Self-heat-production type carbon dioxide capturing and utilizing method and reactor

Abstract

The invention discloses a self-heat-production type carbon dioxide capturing and utilizing method and a reactor, which are used for capturing CO2 from carbon dioxide-containing gas and converting the CO2 into synthesis gas in situ. Carbon dioxide-containing gas enters an adsorption reaction area of the reactor from one side of the partition plate, CO2 in the carbon dioxide-containing gas is adsorbed and captured by a catalytic material in a catalyst bed layer, heat generated in the adsorption reaction process is absorbed by a heat accumulator in the catalyst bed layer, and when the adsorption reaction area reaches the saturated adsorption capacity of an adsorbent, the carbon dioxide-containing gas enters the adsorption reaction area. The gas containing carbon dioxide is switched to enter the conversion reaction area on the other side of the partition plate, at the moment, the reducing gas enters the adsorption reaction area to carry out conversion regeneration on the adsorption reaction area, and after the conversion reaction area reaches the expected saturated adsorption capacity of the adsorbent, the gas containing carbon dioxide is switched to enter the adsorption reaction area; and the reducing gas is switched to enter the conversion reaction area, and the operation is repeated. By means of the device, the energy utilization rate can be fully increased, the emission reduction cost is effectively reduced, and heat in-situ coupling utilization in the adsorption heat release / conversion heat absorption process can be achieved.

Description

Technical Field

[0001] The present invention relates to a method for capturing carbon dioxide from gas and converting and utilizing the same in situ, and in particular to a self-heating carbon dioxide capturing and utilizing method and reactor. Background Art

[0002] Carbon capture, utilization, and storage (CCUS) is a crucial technological approach for addressing global climate change and controlling greenhouse gas emissions. Modern industrial production generates numerous CO2 emissions, including from the cement, steel, power, coal chemical, and refinery industries. To address this issue, various industries are conducting research and exploration into CO2 capture, utilization, and storage. Each industry, in turn, has developed a variety of CO2 capture, utilization, and storage technologies tailored to its specific needs.

[0003] Currently, large-scale carbon capture research focuses on the power industry. Chemical absorption capture of post-combustion flue gas from coal-fired power plants is a relatively mature technology. However, high-temperature flue gas requires sequential heat exchange to absorb at low temperatures. Furthermore, the high cost of solvents and the high energy consumption of regeneration increase energy consumption by approximately 30% for coal-fired power plants. Furthermore, off-site storage of captured CO2 incurs high transportation costs and raises concerns about safety risks. Adsorption is also technically mature, but is generally limited to conditions with a defined gas composition. The adsorbent's capacity and CO2 selectivity are low, resulting in high costs and, generally, limited to low-temperature gases. Membrane methods generally lack a high degree of separation and require multiple stages and / or recycling, resulting in increased complexity, energy consumption, and cost. Furthermore, impurities in the gas can cause blockage. These capture methods only yield high-concentration CO2 gas, and subsequent transportation and utilization remain significant issues. Developing technologies to capture CO2 and convert it into high-value-added chemicals is key.

[0004] In recent years, Huaneng Group launched a CO2 capture demonstration project at its Shanghai Shidongkou Second Power Plant in December 2009. This project utilizes proprietary CO2 capture technology, capturing 120,000 tons of CO2 annually with a purity exceeding 99.5%. Part of the captured CO2 is processed through a refining system and used in the food processing industry, while the remainder is used in industrial production. At the time of its commissioning, this capture unit was the world's largest flue gas CO2 capture facility for coal-fired power plants. The Huaneng Tianjin Green Coal Power 250MW IGCC unit was completed and commissioned in 2011, followed by a 400MW IGCC unit equipped with CO2 capture in 2016. The demonstration project aims to research, develop, demonstrate, and promote near-zero CO2 emissions coal-based power generation systems, while significantly improving power generation efficiency and mastering the design, construction, and operation technologies of large-scale coal gasification projects.

[0005] Currently, three companies have established pilot demonstrations of calcium cycle CO2 capture, including La Pereda's 1.7MWth power plant flue gas CO2 capture demonstration system, Darmstadt's 1MWth power plant flue gas CO2 capture demonstration system, and ITRI Research Institute's 3kWth power plant flue gas CO2 capture pilot. All of them use a calcium cycle double fluidized bed capture system to capture and regenerate CO2 in flue gas.

[0006] All of the aforementioned technologies focus on CO2 capture, not conversion and subsequent utilization. Published patents on CO2 capture and conversion research primarily focus on catalysts. Because CO2 capture is a highly exothermic reaction and the conversion process is highly endothermic, temperature and heat control during the reaction is crucial. Process design and reactor type are crucial to the feasibility of the technology. Common approaches for highly endothermic and exothermic reactions include using coils for heat extraction / supplementation, direct combustion heating, and fluidized and moving beds. These methods present challenges for CO2 capture and conversion. Using coils for heat extraction / supplementation presents challenges in controlling the transition between capture and conversion, with the coils alternating between heat extraction and absorption. Furthermore, due to the uneven reaction within the catalyst bed, localized overheating / undercooling is difficult to avoid. Direct fuel gas heating often leads to post-combustion gas overheating. Taking the commonly used CaO / CaCO3 adsorbent as an example, when the temperature is greater than 850-900℃, the adsorbent will melt and sinter. The invention does not have any measures to prevent sintering; at the same time, inert gases such as N2 and impurity components introduced during the combustion process will also cause severe dilution of the product, resulting in a decrease in the effective gas concentration.

[0007] CN202110287520.5 discloses a method for reducing carbon monoxide synthesis gas using a high-temperature molten heat carrier, carbon dioxide, and carbon powder. This method uses carbon dioxide and carbon powder to absorb the sensible heat and latent heat emitted by the high-temperature heat carrier, raise the temperature to the reduction temperature, and instantly reduce it to carbon monoxide high-energy synthesis gas. The high-temperature volumetric heat capacity of carbon dioxide is used to circulate heat exchange with the granulated high-temperature heat carrier. The entire process is long, and the core equipment is similar to a fluidized bed with a large pressure drop. The process temperature frequently changes between 50°C and 1500°C. The drastic temperature change will inevitably bring energy consumption problems; and the longer process will bring pressure drop problems. Usually, the flue gas pressure is low, and the large pressure drop also limits the use of this technology.

[0008] CN201821322948.9 discloses a catalytic reaction device, the lower part of which is provided with a methane + water vapor hydrogen production catalyst to produce hydrogen, the middle part is fed with carbon dioxide, and the upper part is provided with a carbon dioxide hydrogenation catalyst. Carbon dioxide and hydrogen react to produce carbon monoxide gas at the top. The main problems with this patent are that, first, carbon dioxide hydrogenation is a strongly endothermic reaction. Every 5% reaction of equivalent ratios of CO2 and H2 will cause a temperature drop of about 150°C. Under the type of reactor, the reaction is actually unsustainable and will soon terminate due to the temperature drop; second, the reactor does not involve carbon capture and is only a carbon dioxide hydrogenation reactor.

[0009] CN201410202280.4 discloses a method based on manganese and lanthanide metal catalysts for hydrogenating carbon dioxide to produce carbon monoxide via a reverse water gas reaction. The main issues with this patent are similar to those with CN201821322948.9. First, carbon dioxide hydrogenation is a highly endothermic reaction. Every 5% reaction of equivalent CO2 and H2 results in a temperature drop of approximately 150°C. In this reactor configuration, the reaction is effectively unsustainable and quickly terminates due to the temperature drop. Second, this reactor does not involve carbon capture and is simply a carbon dioxide hydrogenation reactor.

[0010] Currently, published patents and literature, both domestically and internationally, focus on CO2 capture and the CO2 hydrogenation-reverse water gas reaction, while research on CO2 capture and in-situ conversion is rare. Efficiently capturing CO2 at high temperatures and converting the captured CO2 into syngas products in situ for subsequent synthesis of high-value-added light olefins and other chemical products can significantly improve energy efficiency and effectively reduce emission reduction costs. This approach avoids the high energy consumption of capture cooling and conversion heating, addresses the high costs of post-capture CO2 purification and transportation, and the potential safety hazards associated with storage. This is expected to improve the feasibility and economic efficiency of the entire CO2 emission reduction process, and is of great significance. Summary of the Invention

[0011] In view of the above-mentioned deficiencies in the background technology, the present invention provides a self-heating carbon dioxide capture and utilization method and reactor to capture carbon dioxide from high-temperature gas and convert it into synthesis gas in situ.

[0012] To achieve the above-mentioned purpose of the invention, the technical solutions of the self-heating carbon dioxide capture and utilization method and reactor of the present invention are as follows.

[0013] A self-heating carbon dioxide capture and utilization method, characterized by comprising the following steps:

[0014] 1) The carbon dioxide-containing gas enters the adsorption reaction zone of the reactor from one side of the partition and passes through the catalyst bed in the adsorption reaction zone in sequence. The CO2 in the carbon dioxide-containing gas is adsorbed and captured by the catalytic material in the adsorption reaction zone. The heat generated during the adsorption reaction is absorbed by the heat storage body in the catalyst bed. The gas exits the adsorption reaction zone after decarbonization. The adsorption reaction temperature is room temperature to 800°C, preferably 600-750°C.

[0015] 2) When the adsorption reaction zone reaches the saturated adsorption capacity of the adsorbent, the carbon dioxide-containing gas switches to the conversion reaction zone on the other side of the partition. At this time, the reducing gas enters the adsorption reaction zone and passes through the bed of the adsorption reaction zone in sequence. The catalytic material adsorbed with CO2 reacts with the reducing gas, and the carbon dioxide is reduced to CO. The adsorption reaction zone is regenerated. The heat required for the conversion reaction is provided by the heat storage body after the heat absorption in step 1), and the insufficient part is supplemented by a heater or other external heat source. The conversion reaction temperature is 100-950°C, preferably 600-800°C;

[0016] 3) The carbon dioxide-containing gas entering the conversion reaction zone passes through the catalyst bed in the conversion reaction zone in sequence. The CO2 in the carbon dioxide-containing gas is adsorbed and captured by the catalytic material in the catalyst bed, and the heat generated during the adsorption reaction is absorbed by the heat storage body in the catalyst bed;

[0017] 4) When the conversion reaction zone reaches the expected saturated adsorption capacity of the adsorbent, the high-temperature flue gas containing CO2 is switched to the adsorption reaction zone, and the reducing gas is switched to the conversion reaction zone, and the above operation is repeated;

[0018] The catalyst beds in the adsorption reaction zone and the conversion reaction zone are both filled with catalytic materials and heat storage bodies. The catalytic materials refer to materials with dual functions of carbon dioxide adsorption and catalytic conversion, and the heat storage bodies refer to materials with heat storage function.

[0019] The specific calculation formula for the heat B supplemented by the heater or other external heat source in the present invention is as follows:

[0020] B=B2+B3-B1-B4+B5

[0021] Where: B1 represents the heat released by the heat storage body;

[0022] B2 represents the heat loss of the reactor;

[0023] B3 represents the heat absorbed during the conversion process;

[0024] B4 represents the total heat brought in by the inlet reducing gas;

[0025] B5 represents the total heat carried away by the outlet synthesis gas.

[0026] The reactor may be a single reactor or multiple reactors, and the adsorption reaction zone and the conversion reaction zone are the same, both being fixed bed reactors.

[0027] The catalytic material is a CaO material loaded with one or more than two active components of Co, Ni and lanthanide metals, and the heat storage body is corundum, ceramics, mullite, zircon or cordierite.

[0028] The catalytic material and the heat accumulator are uniformly mixed and then loaded into the catalyst bed; or the catalytic material and the heat accumulator are loaded layer by layer in the catalyst bed, that is, a layer of catalytic material and a layer of heat accumulator are loaded in layers.

[0029] In the step 2), the other external heat source is oxygen introduced between the catalyst beds. The oxygen is introduced directly or through a burner or distributor.

[0030] The present invention also provides a reactor for use in the above-mentioned self-heating carbon dioxide capture and utilization method, characterized in that: the reactor includes a shell and a middle partition, the middle partition is arranged in the reactor shell, dividing the reactor into two parts, namely an adsorption reaction zone and a conversion reaction zone, the adsorption reaction zone and the conversion reaction zone are the same, both are fixed bed reaction zones, the adsorption reaction zone and the conversion reaction zone are respectively provided with a gas inlet and a gas outlet, the catalyst beds in the adsorption reaction zone and the conversion reaction zone are filled with catalytic materials and heat storage bodies, the catalytic material refers to a material having the dual functions of carbon dioxide adsorption and catalytic conversion, the heat storage body refers to a material having a heat storage function, and the catalyst beds in the adsorption reaction zone and the conversion reaction zone are single-layer or multi-layer arrangements.

[0031] The reactor of the present invention is arranged using one or more reactors. When multiple reactors are arranged, the adsorption reaction zone and the conversion reaction zone of the reactor can be switched for operation simultaneously or independently switched for operation one by one.

[0032] The adsorption reaction zone and the conversion reaction zone of the present invention are configured with bottom-in and top-out, top-in and bottom-out, side-in and side-out, periphery-in and center-out, or center-in and periphery-out. An oxygen inlet is preferably provided between the catalyst beds of the adsorption reaction zone and the conversion reaction zone to serve as an additional external heat source. Oxygen can be introduced directly or via a burner or distributor.

[0033] The calculation formula for the number of catalyst bed layers C in the adsorption reaction zone and the conversion reaction zone is as follows, where the Roundup function represents rounding up:

[0034] C=Roundup(C1 / C2 / (C3-C4) / C5)

[0035] Where: C1 represents the heat that the reactor needs to supplement through a heater or other external heat source;

[0036] C2 represents the gas flow rate in the reactor during adsorbent conversion and regeneration;

[0037] C3 represents the maximum allowable temperature of the gas in the reactor during adsorbent conversion and regeneration;

[0038] C4 represents the minimum allowable temperature of the gas in the reactor during adsorbent conversion and regeneration;

[0039] C5 represents the specific heat capacity of the gas in the reactor during adsorbent conversion and regeneration.

[0040] In the actual process, the amount and composition of the gas in the reactor area will change each time it passes through a bed layer, so it needs to be calculated layer by layer. However, the calculation principle is the same. Practitioners in this profession only need to make a slight deduction based on the above formula to calculate the corresponding number of layers.

[0041] The desired adsorption conditions (saturated adsorption capacity of the adsorbent) of the present invention can be achieved by timing control according to the designed switching time; by online control according to the carbon dioxide content of the gas after decarbonization; or by other control methods.

[0042] The specific calculation formula for the amount of catalytic material A loaded in the catalyst bed of the present invention is as follows:

[0043] A=A1xA3 / A2

[0044] Where: A1 represents the amount of carbon dioxide to be adsorbed;

[0045] A2 represents the adsorption capacity of the material;

[0046] A3 expresses the design switching time.

[0047] The amount of the heat storage body is usually determined by the inlet temperature of the carbon dioxide-containing gas, the gas composition and specific heat, the heat released by the adsorbed carbon dioxide reaction, the amount and specific heat of the catalytic material, the specific heat of the heat storage body, the heat loss of the reactor, the final temperature of the reactor bed that is desired to be controlled, etc.

[0048] The reducing gas referred to in the present invention refers to a gas that reacts with CO2 to produce CO, or a mixture of one or more of these gases, or a mixture of these gases and an inert gas. Gases that react with CO2 to produce CO typically include H2, CH4, and C2H6. When these reducing gases are introduced, the following reactions occur:

[0049] CO2+2H2=CO+H2O+H2 or CO2+H2=CO+H2O

[0050] CO2+CH4=2CO+2H2

[0051] 2CO2+C2H6=4CO+3H2

[0052] The oxygen reacts with the reducing gas to release heat and generate H2O, CO2, etc. The generated CO2 can then react with the reducing gas to generate synthesis gas. This process does not introduce other new impurities into the synthesis gas. The partial reaction formula is as follows:

[0053] O2+2H2=2H2O

[0054] O2+2CO=2CO2

[0055] 2O2+CH4=CO2+2H2O

[0056] 7O2+2C2H6=4CO2+6H2O

[0057] The advantages of the present invention over the prior art are: 1) CO adsorption and conversion are completed in situ under similar temperature and pressure conditions, which not only fully improves energy utilization and effectively reduces emission reduction costs, but also avoids the high energy consumption of capture cooling and conversion heating, thus solving the high costs of purification and transportation of CO2 after capture, as well as the safety hazards associated with storage. 2) Due to the composite structure of the heat storage body and catalytic material in the reactor of the present invention, the temperature is controlled by the heat storage body itself, eliminating the problems of "runaway temperature" and "local hot spots" that can cause equipment damage. The reactor is inherently safe and completely avoids the possibility of overheating and damage to the reactor and catalytic material caused by uneven reaction and unexpected interruption of the heat exchange medium in traditional reactors. 3) The present invention can achieve in-situ coupled utilization of heat from the adsorption exothermic and conversion endothermic processes, saving more than 50% energy compared to existing reactors. 4) The reactor of the present invention has a low pressure drop and is applicable to most flue gas conditions. 5) The process is simple, easy to operate and maintain, with low investment and a small footprint. 6) In preferred embodiments, the reactor of the present invention can flexibly adjust the catalyst bed temperature in the reactor's conversion and regeneration mode by controlling the oxygen injection rate, without introducing new impurities.

[0058] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but the scope of the present invention is not limited thereto. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 This is a schematic diagram of the process flow of a self-heating carbon dioxide capture and utilization method of the present invention.

[0060] The reference numerals shown in the figures are:

[0061] 1. Carbon dioxide-containing gas, 2. Reducing gas, 3-1 / 2. Oxygen, 4. Flue gas after decarbonization, 5. Product synthesis gas, 6. Reactor, 7. Catalyst bed, 8. Middle partition, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 - Control valve. DETAILED DESCRIPTION

[0062] like Figure 1 As shown, a self-heating carbon dioxide capture and utilization method and reactor.

[0063] The reactor 6 includes a shell and a middle partition 8, which is arranged in the shell of the reactor 6. The middle partition 8 divides the reactor 6 into two parts, namely the adsorption reaction zone and the conversion reaction zone. The adsorption reaction zone and the conversion reaction zone are the same, both are fixed beds, and the adsorption reaction zone and the conversion reaction zone are respectively provided with a gas inlet and a gas outlet. The catalyst beds in the adsorption reaction zone and the conversion reaction zone are filled with catalytic materials and heat storage bodies. The catalytic material refers to a material with dual functions of carbon dioxide adsorption and catalytic conversion, and the heat storage body refers to a material with heat storage function. The catalyst beds in the adsorption reaction zone and the conversion reaction zone are single-layer or multi-layer arrangements.

[0064] The simple process of the self-heating carbon dioxide capture and utilization method of the present invention is:

[0065] Before the device starts operating, all control valves 11 to 20 are in the closed state.

[0066] 1) The control valves 11 and 20 are opened, and the carbon dioxide-containing gas 1 enters the adsorption reaction zone of the reactor 6 from the side of the middle partition 8 through the control valve 11 and passes through the catalyst bed 7 of the adsorption reaction zone in sequence. The CO2 in the carbon dioxide-containing gas is adsorbed and captured by the catalytic material of the catalyst bed 7 of the adsorption reaction zone. The heat generated during the adsorption reaction process is absorbed by the heat storage body in the catalyst bed 7. The decarbonized gas 4 exits the adsorption reaction zone through the control valve 20. The adsorption reaction temperature is between room temperature and 900°C.

[0067] 2) When the adsorption reaction zone reaches the saturated adsorption capacity of the adsorbent, control valves 11 and 20 are closed, and control valves 12, 14, 17, and 19 are opened. The carbon dioxide-containing gas 1 is switched through the control valve 12 to enter the conversion reaction zone on the other side of the partition. At this time, the reducing gas 2 enters the adsorption reaction zone through the control valve 14 and passes through the catalyst bed 7 of the adsorption reaction zone in sequence. The catalytic material 7 that adsorbs CO2 reacts with the reducing gas 2, and the carbon dioxide is reduced to CO. The product synthesis gas 5 exits the reactor through the control valve 17. The heat required for the conversion reaction is provided by the heat storage body after absorbing heat in step 1), and the insufficient part is supplemented by a heater or other external heat source. If the control valve 15 is opened to allow some oxygen 3-1 to enter, heat is generated through the reaction, and the conversion reaction temperature is 100 to 1000°C;

[0068] 3) The high-temperature flue gas 1 containing CO2 entering the conversion reaction zone passes through the catalyst bed 7 of the conversion reaction zone in sequence. The CO2 in the flue gas is adsorbed and captured by the catalytic material in the catalyst bed. The heat generated during the adsorption reaction is absorbed by the heat storage body in the catalyst bed. The decarbonized gas 4 exits the adsorption reaction zone through the control valve 19.

[0069] 4) When the conversion reaction zone reaches the desired adsorbent saturation capacity, control valves 12, 14, 17, and 19 are closed, and control valves 11, 13, 18, and 20 are opened. The high-temperature CO2-containing flue gas 1 is then switched to enter the adsorption reaction zone, and the reducing gas 2 is switched to enter the conversion reaction zone. If the supplemental heat generation method of oxygen flow described in step 2) is used, control valve 15 should also be closed and control valve 16 opened. The above steps are then repeated to achieve regular switching of feeds to different reaction zones.

[0070] The catalyst beds 7 in the adsorption reaction zone and the conversion reaction zone are both filled with catalytic materials and heat storage bodies. The catalytic materials refer to materials with dual functions of carbon dioxide adsorption and catalytic conversion, and the heat storage bodies refer to materials with heat storage function.

[0071] The present invention will be further described below with reference to specific examples, which are merely implementation methods of the present invention under certain specific conditions and should not be considered as limiting the scope of protection of the present invention.

[0072] Example

[0073] The raw material high temperature flue gas is 150000m 3 Take n / h as an example, the flue gas composition is as follows:

[0074] Flue gas composition v％ <![CDATA[CO2]]> 14 <![CDATA[H2O]]> 10 <![CDATA[N2]]> 73 <![CDATA[O2]]> 3

[0075] The flue gas temperature is 640℃ and the flue gas pressure is 10kPa.

[0076] Reactor 6 Adsorption Reaction Mode: 640°C high-temperature flue gas 1 enters reactor 6 from the bottom through control valve 11 on the left side of central partition 8. After passing through catalyst bed 7, CO2 in the flue gas is adsorbed and removed. The decarbonized, purified flue gas 4 is discharged from the top of reactor 6 through control valve 20. After catalyst 7 reaches adsorption saturation capacity, the reactor 6 switches to conversion and regeneration mode.

[0077] 2). The reactor 6 is filled with a CaO-based catalyst. The catalyst core is a Φ3 Al2O3 sphere, and the outside is attached with a 1mm thick CaO sintered material sphere. The outer surface is loaded with active components such as Co and Ni for catalyzing the reaction of CO2 and H2.

[0078] 3). Reactor 6 conversion regeneration mode: 39000m 3 n / h, 730℃ high temperature hydrogen 2 enters the right side of the middle partition 8 of the reactor 6 from the bottom through the control valve 13, passes through the catalyst bed 7, and the saturated CO2 adsorbed on the bed is reduced to the product synthesis gas 5 and discharged through the control valve 18. After the catalyst is fully regenerated, the reactor 6 is switched to the adsorption reaction mode. Open the control valve 16 and pass 2500m 3n / h of oxygen 3-2 can be used to heat the gas between beds. The resulting product synthesis gas 5 is discharged from the top of the reactor 6. The expected composition of the synthesis gas is as follows:

[0079] Element Composition, v% CO 33.8 <![CDATA[H2]]> 22.1 <![CDATA[CO2]]> 1.8 <![CDATA[H2O]]> 42.3 total 100

[0080] 4) After 2 hours, control valves 11, 13, 16, 18, and 20 are closed, hot nitrogen is introduced into the reactor for purging, and control valves 12, 14, 15, 17, and 19 are opened. The cycle is then repeated sequentially according to a time sequence. During the conversion and regeneration of the reaction zone to the left of partition 8 in the middle of reactor 6, control valve 15 is opened to introduce oxygen 3-1 between the catalyst beds to supplement the heat between the beds.

[0081] The flue gas treated in this embodiment can reduce CO2 emissions by 329,000 t / a, while producing 405,000 t / a of synthesis gas as a by-product. Even after deducting water, there is still 237,000 t / a of synthesis gas.

Claims

1. A self-heating carbon dioxide capture and utilization method, characterized in that The steps include: 1) The carbon dioxide-containing gas enters the adsorption reaction zone of the reactor from one side of the partition, and passes through the catalyst bed of the adsorption reaction zone in sequence. The CO2 in the carbon dioxide-containing gas is adsorbed and captured by the catalytic material in the adsorption reaction zone. The heat generated during the adsorption reaction process is absorbed by the heat storage body in the catalyst bed. The gas comes out of the adsorption reaction zone after decarbonization. The adsorption reaction temperature is room temperature to 800°C. 2) When the adsorption reaction zone reaches the saturated adsorption capacity of the adsorbent, the carbon dioxide-containing gas switches to the conversion reaction zone on the other side of the partition. At this time, the reducing gas enters the adsorption reaction zone and passes through the bed of the adsorption reaction zone in sequence. The catalytic material adsorbing CO2 reacts with the reducing gas, and the carbon dioxide is reduced to CO. The adsorption reaction zone is regenerated. The heat required for the conversion reaction is provided by the heat storage body after the heat absorption in step 1), and the insufficient part is supplemented by a heater or other external heat source. The conversion reaction temperature is 100-950°C; 3) The carbon dioxide-containing gas entering the conversion reaction zone passes through the catalyst bed in the conversion reaction zone in sequence, CO2 in the carbon dioxide-containing gas is adsorbed and captured by the catalytic material in the catalyst bed, and the heat generated during the adsorption reaction process is absorbed by the heat storage body in the catalyst bed; 4) When the conversion reaction zone reaches the expected saturated adsorption capacity of the adsorbent, the carbon dioxide-containing gas is switched to enter the adsorption reaction zone, and the reducing gas is switched to enter the conversion reaction zone, and the above operation is repeated; The catalyst beds in the adsorption reaction zone and the conversion reaction zone are filled with catalytic materials and heat storage bodies, wherein the catalytic materials refer to materials having dual functions of carbon dioxide adsorption and catalytic conversion, and the heat storage bodies refer to materials having heat storage functions; The reducing gas refers to a gas that can react with CO2 to generate CO, or a mixture of one or more of these gases, or a mixed gas of an inert gas and one or more of these gases.

2. A self-heating carbon dioxide capture and utilization method according to claim 1, characterized in that: The reactor is a fixed bed reactor, which may be a single reactor or multiple reactors.

3. The self-heating carbon dioxide capture and utilization method according to claim 1, characterized in that: The catalytic material is a CaO material loaded with one or more than two active components of Co, Ni and lanthanide metals, and the heat storage body is corundum, ceramic, mullite, zircon or cordierite.

4. The self-heating carbon dioxide capture and utilization method according to claim 1, characterized in that: The gases that can react with CO2 to generate CO refer to H2, CH4 and C2H6.

5. The self-heating carbon dioxide capture and utilization method according to claim 1, characterized in that: The catalytic material and the heat storage body are uniformly mixed and then loaded into the catalyst bed; or the catalytic material and the heat storage body are loaded layer by layer in the catalyst bed, that is, a layer of catalytic material and a layer of heat storage body are loaded in layers.

6. The self-heating carbon dioxide capture and utilization method according to claim 1, characterized in that: In the step 2), the other external heat source is oxygen introduced between the catalyst beds. The oxygen is introduced directly or through a burner or a distributor.

7. A reactor for use in the self-heating carbon dioxide capture and utilization method according to claim 1, characterized in that: The reactor comprises a shell and a middle partition, which is arranged in the reactor shell to divide the reactor into two parts, namely an adsorption reaction zone and a conversion reaction zone. The adsorption reaction zone and the conversion reaction zone are the same, both are fixed bed reaction zones, the adsorption reaction zone and the conversion reaction zone are respectively provided with a gas inlet and a gas outlet, and the catalyst beds in the adsorption reaction zone and the conversion reaction zone are filled with catalytic materials and heat storage bodies, the catalytic materials refer to materials with dual functions of carbon dioxide adsorption and catalytic conversion, and the heat storage body refers to materials with heat storage function, and the catalyst beds in the adsorption reaction zone and the conversion reaction zone are single-layered or multi-layered.

8. A reactor according to claim 7, characterized in that: The reactor is arranged using one or more reactors. When multiple reactors are arranged, the adsorption reaction zone and the conversion reaction zone of the reactor can be switched for operation simultaneously or independently switched for operation one by one.

9. A reactor according to claim 7, characterized in that: The adsorption reaction zone and the conversion reaction zone are in the form of bottom-in and top-out, top-in and bottom-out, side-in and side-out, periphery-in and middle-out, or middle-in and periphery-out.

10. A reactor according to claim 7, characterized in that: Oxygen inlets are provided between the catalyst beds in the adsorption reaction zone and the conversion reaction zone.

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