CN116037148A - CO oxidation catalyst taking waste rare earth-based denitration catalyst as raw material and preparation method thereof - Google Patents

Abstract

The invention discloses a CO oxidation catalyst taking waste rare earth based denitration catalyst as raw material and a preparation method thereof, wherein the catalyst is used for preparing a CO oxidation catalyst carrier by compounding the waste rare earth based denitration catalyst, diatomite and kaolin, and copper-manganese-lanthanum composite oxide (CuMnLaO) _x ) Is a catalytically active component. The waste rare earth-based denitration catalyst, diatomite and kaolin are prepared into a carrier through the processes of crushing, proportioning, calcining and the like, and CuMnLaO is prepared _x The precursor is prepared into a colloid solution, and then the carrier is immersed in CuMnLaO _x And drying and calcining the precursor colloid solution to obtain the CO oxidation catalyst. The CO oxidation catalyst of the invention not only can thoroughly solve the waste and old problemsThe harmless treatment of the rare earth-based denitration catalyst can also realize the high-added value recycling catalytic oxidation of CO, and has the advantages of simple process, low cost, excellent activity and great advantages in the field of catalytic oxidation of CO.

Description

A CO oxidation catalyst using waste rare earth-based denitrification catalyst as raw material and its preparation method

technical field

The invention provides a CO oxidation catalyst using a waste rare earth-based denitrification catalyst as a raw material and a preparation method thereof, which belong to the fields of recycling of waste products, environmental protection catalytic materials and air pollution control, and are especially suitable for low-temperature catalytic oxidation of CO.

Background technique

The rare earth-based denitrification catalyst is mainly a denitrification catalyst with environmentally friendly rare earth cerium-based composite oxides as the main active component. It is the second industrial flue gas denitrification catalyst that has achieved large-scale application in the world. This has led to a large number of waste rare earth-based denitrification catalysts. On the other hand, the Environmental Protection Network issued the "Notice on Strengthening the Supervision of Waste Flue Gas Denitrification Catalysts", which included the management, regeneration and utilization of waste flue gas denitrification catalysts into hazardous waste management, requiring the improvement of their regeneration, utilization and disposal capabilities. Therefore, the regeneration treatment or resource utilization of waste rare earth-based denitration catalysts has become an environmental protection problem that needs to be solved urgently.

With the continuous growth and massive consumption of coal, oil and natural gas production, CO produced by their incomplete combustion has gradually become one of the main air pollutants. CO inhaled into the human body will lead to tissue necrosis due to lack of oxygen, and in severe cases may endanger human life. In addition, CO will also produce photochemical reactions with NO _x , VOC, etc., causing damage to the ecological environment. At present, CO removal methods include adsorption, CO methanation, and CO catalytic oxidation, etc. Among them, CO catalytic oxidation technology has become the most important method and means to eliminate CO due to its advantages of simplicity, cheapness and high efficiency. The core of this technology is the catalyst. . In the related technologies of existing CO oxidation catalysts, patents (CN202010194813.4, CN202210319520.3, CN202210222829.0) use noble metals as active components, and the cost is too high. Patents (CN202210366374.X, CN201910543206.1, CN201811520481.3, CN201711349954.3) directly use active metals as carriers, or use composite oxides themselves as catalysts to catalyze the oxidation of CO. This method has a low utilization rate of metal oxides and limits Practical applications of catalysts.

The main component of waste rare earth-based denitration catalyst is titanium dioxide carrier with large specific surface area and good stability, and its main active component is environment-friendly rare earth cerium-based composite oxide _. High oxygen storage and release capacity and redox performance. The rich pore structure and large specific surface area of diatomite can better disperse active components. The addition of kaolin can make the catalyst shape better and improve the mechanical strength of the catalyst. Copper oxide and manganese oxide have excellent ability to catalyze the oxidation of CO due to their excellent redox properties. The addition of lanthanum oxide can increase the content of adsorbed oxygen in the catalyst and further promote the catalytic oxidation of CO. By preparing a copper-manganese-lanthanum composite oxide with stronger interaction, the CO oxidation activity can be further improved, the stability of the active component can be improved and the dosage of the active component can be reduced, the utilization rate of the metal active component can be improved, and the cost can be reduced. The successful application of the present invention will not only completely solve the problem of high value-added resource recycling of waste rare earth-based denitrification catalysts, but also better solve CO pollution as a CO oxidation catalyst, reduce the use cost of CO oxidation catalysts, and simplify the processing technology of catalysts , thus bringing huge economic, environmental and social benefits.

Contents of the invention

The purpose of the present invention is to provide a CO oxidation catalyst using waste rare earth-based denitrification catalysts as raw materials, so as to solve the problem of recycling waste catalysts. Another object of the present invention is to provide a preparation method of a CO oxidation catalyst with simple process, low cost and excellent activity in view of the current situation and existing problems of existing CO oxidation catalysts.

Concrete technical scheme of the present invention is:

A CO oxidation catalyst using waste rare earth-based denitration catalysts as raw materials. The catalyst is prepared from waste rare earth-based denitration catalysts, diatomite and kaolin as raw materials. The catalyst carrier is made of copper manganese lanthanum composite oxide (CuMnLaO _x ) components;

Among them, the mass ratio of waste rare earth-based denitration catalyst: diatomite: kaolin is 1: (0.1 ~ 2): (0.01 ~ 0.9); the molar ratio of Cu, Mn and La in the copper manganese lanthanum composite oxide is 1: ( 0.1～1): (0.1～1);

The mass ratio of the carrier: the catalytically active component is 1: (0.01-1).

In the technical scheme of the present invention: the mass ratio of waste rare earth-based denitrification catalyst: diatomite: kaolin is 1: (0.6～1.2): (0.05～0.1); the molar ratio of Cu, Mn and La elements in the copper manganese lanthanum composite oxide The ratio is 1: (0.6-0.8): (0.1-0.2); the mass ratio of carrier: catalytic active component is 1: (0.05-0.2).

In the technical scheme of the present invention: the waste rare earth-based denitrification catalyst is a commercial cerium-based denitrification catalyst after use, and in the catalyst: based on the carrier TiO ₂ , the content of the active component CeO ₂ is 5%-10%. The catalyst is WO ₃ with a content of 5%-10% and ZrO ₂ with a content of 1%-5%.

A kind of preparation method of above-mentioned catalyst, this method comprises the following steps:

(1) Preparation of carrier

Mix the waste rare earth-based denitration catalyst, diatomite powder, kaolin powder and deionized water evenly, and stir at 60-90°C for 1-2 hours to obtain a solid mixed solution; the mixed solution is filtered, dried, and calcined to obtain a catalyst carrier;

(2) Active component colloidal solution preparation

Put copper salt, manganese salt, lanthanum salt, complexing agent and deionized water in the same container, and keep stirring at 60-90°C for 2-4 hours until the solution is clear and transparent to obtain a colloidal solution of the active component.

(3) Catalyst preparation

The catalyst carrier obtained in step (1) is immersed in the active component colloid solution obtained in step (2) for 6-12 hours, and the impregnated catalyst carrier is taken out, dried and calcined to obtain a CO oxidation catalyst.

In the above preparation method: the drying temperature in step (1) is 60-90° C., and the drying time is 6-12 hours; the calcination temperature is 350-550° C., and the calcination time is 2-4 hours.

In the above preparation method: the copper salt described in step (2) is copper nitrate or copper acetate, the manganese salt is manganese nitrate or manganese acetate, and the lanthanum salt is lanthanum nitrate; the complexing agent is Citric Acid Monohydrate or EDTA.

In the above preparation method: the drying temperature in step (3) is 60-90° C., and the drying time is 6-12 hours; the calcination temperature is 350-550° C., and the calcination time is 2-4 hours.

Beneficial effect:

The catalyst of the present invention is suitable for CO purification and removal, and can achieve 100% CO removal efficiency at temperatures above 120°C. The main component of waste rare earth-based denitration catalyst is titanium dioxide carrier with large specific surface area and good stability, and its main active component is environment-friendly rare earth cerium-based composite oxide _. High oxygen storage and release capacity and redox performance. The rich pore structure and large specific surface area of diatomite can better disperse active components. The addition of kaolin can make the catalyst shape better and improve the mechanical strength of the catalyst. Copper oxide and manganese oxide have excellent ability to catalyze the oxidation of CO due to their excellent redox properties. The addition of lanthanum oxide can increase the content of adsorbed oxygen in the catalyst and further promote the catalytic oxidation of CO. By preparing a copper-manganese-lanthanum composite oxide with stronger interaction, the CO oxidation activity can be further improved, the stability of the active component can be improved and the dosage of the active component can be reduced, the utilization rate of the metal active component can be improved, and the cost can be reduced. Compared with the existing CO oxidation catalysts, the catalyst of the present invention will not only completely solve the problem of high value-added recycling of waste rare earth-based denitrification catalysts, but also better solve CO pollution and reduce the use of CO oxidation catalysts as a CO oxidation catalyst Cost, simplifies the processing technology of the catalyst, thus bringing huge economic, environmental and social benefits.

Description of drawings

Fig. 1 is a performance diagram of the CO conversion rate of the CO catalytic oxidation catalyst prepared in Examples 1-4.

Detailed ways

The present invention will be further described below in conjunction with the examples, but the protection scope of the present invention is not limited thereto.

The denitrification performance evaluation method of the catalyst of the present invention is as follows: CO intake concentration is 5000ppm, _O2 content is 20%, _N2 is used as carrier gas, and the total gas flow rate is 1000mL/min. The CO catalytic oxidation reaction was carried out in a fixed bed reaction system, and 3 mL of catalyst with a particle size of 40-60 mesh was taken and loaded into a quartz tube reactor with an inner diameter of 10 mm. The reaction space velocity (GHSV) was set to 20000 h ^-1 , and The reaction temperature range is 80-240°C, and the concentration change of CO before and after the reaction is monitored online by a flue gas analyzer.

The waste rare earth-based denitration catalyst is a used commercial cerium-based denitration catalyst, in which the active component is CeO ₂ (8%), the cocatalysts are WO ₃ (7%) and ZrO ₂ (3%), and the carrier is TiO ₂ .

Example 1:

(1) Preparation of carrier

After crushing and sieving the waste rare earth-based denitration catalyst, diatomite and kaolin, according to the mass ratio of waste rare earth-based denitration catalyst: diatomite: kaolin is 1:0.6:0.05, the mass ratio of waste rare earth-based denitration catalyst: deionized water The ratio is 1:10. Weigh 10g of waste rare earth-based denitrification catalyst powder, 6g of diatomite powder, 0.5g of kaolin powder and 100g of deionized water in the same container, and stir at 60°C for 1h to obtain a solid mixed solution; The above mixed solution was filtered, dried at 60°C for 6h, and calcined at 350°C for 2h to obtain a catalyst carrier.

(2) Active component colloidal solution preparation

According to the molar ratio of Cu:Mn:La element is 1:0.6:0.1, the mass ratio of total metal salt/citric acid monohydrate is 1:0.8, weigh 1.05g copper nitrate, 0.60g manganese nitrate, 0.18g lanthanum nitrate , 1.46g of citric acid monohydrate and 50g of deionized water were placed in the same container, and stirred continuously at 60°C for 2h until the solution was clear and transparent to obtain a colloidal solution of the active component.

(3) Catalyst preparation

According to the mass ratio of the carrier: the catalytic active component is 1:0.05, the catalyst carrier prepared in step (1) is immersed in the active component colloid solution prepared in step (2) for 6 hours, and the impregnated catalyst carrier is taken out at 60°C Drying for 6 hours and calcining at 350°C for 2 hours to obtain a CO oxidation catalyst.

(4) Catalyst performance evaluation is shown in Figure 1.

Example 2:

(1) Preparation of carrier

After crushing and sieving the waste rare earth-based denitration catalyst, diatomite and kaolin, according to the mass ratio of waste rare earth-based denitration catalyst: diatomite: kaolin is 1:0.6:0.05, the mass ratio of waste rare earth-based denitration catalyst: deionized water The ratio is 1:10. Weigh 10g of waste rare earth-based denitrification catalyst powder, 6g of diatomite powder, 0.5g of kaolin powder and 100g of deionized water in the same container, and stir at 60°C for 1h to obtain a solid mixed solution; The above mixed solution was filtered, dried at 60°C for 6h, and calcined at 350°C for 2h to obtain a catalyst carrier.

(2) Active component colloidal solution preparation

According to the molar ratio of Cu:Mn:La element is 1:0.6:0.1, the mass ratio of the total mass of metal salt/EDTA is 1:0.8, weigh 1.12g copper acetate, 0.58g manganese acetate, 0.18g nitric acid Lanthanum, 1.50 g of ethylenediamine tetraacetic acid and 50 g of deionized water were placed in the same container, and stirred continuously at 60°C for 2 hours until the solution was clear and transparent to obtain a colloidal solution of the active component.

(3) Catalyst preparation

According to the mass ratio of the carrier: the catalytic active component is 1:0.05, the catalyst carrier prepared in step (1) is immersed in the active component colloid solution prepared in step (2) for 6 hours, and the impregnated catalyst carrier is taken out at 60°C Drying for 6 hours and calcining at 350°C for 2 hours to obtain a CO oxidation catalyst.

(4) Catalyst performance evaluation is shown in Figure 1.

Example 3:

(1) Preparation of carrier

After crushing and sieving the waste rare earth-based denitration catalyst, diatomite and kaolin, according to the mass ratio of waste rare earth-based denitration catalyst: diatomite: kaolin is 1:1.2:0.1, the mass ratio of waste rare earth-based denitration catalyst: deionized water The ratio is 1:10. Weigh 10g of waste rare earth-based denitration catalyst powder, 12g of diatomite powder, 1g of kaolin powder and 100g of deionized water in the same container, and stir at 60°C for 1h to obtain a solid mixed solution; The mixed solution was filtered, dried at 60° C. for 2 h, and calcined at 350° C. for 2 h to obtain a catalyst carrier.

(2) Active component colloidal solution preparation

According to the molar ratio of Cu:Mn:La element is 1:0.8:0.2, and the mass ratio of the total mass of metal salt/EDTA is 1:1.2, weigh 5.06g of copper acetate, 3.50g of manganese acetate, and 1.65g of nitric acid Lanthanum, 12.25g of ethylenediaminetetraacetic acid and 50g of deionized water were placed in the same container, and stirred continuously at 60°C for 2h until the solution became clear and transparent to obtain a colloidal solution of the active component.

(3) Catalyst preparation

According to the mass ratio of carrier: catalytic active component is 1:0.2, the catalyst carrier prepared in step (1) is immersed in the active component colloid solution prepared in step (2) for 6h, and the impregnated catalyst carrier is taken out at 60°C Drying for 6 hours and calcining at 350°C for 2 hours to obtain a CO oxidation catalyst.

(4) Catalyst performance evaluation is shown in Figure 1.

Example 4:

(1) Preparation of carrier

After crushing and sieving the waste rare earth-based denitration catalyst, diatomite and kaolin, according to the mass ratio of waste rare earth-based denitration catalyst: diatomite: kaolin is 1:1.2:0.1, the mass ratio of waste rare earth-based denitration catalyst: deionized water The ratio is 1:10. Weigh 10g of waste rare earth-based denitration catalyst powder, 12g of diatomite powder, 1g of kaolin powder and 100g of deionized water in the same container, and stir at 90°C for 2h to obtain a solid mixed solution; The mixed solution was filtered, dried at 90°C for 12h, and calcined at 550°C for 4h to obtain a catalyst carrier.

(2) Active component colloidal solution preparation

According to the molar ratio of Cu:Mn:La element is 1:0.8:0.2, and the mass ratio of the total mass of metal salt/EDTA is 1:1.2, weigh 5.06g of copper acetate, 3.50g of manganese acetate, and 1.65g of nitric acid Lanthanum, 12.25g of ethylenediaminetetraacetic acid and 50g of deionized water were placed in the same container, and stirred continuously at 90°C for 4h until the solution became clear and transparent to obtain a colloidal solution of the active component.

(3) Catalyst preparation

According to the mass ratio of the carrier: the catalytic active component is 1:0.2, the catalyst carrier prepared in step (1) is immersed in the active component colloid solution prepared in step (2) for 12 hours, and the impregnated catalyst carrier is taken out at 90°C Drying for 12 hours and calcining at 550°C for 4 hours produces a CO oxidation catalyst.

(4) Catalyst performance evaluation is shown in Figure 1.

Claims (7)

1. A CO oxidation catalyst using waste rare earth based denitration catalyst as raw material is characterized in that the catalyst uses waste rare earth based denitration catalyst, diatomite and kaolin as raw materials to prepare a catalyst carrier, and copper-manganese-lanthanum composite oxide (CuMnLaO _x ) Is a catalytic active component;

wherein, the waste rare earth based denitration catalyst: diatomaceous earth: the mass ratio of the kaolin is 1: (0.1-2): (0.01-0.9); the copper-manganese-lanthanum composite oxide is a composite oxide composed of copper oxide, manganese oxide and lanthanum oxide, and the molar ratio of Cu, mn and La in the copper-manganese-lanthanum composite oxide is 1: (0.1-1): (0.1 to 1);

and (3) a carrier: the mass ratio of the catalytic active components is 1: (0.01-1).

2. The catalyst of claim 1, wherein: waste rare earth-based denitration catalyst: diatomaceous earth: the mass ratio of the kaolin is 1: (0.6-1.2): (0.05-0.1); the molar ratio of Cu, mn and La elements in the copper-manganese-lanthanum composite oxide is 1: (0.6-0.8): (0.1 to 0.2); and (3) a carrier: the mass ratio of the catalytic active components is 1: (0.05-0.2).

3. The catalyst of claim 1, wherein: the waste rare earth based denitration catalyst is a used commercial cerium based denitration catalyst, and the catalyst comprises the following components: in the form of TiO as carrier ₂ Based on the active component CeO ₂ Is 5-10% of WO, and promoter is 5-10% ₃ And ZrO in an amount of 1% to 5% ₂ 。

4. A process for preparing the catalyst of claim 1, wherein: the method comprises the following steps:

(1) Preparation of the Carrier

Uniformly mixing a waste rare earth-based denitration catalyst, diatomite powder, kaolin powder and deionized water, and stirring for 1-2 hours at 60-90 ℃ to obtain a solid mixed solution; the mixed solution is filtered, dried and calcined to obtain a catalyst carrier;

(2) Preparation of active component colloid solution

And (3) placing copper salt, manganese salt, lanthanum salt, complexing agent and deionized water in the same container, and continuously stirring for 2-4 hours at 60-90 ℃ until the solution is clear and transparent, thus obtaining the active component colloid solution.

(3) Catalyst preparation

And (3) immersing the catalyst carrier prepared in the step (1) in the active component colloid solution prepared in the step (2) for 6-12 h, taking out the immersed catalyst carrier, drying and calcining to prepare the CO oxidation catalyst.

5. The method according to claim 4, wherein: the drying temperature in the step (1) is 60-90 ℃ and the drying time is 6-12 h; the calcination temperature is 350-550 ℃, and the calcination time is 2-4 h.

6. The method according to claim 4, wherein: the copper salt in the step (2) is copper nitrate or copper acetate, the manganese salt is manganese nitrate or manganese acetate, and the lanthanum salt is lanthanum nitrate; the complexing agent is citric acid monohydrate or ethylenediamine tetraacetic acid.

7. The method according to claim 4, wherein: the drying temperature in the step (3) is 60-90 ℃ and the drying time is 6-12 h; the calcination temperature is 350-550 ℃, and the calcination time is 2-4 h.

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