols.

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