Carbon dioxide trapping in-situ conversion system

Abstract

The invention discloses a carbon dioxide capture in-situ conversion system. The system comprises a first gas path switching device, a carbon dioxide capture in-situ conversion device, a second gas path switching device and a storage device, a gas inlet of the first gas path switching device is respectively connected with three gas paths corresponding to industrial tail gas, purging gas and reducing gas, and the first gas path switching device is used for switching the type of output gas; the carbon dioxide trapping and in-situ conversion device is used for carrying out trapping and in-situ conversion on carbon dioxide and outputting carbon-containing compounds, purging gas and clean industrial tail gas; a gas inlet of the second gas path switching device is connected with a gas outlet of the carbon dioxide capture in-situ conversion device, and the second gas path switching device is used for correspondingly dividing a carbon-containing compound, purging gas and clean industrial tail gas into three gas paths respectively; the storage device is used for storing the carbon-containing compound. The system can efficiently carry out trapping and in-situ conversion on carbon dioxide in industrial tail gas, so that the industrial operation requirements are met.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon dioxide capture and in-situ conversion, and in particular to a carbon dioxide capture and in-situ conversion system. Background Art

[0002] The acceleration of the global industrialization process has led to the emission of a large amount of carbon dioxide (CO2), which has had a serious impact on the earth's ecological environment. As one of the main greenhouse gases, the rising concentration of CO2 has caused a series of environmental problems such as global warming, rising sea levels, and frequent extreme climate events, posing a huge challenge to human survival and development. Therefore, all countries have listed low-carbon development as a national strategy. Faced with huge pressure to reduce industrial emissions, changing the energy structure, developing clean energy, improving energy efficiency, and implementing carbon capture, storage and utilization (CCUS) technology are the keys to achieving low-carbon development in energy-intensive industries. The development of new and efficient CCUS technology is of great significance to my country's construction of a clean, low-carbon, and efficient modern energy system and the realization of coordinated and sustainable development of energy, environment, economy and society.

[0003] CCUS is divided into carbon capture and storage (CCS) and carbon capture and utilization (CCU) according to the final CO2 treatment method. CCS removes CO2 from the carbon source and compresses it and stores it in underground or marine bedrock. However, CCS is costly and energy-intensive, cannot bring economic benefits, and is severely limited in actual industrial applications. In contrast, CCU can use the obtained high-purity CO2 for conversion and utilization, pay more attention to incorporating CO2 into the carbon cycle, seek long-term sustainable paths, generate economic benefits through the use of CO2, and reduce the total cost of carbon emission reduction. However, traditional CCU usually needs to go through a series of cooling and heating processes such as cooling capture, high-temperature release, cooling transportation and high-temperature conversion, which not only increases the overall cost, but also causes serious energy waste.

[0004] As a derivative of CCU, in-situ CO2 capture and conversion (ICCU) technology integrates CO2 capture and conversion in the same reaction unit, successfully avoiding the large amount of energy consumption and additional costs of traditional CCU technology in the purification, compression, storage and transportation process, and has great industrial application potential in the field of industrial carbon emission reduction. However, current research on ICCU technology focuses on the development of adsorption / catalytic material systems and revealing their operating mechanisms, lacking system design and development based on its own reaction characteristics, making it difficult to meet subsequent actual industrial operation needs. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems in the related art to a certain extent. To this end, the first purpose of the present invention is to propose a carbon dioxide capture and in-situ conversion system, which can efficiently capture and in-situ convert carbon dioxide in industrial tail gas, thereby meeting the needs of industrial operation and solving the technical problem of the lack of system design in the current research on carbon dioxide capture and in-situ conversion technology.

[0006] To achieve the above-mentioned purpose, an embodiment of the first aspect of the present invention proposes a carbon dioxide capture in-situ conversion system, the system comprising: a first gas circuit switching device, the air inlet of the first gas circuit switching device is respectively connected to three gas circuits corresponding to industrial exhaust gas, purge gas, and reducing gas, the first gas circuit switching device is used to switch the type of output gas; a carbon dioxide capture in-situ conversion device, the carbon dioxide capture in-situ conversion device is connected to the output end of the first gas circuit switching device, the carbon dioxide capture in-situ conversion device is provided with a solid adsorption / catalytic material for capturing and in-situ conversion of carbon dioxide, and outputting carbon-containing compounds, purge gas and clean industrial exhaust gas; a second gas circuit switching device, the air inlet of the second gas circuit switching device is connected to the air outlet of the carbon dioxide capture in-situ conversion device, the second gas circuit switching device is used to divide the carbon-containing compounds, purge gas and clean industrial exhaust gas into three gas circuits respectively; a storage device, the storage device is connected to the gas circuits corresponding to the carbon-containing compounds, and is used to store the carbon-containing compounds.

[0007] In addition, the carbon dioxide capture in-situ conversion system according to the above embodiment of the present invention may also have the following additional technical features:

[0008] According to one embodiment of the present invention, there are multiple carbon dioxide capture in-situ conversion devices, which are arranged in parallel, and the type of gas entering the carbon dioxide capture in-situ conversion device is regulated by the first gas path switching device; wherein, when industrial exhaust gas is introduced, the carbon dioxide capture in-situ conversion device is in a carbon dioxide capture state; when purge gas is introduced, the carbon dioxide capture in-situ conversion device is in a purge and purification state; when reducing gas is introduced, the carbon dioxide capture in-situ conversion device is in an in-situ conversion state.

[0009] According to one embodiment of the present invention, the carbon dioxide capture in-situ conversion device includes: a reaction bed, the inlet of the reaction bed is connected to the outlet of the first gas circuit switching device, the outlet of the reaction bed is connected to the inlet of the second gas circuit switching device, and the solid adsorption / catalytic material is arranged in the reaction bed; a first cooler, one end of the first cooler is connected to the outlet of the reaction bed; a dryer, one end of the dryer is connected to the other end of the first cooler; a gas analyzer, the inlet of the gas analyzer is connected to the other end of the dryer, the gas analyzer is used to analyze the gas composition at the outlet of the reaction bed and transmit the gas composition data to the first gas circuit switching device; the first gas circuit switching device regulates the type of gas entering the carbon dioxide capture in-situ conversion device according to the gas composition data.

[0010] According to one embodiment of the present invention, the first gas circuit switching device regulates the type of gas entering the carbon dioxide capture in-situ conversion device according to gas component data, including: when the concentration of carbon dioxide in the gas components at the outlet of the reaction bed is greater than a preset concentration threshold, the first gas circuit switching device stops introducing industrial tail gas into the carbon dioxide capture in-situ conversion device, first switches the introduced gas to purge gas and continues for a preset time, and then switches the introduced gas to reducing gas; when the concentration of carbon-containing compounds in the gas components at the outlet of the reaction bed is zero, the first gas circuit switching device stops introducing reducing gas into the carbon dioxide capture in-situ conversion device, first switches the introduced gas to purge gas and continues for a preset time, and then switches the introduced gas to industrial tail gas.

[0011] According to one embodiment of the present invention, the bed body of the reaction bed is an axial fixed bed reactor or an axial radial fixed bed reactor, which is used to carry the solid adsorption / catalytic material.

[0012] According to one embodiment of the present invention, the system further includes: a first heat exchange device, which is arranged outside the carbon dioxide capture in-situ conversion device and is used to operate the carbon dioxide capture in-situ conversion device at a constant temperature through steam heat exchange when the carbon dioxide capture in-situ conversion device is in a carbon dioxide capture state.

[0013] According to one embodiment of the present invention, the system also includes: a second heat exchange device, the number of the second heat exchange device is three, which are respectively arranged at the intersection of the corresponding gas path of industrial exhaust gas and the corresponding gas path of clean industrial exhaust gas, the intersection of the corresponding gas path of input purge gas and the corresponding gas path of output purge gas, and the intersection of the corresponding gas path of reducing gas and the corresponding gas path of carbon-containing compounds.

[0014] According to one embodiment of the present invention, the storage device includes: a second cooler; a separator, the inlet of the separator is connected to the outlet of the second cooler; a gas compressor, the inlet of the gas compressor is connected to the outlet of the separator; a third cooler, the inlet of the third cooler is connected to the outlet of the gas compressor; and a storage tank, the inlet of the storage tank is connected to the outlet of the third cooler.

[0015] According to one embodiment of the present invention, the in-situ conversion reaction includes one of in-situ methanation, in-situ reverse water gas shift, in-situ methanation dry / wet reforming, in-situ ethane partial dehydrogenation to ethylene, and in-situ methanolization.

[0016] According to one embodiment of the present invention, when the in-situ conversion reaction is in-situ methanation or in-situ reverse water gas shift, the reducing gas is hydrogen; when the in-situ conversion reaction is in-situ methanation dry / wet reforming, the reducing gas is methane.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1) The fixed bed reaction bed and gas detection and analysis instruments can be used to effectively detect the carbon capture and in-situ conversion efficiency, switch the gas path and reaction state in time, and achieve efficient carbon capture and conversion.

[0019] 2) Through constant temperature reaction, the energy consumption demand caused by traditional CCUS variable temperature operation is avoided, and the energy utilization rate is high.

[0020] 3) Use the heat exchange between the outlet gas and the inlet gas to preheat the inlet gas, avoiding the need for additional energy while effectively utilizing the waste heat of the outlet gas.

[0021] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A block diagram of an in-situ conversion system for capturing carbon dioxide according to an embodiment of the present invention;

[0023] Figure 2 A block diagram of an in-situ conversion system for capturing carbon dioxide according to an embodiment of the present invention;

[0024] Figure 3 It is a structural schematic diagram of a carbon dioxide capture in-situ conversion device according to one embodiment of the present invention;

[0025] Figure 4 FIG. 4 is a schematic diagram of the structure of a storage device according to an embodiment of the present invention.

[0026] Reference numerals:

[0027] 10. First gas circuit switching device; 20. Carbon dioxide capture in-situ conversion device; 21. Reactor bed; 22. First cooler; 23. Dryer; 24. Gas analyzer; 30. Second gas circuit switching device; 40. Storage device; 41. Second cooler; 42. Separator; 43. Gas compressor; 44. Third cooler; 45. Storage tank; 50. First heat exchange device; 60. Second heat exchange device. DETAILED DESCRIPTION

[0028] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0029] The carbon dioxide capture in-situ conversion system proposed in an embodiment of the present invention will be described below with reference to the accompanying drawings.

[0030] like Figure 1 As shown, the carbon dioxide capture in-situ conversion system according to the embodiment of the present invention may include: a first gas path switching device 10 , a carbon dioxide capture in-situ conversion device 20 , a second gas path switching device 30 and a storage device 40 .

[0031] Among them, the air inlet of the first gas path switching device 10 is connected to the three gas paths corresponding to industrial tail gas, purge gas, and reducing gas, respectively, and the first gas path switching device 10 is used to switch the type of output gas. The carbon dioxide capture and in-situ conversion device 20 is connected to the output end of the first gas path switching device 10, and the carbon dioxide capture and in-situ conversion device 20 is provided with a solid adsorption / catalytic material for capturing and in-situ conversion of carbon dioxide, and outputting carbon-containing compounds, purge gas, and clean industrial tail gas. The air inlet of the second gas path switching device 30 is connected to the air outlet of the carbon dioxide capture and in-situ conversion device 20, and the second gas path switching device 30 is used to divide the carbon-containing compounds, purge gas, and clean industrial tail gas into three gas paths respectively. The storage device 40 is connected to the gas path corresponding to the carbon-containing compound, and is used to store the carbon-containing compound.

[0032] Specifically, if Figure 1 As shown, when the carbon dioxide in the industrial exhaust gas is captured and converted in situ, the first gas path switching device 10 first switches the gas path corresponding to the industrial exhaust gas to connect to the carbon dioxide capture in situ conversion device 20, so that the solid adsorption / catalytic material in the carbon dioxide capture in situ conversion device 20 adsorbs the carbon dioxide in the industrial exhaust gas and obtains clean industrial exhaust gas. At this time, the second gas path switching device 30 switches the gas path corresponding to the clean industrial exhaust gas to connect to the carbon dioxide capture in situ conversion device 20 to discharge the clean industrial exhaust gas.

[0033] After the adsorption is completed, the first gas path switching device 10 switches the gas path corresponding to the purge gas to connect to the carbon dioxide capture in-situ conversion device 20, so that the purge gas can purge out the residual industrial tail gas in the carbon dioxide capture in-situ conversion device 20 to prevent the residual industrial tail gas from affecting the in-situ conversion of carbon dioxide. At this time, the second gas path switching device 30 switches the gas path corresponding to the output purge gas to connect to the carbon dioxide capture in-situ conversion device 20 to discharge the purge gas. It should be noted that the purge gas can be nitrogen.

[0034] After the purging is completed, the first gas path switching device 10 switches the gas path corresponding to the reducing gas to connect to the carbon dioxide capture in-situ conversion device 20, so that the reducing gas and the carbon dioxide adsorbed in the carbon dioxide capture in-situ conversion device 20 undergo an in-situ conversion reaction to generate carbon-containing compounds. At this time, the second gas path switching device 30 switches the gas path corresponding to the carbon-containing compounds to connect to the carbon dioxide capture in-situ conversion device 20 to store the carbon-containing compounds in the storage device 40.

[0035] Furthermore, after the in-situ conversion is completed, that is, after the adsorbed carbon dioxide in the carbon dioxide capture in-situ conversion device 20 is completely converted into carbon-containing compounds, the first gas path switching device 10 first switches the gas path corresponding to the purge gas to connect to the carbon dioxide capture in-situ conversion device 20, and the second gas path switching device 30 switches the gas path corresponding to the output purge gas to connect to the carbon dioxide capture in-situ conversion device 20 to discharge the purge gas; after the purge is completed, the first gas path switching device 10 switches the gas path corresponding to the industrial exhaust gas to connect to the carbon dioxide capture in-situ conversion device 20, and the second gas path switching device 30 switches the gas path corresponding to the clean industrial exhaust gas to connect to the carbon dioxide capture in-situ conversion device 20, and repeats the above process, and cycles in this way, thereby completing the capture and in-situ conversion of carbon dioxide in the industrial exhaust gas.

[0036] According to one embodiment of the present invention, Figure 2 As shown, there are multiple carbon dioxide capture in-situ conversion devices 20, and the multiple carbon dioxide capture in-situ conversion devices 20 are arranged in parallel. The type of gas entering the carbon dioxide capture in-situ conversion device 20 is regulated by the first gas path switching device 10; wherein, when industrial exhaust gas is introduced, the carbon dioxide capture in-situ conversion device 20 is in a carbon dioxide capture state; when purge gas is introduced, the carbon dioxide capture in-situ conversion device 20 is in a purge purification state; when reducing gas is introduced, the carbon dioxide capture in-situ conversion device 20 is in an in-situ conversion state.

[0037] Specifically, if Figure 2As shown, the first gas circuit switching device 10 can simultaneously control multiple carbon dioxide capture in-situ conversion devices 20 to adsorb and in-situ convert carbon dioxide in industrial exhaust gas. In order to improve the efficiency of adsorption and in-situ conversion, the first gas circuit switching device 10 can simultaneously control multiple carbon dioxide capture in-situ conversion devices 20 to respectively introduce different gases so that the multiple carbon dioxide capture in-situ conversion devices 20 are in different working states. For example, in the same time period, the first part of the multiple carbon dioxide capture in-situ conversion devices 20 is fed with industrial tail gas, and the carbon dioxide capture in-situ conversion devices 20 of this part are in the carbon dioxide capture state; the second part of the multiple carbon dioxide capture in-situ conversion devices 20 is fed with purge gas, and the carbon dioxide capture in-situ conversion devices 20 of this part are in the purge purification state; the third part of the multiple carbon dioxide capture in-situ conversion devices 20 is fed with reducing gas, and the carbon dioxide capture in-situ conversion devices 20 of this part are in the in-situ conversion state; then in the next time period, such as when the carbon dioxide adsorption of the first part of the carbon dioxide capture in-situ conversion device 20 and the in-situ conversion of the third part of the carbon dioxide capture in-situ conversion device 20 are completed at the same time, the first gas path switching device 10 switches the gas type fed into each part of the carbon dioxide capture in-situ conversion device 20, so that each part of the carbon dioxide capture in-situ conversion device 20 performs the next stage of the process. Therefore, by reasonably configuring the adsorption time and the in-situ conversion time, the industrial tail gas can be fed uninterruptedly, so that the carbon dioxide capture in-situ conversion system can uninterruptedly process the industrial tail gas, thereby further improving the efficiency.

[0038] Further, taking three carbon dioxide capture in-situ conversion devices 20 as an example, within the same time period, the first gas circuit switching device 10 can control the first carbon dioxide capture in-situ conversion device 20 to pass industrial exhaust gas, so that the first carbon dioxide capture in-situ conversion device 20 is in a carbon dioxide capture state; control the second carbon dioxide capture in-situ conversion device 20 to pass purge gas, so that the second carbon dioxide capture in-situ conversion device 20 is in a purge and purification state; control the third carbon dioxide capture in-situ conversion device 20 to pass reducing gas, so that the third carbon dioxide capture in-situ conversion device 20 is in an in-situ conversion state; when the carbon dioxide adsorption of the first carbon dioxide capture in-situ conversion device 20 and the in-situ conversion of the third carbon dioxide capture in-situ conversion device 20 are completed at the same time, the first gas circuit switching device 10 switches the gas type passed into each carbon dioxide capture in-situ conversion device 20, so that each carbon dioxide capture in-situ conversion device 20 proceeds to the next stage of the process flow.

[0039] According to one embodiment of the present invention, Figure 3As shown, the carbon dioxide capture in-situ conversion device 20 includes: a reaction bed 21, the inlet of the reaction bed 21 is connected to the outlet of the first gas circuit switching device 10, the outlet of the reaction bed 21 is connected to the inlet of the second gas circuit switching device 30, and the reaction bed 21 is provided with a solid adsorption / catalytic material; a first cooler 22, one end of the first cooler 22 is connected to the outlet of the reaction bed 21; a dryer 23, one end of the dryer 23 is connected to the other end of the first cooler 22; a gas analyzer 24, the inlet of the gas analyzer 24 is connected to the other end of the dryer 23, the gas analyzer 24 is used to analyze the gas composition at the outlet of the reaction bed 21, and transmit the gas composition data to the first gas circuit switching device 10; the first gas circuit switching device 10 regulates the type of gas entering the carbon dioxide capture in-situ conversion device 20 according to the gas composition data.

[0040] Specifically, when industrial exhaust gas is passed into the reaction bed 21, the solid adsorption / catalytic material in the reaction bed 21 adsorbs the carbon dioxide in the industrial exhaust gas, and the clean industrial exhaust gas enters the second gas path switching device 30; when reducing gas is passed into the reaction bed 21, the reducing gas converts the carbon dioxide in the reaction bed 21 in situ, and the obtained carbon-containing compound gas enters the second gas path switching device 30.

[0041] Furthermore, part of the gas output by the reaction bed 21 enters the first cooler 22 to cool the output gas, and then enters the dryer 23 to remove moisture in the output gas. The gas analyzer 24 then analyzes the component data of various gases in the output gas and transmits the gas component data to the first gas path switching device 10.

[0042] Further, according to an embodiment of the present invention, the first gas circuit switching device 10 regulates the type of gas entering the carbon dioxide capture in-situ conversion device 20 according to the gas component data, including: when the concentration of carbon dioxide in the gas component at the outlet of the reaction bed 21 is greater than the preset concentration threshold, the first gas circuit switching device 10 stops passing industrial tail gas to the carbon dioxide capture in-situ conversion device 20, first switches the passing gas to purge gas and continues for a preset time, and then switches the passing gas to reducing gas; when the concentration of carbon-containing compounds in the gas component at the outlet of the reaction bed 21 is zero, the first gas circuit switching device 10 stops passing reducing gas to the carbon dioxide capture in-situ conversion device 20, first switches the passing gas to purge gas and continues for a preset time, and then switches the passing gas to industrial tail gas. Among them, the preset concentration threshold and the preset time can be calibrated according to specific circumstances.

[0043] According to one embodiment of the present invention, the bed body of the reaction bed 21 is an axial fixed bed reactor or an axial radial fixed bed reactor, which is used to carry solid adsorption / catalytic materials.

[0044] According to one embodiment of the present invention, Figure 2 As shown, the carbon dioxide capture in-situ conversion system also includes: a first heat exchange device 50, which is arranged outside the carbon dioxide capture in-situ conversion device 20, and is used for operating the carbon dioxide capture in-situ conversion device 20 at a constant temperature through steam heat exchange when the carbon dioxide capture in-situ conversion device 20 is in a carbon dioxide capture state.

[0045] Specifically, if Figure 2 As shown, the cold flow steam passes through the first heat exchange device 50 to exchange heat with the carbon dioxide capture in-situ conversion device 20 and is converted into hot flow steam, thereby reducing the temperature of the carbon dioxide capture in-situ conversion device 20, so that the carbon dioxide capture in-situ conversion device 20 operates at a constant temperature when it is in the carbon dioxide capture state.

[0046] According to one embodiment of the present invention, Figure 2 As shown, the carbon dioxide capture in-situ conversion system also includes: a second heat exchange device 60, the number of which is three, which are respectively arranged at the intersection of the industrial tail gas corresponding gas path and the clean industrial tail gas corresponding gas path, the intersection of the input purge gas corresponding gas path and the output purge gas corresponding gas path, and the intersection of the reducing gas corresponding gas path and the carbon-containing compound corresponding gas path. It should be noted that the intersection mentioned here only refers to the intersection of two pipelines in space, and the two pipelines are not connected.

[0047] Specifically, the three gas paths corresponding to the gas outlet of the second gas path switching device 30 can exchange heat with the corresponding inlet gas paths through the second heat exchange device 60, thereby achieving the cooling discharge of clean industrial tail gas and output purge gas and the cooling storage of carbon-containing compounds, and at the same time, preheating of the inlet gas path connected to the first gas path switching device 10 can be achieved. In this way, the extra energy demand can be avoided while effectively utilizing the waste heat of the outlet gas.

[0048] According to one embodiment of the present invention, Figure 4 As shown, the storage device 40 includes: a second cooler 41; a separator 42, the inlet of the separator 42 is connected to the outlet of the second cooler 41; a gas compressor 43, the inlet of the gas compressor 43 is connected to the outlet of the separator 42; a third cooler 44, the inlet of the third cooler 44 is connected to the outlet of the gas compressor 43; and a storage tank 45, the inlet of the storage tank 45 is connected to the outlet of the third cooler 44.

[0049] Specifically, after the carbon-containing compound enters the second cooler 41, the water vapor impurities in the carbon-containing compound can be liquefied, and then enter the separator 42 for gas-liquid separation, and the condensed water is discharged to prevent the condensed water from entering the gas compressor 43 and causing liquid shock to the gas compressor 43, thereby causing damage to the gas compressor 43. The gas compressor 43 compresses the carbon-containing compound, and the compressed carbon-containing compound is cooled by the third cooler 44 and stored in the storage tank 45.

[0050] According to one embodiment of the present invention, the in-situ conversion reaction includes one of in-situ methanation, in-situ reverse water gas shift, in-situ methanation dry / wet reforming, in-situ ethane partial dehydrogenation to ethylene, and in-situ methanolization.

[0051] According to one embodiment of the present invention, when the in-situ conversion reaction is in-situ methanation or in-situ reverse water gas shift, the reducing gas is hydrogen; when the in-situ conversion reaction is in-situ methanation dry / wet reforming, the reducing gas is methane.

[0052] Combine the following Figures 2 to 4 The specific processes of in-situ methanation, in-situ reverse water gas shift, and in-situ methanation dry / wet reforming in actual industrial applications are explained respectively.

[0053] The specific process of in-situ methanogenesis of carbon dioxide capture is as follows:

[0054] Industrial tail gas, purge gas nitrogen, and reducing gas hydrogen are directly connected to the first gas path switching device 10, and the gas introduced into the carbon dioxide capture in-situ conversion device 20 is directly regulated by the first gas path switching device 10. The reaction beds 21 of the multiple carbon dioxide capture in-situ conversion devices 20 are filled with Ni / CaO adsorption / catalytic materials and operated at a constant temperature of 600°C and normal pressure. Some of the multiple carbon dioxide capture in-situ conversion devices 20 are in a carbon dioxide capture state connected to the industrial tail gas, and some of the carbon dioxide capture in-situ conversion devices 20 are in a methanation state connected to the reducing gas hydrogen. The gas analyzer 24 configured by the carbon dioxide capture in-situ conversion device 20 monitors the gas components at the outlet of the reaction bed 21 in real time. When the carbon dioxide capture in-situ conversion device 20 completes carbon dioxide capture and the gas analyzer 24 detects that the carbon dioxide concentration at the outlet of the reaction bed 21 reaches a certain value, the gas is switched to be introduced through the first gas path switching device 10, and then after being purged by the purge gas, the reducing gas hydrogen is introduced to enter the in-situ methanation state. Similarly, when the carbon dioxide capture in-situ conversion device 20 completes in-situ methanation and the gas analyzer 24 detects that the outlet gas of the reaction bed 21 has no methane component, the gas is switched through the first gas path switching device 10, and then after being purged with the purge gas, the industrial tail gas is introduced to enter the carbon dioxide capture state. When the carbon dioxide capture in-situ conversion device 20 is in the carbon dioxide capture state, the heat exchange device uses steam medium to exchange heat to ensure the constant temperature operation of the reaction bed 21. The outlet gases of multiple carbon dioxide capture in-situ conversion devices 20 are summarized at the second gas path switching device 30. According to the gas introduced, the outlet gases are summarized as clean industrial tail gas, purge gas and carbon-containing compound gas path. The three gas paths are respectively heat-exchanged with the industrial tail gas, purge gas nitrogen and reducing gas hydrogen gas paths through the second heat exchange device 60 to achieve outlet gas cooling, waste heat recovery and inlet gas preheating. The carbon compound gas is cooled in the storage device 40 by the second cooler 41 and then enters the separator 42 to separate the steam contained in the gas. The gas is then compressed to 5Mp by the gas compressor 43 and then cooled to a suitable temperature by the third cooler 44 before being sent to the storage tank 45 for storage.

[0055] The flue gas components are set to 11% water vapor, 14.5% carbon dioxide, 5% oxygen, 69.5% nitrogen, the flue gas temperature is 80°C, the flue gas flow rate is 2110 tons / hour, and the filling amount of Ni / CaO adsorption / catalytic material in the carbon dioxide capture in-situ conversion device 20 is filled according to the molar ratio of 5 times the carbon dioxide content of the components at the flue gas flow rate of 10 minutes. The flow rate of reducing gas hydrogen is set to 4.1 times the flow rate of carbon dioxide of the flue gas component. Ignoring the energy loss caused by the purge process, according to thermodynamic calculations, the system can operate without any external heat source. The heat load of the industrial tail gas heat exchange device is 284.3MW, the industrial tail gas temperature is preheated from 80°C to 476.7°C by heat exchange, and the clean industrial tail gas temperature is reduced from 600°C to 150°C by heat exchange. The heat load of the heat exchange device between carbonaceous compounds and reducing gas is 140.2MW, the reducing gas temperature is preheated from 25°C to 563°C by heat exchange, and the carbonaceous compound temperature is reduced from 600°C to 110°C by heat exchange. At this time, when the carbon dioxide capture in-situ conversion device 20 is in carbon dioxide capture, the net heat load of the device is -282.7MW (exothermic), and the net heat load of the device is -0.64MW (exothermic) when it is in in-situ conversion.

[0056] The specific process of in-situ reverse water gas shift for carbon dioxide capture is as follows:

[0057] Industrial tail gas, purge gas nitrogen, and reducing gas hydrogen are directly connected to the first gas path switching device 10, and the gas introduced into the carbon dioxide capture in-situ conversion device 20 is directly regulated by the first gas path switching device 10. The reaction beds 21 of multiple carbon dioxide capture in-situ conversion devices 20 are filled with Ni / CaO adsorption / catalytic materials and operated at a constant temperature of 650°C and normal pressure. Some of the multiple carbon dioxide capture in-situ conversion devices 20 are in a carbon dioxide capture state connected to industrial tail gas, and some of the carbon dioxide capture in-situ conversion devices 20 are in a reverse water gas shift state connected to reducing gas hydrogen. The gas analyzer 24 configured by the carbon dioxide capture in-situ conversion device 20 monitors the gas components at the outlet of the reaction bed 21 in real time. When the carbon dioxide capture in-situ conversion device 20 completes carbon dioxide capture and the gas analyzer 24 detects that the carbon dioxide concentration at the outlet of the reaction bed 21 reaches a certain value, the gas is switched to be introduced through the first gas path switching device 10, and then after being purged by the purge gas, the reducing gas hydrogen is introduced to enter the in-situ reverse water gas shift state. Similarly, when the carbon dioxide capture in-situ conversion device 20 completes the in-situ reverse water-gas shift and the gas analyzer 24 detects that the outlet gas of the reaction bed 21 has no carbon monoxide components, the gas is switched to be introduced through the first gas path switching device 10, and then after being purged by the purge gas, the industrial tail gas is introduced to enter the carbon dioxide capture state. When the carbon dioxide capture in-situ conversion device 20 is in the carbon dioxide capture state, the heat exchange device uses steam medium to exchange heat to ensure the constant temperature operation of the reaction bed 21. The outlet gases of multiple carbon dioxide capture in-situ conversion devices 20 are summarized at the second gas path switching device 30. According to the gas introduced, the outlet gases are summarized as clean industrial tail gas, purge gas and carbon-containing compound gas path. The three gas paths are respectively heat-exchanged with the industrial tail gas, purge gas nitrogen and reducing gas hydrogen gas paths through the second heat exchange device 60 to achieve outlet gas cooling, waste heat recovery and inlet gas preheating. The carbon compound gas is cooled in the storage device 40 by the second cooler 41 and then enters the separator 42 to separate the steam contained in the gas. The gas is then compressed to 5Mp by the gas compressor 43 and then cooled to a suitable temperature by the third cooler 44 before being sent to the storage tank 45 for storage.

[0058] The flue gas components are set to 11% water vapor, 14.5% carbon dioxide, 5% oxygen, and 69.5% nitrogen, the flue gas temperature is 80°C, the flue gas flow rate is 2110 tons / hour, and the Ni / CaO adsorption / catalytic material filling amount in the carbon dioxide capture in-situ conversion device 20 is filled according to the molar ratio of 5 times the carbon dioxide content of the component at the flue gas flow rate of 10min. The flow rate of reducing gas hydrogen is set to 2 times the flow rate of flue gas component carbon dioxide. Ignoring the energy loss caused by the purge process, according to thermodynamic calculations, the heat load of the industrial exhaust gas heat exchange device is 317.9MW, the industrial exhaust gas temperature is preheated from 80°C to 521°C by heat exchange, and the clean industrial exhaust gas temperature is reduced from 600°C to 150°C by heat exchange. The heat load of the heat exchange device between carbon-containing compounds and reducing gas is 77.3MW, the reducing gas temperature is preheated from 25°C to 633°C by heat exchange, and the temperature of carbon-containing compounds is reduced from 600°C to 290°C by heat exchange. At this time, when the carbon dioxide capture in-situ conversion device 20 is in the process of carbon dioxide capture, the net heat load of the device is -273.6MW (exothermic), and when it is in the process of in-situ conversion, the net heat load of the device is 457.7MW.

[0059] The specific process of in-situ methane dry reforming with carbon dioxide capture is as follows:

[0060] Industrial tail gas, purge gas nitrogen, and reducing gas methane are directly connected to the first gas path switching device 10, and the first gas path switching device 10 directly controls the gas introduced into the carbon dioxide capture in-situ conversion device 20. The reaction beds 21 of multiple carbon dioxide capture in-situ conversion devices 20 are filled with Ni / CaO adsorption / catalytic materials and operated at a constant temperature of 720°C and normal pressure. Some of the multiple carbon dioxide capture in-situ conversion devices 20 are in a carbon dioxide capture state connected to industrial tail gas, and some of the carbon dioxide capture in-situ conversion devices 20 are in an in-situ methane dry reforming state connected to reducing gas methane. The gas analyzer 24 configured by the carbon dioxide capture in-situ conversion device 20 monitors the gas components at the outlet of the reaction bed 21 in real time. When the carbon dioxide capture in-situ conversion device 20 completes carbon dioxide capture and the gas analyzer 24 detects that the carbon dioxide concentration at the outlet of the reaction bed 21 reaches a certain value, the gas is switched to be introduced through the first gas path switching device 10, and after being purged by the purge gas, the reducing gas methane is introduced to enter the in-situ methane dry reforming state. Similarly, when the carbon dioxide capture in-situ conversion device 20 completes the in-situ methane dry reforming and the gas analyzer 24 detects that the outlet gas of the reaction bed 21 has no carbon monoxide components, the gas is switched through the first gas path switching device 10, and then after being purged by the purge gas, the industrial tail gas is introduced to enter the carbon dioxide capture state. When the carbon dioxide capture in-situ conversion device 20 is in the carbon dioxide capture state, the heat exchange device uses steam medium to exchange heat to ensure the constant temperature operation of the reaction bed 21. The outlet gases of multiple carbon dioxide capture in-situ conversion devices 20 are summarized at the second gas path switching device 30. According to the gas introduced, the outlet gases are summarized as clean industrial tail gas, purge gas and carbon-containing compound gas path. The three gas paths are respectively heat exchanged with the industrial tail gas, purge gas nitrogen and reducing gas methane gas paths through the second heat exchange device 60 to achieve outlet gas cooling, waste heat recovery and inlet gas preheating. The carbon compound gas is cooled in the storage device 40 by the second cooler 41 and then enters the separator 42 to separate the steam contained in the gas. The gas is then compressed to 5Mp by the gas compressor 43 and then cooled to a suitable temperature by the third cooler 44 before being sent to the storage tank 45 for storage.

[0061] The flue gas components are set to 11% water vapor, 14.5% carbon dioxide, 5% oxygen, and 69.5% nitrogen, the flue gas temperature is 80°C, the flue gas flow rate is 2110 tons / hour, and the Ni / CaO adsorption / catalytic material filling amount in the carbon dioxide capture in-situ conversion device 20 is filled according to the molar ratio of 5 times the carbon dioxide content of the component at the flue gas flow rate of 10min. The methane flow rate of the reducing gas is set to 1 times the carbon dioxide flow rate of the flue gas component. Ignoring the energy loss caused by the purge process, according to thermodynamic calculations, the heat load of the industrial exhaust gas heat exchange device is 365.6MW, the industrial exhaust gas temperature is preheated from 80°C to 583°C by heat exchange, and the clean industrial exhaust gas temperature is reduced from 600°C to 150°C by heat exchange. The heat load of the heat exchange device between carbon-containing compounds and reducing gas is 80.3MW, the reducing gas temperature is preheated from 25°C to 707°C by heat exchange, and the carbon-containing compound temperature is reduced from 600°C to 420°C by heat exchange. At this time, when the carbon dioxide capture in-situ conversion device 20 is in the process of carbon dioxide capture, the net heat load of the device is -258.6MW (exothermic), and when it is in the process of in-situ conversion, the net heat load of the device is 919MW.

[0062] In summary, the carbon dioxide capture in-situ conversion system of the embodiment of the present invention avoids the energy consumption requirements brought about by the traditional CCUS variable temperature operation through constant temperature reaction, and has high energy utilization rate. At the same time, the outlet gas and the inlet gas are used for heat exchange to realize the preheating of the inlet gas, thereby avoiding the additional energy demand and effectively utilizing the waste heat of the outlet gas.

[0063] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0064] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0065] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0066] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A carbon dioxide capture in-situ conversion system, characterized in that: The system comprises: A first gas path switching device, wherein the gas inlet of the first gas path switching device is respectively connected to three gas paths corresponding to industrial tail gas, purge gas, and reducing gas, and the first gas path switching device is used to switch the type of output gas; A carbon dioxide capture and in-situ conversion device, the carbon dioxide capture and in-situ conversion device is connected to the output end of the first gas path switching device, and the carbon dioxide capture and in-situ conversion device is provided with a solid adsorption / catalytic material for capturing and in-situ converting carbon dioxide, and outputting carbon-containing compounds, purge gas and clean industrial tail gas; a second gas path switching device, wherein the gas inlet of the second gas path switching device is connected to the gas outlet of the carbon dioxide capture in-situ conversion device, and the second gas path switching device is used to divide the carbon-containing compounds, the purge gas and the clean industrial tail gas into three gas paths respectively; A storage device is connected to the gas path corresponding to the carbon-containing compound and is used to store the carbon-containing compound.

2. The carbon dioxide capture in-situ conversion system according to claim 1, characterized in that: There are multiple carbon dioxide capture in-situ conversion devices, which are arranged in parallel, and the type of gas entering the carbon dioxide capture in-situ conversion device is regulated by the first gas path switching device; wherein, When the industrial tail gas is introduced, the carbon dioxide capture in-situ conversion device is in a carbon dioxide capture state; When the purge gas is introduced, the carbon dioxide capture in-situ conversion device is in a purge and purification state; When the reducing gas is introduced, the carbon dioxide capture in-situ conversion device is in an in-situ conversion state.

3. The carbon dioxide capture in-situ conversion system according to claim 2, characterized in that: The carbon dioxide capture in-situ conversion device comprises: A reaction bed, wherein the inlet of the reaction bed is connected to the gas outlet of the first gas path switching device, the outlet of the reaction bed is connected to the gas inlet of the second gas path switching device, and the solid adsorption / catalytic material is arranged in the reaction bed; a first cooler, one end of which is connected to the outlet of the reaction bed; a dryer, one end of which is connected to the other end of the first cooler; A gas analyzer, the inlet of which is connected to the other end of the dryer, and the gas analyzer is used to analyze the gas components at the outlet of the reaction bed and transmit the gas component data to the first gas path switching device; the first gas path switching device regulates the type of gas entering the carbon dioxide capture in-situ conversion device according to the gas component data.

4. The carbon dioxide capture in-situ conversion system according to claim 3, characterized in that: The first gas path switching device regulates the type of gas entering the carbon dioxide capture in-situ conversion device according to the gas composition data, including: When the concentration of carbon dioxide in the gas components at the outlet of the reaction bed is greater than a preset concentration threshold, the first gas path switching device stops supplying industrial tail gas to the carbon dioxide capture in-situ conversion device, first switches the supplied gas to purge gas and keeps it for a preset time, and then switches the supplied gas to reducing gas; When the concentration of carbon-containing compounds in the gas components at the outlet of the reaction bed is zero, the first gas path switching device stops supplying reducing gas to the carbon dioxide capture in-situ conversion device, first switches the supplied gas to purge gas and maintains it for a preset time, and then switches the supplied gas to industrial exhaust gas.

5. The carbon dioxide capture in-situ conversion system according to claim 3, characterized in that: The bed body of the reaction bed is an axial fixed bed reactor or an axial radial fixed bed reactor, which is used to carry the solid adsorption / catalytic material.

6. The carbon dioxide capture in-situ conversion system according to claim 1, characterized in that: The system further comprises: A first heat exchange device is arranged outside the carbon dioxide capture in-situ conversion device, and is used for operating the carbon dioxide capture in-situ conversion device at a constant temperature through steam heat exchange when the carbon dioxide capture in-situ conversion device is in a carbon dioxide capture state.

7. The carbon dioxide capture in-situ conversion system according to claim 1, characterized in that: The system further comprises: The second heat exchange device, the number of the second heat exchange device is three, which are respectively arranged at the intersection of the corresponding gas path of industrial exhaust gas and the corresponding gas path of clean industrial exhaust gas, the intersection of the corresponding gas path of input purge gas and the corresponding gas path of output purge gas, and the intersection of the corresponding gas path of reducing gas and the corresponding gas path of carbon-containing compounds.

8. The carbon dioxide capture in-situ conversion system according to claim 1, characterized in that: The storage device comprises: Second cooler; a separator, wherein an inlet of the separator is connected to an outlet of the second cooler; a gas compressor, wherein the inlet of the gas compressor is connected to the outlet of the separator; a third cooler, wherein the inlet of the third cooler is connected to the outlet of the gas compressor; A storage tank, wherein the inlet of the storage tank is connected to the outlet of the third cooler.

9. The carbon dioxide capture in-situ conversion system according to claim 1, characterized in that: The in-situ conversion reaction includes one of in-situ methanation, in-situ reverse water gas shift, in-situ methanation dry / wet reforming, in-situ ethane partial dehydrogenation to ethylene, and in-situ methanolization.

10. The carbon dioxide capture in-situ conversion system according to claim 9, characterized in that: When the in-situ conversion reaction is in-situ methanation or in-situ reverse water gas shift, the reducing gas is hydrogen; When the in-situ conversion reaction is in-situ methanation dry / wet reforming, the reducing gas is methane.

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