Carbon dioxide capture device and carbon dioxide capture method

Abstract

The invention relates to the technical field of carbon dioxide trapping, and provides a carbon dioxide trapping device and a carbon dioxide trapping method.The carbon dioxide trapping method comprises the steps that raw material gas containing carbon dioxide is introduced into the interception side of an inorganic separation membrane for first separation treatment, and carbon dioxide in the raw material gas enters the permeation side through the inorganic separation membrane; the permeation side of the inorganic separation membrane is purged through purging airflow, permeation gas containing carbon dioxide is formed, and the purging airflow comprises ammonia gas and water vapor. The inorganic separation membrane is purged by the purging airflow containing ammonia gas and water, so that the separation efficiency and the recovery rate of the inorganic separation membrane are effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of carbon dioxide capture, in particular to a carbon dioxide capture device and a carbon dioxide capture method. BACKGROUND

[0002] The principle of separating carbon dioxide by membrane separation is based on the difference in diffusion rate of different gases in the membrane to realize separation. Under the driving action of pressure, the diffusion rates of each component in the mixed gas in the inorganic membrane are different, thereby realizing selective separation. Compared with high polymer polymeric membranes, inorganic membranes have the characteristics of long service life, high temperature resistance, high pressure resistance and good stability, and have broad application prospects. However, due to the limitation of the separation performance of single-stage membrane, it is necessary to increase the separation pressure and membrane area and the like to improve the recovery rate of inorganic separation membrane for carbon dioxide. Therefore, the way of separating carbon dioxide by inorganic membrane has high cost and low recovery rate. SUMMARY

[0003] Therefore, it is necessary to provide a carbon dioxide capture device and a carbon dioxide capture method with high recovery rate and low cost.

[0004] In a first aspect, the present application provides a carbon dioxide capture method, which comprises:

[0005] feeding raw gas containing carbon dioxide into the retention side of an inorganic separation membrane for first separation treatment, wherein the carbon dioxide in the raw gas penetrates into the permeation side through the inorganic separation membrane; and,

[0006] using a purge gas stream to purge the permeation side of the inorganic separation membrane to form a permeation gas containing carbon dioxide, wherein the purge gas stream comprises ammonia and water vapor.

[0007] In some embodiments, the molar ratio of ammonia to water vapor in the purge gas stream is 1: (5-10).

[0008] In some embodiments, the temperature of the purge gas stream is 100-200℃.

[0009] In some embodiments, the ratio of the volume flow rate of the purge gas stream to the volume flow rate of the raw gas is (0.2-0.6):1.

[0010] In some embodiments, the gas pressure of the retention side of the inorganic separation membrane is 0.3-1.0 MPa, and the temperature is 100-200℃.

[0011] In some embodiments, the gas pressure of the permeation side of the inorganic separation membrane is 0.08-0.12 MPa, and the temperature is 100-200℃.

[0012] In some embodiments, the carbon dioxide capture method further comprises: subjecting the permeate gas to a second separation process, the second separation process being configured to separate the permeate gas into carbon dioxide and an ammonia-containing solution.

[0013] Optionally, the second separation process is performed at a temperature of 20-25°C and a pressure of 0.08-0.12 MPa.

[0014] In some embodiments, the carbon dioxide capture method further comprises: subjecting the ammonia-containing solution to a third separation process, the third separation process being configured to separate the ammonia-containing solution into carbon dioxide and an aqueous ammonia solution.

[0015] Optionally, the third separation process is performed at a temperature of 50-70°C and a pressure of 0.08-0.12 MPa.

[0016] Optionally, the aqueous ammonia solution produced by the third separation process is recycled to be used as a raw material for the purge gas stream.

[0017] In some embodiments, the carbon dioxide capture method further comprises a drying process, the drying process being configured to dry and dehydrate the carbon dioxide produced by the second separation process.

[0018] Optionally, the drying process is further configured to dry and dehydrate the carbon dioxide produced by the third separation process.

[0019] In a second aspect, the present application provides a carbon dioxide capture device, the carbon dioxide capture device comprising:

[0020] a first separator comprising a housing and an inorganic separation membrane disposed in the housing, the inorganic separation membrane dividing the housing into a retention cavity and a permeation cavity, the retention cavity being configured to be fed with a raw gas containing carbon dioxide; and

[0021] a purger connected to the permeation cavity, the purger being configured to purge a side of the inorganic separation membrane close to the permeation cavity to form a permeate gas containing carbon dioxide, the purge gas stream blown by the purger comprising ammonia gas and water vapor.

[0022] In some embodiments, the carbon dioxide capture device further comprises a second separator connected to the permeation cavity, the second separator being configured to separate the permeate gas discharged from the permeation cavity to form carbon dioxide gas and an ammonia-containing solution.

[0023] In some embodiments, the carbon dioxide capture device further comprises a third separator connected to the second separator, the third separator being configured to separate the ammonia-containing solution to form an aqueous ammonia solution and carbon dioxide.

[0024] Optionally, the third separator is further connected with the purger, and the ammonia water solution discharged from the third separator enters the purger as raw material of the purge gas stream.

[0025] In some embodiments, the carbon dioxide capturing device further comprises a dryer, which is connected with the second separator, and the dryer is used for drying the carbon dioxide discharged from the second separator.

[0026] Optionally, the dryer is further connected with the third separator, and the dryer is used for drying the carbon dioxide discharged from the third separator.

[0027] Compared with the prior art, the present application has at least the following beneficial effects:

[0028] In the present application, the permeation side of the inorganic separation membrane is purged by the purge gas stream containing ammonia gas and water vapor, the carbon dioxide on the permeation side is absorbed by the acid-base reaction between ammonia gas and carbon dioxide, so as to reduce the carbon dioxide concentration on the permeation side, improve the separation speed of the inorganic separation membrane for carbon dioxide, and effectively improve the recovery rate of carbon dioxide. In addition, the permeation gas formed after purging can be separated to obtain high-purity carbon dioxide after cooling. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 Fig. 1 is a structural schematic diagram of a carbon dioxide capturing device according to an embodiment of the present application.

[0030] In the figure, 10 is a first separator; 11 is an inorganic separation membrane; 20 is a purger; 30 is a second separator; 40 is a third separator; and 50 is a dryer. DETAILED DESCRIPTION

[0031] The present application will be further described below in conjunction with embodiments and examples. These embodiments and examples are only used to explain the present application and not used to limit the scope of the present application. The purpose of providing these embodiments and examples is to make the disclosure of the present application more thoroughly and comprehensively understood. It should also be understood that the present application can be implemented in many different forms and is not limited to the embodiments and examples described herein. Those skilled in the art can make various modifications or changes without departing from the spirit and scope of the present application, and the equivalent forms obtained by the modifications or changes also fall within the protection scope of the present application. In addition, in the following description, a large number of specific details are given in order to provide a more complete understanding of the present application. It should be understood that the present application can be implemented without one or more of these details.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting of the application.

[0033] In the present application, "optionally", "optional", "option" means optional, that is, selected from "have" or "no" two parallel schemes. If there are multiple "optional" in a technical solution, unless otherwise specified, and there is no contradiction or mutual restriction, each "optional" is independent.

[0034] In the present application, the terms "first", "second", etc. in the "first aspect", "second aspect" and the like are only for the purpose of description, and cannot be understood as indicating or implying relative importance or quantity, nor can it be understood as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first", "second", etc. only serve the purpose of non-exhaustive enumeration description, and should be understood as not constituting a closed limitation on the quantity.

[0035] In the present application, the technical features described in an open manner include closed technical solutions consisting of listed features, and also include open technical solutions containing listed features.

[0036] In the present application, when referring to a numerical interval (i.e. a numerical range), unless otherwise specified, the distribution of optional values within the numerical interval is considered to be continuous, and includes both numerical endpoints (i.e. the minimum value and the maximum value) of the numerical interval, and every value between the two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to the integers within the numerical interval, including the two endpoint integers of the numerical range and every integer between the two endpoints, it is equivalent to directly listing each integer. When multiple numerical ranges are provided to describe a feature or characteristic, these numerical ranges can be combined. In other words, unless otherwise specified, the numerical range disclosed in the present application should be understood to include any and all sub-ranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. The "numerical interval" is allowed to be broadly interpreted as a quantitative interval, such as a percentage interval, a ratio interval, a ratio interval, etc.

[0037] All the documents mentioned in the present application are incorporated by reference into the present application as if each document was individually incorporated by reference. Unless and to the extent that the incorporated documents conflict with the application purpose and / or technical solutions of the present application, the incorporated documents are incorporated by reference in their entirety and for all purposes. When the present application refers to the incorporated documents, the definitions of the relevant technical features, terms, names, phrases, etc. in the incorporated documents are also incorporated by reference into the present application. When the present application refers to the incorporated documents, the examples and preferred modes of the relevant technical features are also incorporated by reference into the present application as far as the present application can be implemented. It should be understood that when the incorporated content conflicts with the description in the present application, the present application is given priority or is modified adaptively according to the description in the present application.

[0038] In the conventional technology, the permeation side of the carbon dioxide separation membrane can be purged to enhance the separation effect of the separation membrane. However, the introduction of the purge gas will affect the purity of the carbon dioxide on the permeation side, and if carbon dioxide gas is used for purging, the separation effect is improved to a low extent.

[0039] Based on this, the first aspect of the present application provides a carbon dioxide capture method, which comprises:

[0040] feeding a raw gas containing carbon dioxide into the retention side of an inorganic separation membrane for first separation treatment, and the carbon dioxide in the raw gas permeates into the permeation side through the inorganic separation membrane; and,

[0041] purging the permeation side of the inorganic separation membrane with a purge gas stream to form a permeation gas containing carbon dioxide, wherein the purge gas stream comprises ammonia gas and water vapor.

[0042] In the present application, the permeation side of the inorganic separation membrane is purged with a purge gas stream containing ammonia gas and water vapor, and the ammonia gas reacts with carbon dioxide to absorb the carbon dioxide on the permeation side, thereby reducing the concentration of carbon dioxide on the permeation side, improving the separation speed of the inorganic separation membrane for carbon dioxide, and effectively improving the recovery rate of carbon dioxide. In addition, the carbon dioxide in the permeation gas formed after purging can be obtained as high-purity carbon dioxide after cooling.

[0043] It should be noted that the inorganic separation membrane in the present application is a non-promoting transfer membrane, which can separate carbon dioxide by utilizing the difference in permeation rate of different gas molecules in the module hole. For example, the inorganic separation membrane can be at least one of a carbon molecular sieve membrane, a zeolite membrane, a porous ceramic membrane, and a MOF membrane. It can be understood that the appropriate inorganic separation membrane can be selected according to the composition of the raw gas.

[0044] In some embodiments, the volume percentage of carbon dioxide in the raw gas is 5% to 50%, for example, it can be 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45% or 50%.

[0045] In some embodiments, the molar ratio of ammonia gas to water vapor in the purge gas stream is 1:(5-10), for example, 1:5, 1:6, 1:7, 1:8, 1:9, or 1:10. The application selects the molar ratio of ammonia gas to water vapor in the purge gas stream as above, which effectively ensures the purging effect and avoids the problem of ammonia escape during desorption.

[0046] In some embodiments, the temperature of the purge gas stream is 100-200°C, for example, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, or 200°C. The application selects the temperature of the purge gas stream as above, which not only effectively ensures the stability of the inorganic separation membrane, but also has good purging effect.

[0047] In some embodiments, the ratio of the volume flow rate of the purge gas stream to the volume flow rate of the raw material gas is (0.2-0.6):1. The application selects the volume flow rate of the purge gas stream as above, which can improve the separation efficiency and avoid membrane surface concentration polarization and dilution of product gas CO2 concentration.

[0048] In some embodiments, the gas pressure on the retention side of the inorganic separation membrane is 0.3-1.0 MPa, for example, 0.3 MPa, 0.4 MPa, 0.5 MPa, 0.6 MPa, 0.7 MPa, 0.8 MPa, 0.9 MPa, or 1.0 MPa.

[0049] In some embodiments, the gas temperature on the retention side of the inorganic separation membrane is 100-200°C, for example, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, or 200°C.

[0050] In some embodiments, the gas pressure on the permeation side of the inorganic separation membrane is 0.08-0.12 MPa. Optionally, 0.1 MPa.

[0051] In some embodiments, the gas temperature on the permeation side of the inorganic separation membrane is 100-200°C, for example, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, or 200°C.

[0052] In some embodiments, the carbon dioxide capturing method further comprises: performing a second separation treatment on the permeate gas, the second separation treatment being configured to separate the permeate gas into carbon dioxide and an ammonia-containing solution. The present application separates the sweep gas mixed in the permeate gas through the second separation treatment, thereby obtaining high-purity carbon dioxide. It can be understood that the ammonia-containing solution contains part of the carbon dioxide and ammonium carbonate or bicarbonate salt.

[0053] Optionally, the temperature of the second separation treatment is 20-25°C, for example, 20°C, 21°C, 22°C, 23°C, 24°C or 25°C. The pressure of the second separation treatment is 0.08-0.12 MPa, optionally 0.1 MPa. Since the permeate gas contains carbon dioxide, ammonia and water vapor, after cooling, the ammonia is dissolved in water to form an ammonia water solution, and reacts with part of the carbon dioxide to form an ammonium bicarbonate solution, and the remaining most of the carbon dioxide gas can be obtained after drying to obtain high-purity carbon dioxide.

[0054] In some embodiments, the carbon dioxide capturing method further comprises: performing a third separation treatment on the ammonia-containing solution, the third separation treatment being configured to separate the ammonia-containing solution into carbon dioxide and an ammonia water solution. Since the ammonia-containing solution contains part of the carbon dioxide or contains carbonate salt, the carbon dioxide in the ammonium bicarbonate solution is separated out through the third separation, thereby further improving the recovery rate of carbon dioxide.

[0055] Optionally, the temperature of the third separation treatment is 50-70°C, for example, 50°C, 55°C, 60°C, 65°C or 70°C. The pressure is 0.08-0.12 MPa, optionally 0.1 MPa. The present application selects the temperature and pressure of the third separation treatment as described above, so that the ammonium bicarbonate solution can be decomposed into carbon dioxide gas and an ammonia water solution, thereby further separating the carbon dioxide and effectively improving the recovery rate of carbon dioxide.

[0056] Optionally, the third separation treatment adopts a desorption separation method.

[0057] Optionally, the ammonia water solution produced by the third separation treatment is heated to form ammonia gas and water vapor for recycling as raw materials of the sweep gas stream. The present application recycles the ammonia water solution produced by the third separation treatment, and the ammonia gas and water vapor formed by heating the ammonia water solution are used as raw materials of the sweep gas stream, thereby realizing recycling and reducing raw material costs. It can be understood that when the concentration of the ammonia water solution produced by the third separation treatment does not meet the use requirements, additional ammonia water can be introduced for adjustment.

[0058] In some embodiments, the carbon dioxide capturing method further comprises a drying treatment, the drying treatment being configured to dry and dehydrate the carbon dioxide produced by the second separation treatment.

[0059] Optionally, the drying treatment also dries and dehydrates the carbon dioxide generated by the third separation treatment.

[0060] Exemplarily, the carbon dioxide capture method is provided, comprising the following steps:

[0061] S1, the pressurized raw material gas is introduced into the retention side of the inorganic separation membrane, the temperature of the raw material gas is 100-200℃, and the pressure of the retention side of the inorganic separation membrane is 0.3-1.0 MPa.

[0062] S2, the permeation side of the inorganic separation membrane is purged by using a purge gas stream, the purge gas stream comprises ammonia and water vapor with a molar ratio of 1: (5-10), the volume ratio of the flow rate of the purge gas stream to the flow rate of the raw material gas in step S1 is (0.2-0.6):1, and the temperature is 100-200℃, the pressure of the permeation side of the inorganic separation membrane is 0.08-0.12 MPa.

[0063] S3, the carbon dioxide permeating through the inorganic separation membrane is mixed with the purge gas stream to form a permeation gas, the permeation gas is introduced into a second separator for separation, the temperature of the second separator is 20-25℃, the pressure is 0.08-0.12 MPa, and an ammonia-containing solution and carbon dioxide are formed.

[0064] S4, the ammonia-containing solution generated in step S3 is introduced into a third separator, the temperature of the third separator is 50-70℃, the pressure is 0.08-0.12 MPa, and an ammonia water solution and carbon dioxide are formed.

[0065] S5, the carbon dioxide generated in steps S3 and S4 is subjected to a drying treatment to obtain a carbon dioxide product.

[0066] S6, the ammonia water solution generated in step S4 is heated and used as a raw material of the purge gas stream for recycling.

[0067] The second aspect of the present application provides a carbon dioxide capture device, as shown in the accompanying drawings, which comprises: Figure 1

[0068] A first separator 10 comprises a shell and an inorganic separation membrane 11 arranged in the shell, the inorganic separation membrane 11 divides the shell into a retention cavity and a permeation cavity, the retention cavity is used for introducing a raw material gas containing carbon dioxide; and

[0069] ​A purger 20 is connected to the permeation cavity, and is used to purge the inorganic separation membrane 11 on the side close to the permeation cavity to form permeation gas containing carbon dioxide. The purging gas stream blown by the purger 20 comprises ammonia and water vapor.

[0070] The present application purges the permeation side of the inorganic separation membrane with the purging gas stream containing ammonia and water vapor, and effectively reduces the carbon dioxide concentration on the permeation side by the reaction between ammonia and carbon dioxide, thereby improving the separation effect of the inorganic separation membrane. Moreover, ammonia and water vapor are easy to separate from the permeation gas, for example, ammonia and water can be separated by cooling treatment, thereby obtaining high-purity carbon dioxide.

[0071] In some embodiments, the carbon dioxide capture device further comprises a second separator 30 connected to the permeation cavity, and the second separator 30 is used to separate the permeation gas discharged from the permeation cavity to form carbon dioxide gas and ammonia-containing solution. Optionally, the second separator 30 can be a cooling separation tank, which separates carbon dioxide in the gaseous state and ammonia and water in the liquid state from the permeation gas by cooling.

[0072] In some embodiments, the carbon dioxide capture device further comprises a third separator 40 connected to the second separator 30, and the third separator 40 is used to separate the ammonia-containing solution to form ammonia water solution and carbon dioxide. Optionally, the third separator 40 can be a desorption tower, which desorbs carbon dioxide from the ammonia-containing solution (containing ammonium bicarbonate, etc.) by heating desorption separation, and the carbonates such as ammonium carbonate also decompose under the action of heating, thereby improving the recovery rate of carbon dioxide.

[0073] Optionally, the third separator 40 is further connected to the purger 20, and the ammonia water solution discharged from the third separator 40 enters the purger 20 as raw material of the purging gas stream. The present application connects the ammonia water solution generated by the third separator 40 to the purger 20, realizes the cyclic regeneration and utilization of the purging gas stream, and reduces the raw material cost.

[0074] In some embodiments, the carbon dioxide capture device further comprises a dryer 50 connected to the second separator 30, and the dryer 50 is used to dry the carbon dioxide discharged from the second separator 30.

[0075] Optionally, the dryer 50 is further connected to the third separator 40, and the dryer 50 is used to dry the carbon dioxide discharged from the third separator 40.

[0076] The embodiments of the present application will be described in detail below with examples. It should be understood that these examples are only used to illustrate the present application and not used to limit the scope of the present application. The experimental methods in the following examples without specific conditions are preferred to refer to the guidance given in the present application, and can also be carried out according to the experimental manual or conventional conditions in the art, or according to the conditions suggested by the manufacturer, or according to the experimental methods known in the art.

[0077] In the following examples and comparative examples, the composition of the raw material gas is 15 vol% carbon dioxide and 85 vol% nitrogen. The inorganic separation membrane is a carbon molecular sieve membrane. The second separator is a cooling separation tank, and the third separator is a desorption tower.

[0078] Example 1

[0079] S1, the pressurized raw material gas is introduced into the retention side of the inorganic separation membrane, the temperature of the raw material gas is 200°C, and the pressure of the retention side of the inorganic separation membrane is 0.5 MPa.

[0080] S2, the permeation side of the inorganic separation membrane is purged with a purge gas stream, the purge gas stream comprises ammonia and water vapor in a molar ratio of 1:10, the volume ratio of the flow rate of the purge gas stream to the flow rate of the raw material gas in step S1 is 0.2:1, and the temperature is 200°C, the pressure of the permeation side of the inorganic separation membrane is 0.1 MPa.

[0081] S3, the carbon dioxide permeating through the inorganic separation membrane is mixed with the purge gas stream to form a permeation gas, the permeation gas is introduced into the second separator for separation, the temperature of the second separator is 25°C, and the pressure is 0.1 MPa, forming an ammonia-containing solution (containing ammonium bicarbonate, etc.) and carbon dioxide.

[0082] S4, the ammonia-containing solution produced in step S3 is introduced into the third separator, the temperature of the third separator is 70°C, and the pressure is 0.1 MPa, forming an ammonia water solution and carbon dioxide.

[0083] S5, the carbon dioxide produced in steps S3 and S4 is subjected to drying treatment to obtain carbon dioxide product.

[0084] S6, the ammonia water solution produced in step S4 is heated and used as a raw material for the purge gas stream for recycling.

[0085] Comparative Example 1

[0086] According to the carbon dioxide capture method of Example 1, carbon dioxide is recovered, the difference being that no purge gas stream is used for purging.

[0087] The purity and recovery rate of the carbon dioxide recovered from the above-mentioned Example 1 and Comparative Example 1 were detected. The volume purity of the carbon dioxide recovered from the present application Example 1 was 91%, and the recovery rate was 70% (single-stage membrane separation), while the volume purity of the carbon dioxide recovered from Comparative Example 1 was 90%, and the recovery rate was 60% (single-stage membrane separation). The recovery rate refers to the ratio of the recovered carbon dioxide to the carbon dioxide content in the raw material.

[0088] In summary, the present application uses a sweep gas stream containing ammonia and water vapor to sweep the permeation side of the inorganic separation membrane, uses the acid-base reaction between ammonia and carbon dioxide to absorb the carbon dioxide on the permeation side, thereby reducing the carbon dioxide concentration on the permeation side, improving the separation speed of the inorganic separation membrane for carbon dioxide, and effectively improving the recovery rate of carbon dioxide. In addition, the carbon dioxide in the permeation gas formed after sweeping is easy to separate, for example, high-purity carbon dioxide can be obtained by simply cooling.

[0089] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description simple, all possible combinations of the technical features in the above-mentioned embodiments are not described, however, as long as the combination of the technical features does not exist contradictory, it should be considered as the scope of the present application.

[0090] The above-mentioned embodiments only express several implementation manners of the present application, the description is more specific and detailed, but it should not be understood as a limitation on the scope of the application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A method of carbon dioxide capture, characterized by, The carbon dioxide capturing method comprises: feeding a raw gas containing carbon dioxide into a retentate side of an inorganic separation membrane to perform a first separation treatment, carbon dioxide in the raw gas permeating through the inorganic separation membrane into a permeate side; and a sweep gas stream is used to sweep the permeate side of the inorganic separation membrane to form a permeate gas containing carbon dioxide, the sweep gas stream comprising ammonia and water vapor.

2. The carbon dioxide capture process of claim 1, wherein, The sweep gas stream satisfies at least one of the following conditions: (1) the molar ratio of ammonia to water vapor in the sweep gas stream is 1:(5-10); (2) the temperature of the sweep gas stream is 100-200℃; (3) the ratio of the volume flow rate of the sweep gas stream to the volume flow rate of the raw gas is (0.2-0.6):

1.

3. The carbon dioxide capture method of claim 1, wherein, The carbon dioxide capturing method satisfies at least one of the following conditions: (1) the gas pressure of the retentate side of the inorganic separation membrane is 0.3-1.0 MPa, and the temperature is 100-200℃; (2) the gas pressure of the permeate side of the inorganic separation membrane is 0.08-0.12 MPa, and the temperature is 100-200℃.

4. The carbon dioxide capture process according to any one of claims 1 to 3, wherein, The carbon dioxide capturing method further comprises: performing a second separation treatment on the permeate gas, the second separation treatment being used to separate the permeate gas to form carbon dioxide and an ammonia-containing solution; Optionally, the temperature of the second separation treatment is 20-25℃, and the pressure is 0.08-0.12 MPa.

5. The carbon dioxide capture method of claim 4, wherein, The carbon dioxide capturing method further comprises: performing a third separation treatment on the ammonia-containing solution, the third separation treatment being used to separate the ammonia-containing solution to form carbon dioxide and an aqueous ammonia solution; Optionally, the temperature of the third separation treatment is 50-70℃, and the pressure is 0.08-0.12 MPa; Optionally, the aqueous ammonia solution produced by the third separation treatment is recycled and used as the raw material of the sweep gas stream.

6. The carbon dioxide capture method of claim 5, wherein, The carbon dioxide capturing method further comprises a drying treatment, the drying treatment being used to dry and dehydrate the carbon dioxide produced by the second separation treatment; Optionally, the drying treatment is also used to dry and dehydrate the carbon dioxide produced by the third separation treatment.

7. A carbon dioxide capture device, characterized by, The carbon dioxide capturing device comprises: a first separator comprising a shell and an inorganic separation membrane arranged in the shell, the inorganic separation membrane dividing the inner cavity of the shell into a retentate cavity and a permeate cavity, the retentate cavity being used to feed a raw gas containing carbon dioxide; and a sweeper connected to the permeate cavity, the sweeper being used to sweep the side of the inorganic separation membrane close to the permeate cavity to form a permeate gas containing carbon dioxide, the sweep gas stream blown out by the sweeper comprising ammonia and water vapor.

8. The carbon dioxide capture device of claim 7, wherein, The carbon dioxide capturing device further comprises a second separator connected to the permeate cavity, the second separator being used to separate the permeate gas discharged from the permeate cavity to form carbon dioxide gas and an ammonia-containing solution.

9. The carbon dioxide capture device of claim 8, wherein, The carbon dioxide capturing device further comprises a third separator connected to the second separator, the third separator being used to separate the ammonia-containing solution to form an aqueous ammonia solution and carbon dioxide. Optionally, the third separator is further connected with the purger, and the ammonia water solution discharged from the third separator enters the purger as raw material of the purge gas flow.

10. The carbon dioxide capture device of claim 9, wherein, The carbon dioxide capturing device further comprises a dryer, which is connected with the second separator, and the dryer is used for drying the carbon dioxide discharged from the second separator. Optionally, the dryer is further connected with the third separator, and the dryer is used for drying the carbon dioxide discharged from the third separator.

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