Preparation method of carbide slag-based MOF material and application of the MOF material in carbon dioxide adsorption

Abstract

The application relates to a preparation method of a carbide slag-based MOF material and application of the carbide slag-based MOF material in carbon dioxide adsorption. The carbide slag is mixed with formic acid, deionized water is added, ball milling is carried out in a ball mill, and then the mixture is washed, filtered and vacuum dried to obtain a solid powder; tetraethylenepentamine is added to anhydrous methanol and stirred to obtain a mixed solution; the obtained solid powder is added to the mixed solution, stirred, washed, filtered and vacuum dried to obtain the carbide slag-based MOF material. The carbide slag-based MOF material prepared from the carbide slag is applied to carbon dioxide adsorption, has the advantages of no pollution to the environment, excellent adsorption performance and good cycle stability. The carbon dioxide adsorption capacity can reach 2.89 mmol / g, and remains stable in 10 cycles. Moreover, the preparation method is simple, green, environmentally friendly and low in cost, and is suitable for large-scale production.

Description

Technical Field

[0001] This invention relates to the field of resource utilization technology of carbide slag, specifically to a method for preparing carbide slag-based MOF materials and their application in carbon dioxide adsorption. Background Technology

[0002] In recent years, rapid industrial development has led to a continuous increase in the consumption of fossil fuels (including coal, oil, and natural gas). The resulting large amounts of CO2 have caused serious environmental problems, such as global warming, ocean acidification, extreme weather events, and species extinction. In June 2022, the concentration of carbon dioxide in the atmosphere exceeded 417 ppm. Therefore, reducing the concentration of CO2 in the atmosphere is essential. Finding a scientifically sound technology to separate or capture CO2 is of great significance.

[0003] Over the past few decades, solid adsorbents (such as zeolites, activated carbon, porous organic polymers, covalent organic frameworks (COFs), and metal-organic frameworks (MOFs)) have become promising candidates for CO2 adsorbents due to their high adsorption capacity and easily controllable texture. Metal-organic frameworks (MOFs) are a new type of solid adsorbent, consisting of an open framework structure composed of metal ions and organic linkers. Since their physical and chemical properties can be fine-tuned by designing and functionalizing SBUs, linkers, and pore environments, MOFs offer great potential for the separation and enrichment of carbon dioxide. However, MOFs suffer from low thermal stability and are prone to decomposition at high temperatures, significantly affecting CO2 adsorption efficiency. Calcium squaric acid MOF is a calcium-based metal-organic framework material with excellent thermal stability and a rigid framework, making it very suitable for carbon dioxide adsorption. Shi et al. (Mechanochemical synthesis of an ethylene sieve UTSA-280[J]. Journal of Solid State Chemistry, 2020, 287.) successfully reacted calcium oxide and calcium hydroxide with squaric acid using a mechanochemical method to form calcium squaric acid MOF, adsorbing 84 cm⁻¹ of CO₂. 3 / g of carbon dioxide. On the one hand, although MOFs have excellent adsorption performance for carbon dioxide, they are mostly physical adsorption, which has the disadvantage of poor adsorption kinetics. Adding amine groups can improve the chemisorption of the adsorbent and enhance the carbon dioxide kinetics and selectivity of the adsorbent. On the other hand, the high cost of MOFs has always been one of the reasons limiting their industrial application.

[0004] Calcium carbide slag is a calcium-based industrial waste generated during the production of acetylene gas. my country's annual calcium carbide slag production is approximately 43 million tons, and the accumulated stockpile exceeds 100 million tons. The large-scale accumulation of calcium carbide slag causes groundwater pollution, soil alkalization, and severe damage to the surrounding ecological environment. Currently, calcium carbide slag is mainly used in the construction, environmental protection, and chemical industries to produce low-value-added products such as carbonized bricks, cement, quicklime, calcium carbonate, and desulfurizing agents. A large amount of calcium carbide slag remains unutilized, and how to rationally utilize it to produce high-value-added products and address environmental issues is a pressing problem. Therefore, the waste treatment and resource utilization of calcium carbide slag has become a topic of great concern. Since the main component of calcium carbide slag is Ca(OH)2, it is a good candidate material for preparing MOF (Metal-Oxide-Foil) materials. Using calcium carbide slag as a raw material can not only reduce the production cost of MOFs and provide a new avenue for their industrialization, but also solve the problem of calcium carbide slag treatment, representing a promising development direction.

[0005] There are currently no reports on the preparation methods of carbide slag-based MOF materials and their application in carbon dioxide adsorption. Summary of the Invention

[0006] The purpose of this invention is to provide a method for preparing carbide slag-based MOF materials and their application in carbon dioxide adsorption, which solves the problems of high cost, low thermal stability and poor adsorption kinetics of existing technologies.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A method for preparing a carbide slag-based MOF material includes the following steps:

[0009] 1) Mix calcium carbide slag with squaric acid, add deionized water, ball mill in a ball mill, wash and filter with deionized water, and vacuum dry to obtain solid powder;

[0010] 2) Add tetraethylenepentamine to anhydrous methanol and stir to obtain a mixed solution;

[0011] 3) Add the solid powder from step 1) to the mixed solution obtained in step 2), stir, wash and filter with anhydrous methanol, and vacuum dry to obtain the carbide slag-based MOF material.

[0012] In the preferred step 1), the mass ratio of carbide slag, succinic acid, and deionized water is 1:(1-2):(1-4); the ball milling frequency is 10-30 Hz, and the ball milling time is 20-60 min.

[0013] In the preferred step 2), the content of tetraethylenepentamine is 10%-50% of the sum of the solid powder and tetraethylenepentamine; the mass ratio of tetraethylenepentamine to anhydrous methanol is 1:(10-40).

[0014] The preferred vacuum drying temperature in step 1) is 100-110℃, and the drying time is 6-12h;

[0015] The vacuum drying temperature in step 3) is 50-70℃, and the drying time is 6-12h;

[0016] The preferred stirring temperature in step 2) is 20-30℃, and the stirring time is 20-30min.

[0017] The stirring temperature in step 3) is 20-30℃, and the stirring time is 6-12h.

[0018] Preferably, the carbide slag mainly comprises more than 90% CaO by mass percentage.

[0019] Preferably, it is used for carbon dioxide adsorption.

[0020] Preferably, the adsorption capacity of the carbon dioxide is 1.96-2.89 mmol / g.

[0021] The above-mentioned method for preparing carbide slag-based MOF materials utilizes carbide slag to produce materials suitable for carbon dioxide adsorption. These materials offer advantages such as being environmentally friendly, producing no byproducts, exhibiting excellent adsorption performance, and demonstrating good cycle stability. The carbon dioxide adsorption capacity can reach 2.89 mmol / g and remains stable throughout 10 cycles.

[0022] The beneficial effects of this invention are:

[0023] 1. The calcium carbide slag and squaric acid provided by the present invention can be synthesized by ball milling at room temperature to form calcium squaric acid MOF material.

[0024] Because tetraethylenepentamine has a strong binding capacity for carbon dioxide, it can improve the adsorption performance and selectivity of carbon dioxide. The prepared carbide slag-based MOF material has high carbon dioxide adsorption capacity and cycle stability.

[0025] 2. The method for preparing carbide slag-based MOF materials provided by the present invention can obtain carbide slag as raw material from acetylene production plants, which is inexpensive; the production process is simple and suitable for large-scale production.

[0026] 3. The carbide slag-based MOF material prepared by this invention has tetraethylenepentamine loaded onto MOFs, which is not easily volatilized and has very little corrosiveness to equipment, thus meeting the requirements of industrial processing. Attached Figure Description

[0027] Figure 1 Carbon dioxide adsorption test diagram of the material prepared in Example 1

[0028] Figure 2 Carbon dioxide adsorption test chart of the material prepared in Example 2

[0029] Figure 3 Carbon dioxide adsorption test chart of the material prepared in Example 3

[0030] Figure 4 Carbon dioxide adsorption test chart of the material prepared in Example 4

[0031] Figure 5 Carbon dioxide adsorption test diagram of the material prepared in Example 5

[0032] Figure 6 Carbon dioxide adsorption test chart of the material prepared in Example 6

[0033] Figure 7 Carbon dioxide adsorption test chart of the material prepared in Example 7 Detailed Implementation

[0034] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0035] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0036] Example 1

[0037] This embodiment provides a method for preparing a carbide slag-based MOF material and its application in carbon dioxide adsorption, including the following steps:

[0038] 1) Take 1.48g of carbide slag, put it and 2.28g of squaric acid into a ball mill jar, add 1.48g of deionized water, ball mill at a frequency of 10HZ for 20min, then wash and filter with deionized water, and dry in a vacuum oven at 100℃ for 6h to obtain solid powder.

[0039] 2) Add 0.17g of tetraethylenepentamine to 8.6ml of anhydrous methanol and stir magnetically at 20℃ for 20min to obtain a mixed solution.

[0040] 3) Add 1.5g of solid powder to the mixed solution in step 2), stir magnetically at 20°C for 12h, wash and filter with methanol, and dry under vacuum at 50°C for 6h to obtain carbide slag-based MOF material.

[0041] 4) Carbon dioxide adsorption experiments were conducted on the obtained carbide slag-based MOF material.

[0042] The material obtained in this embodiment has an adsorption capacity of 2.05 mmol / g for carbon dioxide and remains stable during 10 cycles of desorption. Figure 1 ).

[0043] Example 2

[0044] This embodiment provides a method for preparing a carbide slag-based MOF material and its application in carbon dioxide adsorption, including the following steps:

[0045] 1) Take 1.48g of carbide slag, put it and 1.48g of squaric acid into a ball mill jar, add 3.6g of deionized water, ball mill at a frequency of 15HZ for 30min, then wash and filter with deionized water, and dry in a vacuum oven at 110℃ for 8h to obtain solid powder.

[0046] 2) Add 0.17g of tetraethylenepentamine to 8.6ml of anhydrous methanol and stir magnetically at 20℃ for 25min to obtain a mixed solution.

[0047] 3) Add 1.5g of solid powder to the mixed solution in step 2), stir magnetically at 20°C for 6h, wash and filter with methanol, and dry under vacuum at 60°C for 6h to obtain carbide slag-based MOF material.

[0048] 4) Carbon dioxide adsorption experiments were conducted on the obtained carbide slag-based MOF material.

[0049] The material obtained in this embodiment has an adsorption capacity of 1.96 mmol / g for carbon dioxide and remains stable during 10 cycles of desorption. Figure 2 ).

[0050] Example 3

[0051] This embodiment provides a method for preparing a carbide slag-based MOF material and its application in carbon dioxide adsorption, including the following steps:

[0052] 1) Take 1.48g of carbide slag, put it and 2.96g of squaric acid into a ball mill jar, add 5.92g of deionized water, ball mill at a frequency of 20HZ for 40min, then wash and filter with deionized water, and dry in a vacuum oven at 105℃ for 12h to obtain solid powder.

[0053] 2) Add 0.375g of tetraethylenepentamine to 14.22ml of anhydrous methanol and stir magnetically at 25℃ for 30min to obtain a mixed solution.

[0054] 3) Add 1.5g of solid powder to the mixed solution in step 2), stir magnetically at 25℃ for 8h, wash and filter with methanol, and dry under vacuum at 70℃ for 8h to obtain carbide slag-based MOF material.

[0055] 4) Carbon dioxide adsorption experiments were conducted on the obtained carbide slag-based MOF material.

[0056] The material obtained in this embodiment has an adsorption capacity of 2.2 mmol / g for carbon dioxide and remains stable during 10 cycles of desorption. Figure 3 ).

[0057] Example 4

[0058] This embodiment provides a method for preparing a carbide slag-based MOF material and its application in carbon dioxide adsorption, including the following steps:

[0059] 1) Take 1.48g of carbide slag, put it and 2.28g of squaric acid into a ball mill jar, add 1.48g of deionized water, ball mill at a frequency of 30HZ for 50min, then wash and filter with deionized water, and dry in a vacuum oven at 100℃ for 8h to obtain solid powder.

[0060] 2) Add 0.64g of tetraethylenepentamine to 16.18ml of anhydrous methanol and stir magnetically at 25℃ for 20min to obtain a mixed solution.

[0061] 3) Add 1.5g of solid powder to the mixed solution in step 2), stir magnetically at 30℃ for 12h, wash and filter with methanol, and dry under vacuum at 60℃ for 12h to obtain carbide slag-based MOF material.

[0062] 4) Carbon dioxide adsorption experiments were conducted on the obtained carbide slag-based MOF material.

[0063] The material obtained in this embodiment has an adsorption capacity of 2.34 mmol / g for carbon dioxide and remains stable during 10 cycles of desorption. Figure 4 ).

[0064] Example 5

[0065] This embodiment provides a method for preparing a carbide slag-based MOF material and its application in carbon dioxide adsorption, including the following steps:

[0066] 1) Take 1.48g of carbide slag, put it and 2.28g of squaric acid into a ball mill jar, add 3.6g of deionized water, ball mill at a frequency of 25HZ for 60min, then wash and filter with deionized water, and dry in a vacuum oven at 110℃ for 8h to obtain solid powder.

[0067] 2) Add 1.5g of tetraethylenepentamine to 18.96ml of anhydrous methanol and stir magnetically at 30℃ for 25min to obtain a mixed solution.

[0068] 3) Add 1.5g of solid powder to the mixed solution in step 2), stir magnetically at 25℃ for 8h, wash and filter with methanol, and dry under vacuum at 70℃ for 8h to obtain amine-modified carbide slag-based MOF material.

[0069] 4) Carbon dioxide adsorption experiments were conducted on the obtained carbide slag-based MOF material.

[0070] The material obtained in this embodiment has an adsorption capacity of 2.12 mmol / g for carbon dioxide and remains stable during 10 cycles of desorption. Figure 5 ).

[0071] Example 6

[0072] This embodiment provides a method for preparing a carbide slag-based MOF material and its application in carbon dioxide adsorption, including the following steps:

[0073] 1) Take 1.48g of carbide slag, put it and 2.28g of squaric acid into a ball mill jar, add 5.4g of deionized water, ball mill at a frequency of 15HZ for 30min, then wash and filter with deionized water, and dry in a vacuum oven at 105℃ for 6h to obtain solid powder.

[0074] 2) Add 0.64g of tetraethylenepentamine to 14ml of anhydrous methanol and stir magnetically at 30℃ for 30min to obtain a mixed solution.

[0075] 3) Add 1.5g of solid powder to the mixed solution in step 2), stir magnetically at 30℃ for 12h, wash and filter with methanol, and dry under vacuum at 50℃ for 12h to obtain amine-modified carbide slag-based MOF material.

[0076] 4) Carbon dioxide adsorption experiments were conducted on the obtained carbide slag-based MOF material.

[0077] The material obtained in this embodiment has an adsorption capacity of 2.6 mmol / g for carbon dioxide and remains stable during 10 cycles of desorption. Figure 6 ).

[0078] Example 7

[0079] This embodiment provides a method for preparing a carbide slag-based MOF material and its application in carbon dioxide adsorption, including the following steps:

[0080] 1) Take 1.48g of carbide slag, put it and 2.28g of squaric acid into a ball mill jar, add 5.4g of deionized water, ball mill at a frequency of 15HZ for 30min, then wash and filter with deionized water, and dry in a vacuum oven at 105℃ for 6h to obtain solid powder.

[0081] 2) Add 1g of tetraethylenepentamine to 14ml of anhydrous methanol and stir magnetically at 25℃ for 30min to obtain a mixed solution.

[0082] 3) Add 1.5g of solid powder to the mixed solution in step 2), stir magnetically at 25℃ for 12h, wash and filter with methanol, and dry under vacuum at 60℃ for 12h to obtain amine-modified carbide slag-based MOF material.

[0083] 4) Carbon dioxide adsorption experiments were conducted on the obtained carbide slag-based MOF material.

[0084] The material obtained in this embodiment has an adsorption capacity of 2.89 mmol / g for carbon dioxide and remains stable during 10 cycles of desorption. Figure 7 ).

[0085] Test case

[0086] The carbon dioxide adsorption capacity of the carbide slag-based MOF material prepared by the method described in the above embodiments was tested. The test method included the following steps:

[0087] 500 mg of carbide slag-based MOF material supported by quartz wool was placed in the isothermal heating zone of a fixed-bed reactor. N2 (100 ml / min) was initially introduced, and the isothermal heating zone was maintained at 110°C to desorb the carbide slag-based MOF material. The temperature was then lowered, and the isothermal heating zone was maintained at 25°C. A CO2 / N2 (15% CO2, 85% N2) mixture (100 ml / min) was introduced to allow the carbide slag-based MOF material to adsorb carbon dioxide. The gas was continuously monitored for 30 minutes using a flue gas analyzer. Ten cycles were performed, and the test results are shown in Table 1.

[0088] Table 1. Carbon dioxide adsorption performance test

[0089]

[0090] The carbide slag-based MOF material prepared by this method exhibits excellent carbon dioxide adsorption performance, reaching a maximum of 2.89 mmol / g. This compares to a carbon dioxide adsorption capacity of 1.9 mmol / g reported in the literature, demonstrating the superior adsorption performance of this method.

[0091] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for preparing a carbide slag-based MOF material; characterized in that, Includes the following steps: 1) Take calcium carbide slag and squaric acid, add deionized water, ball mill in a ball mill, wash and filter with deionized water, and vacuum dry to obtain solid powder; the mass ratio of calcium carbide slag, squaric acid and deionized water is 1:(1-2):(1-4); the ball milling frequency is 10-30Hz and the ball milling time is 20-60min; 2) Add tetraethylenepentamine to anhydrous methanol and stir to obtain a mixed solution; the content of tetraethylenepentamine is 10%-50% of the total mass percentage of the solid powder and tetraethylenepentamine; the mass ratio of tetraethylenepentamine to anhydrous methanol is 1:(10-40). 3) Add the solid powder from step 1) to the mixed solution obtained in step 2), stir, wash and filter with anhydrous methanol, and vacuum dry to obtain the carbide slag-based MOF material.

2. The method for preparing the carbide slag-based MOF material as described in claim 1; characterized in that, Step 1) The vacuum drying temperature is 100-110℃ and the drying time is 6-12h.

3. The method for preparing the carbide slag-based MOF material as described in claim 1; characterized in that, In step 2), the stirring temperature is 20-30℃ and the stirring time is 20-30 minutes.

4. The method for preparing the carbide slag-based MOF material as described in claim 1; characterized in that, In step 3), the vacuum drying temperature is 50-70℃ and the drying time is 6-12h.

5. The method for preparing the carbide slag-based MOF material as described in claim 1; characterized in that, In step 3), the stirring temperature is 20-30℃ and the stirring time is 6-12h.

6. The carbide slag-based MOF material prepared by the method of claim 1 is applied to carbon dioxide adsorption.

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