CO2 capture-mineralization integrated material as well as preparation method and application thereof

Abstract

The invention discloses a CO2 capture-mineralization integrated material and a preparation method and application thereof.The preparation method includes the steps that fly ash, an ore guiding agent and alkaline matter are evenly mixed according to the mass ratio of (1-10): (1-4): (0.5-2) to obtain a solid mixture, and in the ore guiding agent, the mass ratio of tetracalcium sulphoaluminate to dicalcium silicate to calcium sulfate dihydrate is (10-20): (5-10): (70-80); uniformly mixing the solid mixture with water according to a mass ratio of the water to the fly ash of (4-10): 1 to obtain a solid-liquid mixture; and reacting the solid-liquid mixture at 30-70 DEG C in a sealed and air-isolated manner for 4-8 hours, carrying out solid-liquid separation on the reaction product, and drying to obtain the product. According to the method for preparing the CO2 trapping-mineralizing integrated material by utilizing the fly ash, active Al and Si in the fly ash are activated to form minerals with high specific surface area through the induction activation action of the ore guiding agent and the alkaline substance, so that the diffusivity of CO2 is improved, the trapping efficiency and total trapping amount of CO2 are improved, and the CO2 trapping-mineralizing integrated material is prepared. And the CO2 trapping-mineralizing integrated material has excellent CO2 trapping and in-situ mineralizing capabilities.

Description

Technical Field

[0001] The present invention belongs to the technical field of carbon dioxide capture materials and specifically relates to a CO 2 Integrated capture-mineralization material and its preparation method and application. Background Art

[0002] The statements herein merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] In the existing carbon fixation technology, the fly ash modified material method mainly includes a slurry-formed mineralization process, and does not involve an adsorption-mineralization coupling method. Moreover, in this method, after a certain modification, the fly ash reacts with CO2 gas in a slurry environment to generate stable carbonate minerals, such as calcium carbonate (CaCO3) or magnesium carbonate (MgCO3). However, this slurry reaction method not only has complex process, high cost and subsequent waste liquid treatment problems, but also has a low CaO content in the fly ash, and its mineralization efficiency has not been significantly improved. Therefore, although the slurry reaction method in the prior art has a certain application basis in the CO2 mineralization of fly ash modified materials, it still faces challenges such as high process complexity, high cost, difficulty in waste liquid treatment and suboptimal mineralization efficiency in practical applications.

[0004] Existing fly ash modification methods (alkaline cellulose, sodium chloride solution, organic amine solvent, ammonium ion solution, high pressure and high temperature, etc.) often require high energy consumption or high-cost raw materials, which greatly reduces the economic efficiency.

[0005] CO based on fly ash modification 2 Mineralized materials have not involved the development of adsorption properties, and have not solved the problem of carbonized film generated by mineralization reactions hindering the continued reaction, resulting in no significant improvement in mineralization efficiency, which limits its application.

[0006] The reaction of modified fly ash to fix carbon is a slurry reaction, which requires precise control of multiple parameters, including the pH value, temperature, and CO2 flow rate of the slurry, to ensure the efficient reaction. This complex process not only requires a high degree of coordination between equipment and operating technology, but also increases the difficulty of process management.

[0007] The waste liquid generated during the carbon fixation reaction needs to be treated to avoid negative impacts on the environment. Waste liquid treatment not only increases the complexity of the process, but also increases production costs. Summary of the invention

[0008] In view of the shortcomings of the prior art, the present invention aims to provide a CO 2 Capture-mineralization integrated material and its preparation method and application. To improve the performance of fly ash in capturing-mineralizing CO 2Improve the efficiency of the process, realize the green value-added utilization of fly ash, and solve the problem of solid waste disposal.

[0009] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0010] In a first aspect, the present invention provides a CO 2 The preparation method of the integrated capture-mineralization material comprises the following steps:

[0011] The fly ash, the ore-introducing agent and the alkaline substance are uniformly mixed in a mass ratio of 1-10:1-4:0.5-2 to obtain a solid mixture, wherein the mass ratio of tetracalcium sulfoaluminate, dicalcium silicate and calcium sulfate dihydrate in the ore-introducing agent is 10-20:5-10:70-80;

[0012] The solid mixture is mixed evenly with water, with the mass ratio of water to fly ash being 4-10:1, to obtain a solid-liquid mixture;

[0013] The solid-liquid mixture is reacted at 30-70°C in a sealed and air-tight state for 4-8 hours, and the reaction product is separated into solid and liquid and dried to obtain the product.

[0014] In some embodiments, the alkaline substance is calcium oxide, sodium hydroxide or sodium silicate.

[0015] Preferably, the alkaline substance is calcium oxide.

[0016] In some embodiments, in the ore-introducing agent, the mass ratio of tetracalcium sulfoaluminate, dicalcium silicate and calcium sulfate dihydrate is 15-20:7-10:70-80.

[0017] Preferably, in the ore-introducing agent, the mass ratio of tetracalcium sulfoaluminate, dicalcium silicate and calcium sulfate dihydrate is 16:9:75.

[0018] In some embodiments, stirring is continued during the reaction at a rate of 400-800 r / min. Stirring is performed at a temperature of 30-70° C. at a rate of 400-800 r / min for 4-8 hours to ensure uniform reaction of the mixture and full activation of the mineral components.

[0019] In some embodiments, the drying temperature is 40-50°C. Minerals are easily decomposed at high temperatures. When a lower temperature is used for drying, the stable existence of the minerals is ensured while the sample is dried.

[0020] In some embodiments, the process further includes crushing and screening the product obtained after drying, and passing the crushed product through a 200-mesh sieve to remove larger particles and obtain modified fly ash with uniform particle size.

[0021] In a second aspect, the present invention provides a CO 2The capture-mineralization integrated material is prepared by the preparation method.

[0022] In a third aspect, the present invention provides the CO 2 Integrated capture-mineralization materials in CO 2 Applications in capture and mineralization.

[0023] The beneficial effects achieved by one or more embodiments of the present invention are as follows:

[0024] The present invention uses fly ash to prepare CO 2 The method of integrated capture-mineralization material activates the active Al and Si in fly ash to form minerals with high specific surface area, such as ettringite and hydrated calcium silicate gel, which are easily mineralized minerals. These minerals form a flower cluster structure, which increases the CO 2 The diffusion capacity of CO 2 The capture efficiency and total amount of CO 2 The integrated capture-mineralization material has excellent CO 2 Capture and in-situ mineralization capabilities.

[0025] CO 2 Mineralization of CO2 captured by integrated capture-mineralization materials 2 Excellent capacity, per gram of CO 2 Capture-Mineralization Materials can capture and mineralize CO 2 Up to 50mg.

[0026] The generated nano-scale calcium carbonate (mainly calcite) has excellent mechanical and filling properties, ensuring the feasibility of subsequent product applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0028] Figure 1 is a process flow chart of an embodiment of the present invention;

[0029] Figure 2 This is an electron microscope image of the sample in Example 1 of the present invention. DETAILED DESCRIPTION

[0030] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0031] The present invention will be further described below in conjunction with the embodiments.

[0032] Example 1

[0033] like Figure 1 As shown, 2g of fly ash, 2g of ore-starting agent (in the ore-starting agent, 16% of tetracalcium sulfoaluminate, 9% of dicalcium silicate, 75% of calcium sulfate dihydrate, % is mass percentage) and 1g of calcium oxide are mixed evenly to obtain a solid mixture; 40g of water is poured into a beaker, and then the solid mixture is poured into the beaker, which is sealed to isolate the air, placed in a constant temperature and constant speed magnetic stirring oil bath pot, and stirred at 550r / min for 6h at 50°C. The slurry is filtered, dried, and passed through a 200-mesh sieve to obtain powdery CO 2 Integrated capture-mineralization materials.

[0034] The test obtained the excitation ratio of Al in fly ash, the generated mass ratio of AFt, the specific surface area, the pore volume and the average pore diameter.

[0035] 2g CO 2 The capture-mineralization integrated material is placed in a mixed atmosphere (15% CO 2 、85%N 2 , 90°C, and a moisture content of 8.4 g / kg dry air) for two hours, then the material is taken out and dried at low temperature, and the carbon fixation amount is obtained by testing.

[0036] Take 10 mg of sample for TG-DTG test to get the specific content of mineral components. Nano calcium carbonate is observed by electron microscope. Figure 2 shown.

[0037] Example 2

[0038] Mix 5g of fly ash, 2g of ore-starting agent (in the ore-starting agent, 16% of tetracalcium sulfoaluminate, 9% of dicalcium silicate, 75% of calcium sulfate dihydrate, % is mass percentage) and 1g of calcium oxide to obtain a solid mixture. Pour 64g of water into a beaker, then pour the solid mixture into the beaker, seal it to isolate the air, place it in a constant temperature and constant speed magnetic stirring oil bath pot, stir it at 70°C and 450r / min for 4h. Filter the slurry, dry it, and pass it through a 200-mesh sieve to obtain CO 2 Integrated capture-mineralization materials.

[0039] The test obtained the excitation ratio of Al in fly ash, the generated mass ratio of AFt, the specific surface area, the pore volume and the average pore diameter.

[0040] 2g CO 2 The capture-mineralization integrated material is placed in a mixed atmosphere (15% CO 2 、85%N 2, 70°C, 8.4 g / kg dry air) for two hours. The material was taken out and dried at low temperature, and the carbon fixation was measured.

[0041] Example 3

[0042] 7g of fly ash, 2g of ore-starting agent (in the ore-starting agent, 16% of tetracalcium sulfoaluminate, 9% of dicalcium silicate, 75% of calcium sulfate dihydrate, % is mass percentage) and 1g of calcium oxide were mixed evenly to obtain a solid mixture. 80g of water was poured into a beaker, and then the solid mixture was poured into the beaker, which was sealed to isolate the air, placed in a constant temperature and constant speed magnetic stirring oil bath pot, and stirred at 650r / min at 30°C for 8h. The slurry was filtered, dried, and passed through a 200-mesh sieve to obtain a powdery capture-mineralized CO 2 Integrated materials.

[0043] The test obtained the excitation ratio of Al in fly ash, the generated mass ratio of AFt, the specific surface area, the pore volume and the average pore diameter.

[0044] 2g of captured-mineralized CO 2 The integrated material is placed in a mixed atmosphere (15% CO 2 、85%N 2 , 30°C, 5.3 g / kg dry air) for two hours. The material was taken out and dried at low temperature, and the carbon fixation was measured.

[0045] Comparative Example 1

[0046] The difference from Example 3 is that the ore-inducing agent is omitted, and the rest is the same as Example 3.

[0047] Comparative Example 2

[0048] The difference from Example 3 is that the ore-inducing agent is all calcium sulfate dihydrate, and the rest is the same as Example 3.

[0049] Comparative Example 3

[0050] The difference from Example 3 is that calcium oxide is omitted, and the rest is the same as Example 3.

[0051] Table 1 Performance comparison table of Examples 1-3

[0052]

[0053]

[0054] As shown in Table 1, the prepared CO 2 The integrated capture-mineralization material successfully stimulated the active elements in fly ash to generate easily mineralized minerals and had good CO 2 Adsorption-mineralization properties.

[0055] Table 2 Performance comparison table of Example 3 and Comparative Examples 1-3

[0056] Test items Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Excitation ratio of Al in fly ash / % 9.81 0 2.30 1.60 The mass percentage of ettringite generated / % 7.24 0 1.12 1.26 <![CDATA[Specific surface area / (m 2 / g)]]> 3.61 1.22 2.15 4.32 <![CDATA[Pore volume / (cm 3 / g)]]> 0.02 0.01 0.01 0.02 Average pore size / nm 24.08 29.18 22.16 17.33 Carbon fixation / (mg / g modified fly ash) 50 0 8 6

[0057] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a CO2 capture-mineralization integrated material, characterized in that: The steps include: The fly ash, the ore-introducing agent and the alkaline substance are uniformly mixed in a mass ratio of 1-10:1-4:0.5-2 to obtain a solid mixture, wherein the mass ratio of tetracalcium sulfoaluminate, dicalcium silicate and calcium sulfate dihydrate in the ore-introducing agent is 10-20:5-10:70-80; The solid mixture is mixed evenly with water, with the mass ratio of water to fly ash being 4-10:1, to obtain a solid-liquid mixture; The solid-liquid mixture is reacted at 30-70°C in a sealed and air-tight state for 4-8 hours, and the reaction product is separated into solid and liquid and dried to obtain the product.

2. The method for preparing the CO2 capture-mineralization integrated material according to claim 1, characterized in that: The alkaline substance is calcium oxide, sodium hydroxide or sodium silicate.

3. The method for preparing the CO2 capture-mineralization integrated material according to claim 2, characterized in that: The alkaline substance is calcium oxide.

4. The method for preparing the CO2 capture-mineralization integrated material according to claim 1, characterized in that: In the ore-introducing agent, the mass ratio of tetracalcium sulfoaluminate, dicalcium silicate and calcium sulfate dihydrate is 15-20:7-10:70-80.

5. The method for preparing the CO2 capture-mineralization integrated material according to claim 4, characterized in that: In the ore-introducing agent, the mass ratio of tetracalcium sulfoaluminate, dicalcium silicate and calcium sulfate dihydrate is 16:9:

75.

6. The method for preparing the CO2 capture-mineralization integrated material according to claim 1, characterized in that: The reaction was continued with stirring at a rate of 400-800 r / min.

7. The method for preparing the CO2 capture-mineralization integrated material according to claim 1, characterized in that: The drying temperature is 40-50°C.

8. The method for preparing the CO2 capture-mineralization integrated material according to claim 1, characterized in that: The method also includes a process of crushing and screening the product obtained after drying, and passing the crushed product through a 200-mesh sieve.

9. A CO2 capture-mineralization integrated material, characterized in that: Prepared by the preparation method described in any one of claims 1 to 8.

10. Use of the CO2 capture-mineralization integrated material according to claim 9 in CO2 capture and mineralization.

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