Method for doubly sealing CO2 by using solid waste chemical reaction and physical bubbles

Abstract

The invention belongs to the technical field of carbon dioxide sequestration, and particularly relates to a method for double sequestration of CO2 by utilizing solid waste chemical reaction and physical bubbles, the method comprises the following steps: mixing a carbon sequestration material and water to obtain slurry, the chemical components of the carbon sequestration material comprise calcium oxide, silicon oxide, aluminum oxide, iron oxide and / or magnesium oxide; when the slurry is in a stirring state, introducing carbon dioxide gas into the slurry in a closed reaction container; naturally solidifying the slurry into which the carbon dioxide gas is introduced, so that the carbon dioxide gas is sealed in the carbon sequestration material in a physical bubble form and a carbonate form to obtain a carbon dioxide sealing material; and the carbon sequestration efficiency of sequestration can be improved.

Description

Technical Field

[0001] This application relates to the technical field of carbon dioxide sequestration, and more specifically, to a method for dual sequestration of CO2 using solid waste chemical reactions and physical bubbles. Background Art

[0002] Disclosing the information of this background art section is intended to enhance the understanding of the overall background of the present invention, and is not necessarily to be regarded as an admission or any form of implication that this information constitutes the prior art already known to those of ordinary skill in the art.

[0003] In recent years, the large-scale emission of carbon dioxide (CO2) has become one of the main factors leading to climate change, environmental damage, and global warming. The global carbon dioxide emissions reached as high as 40.6 billion tons in 2023, and the problem of global warming caused by greenhouse gas emissions is becoming increasingly serious. It is predicted that by 2040, the overall global temperature rise will exceed 1.5 °C, which may then bring dangerous challenges such as extreme climates, glacier melting, and ecological environment damage. To address this challenge, countries around the world are actively taking measures to promote carbon dioxide emission reduction, utilization, and sequestration.

[0004] Carbon dioxide capture, utilization, and sequestration (CCUS) technology is considered to be an important way to address the carbon dioxide emission problem and achieve the carbon neutrality goal at present. CCUS technology mainly includes CO2 capture technology, CO2 utilization technology, and CO2 sequestration technology. Among them, CO2 sequestration technology is mainly divided into geological sequestration, ocean sequestration, and mineralization sequestration. Geological sequestration is to inject CO2 into geological structures such as underground oil fields, gas fields, and saline aquifers for sequestration. Although this can effectively reduce CO2 emissions, there are potential leakage risks, formation deformation, and other safety hazards. Ocean sequestration is to inject CO2 deep into the seabed for sequestration. Although it has a large sequestration potential, its cost is high and it may cause environmental problems such as ocean acidification. Therefore, CO2 mineralization sequestration, as a long-term stable and environmentally friendly sequestration method, has received extensive attention in recent years.

[0005] The principle of CO2 mineralization and storage technology is to generate stable carbonate minerals through the reaction of carbon dioxide with minerals. CO2 mineralization and storage technology can be divided into dry mineralization and wet mineralization. Currently, the commonly used and more effective one is wet mineralization technology. The key to mineralization and storage technology lies in the selection of mineral raw materials. Natural minerals are not suitable for the current large-scale carbon sequestration requirements due to their high mining and transportation costs. Therefore, researchers have begun to explore the use of industrial solid wastes to replace natural minerals for mineralization and storage. Alkaline industrial solid wastes (such as fly ash, steel slag, carbide slag, etc.) have high mineralization potential. Yi Yuanrong et al. used fly ash from power plant combustion as the carrier of carbon sequestration material, and the carbon sequestration efficiency obtained at room temperature was only 0.08%; Chang et al. used steel slag as the carrier of carbon sequestration material, and under high-pressure conditions, the carbon sequestration efficiency obtained was 12.7%; Wu Ge et al. conducted carbon sequestration research using fly ash and steel slag from power plant combustion, and obtained a carbon sequestration efficiency of 1.23% for fly ash and 14.94% for steel slag respectively. Thus, it can be seen that relying solely on CO2 mineralization and storage technology for CO2 storage has low efficiency and is still insufficient to meet the actual carbon sequestration needs. Summary of the Invention

[0006] The present application is provided to solve the above-mentioned defects existing in the prior art. A method for dual storage of CO2 using solid waste chemical reaction and physical bubbles is needed, which can solve the problem of low carbon sequestration efficiency of CO2 mineralization and storage.

[0007] In the first aspect of the present application, a method for dual CO2 mineralization - bubble storage is provided. The method includes: mixing a carbon sequestration material and water to obtain a slurry; while the slurry is in a stirred state, introducing carbon dioxide gas into the slurry in a closed reaction vessel; allowing the slurry after introducing carbon dioxide gas to solidify naturally, so that the carbon dioxide gas is stored in the carbon sequestration material in the form of physical bubbles and in the form of carbonates, to obtain a carbon dioxide storage material.

[0008] In the present invention, before introducing carbon dioxide gas into the slurry, it is dispersed and refined to obtain carbon dioxide microbubbles, and the carbon dioxide microbubbles are introduced into the slurry.

[0009] In the present invention, the volume ratio of the carbon sequestration material to water is 1 - 3:1.

[0010] In the present invention, a shower structure is provided at the gas inlet of the reaction vessel, or the gas inlet of the reaction vessel is connected to an ultrasonic bubble crusher for dispersing and refining carbon dioxide.

[0011] In the present invention, the introduction amount of carbon dioxide microbubbles is 0.3 - 1 L / min.

[0012] In the present invention, the time for introducing carbon dioxide microbubbles while the slurry is in a stirred state is 1 - 3 h.

[0013] In the present invention, the natural solidification time of the slurry after introducing carbon dioxide gas is 2 - 5 days.

[0014] In the present invention, the carbon sequestration material includes waste coal gangue, slag and / or mine filling in the mined - out area of the mine; the chemical composition of the carbon sequestration material includes calcium oxide, silicon oxide, aluminum oxide, iron oxide and / or magnesium oxide.

[0015] In the present invention, the mass concentration of carbon dioxide in the carbon dioxide gas is 70 - 100%.

[0016] In the present invention, the volume of the physical carbon dioxide bubbles in the carbon dioxide sequestration material is 1 - 3 mm 3 。

[0017] In the method for dual sequestration of carbon dioxide mineralization - bubbles provided by each embodiment of the present application, a slurry is obtained from the carbon sequestration material and water. The chemical composition of the carbon sequestration material includes calcium oxide, silicon oxide, aluminum oxide, iron oxide and / or magnesium oxide, so that metal hydroxides are formed in the slurry. Under the stirring state, carbon dioxide gas is fully mixed into the slurry. After the natural solidification process, part of the carbon dioxide gas combines with the carbon sequestration material in the form of carbonate, and due to the material of the carbon sequestration material, part of the carbon dioxide gas is sequestered therein and will not escape, improving the carbon sequestration efficiency of the sequestration. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In the drawings, which are not necessarily to scale, the same reference numerals may describe similar components in different views. The same reference numerals with alphabetical suffixes or different alphabetical suffixes may represent different instances of similar components. The drawings generally illustrate various embodiments by way of example and not limitation, and are used together with the description and the claims to explain the embodiments of the application being claimed. Where appropriate, the same reference numerals are used throughout the drawings to refer to the same or similar parts. Such embodiments are illustrative and not intended to be an exhaustive or exclusive embodiment of the apparatus or method.

[0019] Figure 1 Shows a comparison chart of carbon sequestration rates according to an embodiment of the present application.

[0020] Figure 2 Shows the physical carbon sequestration effect diagram according to an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] To enable those skilled in the art to better understand the technical solutions of the present application, the present application will be described in detail below in conjunction with the drawings and specific embodiments. The embodiments of the present application will be further described in detail below in conjunction with the drawings and specific examples, but shall not be construed as a limitation to the present application.

[0022] The "first", "second" and similar terms used in this application do not denote any order, quantity or importance, but are merely used for distinction. Terms such as "comprising" or "including" mean that the elements before this term cover the elements listed after this term, and do not exclude the possibility of also covering other elements.

[0023] According to an embodiment of the present application, a method for double-sealing CO2 by using solid waste chemical reaction and physical bubbles is provided. The method includes: mixing a carbon sequestration material and water to obtain a slurry, and the chemical composition of the carbon sequestration material includes calcium oxide, silicon oxide, aluminum oxide, iron oxide and / or magnesium oxide; while the slurry is in a stirred state, in a closed reaction vessel, introducing carbon dioxide gas into the slurry; the slurry after introducing the carbon dioxide gas is allowed to naturally solidify, so that the carbon dioxide gas is sealed in the carbon sequestration material in the form of physical bubbles and in the form of carbonates, to obtain a carbon dioxide sequestration material.

[0024] After the carbon sequestration material and water are mixed, at least part of calcium oxide, aluminum oxide, iron oxide and / or magnesium oxide in the carbon sequestration material is hydrolyzed to obtain metal hydroxides. The process of introducing carbon dioxide gas can be carried out in a stirred reaction vessel, introducing carbon dioxide gas while stirring, so that the carbon dioxide gas and the slurry are fully mixed, and a process in which carbon dioxide reacts to form carbonates and metal hydroxides can occur partially. During the natural solidification process, the slurry gradually solidifies and coats the internal carbon dioxide gas. In this way, in addition to forming carbonates, carbon dioxide existing in the form of physical bubbles can also be sealed, improving the carbon sequestration rate.

[0025] In some embodiments, the solidification of the slurry can be carried out in air. For example, the slurry can be poured into a mold and placed in air for natural solidification.

[0026] In some embodiments, before the carbon dioxide gas is introduced into the slurry, it is dispersed and refined to obtain carbon dioxide microbubbles, and the carbon dioxide microbubbles are introduced into the slurry. Smaller carbon dioxide microbubbles can exist more stably in the slurry, perform physical sequestration, and can be fully dispersed in the slurry, and can also fully react with the slurry to perform chemical sequestration.

[0027] If the carbon dioxide is not introduced into the slurry in the form of carbon dioxide microbubbles, larger bubbles have poor dispersibility in the slurry and a faster rising speed, and will quickly escape from the surface of the slurry. This will not only reduce the rate of the mineralization reaction, thereby affecting the carbon sequestration rate of chemical sequestration, but also lead to a decrease in the number of physical bubbles coated with carbon dioxide and uneven distribution, thus significantly reducing the carbon sequestration rate in the form of bubbles. (Affect the carbon sequestration rate in the form of bubbles).

[0028] In some embodiments, the volume ratio of the carbon sequestration material to water is 1-3:1. Adding an appropriate proportion of water enables the carbon sequestration material to form a slurry, so that after natural solidification, it can achieve better carbon dioxide sequestration. The obtained carbon dioxide sequestration material contains solid carbonate and interacts with carbon dioxide microbubbles to form a rich pore structure for storing carbon dioxide microbubbles.

[0029] A shower structure is provided at the gas inlet of the reaction vessel, or the gas inlet of the reaction vessel is connected to an ultrasonic bubble crusher. Further, the aperture of the shower is 0.5-1 mm; the set parameters of the ultrasonic bubble crushing are a frequency of 20-50 kHz and a power of 50-80%.

[0030] In some embodiments, the gas flow rate of the carbon dioxide microbubbles is 0.3-1 L / min. The carbon dioxide microbubbles should not be too large or too small, otherwise it may affect the uniformity of the carbon dioxide microbubbles and reduce the carbon sequestration rate.

[0031] In some embodiments, the time for introducing carbon dioxide microbubbles into the slurry under stirring is 1-3 h. This allows an appropriate amount of carbon dioxide to be introduced into the slurry, and overmixing and overstirring should be avoided, otherwise the sequestration effect of the carbon dioxide microbubbles will be reduced.

[0032] In some embodiments, the time for natural solidification of the slurry after introducing carbon dioxide gas is 2-5 days. For example, 3 days or 4 days, etc., to allow the slurry to solidify fully and form a stable solid structure.

[0033] In some embodiments, the carbon sequestration material includes waste coal gangue, slag, and / or mine filling materials in mined-out areas of mines.

[0034] In some embodiments, the mass concentration of carbon dioxide in the carbon dioxide gas is 70-100%. The method of the present application can sequester carbon dioxide gas with a relatively high concentration.

[0035] In some embodiments, the volume of the carbon dioxide physical bubbles in the carbon dioxide sequestration material is 1-3 mm 3 。

[0036] In some embodiments, the carbon sequestration material is ground before mixing with water. This may include processes such as crushing, coarse grinding, and / or fine grinding. To mix more fully with carbon dioxide microbubbles and form a carbon dioxide sequestration material with a better density in the solidified state.

[0037] The gas refinement and dispersion device involved in each of the following embodiments is an ultrasonic bubble crusher. The set parameters of the ultrasonic bubble crusher are a frequency of 30 kHz and a power of 50%.

[0038] The calculation method of the carbon sequestration rate in this application is: (the amount of carbon dioxide sealed in the carbon sequestration material / the amount of carbon dioxide introduced into the reaction vessel) × 100%.

[0039] Example 1 The carbon sequestration material is a mixed slag produced during the mining process of a mine in Xinjiang, consisting of waste coal gangue and slag. The specific composition is shown in Table 1; the CO2 source used is a gas with a CO2 concentration of 80 - 95% extracted from the waste gas generated by a power plant during combustion.

[0040] Table 1 Main chemical components of the mixed slag (mass fraction%) The mixed slag is crushed and finely ground to a uniform small particle size state; according to the mass ratio of the mixed slag to water of 2:1, it is fully stirred and mixed in a closed stirring cylinder with a diameter of 1 meter and a height of 1.5 meters; after stirring for 20 minutes until the slurry is uniform, CO2 gas is introduced into the slurry at a rate of 1 L / min, and a gas refining and dispersing device is used to ensure that the CO2 gas is input in a dispersed and refined state. The whole process lasts for 2 hours; after the ventilation is completed and stirred evenly, the slurry is poured into a solidification mold for solidification.

[0041] After waiting for 3 days for solidification, the obtained solid sequestration material is detected, and it is observed that there are small CO2 physical bubbles evenly distributed inside. The volume of the carbon dioxide physical bubbles is 1 - 3 mm 3 , and the composition of the material contains a high content of carbonate components. The CO2 chemical sequestration rate achieved by the mineralization reaction reaches 12%, and the CO2 physical sequestration rate achieved by the bubbles reaches 30%. The overall carbon sequestration rate reaches 42%.

[0042] Example 2 The carbon sequestration material is the mine filling material used for gob filling in a mine in Inner Mongolia. The specific composition is shown in Table 2; the CO2 source used is a gas with a CO2 concentration of 80 - 95% extracted from the waste gas generated by a power plant during combustion.

[0043] Table 2 Main chemical components of the mine filling material (mass fraction%) The mine filling material is crushed and finely ground to a uniform small particle size state; according to the mass ratio of mine filling material to water of 2:1, it is fully stirred and mixed in a closed stirring cylinder with a diameter of 1 meter and a height of 1.5 meters; after stirring for 20 minutes until the slurry is uniform, CO2 gas is introduced into the slurry at a rate of 1 L / min, and a gas refinement and dispersion device is used to ensure that the CO2 gas is input in a dispersed and refined state, and the whole process lasts for 2 hours; after the ventilation is completed and stirred evenly, the slurry is poured into a solidification mold for solidification; after waiting for 3 days of solidification, the obtained solid sequestration material is detected, and it is observed that there are small CO2 physical bubbles uniformly distributed inside, and the volume of the carbon dioxide physical bubbles is 1 - 3 mm 3 。

[0044] Since the CaO content of the mine filling material is 21.03% and the calcium element content is relatively low, the CO2 chemical sequestration rate achieved by the mineralization reaction is 6%. However, the CO2 physical sequestration rate achieved by bubble sequestration reaches 28%, which improves the final carbon sequestration efficiency, and the overall carbon sequestration rate reaches 34%.

[0045] Comparative Example 1 CO2 gas is directly introduced into the slurry at a rate of 1 L / min without being dispersed and refined by a gas refinement and dispersion device. Other operation steps are the same as those in Example 1. The CO2 chemical sequestration rate achieved by the mineralization reaction is 8%; since the bubbles are not subjected to dispersion and refinement treatment, no uniformly distributed CO2 physical bubbles are found inside, and only a few bubbles with poor dispersion and different sizes exist. The CO2 physical sequestration rate achieved by bubble sequestration is only 3%, and the overall carbon sequestration rate is 11%.

[0046] Comparative Example 2 The carbon sequestration material is a mixture of cement and fly ash, and the mass ratio of cement to fly ash is 1:1.

[0047] The mixture of cement and fly ash is finely ground to a uniform small particle size state; according to the mass ratio of the mixed slag to water of 2:1, it is fully stirred and mixed in a closed stirring cylinder with a diameter of 1 meter and a height of 1.5 meters; after stirring for 20 minutes until the slurry is uniform, CO2 gas is introduced into the slurry at a rate of 1 L / min, and a gas refinement and dispersion device is used to ensure that the CO2 gas is input in a dispersed and refined state, and the whole process lasts for 2 hours; after the ventilation is completed and stirred evenly, the slurry is poured into a solidification mold for solidification.

[0048] After waiting for 3 days of solidification, the obtained solid sequestration material is detected, and it is observed that there are small CO2 physical bubbles uniformly distributed inside, and the volume of the carbon dioxide physical bubbles is 1 - 3 mm 3, and the composition of the material contains a high content of carbonate components. The chemical CO2 sequestration rate achieved through the mineralization reaction is 11%. The physical CO2 sequestration rate achieved through bubble sequestration reaches 26%, and the overall carbon sequestration rate is 37%.

[0049] In addition, although exemplary embodiments have been described herein, the scope includes any and all embodiments based on this application that have equivalent elements, modifications, omissions, combinations (e.g., solutions that cross various embodiments), adaptations, or alterations. The elements in the claims will be broadly interpreted based on the language used in the claims and are not limited to the examples described in this specification or during the implementation of this application, and the examples will be interpreted as non-exclusive. Thus, this specification and the examples are intended to be considered only as examples, and the true scope and spirit are indicated by the following claims and the full scope of their equivalents.

[0050] The above description is intended to be illustrative rather than restrictive. For example, the above examples (or one or more of them) can be used in combination with each other. For example, those of ordinary skill in the art can use other embodiments when reading the above description. Additionally, in the above detailed description, various features can be grouped together to simplify this application. This should not be construed as an intention that a feature not claimed in the application is necessary for any claim. Instead, the subject matter of this application can be less than all the features of a particular embodiment of the application. Thus, the following claims are incorporated herein as examples or embodiments into the detailed description, where each claim independently serves as a separate embodiment, and considering these embodiments, they can be combined with each other in various combinations or arrangements. The scope of the present invention should be determined with reference to the appended claims and the full scope of the equivalent forms empowered by these claims.

[0051] The above embodiments are only exemplary embodiments of this application and are not used to limit the present invention. The protection scope of the present invention is defined by the claims. Those skilled in the art can make various modifications or equivalent replacements within the essence and protection scope of this application, and such modifications or equivalent replacements should also be regarded as falling within the protection scope of the present invention.

Claims

1. A method for dual CO2 storage using solid waste chemical reaction and physical bubbles, characterized in that: The method comprises: The carbon-fixing material and water are mixed to obtain a slurry; While the slurry is in a stirring state, in a closed reaction container, introducing carbon dioxide gas into the slurry; The slurry after the introduction of carbon dioxide gas is naturally solidified, so that the carbon dioxide gas is sealed in the carbon-fixing material in the form of physical bubbles and carbonates, thereby obtaining a carbon dioxide sealing material.

2. The method according to claim 1, characterized in that Before the carbon dioxide gas is introduced into the slurry, it is dispersed and refined to obtain carbon dioxide microbubbles, and the carbon dioxide microbubbles are introduced into the slurry.

3. The method according to claim 1, characterized in that: The volume ratio of the carbon-fixing material to water is 1-3:

1.

4. The preparation method according to claim 2, characterized in that: A shower structure is arranged at the air inlet of the reaction container, or an ultrasonic bubble crusher is connected to the air inlet of the reaction container to disperse and refine the carbon dioxide.

5. The method according to claim 2, characterized in that: The amount of carbon dioxide microbubbles introduced is 0.3-1L / min.

6. The method according to claim 2, characterized in that The time for introducing carbon dioxide microbubbles into the slurry while it is in a stirring state is 1-3 hours.

7. The method according to claim 1, characterized in that The slurry after the introduction of carbon dioxide gas undergoes natural solidification for 2-5 days.

8. The method according to claim 1, characterized in that: The carbon-fixing material includes waste coal gangue, slag and / or mine fillers in mine goafs; the chemical composition of the carbon-fixing material includes calcium oxide, silicon oxide, aluminum oxide, iron oxide and / or magnesium oxide.

9. The method according to claim 1, characterized in that: The mass concentration of carbon dioxide in carbon dioxide gas is 70-100%.

10. The method according to claim 1, characterized in that The volume of the carbon dioxide physical bubbles in the carbon dioxide storage material is 1-3 mm 3 .

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