Method and device for capturing and utilizing carbon dioxide with in situ utilization of thermal coupling

Abstract

The present invention discloses a method for capturing and utilizing carbon dioxide, comprising the following steps: 1) a gas containing CO2 is introduced into a first reactor containing a catalytic material with the dual function of carbon dioxide adsorption and catalytic conversion, wherein the catalytic material is used to adsorb and capture the CO2 present in the gas; 2) when the catalytic material of the first reactor reaches a predetermined adsorption capacity, the gas containing CO2 is switched and introduced into a second reactor containing a catalytic material with the dual function of carbon dioxide adsorption and catalytic conversion, and at the same time a reducing gas is introduced into the first reactor to react with the catalytic material that has adsorbed CO2, thereby regenerating the catalytic material and generating a process gas containing CO;3) The catalytic material of the second reactor is used to adsorb and capture the CO2 present in the gas entering the reactor, in order to obtain a purified gas from which the CO2 has been removed;4) When the catalytic material in the second reactor reaches a predetermined adsorption capacity, the CO2-containing gas is switched off and reintroduced into the first reactor. Simultaneously, the reducing gas is introduced into the second reactor to react with the catalytic material that has adsorbed CO2, thereby regenerating the catalytic material and generating a process gas containing CO. The present invention also discloses a corresponding carbon dioxide capture and utilization device. The method and device of the present invention achieve the reduction of carbon dioxide emissions and the utilization of carbon dioxide at low cost, avoiding the high energy consumption of cooling for capture and heating for conversion, the high cost of purification and transportation after CO2 capture, and the safety risks caused by burial in conventional technologies.

Description

A method and device for capturing and utilizing carbon dioxide with in-situ coupled heat utilization Technical Field

[0001] The present invention relates to a method for capturing carbon dioxide from CO2-containing gas and converting it into synthesis gas in situ, and in particular to a carbon dioxide capture and utilization method and a carbon dioxide capture and utilization device with in-situ coupled utilization of heat. Technical Background

[0002] Carbon capture, utilization, and storage (CCUS) is the most important technological path for addressing global climate change and controlling greenhouse gas emissions. China has pledged to the world to "peak carbon emissions by 2030" and "achieve carbon neutrality by 2060." The Central Economic Work Conference listed it as one of the eight key tasks for 2021. This "new climate target" will trigger a major change in my country's energy landscape. There are many sources of CO2 emissions in modern industrial production, such as cement, steel, electricity, coal chemical industry, and refineries, which are all major CO2 emitters. In response to the issue of CO2 emissions, various industries have conducted research and exploration on the capture, utilization, and storage of CO2. Each industry has developed a variety of technical methods for CO2 capture, utilization, and storage based on its own characteristics.

[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 before it can be absorbed by solvents at low temperatures. Furthermore, the high cost and energy consumption of solvent 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 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, with strong support from the Chinese government, enterprises, institutions, research institutes, and universities have jointly participated in a series of research projects focusing on supporting policies, relevant theories, and key technologies. A professional research team has been established, resulting in a number of achievements and progress. Details of major domestic industrial pilot and demonstration projects are as follows: Huaneng Group's CO2 capture demonstration project, launched in December 2009 at the Shanghai Shidongkou Second Power Plant, utilizes proprietary CO2 capture technology. The project captures 120,000 tons of CO2 annually, achieving a purity exceeding 99.5%. Part of the captured CO2 is used in a refining system for the food processing industry, while the remainder is used in industrial production. At the time of commissioning, the capture unit was the world's largest CO2 capture unit for coal-fired power plant flue gas. The 250MW IGCC unit of Huaneng Tianjin Green Coal Power was completed and put into operation in 2011, and the 400MW IGCC unit equipped with a CO2 capture device was completed in 2016. The demonstration project aims to research, develop, demonstrate and promote a coal-based power generation system with near-zero CO2 emissions, 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 the 1.7MWth power plant flue gas CO2 capture demonstration system of La Pereda in Spain, the 1MWth power plant flue gas CO2 capture demonstration system of Darmstadt in Germany, and the 3kWth power plant flue gas CO2 capture pilot of ITRI Research Institute in Taiwan, China. All of them use a calcium cycle double fluidized bed cycle capture system to achieve CO2 capture and regeneration in flue gas.

[0006] All of the aforementioned technologies focus on CO2 capture and do not involve 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, on the one hand, presents difficulties in control due to the alternating heat absorption and extraction within the coils as the capture / conversion process switches. On the other hand, due to the uneven reaction within the catalyst bed, localized overheating / undercooling is difficult to avoid. Direct combustion heating often leads to localized overheating of the catalyst bed. Taking the commonly used CaO / CaCO3 adsorbent as an example, when the temperature exceeds 850-900°C, the adsorbent will melt and sinter. However, the CO2 conversion process generally requires a reaction temperature above 500-700°C. If direct supplemental heating is used, the temperature is too high and the adsorbent will melt, sinter and become inactivated. If the temperature is controlled below 800°C, the supplemental heat is very limited due to the temperature difference, or too much fuel gas and combustion-supporting gas need to be supplemented, resulting in severe dilution of the product and a decrease in the effective gas concentration. If a fluidized bed or moving bed is used, since most industrial flue gases are at atmospheric or low pressure, conventional means are basically impossible to achieve due to pressure limitations.

[0007] CN113148951B discloses a method for reducing carbon monoxide synthesis gas using a high-temperature molten heat carrier, carbon dioxide, and carbon powder. This method utilizes carbon dioxide and carbon powder to absorb the sensible and latent heat emitted by the high-temperature heat carrier, raising the temperature to the reduction temperature and instantly reducing it to carbon monoxide high-energy synthesis gas. The high-temperature volumetric heat capacity of carbon dioxide is then used to circulate heat exchange with the granulated high-temperature heat carrier. The entire process is lengthy, and the core equipment is similar to a fluidized bed, resulting in a large pressure drop. The process temperature fluctuates frequently between 50°C and 1500°C, and these drastic temperature changes inevitably lead to energy consumption issues. The lengthy process also leads to pressure drop issues. Flue gas pressure is typically low, and this large pressure drop also limits the use of this technology.

[0008] CN208865610U discloses a catalytic reaction apparatus with a methane + water vapor hydrogen production catalyst at the bottom to produce hydrogen, carbon dioxide introduced into the middle, and a carbon dioxide hydrogenation catalyst at the top. The carbon dioxide and hydrogen react to produce carbon monoxide gas at the top. The main problems with this patent are: first, carbon dioxide hydrogenation is a highly endothermic reaction. Every 5% reaction of equivalent CO2 and H2 will cause a temperature drop of approximately 150°C. Under this reactor type, the reaction is actually unsustainable and quickly terminates due to the temperature drop; second, the reactor does not involve carbon capture and is simply a carbon dioxide hydrogenation reactor.

[0009] CN105080564B discloses a method based on manganese and lanthanide metal catalysts to hydrogenate carbon dioxide and generate carbon monoxide through a reverse water gas reaction. The main problems of this patent are similar to those of CN208865610U. First, carbon dioxide hydrogenation is a highly endothermic reaction. Every 5% reaction of equivalent CO2 and H2 will cause a temperature drop of about 150°C. Under this type of reactor, the reaction is actually unsustainable and will quickly terminate 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.

[0011] All patent and non-patent literature, including but not limited to textbooks and journal articles, mentioned herein are incorporated by reference in their entirety.

[0012] Summary of the Invention

[0013] To solve the above problems, one object of the present invention is to address the deficiencies of the above-mentioned prior art and provide a method for capturing and utilizing carbon dioxide with in-situ coupled heat utilization and a device for capturing and utilizing carbon dioxide with in-situ coupled heat utilization, so as to capture CO2 from high-temperature gas and convert it into synthesis gas in situ.

[0014] To achieve the above objectives, one aspect of the present invention provides a method for capturing and utilizing carbon dioxide, comprising the following steps:

[0015] 1) introducing a gas containing CO2 into a first reactor containing a catalytic material having dual functions of carbon dioxide adsorption and catalytic conversion, and using the catalytic material to adsorb and capture the CO2 in the gas to obtain a purified gas after the CO2 is removed;

[0016] 2) When the catalytic material in the first reactor reaches a predetermined adsorption capacity, the gas containing CO2 is switched to be introduced into a second reactor containing a catalytic material having dual functions of carbon dioxide adsorption and catalytic conversion, and simultaneously a reducing gas is introduced into the first reactor to react with the catalytic material after adsorbing CO2 to regenerate the catalytic material and produce a process gas containing CO;

[0017] 3) in a second reactor, using the catalytic material to adsorb and capture CO2 in the gas entering the reactor to obtain a purified gas after the CO2 is removed;

[0018] 4) When the catalytic material in the second reactor reaches a predetermined adsorption capacity, the gas containing CO2 is switched to be introduced into the first reactor again, and the reducing gas is simultaneously introduced into the second reactor to react with the catalytic material after adsorbing CO2 to regenerate the catalytic material and generate a process gas containing CO;

[0019] 5) Repeat steps 1) to 4)

[0020] Heat exchange is performed between the first and second reactors through a first heat exchange pipeline and a second heat exchange pipeline. The first heat exchange pipeline guides the gas flow from the first reactor through the second reactor and then returns to the first reactor. The gas flow from the first reactor exchanges heat with the gas flow in the second reactor while passing through the second reactor. The second heat exchange pipeline guides the gas flow from the second reactor through the first reactor and then returns to the second reactor. The gas flow from the second reactor exchanges heat with the gas flow in the first reactor while passing through the first reactor.

[0021] Another aspect of the present invention provides a carbon dioxide capture and utilization device, comprising a first reactor, a second reactor, a first heat exchange pipeline, and a second heat exchange pipeline, wherein the first reactor and the second reactor are respectively provided with a catalytic material, characterized in that: the catalytic material is a material having the dual functions of carbon dioxide adsorption and catalytic conversion, wherein heat exchange is performed between the first and second reactors through the first heat exchange pipeline and the second heat exchange pipeline, the first heat exchange pipeline is configured to guide the gas flow from the first reactor through the second reactor and then return to the first reactor, and the gas flow from the first reactor exchanges heat with the gas flow in the second reactor while passing through the second reactor, and the second heat exchange pipeline is configured to guide the gas flow from the second reactor through the first reactor and then return to the second reactor, and the gas flow from the second reactor exchanges heat with the gas flow in the first reactor while passing through the first reactor.

[0022] In the method and apparatus according to the present invention, carbon dioxide adsorption and conversion are completed in situ under similar temperature and pressure conditions, achieving low-cost reduction of carbon dioxide emissions and utilization of carbon dioxide. This avoids the high energy consumption of traditional capture cooling / conversion heating, the high costs of post-capture CO2 purification and transportation, and the safety hazards associated with storage. Because heat exchange between the conversion and adsorption processes in the reactor is continuous and uniform, there are no "flashover" or "local hot spots" that can damage the equipment. The reactor is inherently safe, completely avoiding the possibility of overheating and damage to the reactor and catalytic materials caused by uneven reactions or unexpected interruptions in the heat exchange medium, as is the case with traditional reactors. The method and apparatus according to the present invention achieves in-situ coupled utilization of heat from the adsorption exothermic / conversion endothermic processes, saving over 50% energy compared to existing reactors. The conversion reactor has a low pressure drop, making it suitable for most flue gas operating conditions.

[0023] Other features and advantages of the present application will be described in detail in the following description of the drawings and the detailed description of the embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings are used to provide further understanding of the present application and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present application, but do not constitute a limitation to the present application.

[0025] FIG1 is a schematic diagram of a process flow of a method for capturing and utilizing carbon dioxide with in-situ coupled heat utilization according to the present invention;

[0026] FIG2 is a schematic diagram of a process flow of another method for capturing and utilizing carbon dioxide with in-situ coupled heat utilization according to the present invention.

[0027] FIG3 is a schematic diagram of a process flow of another method for capturing and utilizing carbon dioxide with in-situ coupled heat utilization according to the present invention.

[0028] The figures shown therein are marked as: 1-high-temperature flue gas containing CO2, 2-decarbonized gas (purified gas obtained after removing CO2), 3-reducing gas, 4-synthesis gas, 5-adsorption conversion process gas heat exchange pipeline, 6-conversion adsorption process heat exchange pipeline, 7, 8, 9, 10, 11, 12, 13, 14-control valve, 15-partition, 21-adsorption reactor, 22-conversion reactor, 21-1-primary adsorption reactor, 21-2-secondary adsorption reactor, 22-1-primary conversion reactor, 22-2-secondary conversion reactor, 31-adsorption reactor, 32-conversion reactor, 1#, 2#, 3#, 4#-catalyst bed, 111-catalytic material in the bed.

[0029] Like or similar reference numbers identify like or similar parts throughout the several views of the drawings. DETAILED DESCRIPTION

[0030] The following is a detailed description of the specific embodiments of the present application. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present application and are not intended to limit the present application.

[0031] Any specific numerical value disclosed herein (including the endpoints of a numerical range) is not limited to the exact value of the numerical value, but should be understood to also include values ​​close to the exact value, such as all possible values ​​within ±5% of the exact value. Moreover, for a disclosed numerical range, any combination of the endpoints of the range, between the endpoints and the specific points in the range, and between the specific points can be used to generate one or more new numerical ranges, and these new numerical ranges should also be considered to be specifically disclosed herein.

[0032] Unless otherwise specified, the terms used herein have the same meaning as commonly understood by those skilled in the art. If a term is defined herein and its definition is different from the commonly understood meaning in the art, the definition herein shall prevail.

[0033] In the context of the present invention, carbon capture and utilization (CCU) is the process of capturing carbon dioxide and processing it for further use.

[0034] In the context of the present invention, process gas (also referred to herein as process gas or flow gas) refers to a gas or gas mixture involved in a chemical process. For example, the process gas in step 2) of the present method refers to the gas containing CO generated by the reaction of a CO-adsorbing catalytic material with a reducing gas within a reactor. The process gas typically contains CO and a reducing gas.

[0035] In the context of the present invention, synthesis gas refers to CO, a mixture of CO and a reducing gas, or a mixture of CO, a reducing gas and water vapor. Reducing gas refers to a gas that can react with CO2 to produce CO.

[0036] In the context of the present invention, ambient temperature refers to a temperature of about 20 to about 25°C.

[0037] Carbon dioxide capture and utilization methods

[0038] As described above, in a first aspect, the present application provides a method for capturing and utilizing carbon dioxide, the method comprising the following steps:

[0039] 1) introducing a gas containing CO2 into a first reactor containing a catalytic material having dual functions of carbon dioxide adsorption and catalytic conversion, and using the catalytic material to adsorb and capture the CO2 in the gas to obtain a purified gas after the CO2 is removed;

[0040] 2) When the catalytic material in the first reactor reaches a predetermined adsorption capacity, the gas containing CO2 is switched to be introduced into a second reactor containing a catalytic material having dual functions of carbon dioxide adsorption and catalytic conversion, and simultaneously a reducing gas is introduced into the first reactor to react with the catalytic material after adsorbing CO2 to regenerate the catalytic material and produce a process gas containing CO;

[0041] 3) in a second reactor, using the catalytic material to adsorb and capture CO2 in the gas entering the reactor to obtain a purified gas after the CO2 is removed;

[0042] 4) When the catalytic material in the second reactor reaches a predetermined adsorption capacity, the gas containing CO2 is switched to be introduced into the first reactor again, and the reducing gas is simultaneously introduced into the second reactor to react with the catalytic material after adsorbing CO2 to regenerate the catalytic material and generate a process gas containing CO;

[0043] 5) Repeat steps 1) to 4)

[0044] Heat exchange is performed between the first and second reactors through a first heat exchange pipeline and a second heat exchange pipeline. The first heat exchange pipeline guides the gas flow from the first reactor (sometimes also referred to as process gas, process gas or flow gas in the context of the present invention) through the second reactor and then returns to the first reactor. The gas flow from the first reactor exchanges heat with the gas flow in the second reactor (sometimes also referred to as process gas, process gas or flow gas in the context of the present invention) while passing through the second reactor. The second heat exchange pipeline guides the gas flow from the second reactor through the first reactor and then returns to the second reactor. The gas flow from the second reactor exchanges heat with the gas flow in the first reactor while passing through the first reactor.

[0045] According to some embodiments of the present invention, the reaction temperature of the CO2 adsorption capture process is room temperature-800°C, preferably 400-780°C, and more preferably 600-750°C.

[0046] In some embodiments, the reaction temperature of the catalytic material regeneration process is 100-950°C, preferably 300-900°C, and more preferably 600-800°C. The carbon dioxide adsorption capture process and the catalytic material regeneration process are completed in situ under similar temperature and pressure conditions, avoiding the high energy consumption of capture cooling / conversion heating in traditional technologies. During the catalytic material regeneration process, the CO2 adsorbed in the catalytic material reacts with the reducing gas to produce process gas containing CO. Simultaneously, the CO2 adsorbed in the catalytic material is released from the catalytic material, and thus this process is referred to as a catalytic material regeneration process.

[0047] In some embodiments, the first reactor and the second reactor each independently have one or more catalyst beds filled with the catalytic material. In some embodiments, the catalyst beds in each of the first and second reactors are filled with a catalytic material, which refers to a material having the dual functions of carbon dioxide adsorption and catalytic conversion. The catalytic material includes an adsorption component and a catalytic component. The adsorption component is a component capable of adsorbing carbon dioxide at the reactor temperature, including but not limited to alkaline earth metal oxides such as calcium oxide and magnesium oxide. The catalytic component is a component capable of catalyzing the reaction of CO2 with a reducing gas, which may include a catalyst component and an optional co-catalyst component. The catalytic component includes, for example, Fe, Co, Ni, lanthanides, Ru, Cu, Pd, In, Rh, Ir, Pt, oxides of these elements, or mixtures of two or more of the foregoing substances. The mass ratio of the adsorption active component to the catalytic component is 1:0.01 to 1, preferably 1:0.1 to 0.5. The catalytic component and the adsorption component may exist separately, that is, separate catalytic component particles or shaped bodies and separate adsorption component particles or shaped bodies. Preferably, the catalytic component and the adsorbent component are co-existing in the same catalytic material. The catalytic material can be in the form of particles or shaped bodies, supported or unsupported. The preparation methods of the catalyst itself are well known in the art, including, for example, precipitation / coprecipitation methods, sol-gel methods, hydro / solvothermal methods, solid-phase reaction methods (grinding, high-temperature roasting, melting), flame pyrolysis methods, impregnation methods, deposition-precipitation methods, ion exchange methods, physical / chemical vapor deposition methods, chemical grafting / grafting methods, etc.

[0048] In some embodiments, the CO2-containing gas comprises high-temperature CO2-containing flue gas, which can be from, for example, a cement plant, a steel plant, a power plant, a coal chemical plant, or a refinery. The gas temperature is 400°C to 900°C, preferably 500°C to 800°C, and more preferably 600°C to 750°C.

[0049] In some embodiments, the heat exchange pipeline exchanges heat between the adsorption reactor and the conversion reactor, enabling in-situ coupled heat utilization within the device. In the methods and devices according to the present invention, because heat exchange between the conversion and adsorption processes occurs continuously and uniformly within the reactor, there are no issues such as "runaway temperatures" or "local hot spots" that could damage the equipment. The reactor is inherently safe, completely avoiding the potential for overheating and damage to the reactor and catalytic materials caused by uneven reactions or unexpected interruptions in the heat exchange medium, as is common in traditional reactors.

[0050] In some embodiments, additional heat is added to the reactor where the catalytic material regeneration occurs, wherein the heat addition includes heating the reducing gas, and providing an electric heater or a gas pipeline in the reactor to heat the reactor.

[0051] In some embodiments, the reducing gas refers to a gas that can react with CO2 to generate CO, for example, comprising any one or more of H2, CH4 and C2H6, or comprising any one or more of H2, CH4 and C2H6 and an inert gas (such as nitrogen). The reducing gas may also contain a small amount of other gases, including olefins and lower alkanes, as long as their content does not impair the conversion reaction occurring in the conversion reactor. These reducing gases react with the CO2 adsorbed by the catalytic material in the reactor where the catalytic material is regenerated to produce a gas containing CO, regenerate the catalytic material, and enable it to continue to adsorb CO2 in the next cycle.

[0052] When these gases are introduced separately, the following reactions will occur: CO2+2H2=CO+H2O+H2 or CO2+H2=CO+H2O CO2+CH4=2CO+2H2 2CO2+C2H6=4CO+3H2

[0053] The first and second reactors of the present invention are the same. In this specification, the reactor in which the adsorption process occurs is referred to as the adsorption reactor, and the reactor in which the conversion reaction (catalytic material regeneration) occurs is referred to as the conversion reactor. For ease of description, the reactor in which the adsorption process occurs when first mentioned is sometimes referred to as the adsorption reactor, and the reactor in which the conversion reaction occurs when first mentioned is sometimes referred to as the conversion reactor, without changing their names.

[0054] The first reactor and the second reactor can be fixed bed reactors, and can be a single reactor or multiple reactors. The adsorption reactor and the conversion reactor can have 1, 2, 3, 4, 5 or more catalyst beds, and the catalyst beds are filled with catalytic materials.

[0055] The reactor of the present invention, the amount of catalytic material A (m 3 ) is determined by the amount of carbon dioxide to be adsorbed A1 (t / h), the material adsorption capacity A2 (t / m 3 ) and the design switching time A3 (h), the specific calculation formula is as follows: A=A1×A3 / A2

[0056] Where: A1 represents the amount of carbon dioxide to be adsorbed;

[0057] A2 represents the adsorption capacity of the material;

[0058] A3 expresses the design switching time.

[0059] The predetermined adsorption capacity (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.

[0060] According to some embodiments of the present invention, the adsorption reactor and the conversion reactor are each independently configured as one or more reactors. When the adsorption reactor or the conversion reactor is configured as multiple reactors,

[0061] The following switching methods can be used:

[0062] Multiple reactors switch feeds simultaneously, or

[0063] Each reactor switches feed independently;

[0064] Furthermore, when switching the feed between the first reactor and the second reactor, the following switching method can be used:

[0065] Feed switching is performed between one first reactor and multiple second reactors.

[0066] Feed switching between multiple second reactors and one second reactor, or

[0067] Feed switching is performed between the multiple first reactors and the multiple second reactors.

[0068] The specific setting of the above switching mode can be calculated by those skilled in the art based on the heat matching conditions of the adsorption and conversion processes.

[0069] For the sake of clarity, each feature disclosed for the method in this application is also applicable to the disclosure for the device, unless a person skilled in the art considers it to be obviously unreasonable.

[0070] Carbon dioxide capture and utilization device

[0071] As described above, the second aspect of the present invention provides a carbon dioxide capture and utilization device, comprising a first reactor, a second reactor, a first heat exchange pipeline, and a second heat exchange pipeline. The first reactor and the second reactor are each provided with a catalytic material, characterized in that the catalytic material is a material having the dual functions of carbon dioxide adsorption and catalytic conversion. Heat exchange is performed between the first and second reactors via the first heat exchange pipeline and the second heat exchange pipeline. The first heat exchange pipeline is configured to guide a gas stream from the first reactor through the second reactor and then back to the first reactor. The gas stream from the first reactor exchanges heat with the gas stream in the second reactor while passing through the second reactor. The second heat exchange pipeline is configured to guide a gas stream from the second reactor through the first reactor and then back to the second reactor. The gas stream from the second reactor exchanges heat with the gas stream in the first reactor while passing through the first reactor. In the context of the present invention, the first heat exchange pipeline is also referred to as an adsorption conversion process gas heat exchange pipeline, and the second heat exchange pipeline is also referred to as a conversion adsorption process gas heat exchange pipeline.

[0072] In some embodiments according to the second aspect of the present invention, the reactor is a fixed bed reactor.

[0073] In some embodiments according to the second aspect of the present invention, the adsorption reactor and / or the conversion reactor has 1, 2, 3, 4, 5 or more catalyst beds. The catalyst beds are filled with catalytic materials.

[0074] In some embodiments of the second aspect of the present invention, the heat exchange pipeline includes a heat exchange structure such as a heat exchange tube, a plate heat exchanger, or a pipe box. The heat exchange tube can be in the form of a finned tube, a coil, or a serpentine tube. The pipe box can contain a heat exchange component. The heat exchange tube can contain a heat exchange medium.

[0075] In some embodiments according to the second aspect of the present invention, the reactor inlet and outlet types include bottom-in and top-out, top-in and bottom-out, side-in and side-out, periphery-in and middle-out, middle-in and periphery-out, etc.

[0076] In some embodiments of the second aspect of the present invention, a partition is further provided in the adsorption reactor and the conversion reactor. The partition is disposed across the entire cross-section of the reactor to isolate the process gas so that the process gas is directed through the heat exchange pipeline. If multiple catalyst beds are present, the partition is disposed between two adjacent catalyst beds.

[0077] The present invention is suitable for treating carbon dioxide-containing gases (such as high-temperature flue gas containing CO2), capturing CO2 from the gas and converting it into synthesis gas in situ. The optimal temperature range for use with the present invention is between room temperature and 800°C. If the temperature of the gas being treated is too high, it can be lowered to a suitable temperature range by, for example, recovering heat; if the temperature is too low, it can be raised to a suitable temperature range by, for example, heating.

[0078] The carbon dioxide capture and utilization device according to the present invention has a simple process, is easy to operate and maintain, requires low investment, and occupies a small area.

[0079] Detailed description

[0080] The present invention will be further described below with reference to the accompanying drawings.

[0081] As shown in FIG1 , a method and apparatus for capturing and utilizing carbon dioxide by coupling heat in situ is provided. The number of reactors may be one or more. FIG1 shows two reactors, one of which is in an adsorption reaction state and the other in a conversion and regeneration state. During the first adsorption reaction, the reducing gas in the conversion reactor absorbs the heat of the adsorption reaction and passes through. After the first adsorption cycle is completed, the conversion and regeneration process begins in the adsorption reactor, and the conversion reactor begins to perform an adsorption reaction. From then on, the adsorption reaction and the conversion reaction achieve in-situ coupling of heat. For the sake of convenience, the present invention refers to the two reactors as the adsorption reactor and the conversion reactor, respectively.

[0082] The present invention can also utilize multiple reactors, as shown in FIG2 . Two reactors are in the adsorption reaction state, and two reactors are in the conversion and regeneration state, meaning multiple adsorption reactors and multiple conversion reactors are possible. When multiple reactors are used, they can be switched simultaneously or independently, minimizing fluctuations in upstream gas flow.

[0083] The present invention can also include multiple reactors, as shown in FIG3 . Two reactors are in the adsorption reaction state, and one reactor is in the conversion and regeneration state. The reactor interior is divided into different functional zones by partitions or other means.

[0084] For ease of description, the following uses the two reactors shown in Figure 1 as an example. One reactor is an adsorption reactor, and the other is a conversion reactor. Before the device begins operation, control valves 7-14 are all closed. The steps of the in-situ heat-coupled CO2 capture and utilization method are as follows:

[0085] 1) Control valves 7 and 11 are opened, and the high-temperature flue gas 1 containing CO2 enters the adsorption reactor 21 through the control valve 7. The CO2 in the flue gas is adsorbed and captured by the catalytic material in the catalyst bed. A portion of the adsorption reaction heat generated by each bed enters the conversion reactor 22 through the adsorption conversion process gas heat exchange pipeline 5, exchanges heat with the process gas for cooling, and then returns to the next catalyst bed. A portion of the heat is taken out by the process gas from the conversion reactor 22 through the conversion adsorption process gas heat exchange pipeline 6. The high-temperature flue gas 1 containing CO2 passes through the adsorption reactor catalyst beds 1#, 2#, and 3# in sequence according to the above steps. The decarbonized gas 2 comes out of the adsorption reactor 21 through the control valve 11. At this time, the adsorption reactor 21 is in an adsorption state, and the adsorption reaction temperature is room temperature to 800°C, preferably in the temperature range of 600-750°C. In this step, the partition 15 is used to isolate the material exchange between the two catalyst beds. For example, above catalyst bed 1# in adsorption reactor 21, partition 15 forces process gas from adsorption reactor 21 to pass through adsorption conversion process gas heat exchange line 5, then through conversion reactor 22, and then back to adsorption reactor 21. Within conversion reactor 22, adsorption conversion process gas heat exchange line 5 passes through conversion reactor 22 below partition 15. During this process, the adsorption conversion process gas in adsorption conversion process gas heat exchange line 5 on the hot side exchanges heat with the process gas in conversion reactor 22 below adsorption conversion process gas line 5 on the cold side. Specifically, the higher-temperature process gas in adsorption conversion process gas heat exchange line 5 transfers heat to the lower-temperature process gas in conversion reactor 22. It should be noted that during this process, the process gas in adsorption conversion process gas heat exchange line 5 only exchanges heat with the process gas in conversion reactor 22; no material exchange occurs. In other words, the process gas in adsorption conversion process gas heat exchange line 5 does not enter conversion reactor 22. The adsorption conversion process gas heat exchange line 5 bypasses the partition 15 and passes through the conversion reactor 22 above the partition 15. During this process, the adsorption conversion process gas in the adsorption conversion process gas heat exchange line 5 on the hot side exchanges heat with the process gas in the conversion reactor 22 on the cold side above the adsorption conversion process gas heat exchange line 5. Thereafter, the adsorption conversion process gas is guided back to the adsorption reactor 21 above the partition 15 and continues upward through the catalyst bed 2#. Similarly, above the catalyst bed 1# in the conversion reactor, the partition 15 forces the process gas in the conversion reactor 22 to pass through the conversion adsorption process gas heat exchange line 6, through the adsorption reactor 21, and then back to the conversion reactor 22. The conversion adsorption process gas heat exchange line 6 passes through the adsorption reactor 21 below the partition 15. During this process, the conversion adsorption process gas in the conversion adsorption process gas heat exchange line 6 on the cold side exchanges heat with the process gas in the adsorption reactor 21 on the hot side below the conversion adsorption process gas heat exchange line 6.Specifically, the lower-temperature process gas in the conversion adsorption process gas heat exchange line 6 absorbs heat from the higher-temperature process gas in the adsorption reactor 21. It should be noted that during this process, the process gas in the conversion adsorption process gas heat exchange line 6 only exchanges heat with the process gas in the adsorption reactor 21; no material exchange occurs. In other words, the process gas in the conversion adsorption process gas heat exchange line 6 does not enter the adsorption reactor 21. The conversion adsorption process gas heat exchange line 5 bypasses the partition 15 and passes through the adsorption reactor 21 above the partition 15. During this process, the conversion adsorption process gas in the conversion adsorption process gas heat exchange line 6 on the cold side exchanges heat with the process gas in the adsorption reactor 21 above the conversion adsorption process gas heat exchange line 6 on the hot side. Thereafter, the conversion adsorption process gas is guided by the conversion adsorption process gas heat exchange line 6 back to the conversion reactor 22 above the partition 15, where it continues upward through the catalyst bed 2#. The above-mentioned adsorption conversion process gas heat exchange pipeline 5 and conversion adsorption process gas heat exchange pipeline 6 can also be the hot side and cold side of a plate heat exchanger.

[0086] 2) When the adsorption reactor 21 reaches the saturated adsorption capacity of the adsorbent, the control valves 7 and 11 are closed, the control valves 9 and 14 are opened, and the high-temperature flue gas 1 containing CO2 is switched to enter the conversion reactor 22 through the control valve 9. At this time, the control valves 8 and 12 are opened, and the reducing gas 3 enters the adsorption reactor 21 through the control valve 8 and passes through the adsorption reactor beds 1#, 2#, and 3# in sequence. The catalytic material adsorbed with CO2 reacts with the reducing gas, and the carbon dioxide is reduced to CO. The heat required for the conversion reaction is provided by the adsorption reaction heat described in step 1) through the adsorption conversion process gas heat exchange pipeline 5 and the conversion adsorption process gas heat exchange pipeline 6. The synthesis gas 4 comes out of the adsorption reactor 21 through the control valve 12. At this time, the adsorption reactor 21 is in a conversion state, and the reaction temperature of the conversion reactor is 100-950°C, preferably in the temperature range of 600-800°C;

[0087] 3) The high-temperature flue gas containing CO2 entering the conversion reactor 22 passes through the catalyst bed of the conversion reactor in sequence. The CO2 in the flue gas is adsorbed and captured by the catalytic material in the catalyst bed. Heat is exchanged through the adsorption conversion process gas heat exchange pipeline 5 and the conversion adsorption process gas heat exchange pipeline 6. The decarbonized gas 2 exits the conversion reactor 22 through the control valve 14;

[0088] 4) When the conversion reactor reaches the saturated adsorption capacity of the adsorbent, the conversion reactor and the adsorption reactor exchange functions, that is, the conversion reactor is used for adsorption reaction, and the adsorption reactor 21 is used for conversion. At this time, control valves 9 and 14 are closed, 7 and 11 are opened, and the CO2-containing high-temperature flue gas 1 is switched to enter the adsorption reactor 21. Control valves 8 and 12 are closed, control valves 10 and 13 are opened, and the reducing gas 3 is switched to enter the conversion reactor 22. The above operation is repeated.

[0089] The exchange of feeds between the two reactors may involve steps such as pre-switch purging, which will not be described in detail in the present invention. The purging can be performed using an inert gas such as nitrogen.

[0090] Example

[0091] The present invention will be further described below with reference to specific examples. The examples are merely examples of implementation methods of the present invention under specific conditions and should not be construed as limiting the scope of protection of the present invention. The data in the examples are derived by the inventors through simulation calculations based on their prior experience, and slight deviations may exist in actual operation.

[0092] Preparation example:

[0093] General description of the preparation method of catalytic materials

[0094] The CaO-based catalytic material is synthesized using the sol-gel method. The synthesized catalytic material is a composite material with a porous structure. The specific steps are as follows:

[0095] (1) Calcium nitrate or calcium chloride, Fe salt as a catalyst component, and Co, Ni or Pd salt as a co-catalyst component (the salt may be in the form of chloride, nitrate or acetate) are sequentially added to an aqueous solution. After all components are fully dissolved, an organic template such as citric acid, ammonium citrate, oxalic acid, ammonium oxalate is added to obtain a mixed solution. The molar ratio of the calcium salt to the organic template is 1:1.5 to 3;

[0096] (2) stirring the mixed solution in step (1) to fully dissolve it, letting it stand for 1 to 2 hours, and then heating it in a water bath at 60 to 90° C. and continuing to stir it for 3 to 8 hours to obtain a translucent sol;

[0097] (3) heating the translucent sol in step (2) at 100-150° C. for 10-14 hours, and drying to obtain a xerogel;

[0098] (4) The dry gel in step (3) is extruded into a composite material with a diameter of 3 to 5 mm through an extruder, and calcined in a muffle furnace at a calcination temperature of 800 to 900° C. for 4 to 8 hours to obtain a catalytic material.

[0099] Example 1: (Take the process of Figure 1 as an example)

[0100] Raw material high temperature flue gas 100000m 3 Take n / h as an example, the flue gas composition is as follows:

[0101] The flue gas temperature is 678° C., and the flue gas pressure is 10 kPa (gauge pressure). The adsorption reactor 21 and the conversion reactor 22 are switched in operation. When the adsorption reactor 21 is in the adsorption state, the conversion reactor 22 is in the conversion regeneration state.

[0102] 1) Control valves 7 and 11 are opened, and the 678°C high-temperature flue gas 1 enters the adsorption reactor 21 from the bottom.

[0103] 2) The adsorption reactor 21 is equipped with catalyst beds 1#, 2#, and 3# of CaO-based catalytic material 111, and the catalytic material is loaded with Co active components for catalyzing the reaction of CO2 and H2.

[0104] 3) According to calculations, with a 2-hour switching cycle, each reactor needs to be filled with 3.16m3 of catalytic material. 3 The adsorption process reaction exothermic load is 33.76MW, which is exchanged with the process gas in the conversion reactor 22 through the adsorption conversion process gas heat exchange pipeline 5.

[0105] 4) Control valves 7 and 11 are opened, and the flue gas enters the adsorption reactor 21 through the control valve 7. The high-temperature CO2 gas passes through the catalyst beds 1#, 2#, and 3# in sequence. In the catalyst bed, the CaO in the catalytic adsorption material reacts with CO2 to form CaCO3. The heat released raises the temperature of the flue gas and the bed. After adsorption in the adsorption reactor 21, the purified flue gas temperature is 727°C, and the purified flue gas volume is 71272.5m 3 n / h, after coming out from the top of the adsorption reactor 21, it is sent to the chimney for discharge after heat recovery.

[0106] 5) At the same time, the control valves 10 and 13 are opened, and in the other conversion reactor 22, the CaCO3 in the catalytic adsorption material reacts with the introduced excess H2 at 730°C to generate CaO, CO and water. The required heat of 32.07MW is obtained from the adsorption reactor 21 through the adsorption conversion process gas heat exchange pipeline 5 and the conversion adsorption process gas heat exchange pipeline 6. The insufficient heat is supplemented by external heat. In this embodiment, the insufficient heat of approximately 8.44MW can be brought in by heating the reducing gas H2, or it can be supplemented by setting an electric heater or a gas pipeline in the conversion reactor.

[0107] 6) The amount of reaction product synthesis gas 4 is 47958.0m 3 n / h, the synthesis gas temperature is 500 ° C, and it is discharged through the gas outlet of the conversion reactor 22. The expected composition of the synthesis gas is as follows:

[0108] 7) After 2 hours, the reactor is purged with hot nitrogen, and control valves 7, 10, 11, and 13 are closed, while valves 8, 9, 12, and 14 are opened, switching between flue gas and hydrogen feed. The cycle is then cycled sequentially according to the time sequence control.

[0109] The flue gas treated in this embodiment can reduce CO2 emissions by 303,000 t / a and produce 246,000 t / a of synthesis gas as a by-product.

[0110] This method requires approximately 8.44 MW of external heat. According to literature, using solvent absorption to treat CO2 flue gas of the same scale would require approximately 11.36 MW of external heat, primarily for absorbent regeneration, representing a 34.6% increase in energy consumption compared to this method. Furthermore, this method minimizes the pressure drop across the system to less than 10 kPa.

[0111] Example 2: (Take the process of Figure 2 as an example)

[0112] Raw material high temperature flue gas 6700m 3 Take n / h as an example, the flue gas composition is as follows:

[0113] The flue gas temperature is 678°C and the flue gas pressure is 10 kPa (gauge pressure). The primary adsorption reactor 21-1, the secondary adsorption reactor 21-2, and the primary conversion reactor 22-1, the secondary conversion reactor 22-2 are switched in operation. When the adsorption reactors 21-1 and 21-2 are in the adsorption state, the conversion reactors 22-1 and 22-2 are in the conversion regeneration state.

[0114] 1) Control valves 7 and 11 are opened, and the 678°C high-temperature flue gas 1 enters from the lower part of the primary adsorption reactor 21-1 and passes through the catalyst beds 1# and 2# in the primary adsorption reactor 21-1 and the catalyst beds 3# and 4# in the secondary adsorption reactor 21-2 in sequence.

[0115] 2) The first-stage adsorption reactor 21-1 and the second-stage adsorption reactor 21-2 are both equipped with catalyst beds 1#, 2#, 3#, and 4# of CaO-based catalytic material 111, and the catalytic material is loaded with Co active components for catalyzing the reaction of CO2 and H2.

[0116] 3) According to calculations, with a 2-hour switching cycle, each reactor needs to be filled with 0.41m3 of catalytic material. 3 The adsorption process reaction exothermic load is 3.96MW, which is exchanged with the process gas in the primary conversion reactor 22-1 and the secondary conversion reactor 22-2 through the adsorption conversion process gas heat exchange pipeline 5.

[0117] 4) Control valves 7 and 11 are opened, and the flue gas enters the primary adsorption reactor 21-1 and the secondary adsorption reactor 21-2 through control valve 7. The high-temperature CO2 gas passes through catalyst beds 1#, 2#, 3#, and 4# in sequence. In the catalyst beds, the CaO in the catalytic adsorption material reacts with CO2 to form CaCO3. The heat released raises the temperature of the flue gas and the beds. After adsorption in the primary adsorption reactor 21-1 and the secondary adsorption reactor 21-2, the purified flue gas temperature reaches 727°C, and the purified flue gas volume reaches 2728.7m 3 n / h, after coming out from the top of the secondary adsorption reactor 21-2, it is sent to the chimney for discharge after heat recovery.

[0118] 5) At the same time, the control valves 10 and 13 are opened, and in the other two conversion reactors 22-1 and 22-2, the CaCO3 in the catalytic adsorption material reacts with the introduced excess H2 at 730°C to generate CaO, CO and water. The required heat of 3.76MW is obtained from the primary adsorption reactor 21-1 and the secondary adsorption reactor 21-2 through the adsorption conversion process gas heat exchange pipeline 5 and the conversion adsorption process gas heat exchange pipeline 6. The insufficient heat of about 0.99MW can be brought in by heating the reducing gas H2, or it can be supplemented by setting an electric heater or a gas pipeline in the conversion reactor.

[0119] 6) The amount of reaction product synthesis gas 4 is 5623.1m 3 n / h, the synthesis gas temperature is 500 ° C, and it is discharged through the gas outlet of the secondary conversion reactor 22-2. The expected composition of the synthesis gas is as follows:

[0120] 7) After 2 hours, the reactor is purged with hot nitrogen, and control valves 7, 10, 11, and 13 are closed, while valves 8, 9, 12, and 14 are opened, switching between flue gas and hydrogen feed. The cycle is then cycled sequentially according to the time sequence control.

[0121] The flue gas treated in this embodiment can reduce CO2 emissions by 35,000 t / a and produce 29,000 t / a of synthesis gas as a by-product.

[0122] Example 3: (Take the process of Figure 3 as an example)

[0123] The raw material high temperature flue gas is 25000m 3 Take n / h as an example, the flue gas composition is as follows:

[0124] The flue gas temperature is 678°C and the flue gas pressure is 10 kPa (gauge pressure). The primary adsorption reactor 21-1, the secondary adsorption reactor 21-2, and the conversion reactor 22 are switched in operation. When the primary adsorption reactor 21-1 and the secondary adsorption reactor 21-2 are in the adsorption state, the conversion reactor 22 is in the conversion regeneration state.

[0125] 1) Control valves 7 and 11 are opened, and the 678°C high-temperature flue gas 1 enters from the lower part of the primary adsorption reactor 21-1 and passes through the catalyst beds 1# and 2# in the primary adsorption reactor 21-1 and the catalyst beds 3# and 4# in the secondary adsorption reactor 21-2 in sequence.

[0126] 2) The first-stage adsorption reactor 21-1 and the second-stage adsorption reactor 21-2 are equipped with catalyst beds 1#, 2#, 3#, and 4# of CaO-based catalytic material 111, and the catalytic material is loaded with Co active components for catalyzing the reaction of CO2 and H2.

[0127] 3) According to calculations, based on a 2-hour switching cycle, 0.79m3 of catalytic material needs to be filled into the primary and secondary adsorption reactors. 3 1.58m3 of catalytic material needs to be filled into the conversion reactor. 3 The adsorption process reaction exothermic load is 13.50MW, which is exchanged with the process gas in the conversion reactor 22 through the adsorption conversion process gas heat exchange pipeline 5.

[0128] 4) Control valves 7 and 11 are opened, and the flue gas enters the primary adsorption reactor 21-1 and the secondary adsorption reactor 21-2 through the control valve 7. The high-temperature CO2 gas passes through the catalyst beds 1#, 2#, 3#, and 4# in sequence. In the catalyst bed, the CaO in the catalytic adsorption material reacts with CO2 to form CaCO3. The heat released increases the temperature of the flue gas and the bed. After adsorption in the primary adsorption reactor 21-1 and the secondary adsorption reactor 21-2, the purified flue gas temperature is 727°C and the purified flue gas volume is 11136.3m 3 n / h, after coming out from the top of the secondary adsorption reactor 21-2, it is sent to the chimney for discharge after heat recovery.

[0129] 5) At the same time, the control valves 10 and 13 are opened, and in the conversion reactor 22, the CaCO3 in the catalytic adsorption material reacts with the introduced excess H2 at 730°C to generate CaO, CO and water. 12.83MW of the required heat is obtained from the primary adsorption reactor 21-1 and the secondary adsorption reactor 21-2 through the adsorption conversion process gas heat exchange pipeline 5 and the conversion adsorption process gas heat exchange pipeline 6. The insufficient heat of about 3.37MW can be brought in by heating the reducing gas H2, or it can be supplemented by setting an electric heater or a gas pipeline in the conversion reactor.

[0130] 6) The amount of reaction product synthesis gas 4 is 19183.2m 3 n / h, the synthesis gas temperature is 500 ° C, and it is discharged through the gas outlet of the conversion reactor 22. The expected composition of the synthesis gas is as follows:

[0131] 7) After 2 hours, the reactor is purged with hot nitrogen, and control valves 7, 10, 11, and 13 are closed, while valves 8, 9, 12, and 14 are opened, switching between flue gas and hydrogen feed. The cycle is then cycled sequentially according to the time sequence control.

[0132] The flue gas treated in this embodiment can reduce CO2 emissions by 116,000 t / a and produce 99,000 t / a of synthesis gas as a by-product.

[0133] Example 4: (taking the process of Figure 1 as an example)

[0134] Raw material high temperature flue gas 100000m 3 Take n / h as an example, the flue gas composition is as follows:

[0135] The flue gas temperature is 678° C., and the flue gas pressure is 10 kPa (gauge pressure). The adsorption reactor 21 and the conversion reactor 22 are switched in operation. When the adsorption reactor 21 is in the adsorption state, the conversion reactor 22 is in the conversion regeneration state.

[0136] 1) Control valves 7 and 11 are opened, and the 678°C high-temperature flue gas 1 enters the adsorption reactor 21 from the bottom.

[0137] 2) The adsorption reactor 21 is equipped with catalyst beds 1#, 2#, and 3# of CaO-based catalytic material 111, and the catalytic material is loaded with Ni active components for catalyzing the reaction of CO2 and CH4.

[0138] 3) According to calculations, with a 2-hour switching cycle, each reactor needs to be filled with 3.16m3 of catalytic material. 3 The adsorption process reaction exothermic load is 33.76MW, which is exchanged with the process gas in the conversion reactor 22 through the adsorption conversion process gas heat exchange pipeline 5.

[0139] 4) Control valves 7 and 11 are opened, and the flue gas enters the adsorption reactor 21 through the control valve 7. The high-temperature CO2 gas passes through the catalyst beds 1#, 2#, and 3# in sequence. In the catalyst bed, the CaO in the catalytic adsorption material reacts with CO2 to form CaCO3. The heat released raises the temperature of the flue gas and the bed. After adsorption in the adsorption reactor 21, the purified flue gas temperature is 727°C, and the purified flue gas volume is 71272.5m 3 n / h, after coming out from the top of the adsorption reactor 21, it is sent to the chimney for discharge after heat recovery.

[0140] 5) At the same time, control valves 10 and 13 are opened, and in another conversion reactor 22, CaCO3 in the catalytic adsorption material reacts with the introduced excess CH4 at 730°C to produce CaO, CO and water. 32.07 MW of the required heat is obtained from the adsorption reactor 21 through the adsorption conversion process gas heat exchange pipeline 5 and the conversion adsorption process gas heat exchange pipeline 6. The insufficient heat, approximately 8.44 MW, can be introduced by heating the reducing gas, or it can be supplemented by installing an electric heater or a gas pipeline in the conversion reactor.

[0141] 6) The amount of reaction product synthesis gas 4 is 47958.0m 3 n / h, the synthesis gas temperature is 500 ° C, and it is discharged through the gas outlet of the conversion reactor 22. The expected composition of the synthesis gas is as follows:

[0142] 7) After 2 hours, the reactor is purged with hot nitrogen, and control valves 7, 10, 11, and 13 are closed, while valves 8, 9, 12, and 14 are opened, switching between the flue gas and CH4 feeds. The cycle then continues in sequence according to the time sequence control.

[0143] The flue gas treated in this embodiment can reduce CO2 emissions by 304,000 t / a and produce 238,000 t / a of synthesis gas as a by-product.

[0144] Example 5:

[0145] Raw material high temperature flue gas 100000m 3 Take n / h as an example, the flue gas composition is as follows:

[0146] The flue gas temperature is 678° C., and the flue gas pressure is 10 kPa (gauge pressure). The adsorption reactor 21 and the conversion reactor 22 are switched in operation. When the adsorption reactor 21 is in the adsorption state, the conversion reactor 22 is in the conversion regeneration state.

[0147] 1) Control valves 7 and 11 are opened, and the 678°C high-temperature flue gas 1 enters the adsorption reactor 21 from the bottom.

[0148] 2) The adsorption reactor 21 is equipped with catalyst beds 1#, 2#, and 3# of CaO-based catalytic material 111, and the catalytic material is loaded with La active components for catalyzing the reaction of CO2 and CH4.

[0149] 3) According to calculations, with a 2-hour switching cycle, each reactor needs to be filled with 3.16 MW of catalytic material. The adsorption process reaction exothermic load is 33.76 MW, which is exchanged with the process gas in the conversion reactor 22 through the adsorption conversion process gas heat exchange pipeline 5.

[0150] 4) Control valves 7 and 11 are opened, and the flue gas enters the adsorption reactor 21 through the control valve 7. The high-temperature CO2 gas passes through the catalyst beds 1#, 2#, and 3# in sequence. In the catalyst bed, the CaO in the catalytic adsorption material reacts with CO2 to form CaCO3. The heat released raises the temperature of the flue gas and the bed. After adsorption in the adsorption reactor 21, the purified flue gas temperature is 727°C, and the purified flue gas volume is 71272.5m 3 n / h, after coming out from the top of the adsorption reactor 21, it is sent to the chimney for discharge after heat recovery.

[0151] 5) At the same time, control valves 10 and 13 are opened, and in another conversion reactor 22, CaCO3 in the catalytic adsorption material reacts with the introduced excess CH4 at 730°C to produce CaO, CO and water. 32.07 MW of the required heat is obtained from the adsorption reactor 21 through the adsorption conversion process gas heat exchange pipeline 5 and the conversion adsorption process gas heat exchange pipeline 6. The insufficient heat, approximately 8.44 MW, can be introduced by heating the reducing gas, or it can be supplemented by installing an electric heater or a gas pipeline in the conversion reactor.

[0152] 6) The amount of reaction product synthesis gas 4 is 47958.01m 3 n / h, the synthesis gas temperature is 500 ° C, and it is discharged through the gas outlet of the conversion reactor 22. The expected composition of the synthesis gas is as follows:

[0153] 7) After 2 hours, the reactor is purged with hot nitrogen, and control valves 7, 10, 11, and 13 are closed, while valves 8, 9, 12, and 14 are opened, switching between the flue gas and CH4 feeds. The cycle then continues in sequence according to the time sequence control.

[0154] The flue gas treated in this embodiment can reduce CO2 emissions by 301,000 t / a and produce 240,000 t / a of synthesis gas as a by-product.

[0155] Example 6:

[0156] Raw material high temperature flue gas 100000m 3 Take n / h as an example, the flue gas composition is as follows:

[0157] The flue gas temperature is 678° C., and the flue gas pressure is 10 kPa (gauge pressure). The adsorption reactor 21 and the conversion reactor 22 are switched in operation. When the adsorption reactor 21 is in the adsorption state, the conversion reactor 22 is in the conversion regeneration state.

[0158] 1) Control valves 7 and 11 are opened, and the 678°C high-temperature flue gas 1 enters the adsorption reactor 21 from the bottom.

[0159] 2) The adsorption reactor 21 is equipped with catalyst beds 1#, 2#, and 3# of CaO-based catalytic material 111, and the catalytic material is loaded with Co active components for catalyzing the reaction of CO2 and CH4.

[0160] 3) According to calculations, with a 2-hour switching cycle, each reactor needs to be filled with 4.42m3 of catalytic material. 3 The adsorption process reaction exothermic load is 67.51MW, which is exchanged with the process gas in the conversion reactor 22 through the adsorption conversion process gas heat exchange pipeline 5.

[0161] 4) Control valves 7 and 11 are opened, and the flue gas enters the adsorption reactor 21 through control valve 7. The high-temperature CO2 gas passes through catalyst beds 1#, 2#, and 3# in sequence. In the catalyst bed, CaO in the catalytic adsorption material reacts with CO2 to form CaCO3. The heat released raises the temperature of the flue gas and the bed. After adsorption in the adsorption reactor 21, the purified flue gas temperature is 727°C, and the purified flue gas volume is 35636.3m 3 n / h, after coming out from the top of the adsorption reactor 21, it is sent to the chimney for discharge after heat recovery.

[0162] 5) At the same time, control valves 10 and 13 are opened, and in another conversion reactor 22, CaCO3 in the catalytic adsorption material reacts with the introduced excess CH4 at 730°C to produce CaO, CO and water. 64.13 MW of the required heat is obtained from the adsorption reactor 21 through the adsorption conversion process gas heat exchange pipeline 5 and the conversion adsorption process gas heat exchange pipeline 6. The insufficient heat, approximately 16.88 MW, can be introduced by heating the reducing gas, or it can be supplemented by installing an electric heater or a gas pipeline in the conversion reactor.

[0163] 6) The amount of reaction product synthesis gas 4 is 95916.02m 3 n / h, the synthesis gas temperature is 500 ° C, and it is discharged through the gas outlet of the conversion reactor 22. The expected composition of the synthesis gas is as follows:

[0164] 7) After 2 hours, the reactor is purged with hot nitrogen, and control valves 7, 10, 11, and 13 are closed, while valves 8, 9, 12, and 14 are opened, switching between the flue gas and CH4 feeds. The cycle then continues in sequence according to the time sequence control.

[0165] The flue gas treated in this embodiment can reduce CO2 emissions by 600,000 t / a and produce 625,000 t / a of synthesis gas as a by-product.

[0166] The preferred embodiments of the present application are described in detail above. However, the present application is not limited to the specific details of the above embodiments. Within the technical concept of the present application, various simple modifications can be made to the technical solution of the present application, and these simple modifications all fall within the scope of protection of the present application.

[0167] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this application will not further describe various possible combinations.

[0168] In addition, the various implementation methods of the present application may be arbitrarily combined, and as long as they do not violate the concept of the present application, they should also be regarded as the contents disclosed in the present application.

Claims

1. A method for capturing and utilizing carbon dioxide, comprising the following steps: 1) introducing a gas containing CO2 into a first reactor containing a catalytic material having dual functions of carbon dioxide adsorption and catalytic conversion, and using the catalytic material to adsorb and capture the CO2 in the gas to obtain a purified gas after the CO2 is removed; 2) When the catalytic material in the first reactor reaches a predetermined adsorption capacity, the gas containing CO2 is switched to be introduced into a second reactor containing a catalytic material having dual functions of carbon dioxide adsorption and catalytic conversion, and simultaneously a reducing gas is introduced into the first reactor to react with the catalytic material after adsorbing CO2 to regenerate the catalytic material and produce a process gas containing CO; 3) in a second reactor, using the catalytic material to adsorb and capture CO2 in the gas entering the reactor to obtain a purified gas after the CO2 is removed; 4) When the catalytic material in the second reactor reaches a predetermined adsorption capacity, the gas containing CO2 is switched to be introduced into the first reactor again, and the reducing gas is simultaneously introduced into the second reactor to react with the catalytic material after adsorbing CO2 to regenerate the catalytic material and generate a process gas containing CO; 5) Repeat steps 1) to 4) Heat exchange is performed between the first and second reactors through a first heat exchange pipeline and a second heat exchange pipeline. The first heat exchange pipeline guides the gas flow from the first reactor through the second reactor and then returns to the first reactor. The gas flow from the first reactor exchanges heat with the gas flow in the second reactor while passing through the second reactor. The second heat exchange pipeline guides the gas flow from the second reactor through the first reactor and then returns to the second reactor. The gas flow from the second reactor exchanges heat with the gas flow in the first reactor while passing through the first reactor.

2. The method for capturing and utilizing carbon dioxide according to claim 1, wherein: The reaction temperature of the CO2 adsorption capture process is room temperature-800°C, preferably 400-780°C, more preferably 600-750°C, and the reaction temperature of the catalytic material regeneration process is 100-950°C, preferably 300-900°C, more preferably 600-800°C.

3. The method for capturing and utilizing carbon dioxide according to claim 1 or 2, wherein: The first reactor and the second reactor each independently have one or more catalyst beds filled with the catalytic material.

4. The method for capturing and utilizing carbon dioxide according to any one of claims 1 to 3, wherein: In the heat exchange process, the heat in the reactor captured by adsorption is transferred to the reactor where the regeneration of the catalytic material occurs.

5. The method for capturing and utilizing carbon dioxide according to any one of claims 1 to 4, characterized in that: Additional heat is added to the reactor in the catalytic material regeneration process, wherein the heat addition method includes heating the reducing gas and / or arranging an electric heater or a gas pipeline in the reactor to heat the reactor.

6. The method for capturing and utilizing carbon dioxide according to any one of claims 1 to 5, characterized in that: The reducing gas is a gas that can react with CO2 to generate CO, preferably comprising H2, CH4, C2H6 or a mixture thereof, or comprising the above gases and an inert gas.

7. The method for capturing and utilizing carbon dioxide according to any one of claims 1 to 6, characterized in that: The switching described in steps 2) and 4) is implemented as follows: Calculating a predetermined switching time based on the CO2 flow rate and the saturated adsorption capacity of the catalytic material, and performing switching when the predetermined switching time is reached; or The carbon dioxide content in the purified gas after CO2 removal is monitored and switched when it reaches a predetermined carbon dioxide content.

8. The method for capturing and utilizing carbon dioxide according to any one of claims 1 to 7, characterized in that: The first reactor and the second reactor are independently configured as one or more reactors. When the first reactor and / or the second reactor are configured as multiple reactors, the following switching method can be adopted: Multiple reactors switch feeds simultaneously, or Each reactor switches feed independently; Furthermore, when switching the feed between the first reactor and the second reactor, the following switching method can be used: Feed switching is performed between one first reactor and multiple second reactors. Feed switching between multiple second reactors and one second reactor, or Feed switching is performed between the multiple first reactors and the multiple second reactors.

9. The method for capturing and utilizing carbon dioxide according to any one of claims 1 to 8, wherein the gas containing CO2 is selected from flue gas from cement plants, steel plants, power plants, coal chemical plants, and refineries, and the temperature of the gas is preferably 400°C-900°C, more preferably 500°C-800°C, and even more preferably 600°C-750°C.

10. The method for capturing and utilizing carbon dioxide according to any one of claims 1 to 9, wherein the catalytic material comprises an adsorption component and a catalytic component, wherein the adsorption component comprises an alkaline earth metal oxide, preferably calcium oxide or magnesium oxide or a mixture thereof, and the catalytic component comprises a catalyst capable of catalyzing the reaction of carbon dioxide with a reducing gas, preferably Fe, Co, Ni, lanthanides, Ru, Cu, Pd, In, Rh, Ir, Pt, oxides of these elements, or a mixture of two or more of the foregoing substances.

11. A carbon dioxide capture and utilization device, comprising a first reactor, a second reactor, a first heat exchange pipeline, and a second heat exchange pipeline, wherein the first reactor and the second reactor are respectively provided with a catalytic material, characterized in that: The catalytic material is a material having the dual functions of carbon dioxide adsorption and catalytic conversion, wherein heat exchange is performed between the first and second reactors through a first heat exchange pipeline and a second heat exchange pipeline, the first heat exchange pipeline is configured to guide the gas flow from the first reactor through the second reactor and then return to the first reactor, and the gas flow from the first reactor exchanges heat with the gas flow in the second reactor while passing through the second reactor, and the second heat exchange pipeline is configured to guide the gas flow from the second reactor through the first reactor and then return to the second reactor, and the gas flow from the second reactor exchanges heat with the gas flow in the first reactor while passing through the first reactor.

12. The carbon dioxide capture and utilization device according to claim 11, characterized in that: The first and second reactors are fixed bed reactors, and the first reactor and the second reactor are each independently provided with one or more catalyst beds filled with the catalytic material, preferably multiple catalyst beds.

13. The carbon dioxide capture and utilization device according to claim 11 or 12, characterized in that: The first reactor and the second reactor are both provided with partitions, which are used to isolate the process gas so that the process gas is guided through the heat exchange pipeline. Preferably, when there are multiple catalyst beds, the separator is disposed between each pair of adjacent catalyst beds in the multiple catalyst beds.

14. The carbon dioxide capture and utilization device according to any one of claims 11 to 13, characterized in that: The heat exchange pipeline includes a heat exchange tube, a plate heat exchanger or a tube box, and the heat exchange tube adopts a fin tube, a coil or a serpentine tube type.

15. The carbon dioxide capture and utilization device according to any one of claims 11 to 14, characterized in that: The first reactor and the second reactor are independently configured as one or more reactors. When the first reactor and / or the second reactor are provided in multiple units, the following switching method can be adopted: Multiple reactors switch feeds simultaneously, or Each reactor switches feed independently; Furthermore, when switching the feed between the first reactor and the second reactor, the following switching method can be used: Feed switching is performed between one first reactor and multiple second reactors. Feed switching between multiple second reactors and one second reactor, or Feed switching is performed between the multiple first reactors and the multiple second reactors.