Improved catalytic reactor for the conversion of carbon dioxide and hydrogen into synthesis gas

Abstract

The present invention generally relates to a reactor for producing low carbon synthesis gas from captured carbon dioxide and renewable hydrogen. Hydrogen is produced from water using a renewable electricity powered electrolyzer or from other methods in low carbon hydrogen production. The improved catalytic reactor is energy efficient and robust when operating at temperatures up to 1800°F. Carbon dioxide conversion efficiency is greater than 75% and carbon monoxide selectivity is greater than 98%. The catalytic reactor is constructed of materials that are physically and chemically robust up to 1800°F. As a result, these materials are constructed of materials that do not react with the mixture of hydrogen and carbon dioxide or the products of carbon monoxide and water vapor. The reactor materials are not catalytically active or do not change the physical and chemical composition of the conversion catalyst. Electrical resistance heating elements are incorporated within the catalyst bed of the reactor, so that the internal temperature at any point in the reactor does not drop more than 100°F from the inlet. The catalytic process exhibits less than 0.5% degradation in performance per 1000 operating hours.

Description

Technical Field

[0001] The present invention relates to an improved catalytic reactor for performing an endothermic reaction, and more particularly to an improved catalytic reactor for efficiently converting carbon dioxide and hydrogen into synthesis gas. The stable and safe operation of this improved catalytic reactor can be maintained over a long period under a wide range of operating conditions, and in some cases, the conversion rate exceeds 75%. The catalytic reactor is constructed of a physically and chemically robust material at a temperature up to 1800°F and does not react with the reactants of hydrogen and carbon dioxide or the products of carbon monoxide and steam. The individual hydrogen and carbon dioxide streams are compressed, heated to a desired temperature, mixed in an appropriate volume ratio, and delivered into the improved catalytic reactor. In another embodiment, hydrogen and carbon dioxide are heated together before being introduced into the catalytic reactor. For the purpose of minimizing emissions, an integrated reactor heater may utilize both natural gas and electricity. The reactor design incorporates heating into the catalyst bed to supply thermal energy to the endothermic reaction. Alternatively, the gas may be heated before entering the bed and the incorporated heating may not be used to obtain the desired result.

Background Art

[0002] The adverse effects of greenhouse gas emissions on the climate and ecological environment have been increasingly regarded as a problem, and it has become clear what climate scientists have been predicting for a long time. The world's average temperature has risen by more than 1°C compared to the pre-industrial era, and in some regions, warming exceeding 5°C is progressing (Schuetzle, 2020; Rohde, 2021). To slow down and ultimately stop the rise in the Earth's temperature, it is necessary to significantly reduce the emissions of carbon dioxide and other greenhouse gases and ultimately reach net zero. Technologies for carbon capture and utilization are essential elements for achieving the goals of the Paris Agreement, such as keeping global warming below 2°C, along with a significant reduction in carbon dioxide emissions (Gutierrez et al, 2021).

[0003] Carbon capture and storage (CCS) will play a fundamental role in achieving these goals. Most ongoing CCS projects involve injecting carbon dioxide into sedimentary basins, requiring impermeable rocks to prevent the carbon dioxide from returning to the surface. Direct air capture (DAC) is a technology that directly captures carbon dioxide from the air using engineered mechanical systems. The technology of capturing carbon dioxide from the atmosphere has been considered for some time, and several small-scale pilot plants are in operation (Spector and Dodge, 1946). Plant designs typically incorporate fans and filtration systems, which selectively remove carbon dioxide. The captured carbon dioxide is later released, and the filtration system is regenerated. Permanent storage of captured carbon dioxide can be achieved by mineralization. In-situ mineralization is a promising means for permanent storage of carbon, but its large-scale implementation has not yet been explored beyond pilot and field-based experiments.

[0004] Carbon dioxide should be considered a valuable carbon source for the sustainable production of liquid fuels and chemicals. The importance of carbon dioxide utilization in carbon management has long been recognized, and carbon dioxide is predicted to play a crucial role as a future fuel in the post-fossil fuel era (Hepburn et al, 2019). In recent years, Alden and his collaborators have theoretically explained the potential of carbon dioxide utilization (CDU), where carbon dioxide is converted into chemicals, which is projected to reach approximately 0.3–0.6 GTCO2 / year by 2050, and the potential of CDU, where carbon dioxide is converted into fuel, which is estimated to range from 1–4.2 GTCO2 / year at its peak. Reverse water-gas shift (RWGS) has been proposed and marketed as a potentially viable solution for achieving decarbonization on a scale of several GTCO2 / year (Artz et al, 2018).

[0005] Carbon dioxide hydrogenation (CO2H) involves a reverse water-gas shift (RWGS) reaction and is a technology that converts carbon dioxide into other carbonaceous species, such as carbon monoxide, which are important precursors for the production of liquid fuels such as diesel and gasoline, as well as chemicals.

[0006] While the CO2H and RWGS reaction approaches offer advantages such as rapid reaction rates, excellent selectivity, and immediate technical readiness, renewable hydrogen production is necessary to minimize the carbon footprint. Currently, most hydrogen is produced from fossil fuels through steam reforming of natural gas or gasification of coal, depending on the desired ratio of hydrogen to carbon monoxide. This is an important method for hydrogen production for the time being, but efforts to reduce carbon dioxide emissions are required. Combining natural gas reforming with carbon capture, utilization, and storage is a step toward reducing emissions. Biomass can also be converted into hydrogen in various ways. Because biomass removes carbon dioxide from the atmosphere, it can reduce net carbon emissions in combination with CCS. Electricity can also be used in hydrogen production. Since electricity can be supplied from various renewable energy sources such as solar, wind, and geothermal energy, it is a promising option for carbon-free hydrogen production.

[0007] The RWGS reaction is a suitable method for sustainable synthesis gas production, particularly when producing hydrogen from renewable energy sources such as wind or solar energy. A considerable amount of research has been conducted toward the development of industrial RWGS processes, including efficient catalyst systems, reactor units, and even pilot-scale processes. However, progress in implementing RWGS on an industrial scale remains elusive. One key challenge is the selection of materials for reactors, piping, analytical instruments, and instrumentation. Handling carbonaceous gas mixtures remains a challenge under high temperature and pressure. Another concern is the thermal management of the RWGS reactor to achieve safe and stable operation with high conversion rates over long periods.

[0008] The RWGS reaction (Equation 1) is a reversible hydrogenation reaction of carbon dioxide, producing carbon monoxide and water vapor. Since carbon dioxide is a relatively unreactive molecule, the conversion from carbon dioxide to carbon monoxide is endothermic. This is energy-intensive and favorable at high temperatures. At low temperatures, methanation, also known as the Sabatier reaction, is more favorable than the RWGS reaction (Equation 2). [ka]

[0009] Since the RWGS reaction is an endothermic reaction, it requires high temperatures and heat transfer is limited. Therefore, optimizing the heat transfer characteristics and residence time in the catalytic reactor is particularly important.

[0010] While much research is being conducted towards the development of CO2H or RWGS catalytic reactors, there is still a lack of understanding regarding optimal reactor geometry, thermal management, and material selection. For industrial RWGS reactors to be commercially viable, they must meet the following design and operating requirements: 1. Use catalyst reactor materials that are physically and chemically robust up to 1800°F. 2. The materials used in the walls and equipment of the catalytic reactor must not react unfavorably with hydrogen, carbon dioxide, carbon monoxide, and water vapor. 3. An energy-efficient catalytic reactor heating system that utilizes renewable or low-carbon electricity. 4. Catalytic reactor and associated piping that minimize carbon generation. 5. The linear decrease in the carbon dioxide conversion rate is less than 1.0% / 50°F between 1250 and 1750°F. 6. The carbon dioxide conversion rate exceeds 75% per pass at temperatures above 1250°F. 7. The selectivity of carbon monoxide must exceed 98%.

[0011] Commercial reactors used for high-temperature reactions are typically constructed from either precast refractory or stainless steel. Their shape is usually a cylindrical metal shell with a thick refractory layer and an inner metal liner. The refractory lining typically constitutes a safety or backup layer behind the working lining that comes into contact with the furnace contents. Because each material has a different coefficient of thermal expansion, the temperature gradient within the system and the properties of all materials must be carefully considered. Excessive stress due to refractory expansion should not lead to cracking of the reactor shell and subsequent failure of the lining. This is, of course, a safety consideration, but it also significantly impacts the reactor's lifespan.

[0012] A common type of industrial catalytic reactor is one used for endothermic steam reforming of methane or other hydrocarbons. These endothermic steam reforming reactors consist of high-temperature steel tubes filled with catalyst. These reactors are typically heated externally using gas burners or electric heaters. A drawback of this design is that the heating of the reactor and tubes is not uniform. This often leads to a reduced lifespan of the reactor shell and tubes. Below operating temperatures, conversion efficiency decreases, and carbon deposition can occur. Above operating temperatures, metal deformation can occur, and catalyst sintering, melting, and surface vanishing can occur (Eigenberger et al, 2012). Metal dusting, where metals carburize and decompose, is a specific type of corrosion that can occur in reforming reactors when operating temperatures exceed the design temperature.

[0013] The series connection of endothermic catalytic reactors is known in the present art. Typically, one long endothermic reactor is divided into three smaller reactors. By reheating the process flow between reactors, the temperature of the process flow is returned to the temperature required to efficiently convert the reactants and suppress undesirable secondary reactions. For example, in a three-catalyst reactor system, the reactors are typically progressively longer. Usually, the first catalyst bed is shorter than the next reactor because heat is quickly lost by the process flow, which can lead to undesirable reactions, and therefore the flow needs to be reheated to maintain efficiency (Process Technology and Operator Academy, 2015). Multi-reactor systems have drawbacks such as additional piping and high capital costs.

[0014] To reduce energy consumption, the integration of endothermic and exothermic catalytic reactors has been proposed. However, in most cases, such integration is impractical and often costly (Rahimpour et al, 2012). The integration of waste heat reactions and endothermic reactions is often a more economical means of synthesis gas production. Maass et al. (2021) disclose a two-compartment reactor. In this reactor, coke oven gas is used, and in the first compartment, hydrogen and carbon dioxide are converted to carbon monoxide and water vapor, and then in the second compartment, this generated water vapor reforms hydrocarbons present in the coke oven gas, thereby producing synthesis gas. Such methods require the initial introduction of heat from an upstream heat source such as a coke oven, and require the synthesis gas production to be integrated with existing industrial processes.

[0015] The use of the production flow of reformed gas as a heat source in heat exchange reforming is known in the art. Fuderer (1984) describes an endothermic catalytic reactor in which hydrocarbon feed is introduced in parallel to a tubular reformer and a heat exchange reformer. The partially reformed gas from this tubular reformer is used as a heat source for the reforming reaction in the heat exchange reformer.

[0016] Several previous studies have shown that at high temperatures, the metallurgy of the reactor can affect the performance of the catalyst, and have advised screening catalysts only in quartz reactors. Bustamante et al. (2004) found that in Inconel reactors, the catalytic effect of nickel in Inconel 600 resulted in a carbon dioxide conversion rate two orders of magnitude higher than in quartz reactors.

[0017] However, no research has been conducted to develop optimal metallurgy or refractories that specifically address the challenges of endothermic reactors operating in high-temperature, high-pressure, and highly reducing environments. Furthermore, no research exists that investigates the long-term use of specific materials and reactor designs.

[0018] Metal dusting is a carburizing process that occurs when a carbonaceous gas passes over the surface of a catalyst metal. The initial formation of powdery coke can obstruct gas flow, potentially requiring higher pressure and temperature gradients. This is particularly important in industrial heat exchangers. This phenomenon can lead to the formation of metal particles on the material surface, material decomposition, and ultimately, fatal failure, which is why appropriate material selection is a unique challenge in RWGS (Return-on-Warm Gases).

[0019] Carbon can be formed on the metal surface through the following reactions: [ka] Grabke et al. (1975) and Shatynski et al. (1978) demonstrated that among the aforementioned reactions, Equation 3 exhibits the fastest kinetics, resulting in significant metal dusting in a high-temperature CO-H2 environment. Equation 4 is known as the Boudouard reaction, but its kinetics are relatively slow, and therefore it is considered to play a small role.

[0020] The formation of carbon also occurs by solid reactions involving the dissolution of metal carbides. For iron and steel alloys, Hochman (1977) and Grabke (1999) proposed that carbon formed from metal dusting forms cementite M3C (M = Fe, Ni) by the diffusion of CO into the metal. A part of the cementite then resists subsequent penetration. Nevertheless, as a result of the high carbon activity at the metal surface, coke is locally nucleated. The decrease in carbon activity reduces the stability of Fe3C and Ni3C, thereby causing their decomposition. Carbon and metal diffuse to the metal surface, thereby forming further coke and metal particles on the surface. Subsequently, the metal nanoparticles on the surface act as catalysts to further accelerate this process and material decomposition. Another problem related to the selection of RWGS process materials, the material corrosion mechanism, is a form of internal oxidation of chromium-nickel-iron alloys that causes embrittlement. This term was coined because in various alloys, Cr2O3 is formed, so the fracture surface has a green appearance. The newly formed fracture surface exhibits a green color due to internal oxide precipitates that caused embrittlement, from which the term "green rot" was coined. SUMMARY OF THE INVENTION

[0021] The present invention describes an improved commercial-scale catalyst reactor design for efficiently converting a carbon dioxide and hydrogen mixture into synthesis gas. The present invention also proposes the selection and assembly of novel materials that can be employed in commercial-scale reactors, heat exchangers, and analytical devices to maximize performance and device lifespan. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] [Figure 1]Figure 1 shows an improved catalytic reactor 100. The reactor comprises an outer shell 101 capable of withstanding the desired maximum operating pressure, a refractory layer 102 provided directly inside the metal shell, which does not chemically react with carbon monoxide, carbon dioxide, hydrogen and steam under high temperature and high pressure, an inner sleeve 103 made of a superalloy and / or alumina, a catalyst bed 104, and an electric resistance heating element 105 incorporated in the catalyst bed. Induction heating methods or other types of electric heating methods can also be used. A reactant gas blend 106 of hydrogen and carbon dioxide is supplied into the catalytic reactor 100 and maintained at a temperature of 1200°F to 1700°F and a pressure between 0 and 500 psig through the reactor. The reactant gas mixture is converted into syngas (hydrogen and carbon monoxide) and water, along with unreacted carbon dioxide. [Figure 2] Figure 2 shows an embodiment of the catalytic reactor shown in Figure 1, where the catalyst bed is divided into a plurality of short zones 201 and has a sheathed electric resistance heating element 202 between each zone. [Figure 3] Figure 3 shows an embodiment of the catalytic reactor shown in Figure 1, where a heating element 301 is vertically incorporated into the catalyst bed 302. Induction heating or other forms of electric heating can also be used.

Mode for Carrying Out the Invention

[0023] The structure of the catalytic reactor 100 is depicted in Figure 1. The length and width of the reactor depend on the desired synthesis gas output and may range from 1 to 10 feet or more in width and 1 to 40 feet or more in length. The outer shell 101 is made of a metal capable of operating at a differential pressure of 500 psi or more, and such metals include, but are not limited to, carbon steel, stainless steel, and titanium. The outer shell defines the shape of the reactor and may be any shape known in the art of catalytic reactors. The thickness of the outer shell is determined by the desired maximum operating pressure of the reactor and may range from 1 / 4 inch to 10 inches. The outer shell is protected from the corrosive and high-temperature internal reactor environment by a refractory layer 102. This layer insulates the reactor so that the surface temperature of the outer shell does not exceed 600°F, more preferably 400°F, and even more preferably 200°F. The refractory material may be made of any insulating material and may consist of materials including, but not limited to, alumina, calcium aluminate, magnesium aluminate, silicon carbide, and silicon nitride.

[0024] The refractory material does not react with carbon monoxide, carbon dioxide, hydrogen, and water vapor under operating conditions. In some embodiments, the refractory material includes a catalytically active material. In some embodiments, the refractory layer consists of a single layer or multiple sub-layers made of the same or different types of materials. This layer may be cast directly into the reactor using castable refractory material or may consist of cemented refractory bricks. The total thickness of the refractory layer may vary from 6 to 18 inches.

[0025] In applications where there is a risk of cracking in the refractory, an inner sleeve 103 may be fitted. The inner sleeve is made of a high-temperature alloy, which includes, but is not limited to, the alloys shown in Table 1. The material of the inner sleeve may be alumina. High-temperature alloys include materials in which the weight percentage of nickel is 29–75 wt% and the weight percentage of chromium is 13–32 wt%. The inner sleeve can withstand a maximum temperature of 1800°F and does not react with carbon monoxide, carbon dioxide, hydrogen, and water vapor under reaction conditions. Some of the listed materials may require passivation treatment to minimize the risk of green rod formation or metal dusting. In some embodiments, this passivation consists of forming an oxide layer to reduce the chemical potential for green rod formation and metal dusting. In some embodiments, the passivation layer or coating may consist of the formation of a stable oxide under reaction conditions. This passivation layer contains a metal oxide selected from the group including iron oxide, nickel oxide, chromium oxide, cobalt oxide, molybdenum oxide, tungsten oxide, copper oxide, niobium oxide, calcium oxide, magnesium oxide, alumina, or titania. This passivation layer may contain not only mixed oxides of the above components, but also physical mixtures. Depending on the type of apparatus, the passivation may be established during material construction or commercial plant startup before exposure to CO2 and H2. The chemical stability of the alloy used in this application may also be enhanced by forming a nitride passivation layer. The thickness of the passivation layer varies from thin passivations of a few microns to deeper layers of the bulk phase. The thickness and selection of the passivation layer may be chosen depending on the optimized thermal conductivity or thermal insulation properties, material strength, and chemical resistance.

[0026] [Table 1]

[0027] In Figure 1, a reactant gas blend 106 containing hydrogen and carbon dioxide is introduced into the reactor through an inlet nozzle 107 at a temperature of 1250–1750°F and a pressure of 0–500 psig. The reactor inlet section 108 is empty to allow the reactant gas flow to develop sufficiently before contacting the catalyst bed 104. Upon contact with the catalyst bed, the hydrogen and carbon dioxide gas blend begins to react, producing carbon monoxide and vapor. As the endothermic reaction progresses, the gas temperature decreases, but the lost heat is returned to the gas mixture by a heater 105 incorporated into the catalyst bed. The heater is protected by a layer of high-temperature alloy, such as an inner sleeve 103, to prevent the process gas mixture from directly contacting the elements. Alternatively, the heater may be housed in refractory material. The reactant gas blend undergoes conversion to synthesis gas along the reactor until it reaches the outlet nozzle 109. The total conversion rate of carbon dioxide at the reactor outlet is at least 75%, and the outlet gas mixture 110 is at least 100°F lower in temperature than the inlet gas mixture 106.

[0028] In some embodiments, the heater 105 consists of a resistance electric heating element, a fuel combustion burner, or a combination of the two. The fuel for the firing burner may include natural gas, hydrogen, a combination thereof, or any other suitable fuel. The electric heater is powered by a carbon-free or low-carbon power source such as wind, solar, geothermal, or nuclear power. When a natural gas heater is used, it is incorporated to minimize the combustion of natural gas or other fuels and carbon dioxide emissions. Combining electric and gas heaters within the catalyst bed of a single reactor allows for further optimization of carbon dioxide emissions. Electric heating can be used to bring the catalyst bed to a temperature of 1000–1200°F, thereby reducing the amount of natural gas required to heat the bed to a final temperature of 1600–1800°F.

[0029] In one embodiment of the improved catalytic reactor (Figure 2), the catalyst bed is divided into several short sections 201, with an electric resistance heating element 202 between each section. A reactant gas blend of hydrogen and carbon monoxide is introduced into the reactor at a temperature of 1250–1750°F and a pressure of 0–500 psig. The gas comes into contact with a first catalyst section and undergoes an endothermic RWGS reaction, with the temperature dropping by less than 100°F along the section. A high-temperature alloy sheath 203 penetrates horizontally through the outer shell to house one of the resistance electric heating elements 202. The sheath is positioned between the first catalyst and the second catalyst, returning the gases to their original temperatures. Power to the resistance heating element may be controlled based on the temperature of the gas leaving the first catalyst section. The process gas flows alternately around the heating element through the remaining catalyst sections until a desired conversion rate of carbon dioxide is achieved. The number of catalyst sections may vary from 2 to 100. In another embodiment of the improved catalytic reactor, multiple sheaths housing resistance heating elements penetrate the reactor around its periphery in each heating zone and terminate at the center of the reactor. The number of heating elements per zone may vary from 1 to 10 or more.

[0030] In yet another embodiment of the improved catalytic reactor (Figure 3), the reactor has a single catalyst bed 301, and a sheath 302 housing a resistive or other type of electric heating element 303 penetrates the reactor vertically and traverses the entire length of the catalyst bed. These sheaths and elements may enter the reactor from the top, bottom, or both, and the number of these sheaths and elements may vary from 1 to 10 or more. The heating element 303 supplies evenly distributed heat to the catalyst and process gas, thereby maintaining a relatively constant temperature along the reactor and enabling the reactor to operate pseudo-isothermally. [Examples]

[0031] Example 1: Flows containing carbon dioxide and other waste gases are generated by industrial processes or captured from the ambient air. These flows are then supplied to a carbon dioxide capture facility. The carbon dioxide capture facility uses adsorbents such as methyldiethanolamine (MDEA) to capture the carbon dioxide. Relatively pure carbon dioxide is regenerated from the adsorbent by heating.

[0032] Within the carbon capture facility site, low-carbon electricity from wind power plants, solar power plants, nuclear power plants, or other low-carbon sources is available. High-purity water is produced from locally available water. Low-carbon hydrogen is produced from pure water by electrolysis.

[0033] Low-carbon electricity is used in the electrolysis process to decompose water into hydrogen and oxygen gases. The electrolytic cell in this example is a proton exchange membrane (PEM) electrolytic cell. This electrolytic cell produces hydrogen and oxygen at 300 psig each.

[0034] Pressurized hydrogen is electrically heated to 1650°F and mixed with carbon dioxide, which is also compressed to 300 psig and electrically heated to 1650°F. These hydrogen and carbon dioxide are mixed in a volume ratio of 3.4 / 1.0, and the flow rate of this mixture is adjusted to provide a gas space velocity of approximately 15,000 hr⁻¹ within the catalytic reactor.

[0035] Since this catalytic reaction is endothermic, the temperature of the mixture decreases as the reactant gas is converted to synthesis gas on the catalyst bed. In this embodiment, the heating element is positioned vertically so that the reactant gas temperature does not drop by more than 50°F from the inlet at any point in the reactor. In this embodiment, the total conversion rate of carbon dioxide is 85%, and the CO selectivity is 99%. The volume composition of the dry gas from the catalytic reactor after water has been removed from the product stream is H272%, CO24%, and CO24%.

[0036] Example 2 A gas blend with a volume ratio of carbon dioxide / hydrogen of 3.0 / 1.0 is introduced into the catalytic reactor at a temperature of 1400°F and a pressure of 100 psig. The gas flows over the catalyst bed and is reheated by an integrated electric heating element, as in Example 1. The conversion rate of CO2 at the reactor outlet is 75%, and the CO selectivity is 99%. After water is removed from the product flow, the volume composition of the dry synthesis gas is 77%, 3%, CO2, and 6%.

[0037] References US Patent 4,337,170 A1 07 / 1982 Fuderer 7,718,832 B1 05 / 2010 Schuetzle et al. 11,078,077 08 / 2021 Maass et al.

[0038] U.S. Patent Application 2003 / 0113244 Al 06 / 2003 DuPont et al

[0039] Non-patent literature Artz, J., Muller, TE, Thenert, K., Kleinekorte, J., Meys, R., Sternberg, A., Bardow, A, Leitner, W: Sustainable conversion of carbon dioxide: An integrated review of catalysis and life cycle assessment. Chemical Reviews, 118, 434-504 (2018). Bustamante, F. et al: High-temperature kinetics of the homogeneous reverse water-gas shift reaction, American Institute of Chemical Engineers, AIChE J, 50, 1028-1041 (2004). Eigenberger, G., Ruppel, W.: Catalytic fixed-bed reactors, reaction engineering (part 10), Wiley Online Library, Hoboken, New Jersey (2012). Field, CB; Mach, KJ: Rightsizing carbon dioxide removal, Science 356, 706-707 (2017). Hepburn, C.; Adlen, E.; Beddington, J.; Carter, EA; Fuss, S.; Mac Dowell, N.; Minx, JC; Smith, P.; Williams, CK: The technological and economic prospects for CO2 utilization and removal, Nature, 575 (7781), 87-97 (2019). Gutierrez JM et al: Climate Change 2021: The Physical Science Basis. Intergovernmental Panel on Climate Change (IPCC): Sixth Assessment Report (AR6), August 9, 2021 (www.ipcc.ch / assessment-report / ar6). Mac Dowell, N.; Fennell, PS; Shah, N.; Maitland, GC. The role of CO2 capture and utilization in mitigating climate change. Nat. Climate Change, 7 (4), 243-249 (2017). Process Technology and Operator Academy, Endothermic vs. Exothermic Reactors (2015) (www.processtechacademy.com). Ranjbar, A.; Aghamiri, SF; Irankhah, A.: Effect of MgAl2O4 catalyst support synthesis method on the catalytic activity of nickel nano catalyst in reverse water-gas sift reaction, Iranian Journal of Chemical Engineering, 16, 3 (2019). Rahimpour, MR, Dehnavi, MR, Allahgholipour, F., Iranshahi, D., Jokar, SM: Assessment and comparison of different catalytic coupling exothermic and endothermic reactions: a review, Applied Energy, 99, 496-512 (2012). Rohde, R., Global Temperature Report for 2020, Berkeley Earth (2021). Schuetzle, D.: Historical and predicted global climate changes and some potential accelerated climate moderation approaches, Global Climate Action Summit, San Francisco, CA, 1-42 (2020) (www.researchgate.net). Shukla, PR et al: Climate Change and Land: an IPCC special report on climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystems, 2019 Intergovernmental Panel on Climate Change (2019) (www.ipcc.ch). Spector, N.A., BF Dodge, Removal of carbon dioxide from atmospheric air, Trans. Am. Inst. Chem. Engrs., 42, 827-48 (1946)

Claims

1. A catalytic reactor for producing synthesis gas from a mixture of hydrogen and carbon dioxide, a. Inlet nozzle (107) and b. A metal outer shell (101) with a thickness of 0.635 cm (1 / 4 inch) to 25.4 cm (10 inches), c. A refractory layer (102) having a thickness of 15.24 to 45.72 cm (6 to 18 inches) and containing insulating material, d. An inner sleeve (103) made from at least one high-temperature alloy, wherein the high-temperature alloy contains nickel and chromium, the nickel making up 29 to 75% by weight of the alloy and the chromium making up 13 to 32% by weight of the alloy, e. A catalyst bed (104) capable of converting a mixture of carbon dioxide and hydrogen into carbon monoxide and vapor, f. One or more resistive electric heating elements (105), g. Outlet nozzle (109) and Includes, A high-temperature alloy sheath penetrates the outer shell, and the sheath houses one of the resistive electric heating elements. The high-temperature alloy contains nickel and chromium, wherein the nickel is 29 to 75% by weight of the alloy, and the chromium is 13 to 32% by weight of the alloy. A catalytic reactor (100) having multiple catalytic regions separated by at least one high-temperature alloy sheath, the number of which is 2 to 100.

2. The catalytic reactor (100) according to claim 1, wherein a single catalyst bed (104) is horizontally penetrated by a plurality of resistive electric heating elements (105).

3. The catalytic reactor (100) according to claim 1, wherein a single catalyst bed (104) is vertically penetrated by a plurality of resistive electric heating elements (105).

4. The catalytic reactor (100) according to claim 1, wherein the refractory layer (102) comprises one or more layers of alumina, calcium aluminate, magnesium aluminate, silicon carbide, or silicon nitride.

5. The catalytic reactor (100) according to claim 1, wherein the surface of the inner sleeve (103) is passivated to reduce the chemical potential of green rod and metal dusting.

6. The catalytic reactor (100) according to claim 5, wherein the passivation layer contains a metal oxide selected from the group consisting of iron oxide, nickel oxide, chromium oxide, cobalt oxide, molybdenum oxide, tungsten oxide, copper oxide, niobium oxide, calcium oxide, magnesium oxide, alumina, or titania.

7. The catalytic reactor (100) according to claim 1, wherein a plurality of sheaths housing resistive electric heating elements (105) penetrate the outer shell (101) around its outer circumference in each heating area and terminate in the center of the reactor.

8. The catalytic reactor (100) according to claim 7, wherein the number of heating elements per heating area varies from 2 to 10.

9. A method for producing synthesis gas, a. A step of producing hydrogen by electrolysis using low-carbon electricity, b. The step of reacting a stream containing hydrogen and carbon dioxide in the catalytic reactor described in claim 1, Includes, c. The catalytic reactor is operated at a temperature of 676.7 to 954.4°C (1250 to 1750°F) and a pressure of 0.101 to 3.55 MPa (0 to 500 psig). The carbon dioxide conversion rate is over 75% per pass, and the CO selectivity exceeds 98%, generating a stream of RWGS products containing carbon monoxide. method.

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