Methods and applications for preparing functional composite microsphere catalysts using titanium-containing slag

Abstract

This invention discloses a method for preparing functional composite microsphere catalysts using titanium-containing slag. The method involves ball milling and sieving dried titanium-containing slag to obtain titanium-containing slag powder; placing the titanium-containing slag powder in hydrochloric acid solution at room temperature with stirring and acid leaching, followed by solid-liquid separation and solid washing to obtain acid-treated slag; adding the acid-treated slag to NaOH solution for reaction, cooling to room temperature, then sequentially adding anhydrous ethanol and ammonia water, adjusting the pH to 9-11, aging, separating the solid and liquid, and washing and drying the solid to obtain microspheres; adding the microspheres to deionized water for ultrasonic mixing, then adding them to an ammonia solution to obtain a microsphere suspension; adding the microsphere suspension to a stirred mixture of Ni(NO3)2·6H2O and NH4Cl, continuing stirring after precipitate formation, and then transferring the mixture to a polytetrafluoroethylene hydrothermal reactor for hydrothermal reaction, followed by solid-liquid separation, solid washing and drying to obtain the functional composite microsphere catalyst; the catalyst prepared by this invention exhibits good reforming effect in CO2-CH4 reforming reactions, achieving the purpose of resource reuse.

Description

Technical Field

[0001] This invention belongs to the field of solid waste secondary utilization, specifically relating to a method and application for preparing functional composite microsphere catalysts using titanium-containing slag. Background Technology

[0002] In the process of my country's comprehensive and rapid development, the metallurgical industry, as a crucial foundational industry of the national economy, has made significant contributions to economic and social development. However, it has also generated a large amount of solid waste. Accumulated waste slag not only occupies vast amounts of land resources, but the loss of metal elements from the slag also causes serious environmental pollution, with some useful elements being wasted. Therefore, how to achieve the resource utilization of titanium-containing slag and realize healthy development under the "dual carbon" background has become an important issue that urgently needs to be addressed.

[0003] Traditional methods for treating titanium-containing slag, such as the production of cement, concrete, slag bricks, and glass, can partially realize the resource utilization of blast furnace slag, but cannot efficiently realize its value. Therefore, researchers have begun to focus on developing new utilization pathways, such as the extraction of valuable metals, the preparation and application of functional material catalysts and adsorbents, to fully realize the high-value utilization of blast furnace slag. In the current context of increasingly serious environmental pollution problems, especially global warming caused by the annual emission of over 10 billion tons of greenhouse gases such as CO2 and CH4, which seriously affects all aspects of human life, how to combine the resource utilization of solid waste with the synergistic capture and utilization of CO2 to improve environmental pollution has become a current research hotspot. In view of this, methane dry reforming (CH4 + CO2 → 2H2 + 2CO, ∆H) is being studied. 0 (298K=+247 kJ / mol) is a promising process that provides an effective way to convert them into valuable syngas, which can then be further converted into various chemicals by adjusting the H2 / CO ratio. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a method for preparing functional composite microsphere catalysts using titanium-containing slag, and applies it to the CO2-CH4 reforming reaction to produce syngas.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] 1. Preparation of functional composite microsphere catalysts

[0007] (1) Titanium-containing slag is dried at 60~80℃, mechanically ball-milled and passed through a 180-mesh sieve to obtain titanium-containing slag powder;

[0008] (2) Place the titanium-containing slag powder in a 4-6 mol / L hydrochloric acid solution and stir and leach at room temperature for 3-5 hours. Separate the solid and liquid, wash the solid until neutral, and obtain acid-treated slag (ATBFS).

[0009] (3) Mix ATBFS and 1-3 mol / L NaOH solution, stir at 100-150℃ for 2-4 h, stop heating, and let it cool to room temperature. Then add anhydrous ethanol and ammonia water in sequence, mix well, adjust pH to 9-11, age for 12 h, separate solid and liquid, wash and dry the solid to obtain microspheres.

[0010] The mass-to-volume ratio of acid-treated residue to anhydrous ethanol (g:mL) is 1:4-7.5, and the mass-to-volume ratio of acid-treated residue to ammonia water (25-28%) (g:mL) is 1:1-2.5.

[0011] (4) Microspheres were added to deionized water and ultrasonically mixed. Then, they were added to ammonia solution to prepare microsphere suspension. The microsphere suspension was added dropwise to a mixture of Ni(NO3)2·6H2O and NH4Cl under stirring. After the precipitate was formed, stirring was continued for 20 min. Then, it was transferred to a polytetrafluoroethylene hydrothermal reactor and hydrothermally reacted at 120-180℃ for 12-96 h. The solid and liquid were separated, and the solid was washed and dried to obtain the functional composite microsphere catalyst.

[0012] The mass-to-volume ratio of microspheres to ammonia water (g:mL) is 1:20-25, the mass ratio of microspheres to Ni(NO3)2·6H2O is 1:2-2.5, and the mass ratio of microspheres to NH4Cl is 1:1-2.

[0013] Another objective of this invention is to apply the functional composite microsphere catalyst prepared by the above method to the preparation of syngas in the CO2-CH4 reforming reaction.

[0014] The present invention has the following advantages over the prior art:

[0015] This invention uses titanium-containing industrial solid waste as raw material and prepares functional composite microsphere catalyst materials through acid leaching, alkali leaching, and hydrothermal methods. The material has a good reforming effect, achieving both environmental friendliness and resource reuse, thus achieving certain economic benefits. Attached Figure Description

[0016] Figure 1 This is a SEM image of the functional composite microsphere catalyst prepared in Example 1. Detailed Implementation

[0017] To better understand the specific content of this invention, the following specific examples are provided for detailed explanation. However, the scope of protection of this invention is not limited to the following content. The titanium-containing slag in the following examples is produced by extracting titanium from water-quenched slag generated from vanadium-titanium magnet blast furnace smelting. The main chemical composition is CaO (mass fraction 27.96%), TiO2 (mass fraction 12.63%), SiO2 (mass fraction 25.22%), Al2O3 (mass fraction 12.19%), MgO (mass fraction 9.59%) and Fe2O3 (mass fraction 8.59%).

[0018] Example 1: Method and application of preparing functional composite microsphere catalysts from titanium-containing slag

[0019] (1) The titanium-containing slag was placed in an electric oven at 60°C for 48 hours and dried. After ball milling for 2 hours, it was passed through a 180-mesh sieve to obtain titanium-containing slag powder.

[0020] (2) Place the titanium slag powder in a 5 mol / L hydrochloric acid solution (the volume ratio of acid to slag in mL:g is 12:1), stir and acid leaching at room temperature for 4 h, centrifuge, collect the solid, wash the solid with water until neutral, and obtain acid-treated slag (ATBFS).

[0021] (3) Place 2.5g of ATBFS in 72mL of 2mol / L NaOH solution and mix with a magnetic stirrer at 120℃ for 3h, then stop heating. After cooling to room temperature, add 10mL of anhydrous ethanol and 3mL of NH3·H2O (25%) in sequence, age for 12h, centrifuge, wash the solid three times alternately with deionized water and anhydrous ethanol, and dry at 80℃ for 12h to obtain microspheres;

[0022] (4) Weigh 0.48 g of Ni(NO3)2·6H2O and 0.3 g of NH4Cl and dissolve them in 10 mL of deionized water to prepare a mixture of Ni(NO3)2·6H2O and NH4Cl. Add 0.2 g of microspheres to 40 mL of deionized water, mix by sonication, and then add 5 mL of ammonia (25%). Sonicate for 10 min to obtain a microsphere suspension. Add the microsphere suspension dropwise to the stirred mixture of Ni(NO3)2·6H2O and NH4Cl. After the precipitate is formed, continue stirring for 20 min. Transfer the mixture to a polytetrafluoroethylene hydrothermal reactor and hydrothermally heat it at 170 °C for 12 h. Separate the solid and liquid. Wash the solid three times with deionized water and anhydrous ethanol alternately, and dry it at 80 °C for 12 h to obtain the functional composite microsphere catalyst. Its SEM image is shown in [image missing]. Figure 1 As can be seen from the figure, the microsphere morphology of the catalyst and the active metal nickel attached to the surface of the spheres form a nickel-based reforming catalyst.

[0023] (5) Take 0.1g of functional composite microsphere catalyst and load it into a quartz tube (6 mm × 4 mm × 40 cm). Pass Ar (30 mL / min) through it and raise the system temperature to 850℃. After reducing the catalyst with H2 / Ar (30 mL / min) mixed gas for 1 h, pass mixed gas (CO2:CH4:Ar=1:1:1, space velocity=60000 mL / g·h, 850℃) through it. Analyze the tail gas after the reaction using a gas chromatograph. After 24 h, the conversion rates of CO2 and CH4 of the catalyst during the reforming reaction are still maintained at 72.56% and 67.41%, respectively, and the H2 / CO ratio is maintained at 0.75.

[0024] Example 2: Method and application of preparing functional composite microsphere catalysts from titanium-containing slag

[0025] (1) The titanium-containing slag was placed in an electric oven at 70°C and dried for 40 h. After ball milling for 3 h, it was passed through a 180-mesh sieve to obtain titanium-containing slag powder.

[0026] (2) Place the titanium slag powder in a 5 mol / L hydrochloric acid solution (the volume ratio of acid to slag in mL:g is 12:1), stir and acid leaching at room temperature for 4 h, centrifuge, collect the solid, wash the solid with water until neutral, and obtain acid-treated slag (ATBFS).

[0027] (3) Place 1.5g of ATBFS in 72mL of 2mol / L NaOH solution and mix with a magnetic stirrer at 120℃ for 3h, then stop heating. After cooling to room temperature, add 10mL of anhydrous ethanol and 3mL of NH3·H2O (25%) in sequence, age for 12h, centrifuge, wash the solid three times alternately with deionized water and anhydrous ethanol, and dry at 80℃ for 12h to obtain microspheres;

[0028] (4) Weigh 0.48g of Ni(NO3)2·6H2O and 0.3g of NH4Cl and dissolve them in 10mL of deionized water to prepare a mixture of Ni(NO3)2·6H2O and NH4Cl; add 0.2g of microspheres to 40mL of deionized water, mix by sonication, and then add 5mL of ammonia (25%). Sonicate for 10min to prepare a microsphere suspension. Add the microsphere suspension dropwise to the stirred mixture of Ni(NO3)2·6H2O and NH4Cl. After the precipitate is formed, continue stirring for 20min. Then transfer it to a polytetrafluoroethylene hydrothermal reactor and hydrothermally heat it at 170℃ for 96h. Separate the solid and liquid. Wash the solid three times with deionized water and anhydrous ethanol alternately, and dry it at 80℃ for 12h to obtain a functional composite microsphere catalyst.

[0029] (5) Take 0.1g of functional composite microsphere catalyst and load it into a quartz tube (6 mm × 4 mm × 40 cm). Pass Ar (30 mL / min) through it and raise the system temperature to 750℃. After reducing the catalyst with H2 / Ar (30 mL / min) mixed gas for 1h, pass mixed gas (CO2:CH4:Ar=1:1:1, space velocity=60000 mL / g·h, 750℃) through it. Analyze the tail gas after the reaction using a gas chromatograph. After 24h, the conversion rates of CO2 and CH4 of the catalyst during the reforming reaction are still maintained at 75.30% and 73.07% respectively, and the H2 / CO ratio is maintained at 0.76.

[0030] Example 3: Method and application of preparing functional composite microsphere catalysts from titanium-containing slag

[0031] (1) The titanium-containing slag was placed in an electric oven at 80°C and dried for 36 hours. After ball milling for 2.5 hours, it was passed through a 180-mesh sieve to obtain titanium-containing slag powder.

[0032] (2) Place the titanium slag powder in a 5 mol / L hydrochloric acid solution (the volume ratio of acid to slag in mL:g is 12:1), stir and acid leaching at room temperature for 4 h, centrifuge, collect the solid, wash the solid with water until neutral, and obtain acid-treated slag (ATBFS).

[0033] (3) Place 2.0 g of ATBFS in 72 mL of 2 mol / L NaOH solution and mix with a magnetic stirrer at 120 °C for 3 h, then stop heating. After cooling to room temperature, add 10 mL of anhydrous ethanol and 3 mL of NH3·H2O (25%) in sequence, age for 12 h, centrifuge, wash the solid three times alternately with deionized water and anhydrous ethanol, and dry at 80 °C for 12 h to obtain microspheres;

[0034] (4) Weigh 0.48g of Ni(NO3)2·6H2O and 0.3g of NH4Cl and dissolve them in 10mL of deionized water to prepare a mixture of Ni(NO3)2·6H2O and NH4Cl; add 0.2g of microspheres to 40mL of deionized water, mix by sonication, and then add 5mL of ammonia (25%). Sonicate for 10min to obtain a microsphere suspension. Add the microsphere suspension dropwise to the stirred mixture of Ni(NO3)2·6H2O and NH4Cl. After the precipitate is formed, continue stirring for 20min. Transfer the mixture to a polytetrafluoroethylene hydrothermal reactor and hydrothermally heat it at 140℃ for 72h. Separate the solid and liquid. Wash the solid three times with deionized water and anhydrous ethanol alternately, and dry it at 80℃ for 12h to obtain a functional composite microsphere catalyst.

[0035] (5) Take 0.1g of functional composite microsphere catalyst and load it into a quartz tube (6 mm × 4 mm × 40 cm). Pass Ar (30 mL / min) through it and raise the system temperature to 750℃. After reducing the catalyst with H2 / Ar (30 mL / min) mixed gas for 1 h, pass a mixed gas (CO2:CH4:Ar=1:1:1, space velocity=60000 mL / g·h, 750℃) through it. Analyze the tail gas after the reaction using a gas chromatograph. After 24 h, the conversion rates of CO2 and CH4 of the catalyst during the reforming reaction are still maintained at 68.85% and 66.26% respectively, and the H2 / CO ratio is maintained at 0.73.

[0036] Example 4: Method and application of preparing functional composite microsphere catalysts from titanium-containing slag

[0037] (1) The titanium-containing slag was placed in an electric oven at 65°C and dried for 45 hours. After ball milling for 2 hours, it was passed through a 180-mesh sieve to obtain titanium-containing slag powder.

[0038] (2) Place the titanium slag powder in a 5 mol / L hydrochloric acid solution (the volume ratio of acid to slag in mL:g is 12:1), stir and acid leaching at room temperature for 4 h, centrifuge, collect the solid, wash the solid with water until neutral, and obtain acid-treated slag (ATBFS).

[0039] (3) Place 2.5g of ATBFS in 72mL of 2mol / L NaOH solution and mix with a magnetic stirrer at 120℃ for 3h, then stop heating. After cooling to room temperature, add 10mL of anhydrous ethanol and 3mL of NH3·H2O (25%) in sequence, age for 12h, centrifuge, wash the solid three times alternately with deionized water and anhydrous ethanol, and dry at 80℃ for 12h to obtain microspheres;

[0040] (4) Weigh 0.48g of Ni(NO3)2·6H2O and 0.3g of NH4Cl and dissolve them in 10mL of deionized water to prepare a mixture of Ni(NO3)2·6H2O and NH4Cl; add 0.2g of microspheres to 40mL of deionized water, mix by sonication, and then add 5mL of ammonia (25%). Sonicate for 10min to obtain a microsphere suspension. Add the microsphere suspension dropwise to the stirred mixture of Ni(NO3)2·6H2O and NH4Cl. After the precipitate is formed, continue stirring for 20min. Transfer the mixture to a polytetrafluoroethylene hydrothermal reactor and hydrothermally heat it at 140℃ for 12h. Separate the solid and liquid. Wash the solid three times with deionized water and anhydrous ethanol alternately, and dry it at 80℃ for 12h to obtain a functional composite microsphere catalyst.

[0041] (5) Take 0.1g of functional composite microsphere catalyst and load it into a quartz tube (6 mm × 4 mm × 40 cm). Pass Ar (30 mL / min) through it and raise the system temperature to 650℃. After reducing the catalyst with H2 / Ar (30 mL / min) mixed gas for 1 h, pass mixed gas (CO2:CH4:Ar=1:1:1, space velocity=60000 mL / g·h, 650℃) through it. Analyze the tail gas after the reaction using a gas chromatograph. After 24 h, the conversion rates of CO2 and CH4 of the catalyst during the reforming reaction were still maintained at 45.17% and 43.12% respectively, and the H2 / CO ratio was maintained at 0.71.

[0042] As can be seen from Examples 1-4 above, the present invention uses titanium-containing solid waste slag as raw material and prepares functional composite microsphere catalyst materials through acid leaching, alkali leaching, hydrothermal and other methods; the material has good CO2-CH4 reforming effect.

Claims

1. Application of a functional composite microspherical catalyst prepared from titanium-containing slag in a CO2-CH4 reforming reaction. The functional composite microspherical catalyst is prepared by ball milling and sieving dry titanium-containing slag to obtain titanium-containing slag powder, stirring the titanium-containing slag powder in a hydrochloric acid solution at room temperature for 3-5 h, solid-liquid separation, washing the solid to neutral, obtaining acid-treated slag, adding the acid-treated slag to a NaOH solution, stirring at 100-150°C for 2-4 h, cooling to room temperature, sequentially adding anhydrous ethanol and ammonia water, adjusting the pH to 9-11, aging, solid-liquid separation, washing and drying the solid to obtain microspheres.

2. Use according to claim 1, characterized in that: The concentration of hydrochloric acid is 4-6 mol / L, and the concentration of NaOH solution is 1-3 mol / L.

3. Use according to claim 1, characterized in that: The mass-volume ratio g:mL of acid-treated slag to anhydrous ethanol is 1:4-7.5, and the mass-volume ratio g:mL of acid-treated slag to ammonia water is 1:1-2.

5.

4. Use according to claim 1, characterized in that: The mass-volume ratio g:mL of microspheres to ammonia water is 1:20-25, the mass ratio of microspheres to Ni(NO3)2·6H2O is 1:2-2.5, and the mass ratio of microspheres to NH4Cl is 1:1-2.

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