A method for carbon dioxide capture, storage and transport

Abstract

The application discloses a method for carbon dioxide capture, storage and transportation. The method uses guanidine sulfate powder to selectively absorb carbon dioxide in a gas mixture or pure carbon dioxide. When carbon dioxide under a certain pressure is contacted with guanidine sulfate, the carbon dioxide reacts with the guanidine sulfate to form a carbon dioxide-guanidine sulfate clathrate. The application uses guanidine sulfate powder to achieve efficient and low-energy carbon dioxide capture. The obtained carbon dioxide-guanidine sulfate clathrate can realize carbon dioxide storage and transportation at normal temperature and pressure. Moreover, the carbon dioxide separated by the method has extremely high purity, and the carbon dioxide purity can reach 100% in theory.

Description

TECHNICAL FIELD

[0001] The present application relates to a method for carbon dioxide capture, storage and transportation, in particular a method for carbon dioxide capture, storage and transportation using guanidine sulfate solid powder as adsorbent. BACKGROUND

[0002] Carbon capture, utilization and storage (CCUS) is one of the key technologies to combat global climate change and is highly valued by countries around the world. Carbon dioxide is a major greenhouse gas and an important industrial product, widely used in chemical industry, welding, casting, food and preservation, etc. Capturing carbon dioxide at low cost and transporting it to the desired location not only reduces carbon emissions, but also creates economic value. In the CCUS industry chain, carbon dioxide storage and transportation are crucial and can make a significant contribution to reducing the impact of climate change. After capturing carbon dioxide from the production process, it needs to be safely and cost-effectively transported to the use location or stored, and at the same time, it needs to be controllably released with high-purity carbon dioxide. Currently, carbon dioxide storage and transportation mainly use liquid phase, which is divided into high-pressure gas cylinders at room temperature and low-pressure storage tanks at low temperature. However, the existing technology faces challenges and risks, with the disadvantages of slow filling speed, low transportation efficiency, complicated operation, environmental pollution, and the need for special containers. Safe methods are needed for storing and transporting carbon dioxide to avoid leaks and other environmental problems.

[0003] In summary, the current carbon dioxide capture and post-capture transportation and storage technology has the risk of high cost and low efficiency. This hinders the low-cost and efficient implementation of CCUC. SUMMARY

[0004] To solve the above technical problems, the present application provides a low-cost and efficient method for carbon dioxide capture, storage and transportation. To this end, the present application adopts the following technical solutions:

[0005] <1>. A method for carbon dioxide capture, storage and transportation, the method comprising: using guanidine sulfate powder to selectively absorb carbon dioxide in a gas mixture or pure carbon dioxide to obtain a carbon dioxide@guanidine sulfate sample.

[0006] <2>. The method of <1>, wherein the selective absorption comprises contacting the guanidine sulfate powder with carbon dioxide gas at different pressures.

[0007] <3>. The method of any one of the above, wherein the time required for the contacting depends on the carbon dioxide pressure, with higher pressure requiring less time for the contacting.

[0008] <4>. The method of any one of the above, wherein the time required for the contacting also depends on the ambient temperature at the time of the contacting.

[0009] <5>. The method according to any one of the above, wherein the contacting is carried out at room temperature.

[0010] <6>. The method according to claim 1, wherein the method further comprises heating the carbon dioxide @ guanidinium sulfate sample at a temperature range of 50-100°C to release high purity carbon dioxide.

[0011] <7>. The method according to any one of the above, wherein the method further comprises recycling the obtained guanidinium sulfate for the next round of carbon dioxide adsorption.

[0012] <8>. The method according to any one of the above, wherein the method comprises:

[0013] The carbon dioxide @ guanidinium sulfate sample is stored and / or transported at room temperature and normal pressure.

[0014] <9>. The method according to any one of the above, wherein the carbon dioxide @ guanidinium sulfate sample is stored in a plastic container or a glass container at room temperature for at least 30 days without carbon dioxide desorption.

[0015] <10>. The method according to any one of the above, wherein the guanidinium sulfate powder has the crystal structure parameters of a = b = c = 17.7640, α = β = γ = 90°, the chemical formula of [C(NH2)3]2SO4, and the CAS number of 594-14-9.

[0016] The method of the present application can be directly stored or transported after capturing carbon dioxide, and does not require high-cost containers such as steel cylinders or low-temperature equipment during transportation, and can store 60 times the volume of carbon dioxide at room temperature and normal pressure. High-purity carbon dioxide can be released by heating at a relatively low temperature, and the theoretical purity of carbon dioxide can reach 100%. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is the adsorption / desorption isotherm of solid guanidinium sulfate powder at 25°C in the range of 0-1.5 MPa, and the mass percentage of carbon dioxide in the powder after adsorbing carbon dioxide is 17%, wherein the mass percentage refers to the ratio of the mass of carbon dioxide to the total mass of the carbon dioxide @ guanidinium sulfate sample;

[0018] Figure 2 is the adsorption / desorption isotherm of solid guanidinium sulfate powder at 25°C in the range of 0-5 MPa, and the mass percentage of carbon dioxide in the powder after adsorbing carbon dioxide is 24%;

[0019] Figure 3 is the X-ray powder diffraction pattern of the guanidinium sulfate powder used in the examples of the present application and the obtained carbon dioxide @ guanidinium sulfate sample;

[0020] Figure 4 The thermogravimetric curve of carbon dioxide @ guanidine sulfate shows that it can release carbon dioxide by heating;

[0021] Figure 5 11.3g of guanidine sulfate powder stored 2.3g of carbon dioxide in a glass bottle at room temperature and pressure. DETAILED DESCRIPTION

[0022] To solve the shortcomings of existing carbon dioxide capture, storage and transportation technologies, the present inventors propose a method for carbon dioxide capture, storage and transportation, which fixes carbon dioxide molecules in the crystal lattice through suitable materials and can be directly used for storage and transportation. In the guanidine sulfate aqueous solution carbon dioxide capture technology disclosed (patent application number 202210271224.0), carbon dioxide under certain pressure is dissolved in the aqueous solution, and through supramolecular interaction with guanidine ions and sulfate ions in the solution, a clathrate is formed and precipitated to realize carbon dioxide capture. However, guanidine sulfate powder or crystal itself is not a porous material and cannot effectively adsorb nitrogen, hydrogen and other gases.

[0023] However, surprisingly, the carbon dioxide capture, storage and transportation technology of the present invention is achieved by using guanidine sulfate solid powder as the adsorbent for carbon dioxide. The inventors used, for example, crystalline guanidine sulfate solid powder (C2H 12 N6O4S, CAS number: 594-14-9) for carbon dioxide adsorption, and surprisingly obtained good technical effects for carbon dioxide capture, storage and transportation.

[0024] Therefore, the present disclosure provides a method for carbon dioxide capture, storage and transportation, in which guanidine sulfate powder is used as an adsorbent to selectively absorb carbon dioxide in a gas mixture or pure carbon dioxide to obtain a carbon dioxide @ guanidine sulfate sample. The term "gas mixture" refers to a gas mixture of carbon dioxide and at least one other gas. There is no particular limitation on the mass ratio of carbon dioxide in the gas mixture, for example, the mixture can contain 1-99% (mass percent) of carbon dioxide, and the higher the proportion of carbon dioxide, the easier the adsorption occurs.

[0025] In embodiments of this application, guanidine sulfate powder can be contacted with carbon dioxide gas at different pressures to form a carbon dioxide@guanidine sulfate sample, which is an inclusion complex. The pressure of the carbon dioxide primarily affects the rate of carbon dioxide absorption by the guanidine sulfate powder. According to the adsorption curve, adsorption of carbon dioxide can also occur at lower pressures below one atmosphere. However, preferably, the guanidine sulfate powder is contacted with carbon dioxide gas at higher pressures. For example, the pressure of the carbon dioxide gas can be 0.2 MPa, 0.5 MPa, 1 MPa, 2 MPa, 3 MPa, 6 MPa, etc., or any pressure range formed by these values ​​as endpoints, such as 0.5 MPa-2 MPa.

[0026] In embodiments of this application, guanidine sulfate powder can be contacted with carbon dioxide gas at different temperatures to form a carbon dioxide@guanidine sulfate sample. For example, the contact can be performed at room temperature or at an elevated temperature.

[0027] Appendix Figure 1 The low-pressure CO2 adsorption curve of guanidine sulfate powder at 25℃ is shown. Guanidine sulfate powder was heated to 100℃ and degassed under vacuum for 2 hours. The isothermal adsorption-desorption curves were then measured on a gas adsorption analyzer within the range of 0-15 bar (0-1.5 MPa) at 25℃, indicating that its adsorption capacity for carbon dioxide within this pressure range can reach 17%.

[0028] Appendix Figure 2 The high-pressure CO2 adsorption curve of guanidine sulfate powder at 25℃ is shown. Guanidine sulfate powder was heated to 100℃ and degassed under vacuum for 2 hours. The isothermal adsorption-desorption curves were then measured on a gas adsorption apparatus at 25℃ within the range of 0-50 bar (0-5 MPa), indicating that its adsorption capacity for carbon dioxide within this pressure range can reach 24% by mass.

[0029] Without being bound by any theory, the inventors of the present application believe that when the guanidine sulfate powder is exposed to a certain carbon dioxide pressure, carbon dioxide molecules diffuse into and are eventually fixed in the crystal lattice of guanidine sulfate, forming a carbon dioxide@guanidine sulfate sample, which is a solid powder. Unlike conventional porous physical adsorbents, the guanidine sulfate solid powder itself is a non-porous material and has no adsorption for nitrogen. Because carbon dioxide molecules have weak interactions with guanidinium ions in guanidine sulfate, they can diffuse into the crystal lattice of guanidine sulfate, forming a crystalline carbon dioxide@guanidine sulfate powder with long-range order and a fixed crystal structure. That is, the inventors of the present application believe that the present application is based on the supramolecular interaction between carbon dioxide molecules and guanidinium ions in guanidine sulfate. Under certain temperature and pressure conditions, carbon dioxide molecules can be effectively adsorbed, diffused and transported in non-porous solids, and can achieve an adsorption of up to 24% (carbon dioxide mass fraction). This technology is completely different from the adsorption of carbon dioxide by guanidine sulfate aqueous solution in science and technology, and the application fields include storage, transportation, carbon dioxide energy storage, etc.

[0030] The applicant believes that the process of adsorbing carbon dioxide by guanidine sulfate solid is completely different from that of adsorbing carbon dioxide by aqueous solution. In the process of adsorbing by aqueous solution, free guanidinium ions, sulfate ions and carbon dioxide molecules dissolved in water in the aqueous solution interact and crystallize and precipitate. For guanidine sulfate powder, carbon dioxide molecules diffuse into the non-porous crystal lattice of guanidine sulfate, while the positions of sulfate and guanidinium ions move, forming a new crystal structure of carbon dioxide@guanidine sulfate containing carbon dioxide molecules.

[0031] In the present application, the conditions under which guanidine sulfate solid powder successfully absorbs are speculated to be: a: supramolecular interaction with carbon dioxide molecules, without forming chemical bonds but being able to bind carbon dioxide molecules in the crystal lattice of the adsorbent. b: a large number of hydrogen bonds exist in the crystal structure of the adsorbent, because hydrogen bonds have a certain flexibility and flexibility, allowing carbon dioxide molecules to diffuse in the non-porous structure, and can form a stable structure after recombination.

[0032] The present application can obtain a carbon dioxide@guanidine sulfate sample with a carbon dioxide volume and mass ratio of up to 0.252 g·cm -3 and 17 wt% (Appendix Figure 1 ) under the condition of 25℃, 0-15 bar (0-1.5 Mpa) carbon dioxide gas pressure. The carbon dioxide@guanidine sulfate sample contains 60 times the volume of carbon dioxide gas under the same temperature and pressure conditions, and the pressure of carbon dioxide under the same temperature and volume reaches 6 Mpa (compression ratio 60), which proves the superiority of carbon dioxide storage and transportation. The adsorption curve at room temperature shows that the adsorption capacity can reach 24 wt% (Appendix Figure 2 ).

[0033] In embodiments of the present application, the obtained carbon dioxide@ guanidine sulfate sample is heated at a temperature range of 50-100°C to release high purity carbon dioxide. Moreover, after the release of high purity carbon dioxide, the obtained guanidine sulfate can be directly recycled for the next round of carbon dioxide adsorption.

[0034] In embodiments of the present application, the obtained carbon dioxide@ guanidine sulfate sample can be stored and / or transported under normal temperature and pressure. Moreover, no high-cost container such as a steel cylinder or low-temperature equipment is required during transportation. For example, the carbon dioxide@ guanidine sulfate sample after capturing carbon dioxide can be stored in a low-cost container such as plastic. Without being bound by any theory, the applicant believes that this is because the guanidine sulfate powder produced by the decomposition of the particle surface carbon dioxide@ guanidine sulfate coats the outside of the undecomposed carbon dioxide@ guanidine sulfate, preventing further decomposition of the internal carbon dioxide@ guanidine sulfate, thus greatly reducing the cost of carbon dioxide storage and transportation, while improving the safety of the process.

[0035] Figure 1 shows the powder X-ray diffraction pattern of the guanidine sulfate powder used in the present application and the obtained carbon dioxide@ guanidine sulfate clathrate. The guanidine sulfate powder was placed in a carbon dioxide environment of 1 MPa and 25°C, and after 12 h, the guanidine sulfate was completely converted to carbon dioxide@ guanidine sulfate. Figure 3 Figure 2 shows the thermogravimetric curve of the carbon dioxide@ guanidine sulfate clathrate. The carbon dioxide@ guanidine sulfate was placed in a thermogravimetric analyzer, and the heating rate was set to 10°C / min, and the mass gradually decreased as the carbon dioxide was released. It is proved that carbon dioxide can be released at a lower temperature.

[0036] Figure 4 Figure 3 shows the mass change diagram of guanidine sulfate before and after adsorbing carbon dioxide. A glass bottle containing 11.3 g of guanidine sulfate was placed in a carbon dioxide atmosphere of 2 MPa, and the temperature was set to 25°C. After standing for 24 h, it was taken out and weighed, and the mass increased to 13.6 g, of which the mass percentage of carbon dioxide was 16.9%.

[0037] The benefits of the present application compared to existing carbon dioxide capture, storage and transportation technologies are that the capture process is not affected by nitrogen and water vapor, etc., the obtained carbon dioxide@ guanidine sulfate powder after capture can be directly used for storage and transportation; no high-cost container such as a steel cylinder or low-temperature equipment is required during transportation, and 60 times the volume of carbon dioxide gas can be stored; high purity carbon dioxide can be released by heating at a lower temperature (for example, heating at a temperature range of 50-100°C), and the guanidine sulfate powder after the release of carbon dioxide can be directly used for new cycles. Figure 5

[0038] ​​​

[0039] In particular, compared with the inventor's previous work (carbon dioxide capture technology using aqueous guanidine sulfate solution (patent application number 202210271224.0, the entire contents of which are incorporated herein by reference), the benefits are that a: the process is simpler and does not require the introduction of water. b: after the solid guanidine sulfate powder absorbs carbon dioxide to form carbon dioxide@guanidine sulfate, there is no need to separate it from water, and it can be directly stored or transported. c: guanidine sulfate powder can be applied to carbon dioxide energy storage devices. Excess electrical energy is compressed into carbon dioxide by a compressor to enter the guanidine sulfate powder lattice, converting electrical energy into chemical energy. When there is a shortage of electrical energy, the carbon dioxide@guanidine sulfate powder is heated to release carbon dioxide to drive a turbine to convert chemical energy into electrical energy.

[0040] The application scenarios of the present application include but are not limited to:

[0041] 1. Capture and purification of carbon dioxide. Solid guanidine sulfate powder can selectively absorb carbon dioxide molecules, store carbon dioxide in the form of molecules in carbon dioxide@guanidine sulfate solid powder, and the capture process is not affected by water vapor and the like. The generated carbon dioxide@guanidine sulfate powder can be decomposed at a lower temperature to release high-purity carbon dioxide gas for use in food, electronic gas and other fields.

[0042] 2. Carbon dioxide storage and transportation. Carbon dioxide@guanidine sulfate can be stored and transported in low-cost containers such as plastic.

[0043] 3. In addition, it has potential in carbon dioxide energy storage, as the compression ratio of carbon dioxide in carbon dioxide@guanidine sulfate powder is as high as 60 compared with gaseous carbon dioxide at normal temperature and pressure, which greatly reduces the floor area of the gas storage system.

[0044] Embodiments

[0045] The present application will be further illustrated in more detail by the following examples.

[0046] The guanidine sulfate solid powder (C2H 12 N6O4S) used in the embodiments of the present application is from CAS No. 594-14-9 or 1184-68-5.

[0047] Example 1

[0048] Take 3 g of guanidine sulfate powder in a high-pressure reactor, replace the gas in the reactor with 1 MPa of carbon dioxide gas for 3 times, then set the gas pressure in the reactor to 1 MPa, close the high-pressure reactor valve. Let the reactor stand for 4 hours. After opening the reactor, the solid powder is weighed, the mass increases by 0.58 g, the mass percentage of adsorbed carbon dioxide is 16.2%, and the conversion rate is 95.3%. The conversion rate actually refers to the same below) the amount of substance actually converted to carbon dioxide guanidine sulfate and the amount of substance of carbon dioxide guanidine sulfate that should be theoretically obtained. The obtained solid powder is placed in a glass bottle, heated at 60°C to release carbon dioxide.

[0049] Example 2

[0050] Take 3 g of guanidine sulfate powder in a high-pressure reactor, replace the gas in the reactor with 0.5 MPa of carbon dioxide gas for 3 times, then set the gas pressure in the reactor to 0.5 MPa, close the high-pressure reactor valve. Let the reactor stand for 4 hours. After opening the reactor, the solid powder is weighed, the mass increases by 0.46 g, the mass percentage of adsorbed carbon dioxide is 13.29%, and the conversion rate is 78.2%. The obtained solid powder is placed in a glass bottle, heated at 60°C to release carbon dioxide.

[0051] Example 3

[0052] Take 3 g of guanidine sulfate powder in a high-pressure reactor, replace the gas in the reactor with 0.5 MPa of carbon dioxide gas for 3 times, then set the gas pressure in the reactor to 0.5 MPa, keep the high-pressure reactor valve connected to the carbon dioxide steel cylinder. Let the reactor stand for 2 hours. After opening the reactor, the solid powder is weighed, the mass increases by 0.54 g, the mass percentage of adsorbed carbon dioxide is 15.25%, and the conversion rate is 89.7%. The obtained solid powder is placed in a glass bottle, heated at 60°C to release carbon dioxide.

[0053] Example 4

[0054] Take 3 g of guanidine sulfate powder in a high-pressure reactor, replace the gas in the reactor with 2 MPa of mixed gas (15% carbon dioxide, 85% nitrogen) for 3 times, then set the gas pressure in the reactor to 2 MPa. Let the reactor stand for 4 hours. After opening the reactor, the solid powder is weighed, the mass increases by 0.52 g, the mass percentage of adsorbed carbon dioxide is 14.8%, and the conversion rate is 87.1%. The obtained solid powder is placed in a glass bottle, heated at 60°C to release carbon dioxide.

[0055] Example 5

[0056] Take 3g of guanidine sulfate powder into a high-pressure reactor, replace the gas in the reactor with 2Mpa mixed gas (15% carbon dioxide, 80% nitrogen, 5wt% water vapor) for 3 times, and then set the gas pressure in the reactor to 2MPa. Let the reactor stand for 4 hours. After opening the reactor, the solid powder is weighed, the mass increases by 0.51g, the mass percentage of adsorbed carbon dioxide is 14.5%, and the conversion rate is 85.3%. The obtained solid powder is placed in a glass bottle, and the carbon dioxide is released by heating at 60℃.

[0057] Example 6

[0058] The solid carbon dioxide-guanidine sulfate sample after capturing carbon dioxide is placed in a plastic bottle and the cap is tightened. The mass of the solid in the bottle is 27.8g, containing 4.70g of carbon dioxide, with a mass percentage of 16.9%. After being placed at room temperature for three days, the mass of the solid in the bottle is 27.6g, and the mass percentage of carbon dioxide is 16.3%. After being placed at room temperature for 10 days, the mass of the solid in the bottle is 27.5g, and the mass percentage of carbon dioxide is 16.0%. After being placed at room temperature for 30 days, the mass of the solid in the bottle is still 27.5g, and the mass percentage of carbon dioxide is 16.0%. The powder is heated to 50℃, and the carbon dioxide is completely released.

[0059] Example 6 demonstrates that the carbon dioxide-guanidine sulfate sample has potential application in carbon dioxide transportation and storage, as it can be stored at normal temperature and pressure in ordinary containers, with the amount of carbon dioxide remaining essentially unchanged. Example 6 also shows that the carbon dioxide-guanidine sulfate sample obtained by the present application can be stored in plastic containers or glass containers at room temperature for at least 30 days without or almost without carbon dioxide desorption.

[0060] The above merely illustrates the specific embodiments of the present disclosure, but the protection scope of the present disclosure is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present disclosure, which shall be covered within the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure shall be subject to the protection scope of the claims.

[0061] Industrial applicability

[0062] The present application realizes efficient and low-energy carbon dioxide capture using guanidine sulfate powder, and the obtained carbon dioxide-guanidine sulfate clathrate can realize carbon dioxide storage and transportation at normal temperature and pressure. Moreover, the carbon dioxide separated by the method of the present application has extremely high purity, and the theoretical purity of carbon dioxide can reach 100%. Therefore, the present application will have good industrial application prospects.

Claims

1. A method for carbon dioxide capture, storage, and transport, the method comprising: The carbon dioxide @ guanidine sulfate sample is obtained by absorbing carbon dioxide in a gas mixture or pure carbon dioxide using guanidine sulfate powder with crystal structure parameters: a = b = c = 17.7640, α = β = γ = 90°.

2. The method of claim 1, wherein the absorbing comprises contacting the guanidine sulfate powder with carbon dioxide gas at different pressures.

3. The method of claim 2, wherein the time required for the contacting depends on the carbon dioxide pressure, and the higher the pressure, the shorter the time required for the contacting.

4. The method of claim 2, wherein the time required for the contacting also depends on the ambient temperature at the time of the contacting.

5. The method of claim 2, wherein the contacting is performed at room temperature.

6. The method of claim 1, wherein the method further comprises: The carbon dioxide @ guanidine sulfate sample is heated at a temperature range of 50-100 °C to release high purity carbon dioxide.

7. The method of claim 6, wherein the method further comprises: The obtained guanidine sulfate is directly recycled for the next round of carbon dioxide absorption.

8. The method of claim 1, wherein the method comprises: The carbon dioxide @ guanidine sulfate sample is stored and / or transported at room temperature and pressure.

9. The method of claim 8, wherein the carbon dioxide @ guanidine sulfate sample is stored in a plastic container or a glass container at room temperature for at least 30 days without carbon dioxide desorption.

10. The method of claim 1, wherein the guanidine sulfate powder has a chemical formula of: [C(NH2)3]2SO4, and a CAS number of: 594-14-9.

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