Dust removal and denitration integrated filter cloth, preparation method and application thereof

Abstract

The application discloses a dust removal and denitration integrated filter cloth and a preparation method and application thereof, and takes needle felt as a carrier, fills a filamentous activated carbon denitration catalyst between a base layer and a back dust layer, and realizes multifunctionalization of the filter cloth in dust removal and denitration. The filled filamentous activated carbon denitration catalyst takes activated carbon as a carrier, takes sugar substances as activated carbon precursors, takes CeO2 as an active component, and takes La2O3 as a catalyst promoter. The three precursors are uniformly mixed, and a high-temperature centrifugal method is used to form a filamentous structure, and finally, the filamentous activated carbon denitration catalyst is formed by calcination under an inert atmosphere. The synthesized filamentous activated carbon denitration catalyst has a high specific surface area, and the active component and the catalyst promoter are uniformly dispersed. The prepared dust removal and denitration integrated filter cloth has good air permeability and high denitration efficiency.

Description

Technical Field

[0001] This invention provides a method for preparing an integrated dust removal and denitrification filter cloth, which belongs to the field of air pollution control. Background Technology

[0002] With the rapid development of industrialization and urbanization, industries such as thermal power, cement, and steel have flourished, resulting in the generation of large amounts of nitrogen oxides (NOx) smoke. NOx is a major cause of smog, acid rain, and photochemical smog. Among existing flue gas denitrification technologies, selective catalytic reduction (SCR) technology is highly efficient and stable, making it the mainstream technology and development direction for flue gas denitrification both domestically and internationally. Along with NOx, a large amount of dust is also emitted, which is one of the main air pollutants, especially fine particulate matter smaller than PM10. Prolonged suspension in the air reduces atmospheric visibility and contributes to the outbreak of various diseases.

[0003] Currently, most domestic patents related to integrated dust removal and denitrification achieve the simultaneous removal of NOx and dust by growing active components on filter cloth, such as patents CN102120116A, CN102145241A, and CN102772953A. This method can cause blockage of the filter cloth pores, resulting in poor air permeability; at the same time, the space velocity at the filter cloth pores is relatively high, which can easily cause the active components to detach. Synthesizing a highly efficient denitrification catalyst with a unique filamentous structure and filling it inside the filter cloth can effectively solve these problems. Summary of the Invention

[0004] The purpose of this invention is to address the problem of high NOx concentration in the tail gas of SCR denitrification towers by providing an integrated dust removal and denitrification filter cloth for NOx fine removal. Another purpose of this invention is to provide a method for preparing a filamentous activated carbon denitrification catalyst.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A dust removal and denitrification integrated filter cloth, the filter cloth uses needle-punched felt as a carrier, the needle-punched felt consists of a dust-attracting layer, a base layer and a dust-backing layer from the inside to the outside, and filamentous activated carbon denitrification catalyst is filled between the base layer and the dust-backing layer, and is prepared by needle punching and connecting.

[0007] The filamentous activated carbon denitrification catalyst uses activated carbon as a support, CeO2 as the active component, and La2O3 as a co-catalyst. Based on the mass of the support, the mass percentage of the active component is 3-5%, and the mass percentage of the co-catalyst is 1-3%.

[0008] A method for preparing the above-mentioned integrated dust removal and denitrification filter cloth, comprising the following steps:

[0009] (1) Dissolve the activated carbon precursor, active component precursor and co-catalyst precursor in water, then stir and dry at 80-100℃, and crush the resulting crystalline mixture and screen it into 10-20 mesh fine particles for later use.

[0010] (2) The fine particles were transferred to a high-temperature centrifuge and centrifuged at 200-250°C to obtain a filamentous mixture. The mixture was then calcined at 500-600°C under an inert atmosphere for 2-4 hours to obtain a filamentous activated carbon denitrification catalyst.

[0011] (3) Fill the space between the needle-punched felt base layer and the dust-backing layer with filamentous activated carbon denitrification catalyst and fix it by needle-punching and hooking.

[0012] In the above preparation method: the filamentous activated carbon denitration catalyst uses activated carbon as a support and fructose, glucose, lactose, sucrose or maltose as a support precursor; the active component precursor is cerium nitrate and the co-catalyst precursor is lanthanum nitrate.

[0013] In the above preparation method: the centrifugation speed in step (2) is 6000-8000 rad / min.

[0014] In the above preparation method: the inert atmosphere in step (2) is at least one of N2, Ar and He.

[0015] In the above preparation method: the thickness of the filamentous activated carbon denitrification catalyst filling in step (3) is 2 to 20 mm.

[0016] In the technical solution of the present invention, the catalyst is used in dust removal and denitrification, and the applicable temperature range of the catalyst is 150-200℃.

[0017] Beneficial effects:

[0018] The filamentous activated carbon denitrification catalyst synthesized in this invention has a high specific surface area and uniform dispersion of active components and co-catalysts. When the filamentous activated carbon denitrification catalyst is filled into the filter cloth interlayer, its unique filamentous structure effectively prevents catalyst exposure and ensures the air permeability of the filter cloth, while simultaneously providing secondary purification of the flue gas, achieving integrated dust removal and denitrification of the filter cloth. Attached Figure Description

[0019] Figure 1 This is a cross-sectional view of the filter cloth.

[0020] Figure 2 The diagram shows the catalytic activity of the examples. Detailed Implementation

[0021] The present invention will be further described below with reference to embodiments, but the scope of protection of the present invention is not limited thereto: Embodiment 1

[0022] 96.6 g of fructose, 1.514 g of cerium nitrate, and 0.532 g of lanthanum nitrate were weighed and dissolved in 100 ml of deionized water. The mixture was stirred and dried at 80 °C to obtain a crystalline mixture. The crystalline mixture was crushed and screened to 10–20 mesh fine particles, then transferred to a high-temperature centrifuge. The filamentous mixture was collected at 200 °C and 6000 rad / min. It was then transferred to an atmosphere furnace and calcined at 500 °C under N2 atmosphere for 2 h to obtain a filamentous activated carbon denitrification catalyst. The filamentous activated carbon denitrification catalyst was filled between the filter cloth base layer and the dust-backing layer to a thickness of 2 mm, and sealed and fixed by needle-punching. The mass percentage of the active component was 3%, and the mass percentage of the co-catalyst was 1%.

[0023] Activity test: Cut the filter cloth to fit the cross-section of the reaction tube, and then fill it into the center of the reaction tube. Introduce a mixed gas (space velocity 50,000 h⁻¹) into the reaction tube. -1 (NO 100ppm, O2 10%, NH3 100ppm, N2 as carrier gas), starting from room temperature, the temperature was increased, and the tail gas concentration was measured after holding at 20℃ for 20 minutes every 20℃ in the 100-200℃ range. Catalytic activity is shown in [reference needed]. Figure 2 .

[0024] Example 2

[0025] 99.5 g of glucose, 1.766 g of cerium nitrate, and 0.797 g of lanthanum nitrate were weighed and dissolved in 100 ml of deionized water. The mixture was stirred and dried at 90 °C to obtain a crystalline mixture. The crystalline mixture was crushed and screened to 10–20 mesh fine particles, then transferred to a high-temperature centrifuge. The filamentous mixture was collected at 210 °C and 6500 rad / min. It was then transferred to an atmosphere furnace and calcined at 550 °C under an Ar atmosphere for 3 h to obtain a filamentous activated carbon denitrification catalyst. The filamentous activated carbon denitrification catalyst was filled between a filter cloth base layer and a dust-backing layer to a thickness of 5 mm, and sealed and fixed by needle-punching. The mass percentage of the active component was 3.5%, and the mass percentage of the co-catalyst was 1.5%.

[0026] Activity test: Cut the filter cloth to fit the cross-section of the reaction tube, and then fill it into the center of the reaction tube. Introduce a mixed gas (space velocity 50,000 h⁻¹) into the reaction tube. -1 (NO 100ppm, O2 10%, NH3 100ppm, N2 as carrier gas), starting from room temperature, the temperature was increased, and the tail gas concentration was measured after holding at 20℃ for 20 minutes every 20℃ in the 100-200℃ range. Catalytic activity is shown in [reference needed]. Figure 2 .

[0027] Example 3

[0028] 92.6 g of lactose, 2.018 g of cerium nitrate, and 1.063 g of lanthanum nitrate were weighed and dissolved in 100 ml of deionized water. The mixture was stirred and dried at 100 °C to obtain a crystalline mixture. The crystalline mixture was crushed and screened to 10–20 mesh fine particles, then transferred to a high-temperature centrifuge. The filamentous mixture was collected at 230 °C and 7000 rad / min. It was then transferred to an atmosphere furnace and calcined at 600 °C under a He atmosphere for 4 h to obtain a filamentous activated carbon denitrification catalyst. The filamentous activated carbon denitrification catalyst was filled between a filter cloth base layer and a dust-backing layer to a thickness of 10 mm, and sealed and fixed by needle-punching. The mass percentage of the active component was 4%, and the mass percentage of the co-catalyst was 2%.

[0029] Activity test: Cut the filter cloth to fit the cross-section of the reaction tube, and then fill it into the center of the reaction tube. Introduce a mixed gas (space velocity 50,000 h⁻¹) into the reaction tube. -1 (NO 100ppm, O2 10%, NH3 100ppm, N2 as carrier gas), starting from room temperature, the temperature was increased, and the tail gas concentration was measured after holding at 20℃ for 20 minutes every 20℃ in the 100-200℃ range. Catalytic activity is shown in [reference needed]. Figure 2 .

[0030] Example 4

[0031] 114.3 g of maltose, 2.271 g of cerium nitrate, and 1.329 g of lanthanum nitrate were weighed and dissolved in 100 ml of deionized water. The mixture was stirred and dried at 90 °C to obtain a crystalline mixture. The crystalline mixture was crushed and screened to 10–20 mesh fine particles, then transferred to a high-temperature centrifuge. The filamentous mixture was collected at 220 °C and 7500 rad / min. It was then transferred to an atmosphere furnace and calcined at 500 °C under N2 atmosphere for 2 h to obtain a filamentous activated carbon denitrification catalyst. The filamentous activated carbon denitrification catalyst was filled between the filter cloth base layer and the dust-backing layer to a thickness of 15 mm, and sealed and fixed by needle-punching. The mass percentage of the active component was 4.5%, and the mass percentage of the co-catalyst was 2.5%.

[0032] Activity test: Cut the filter cloth to fit the cross-section of the reaction tube, and then fill it into the center of the reaction tube. Introduce a mixed gas (space velocity 50,000 h⁻¹) into the reaction tube. -1 (NO 100ppm, O2 10%, NH3 100ppm, N2 as carrier gas), starting from room temperature, the temperature was increased, and the tail gas concentration was measured after holding at 20℃ for 20 minutes every 20℃ in the 100-200℃ range. Catalytic activity is shown in [reference needed]. Figure 2 .

[0033] Example 5

[0034] 89.3 g of sucrose, 2.523 g of cerium nitrate, and 1.595 g of lanthanum nitrate were weighed and dissolved in 100 ml of deionized water. The mixture was stirred and dried at 100 °C to obtain a crystalline mixture. The crystalline mixture was crushed and screened to 10–20 mesh fine particles, then transferred to a high-temperature centrifuge. The filamentous mixture was collected at 250 °C and 8000 rad / min. It was then transferred to an atmosphere furnace and calcined at 600 °C under a N2 atmosphere for 3 h to obtain a filamentous activated carbon denitrification catalyst. The filamentous activated carbon denitrification catalyst was filled between a filter cloth base layer and a dust-backing layer to a thickness of 20 mm, and sealed and fixed by needle-punching. The mass percentage of the active component was 5%, and the mass percentage of the co-catalyst was 3%.

[0035] Activity test: Cut the filter cloth to fit the cross-section of the reaction tube, and then fill it into the center of the reaction tube. Introduce a mixed gas (space velocity 50,000 h⁻¹) into the reaction tube. -1 (NO 100ppm, O2 10%, NH3 100ppm, N2 as carrier gas), starting from room temperature, the temperature was increased, and the tail gas concentration was measured after holding at 20℃ for 20 minutes every 20℃ in the 100-200℃ range. Catalytic activity is shown in [reference needed]. Figure 2 .

[0036] Comparative Example 1

[0037] 2.523g of cerium nitrate and 1.595g of lanthanum nitrate were dissolved in 50ml of deionized water. Then, 20g of 10-20 mesh activated carbon was added to the solution and stirred for 2 hours. The activated carbon was filtered out and thoroughly dried. The dried activated carbon was transferred to an atmosphere furnace and calcined at 300℃ under N2 atmosphere for 3 hours to obtain an activated carbon denitrification catalyst. The activated carbon denitrification catalyst was filled between the filter cloth base layer and the dust-backing layer to a thickness of 20mm and sealed and fixed by needle-punching.

[0038] Activity test: Cut the filter cloth to fit the cross-section of the reaction tube, and then fill it into the center of the reaction tube. Introduce a mixed gas (space velocity 50,000 h⁻¹) into the reaction tube. -1 (NO 100ppm, O2 10%, NH3 100ppm, N2 as carrier gas), starting from room temperature, the temperature was increased, and the tail gas concentration was measured after holding at 20℃ for 20 minutes every 20℃ in the 100-200℃ range. Catalytic activity is shown in [reference needed]. Figure 2 .

[0039] Comparative results: Compared with Example 5, the denitrification activity in the 100-200℃ range was 9-28%, which is low, and black small particles appeared in the back dust layer, making the catalyst easy to expose.

Claims

1. A method for preparing an integrated dust removal and denitrification filter cloth, characterized in that: The filter cloth uses needle-punched felt as a carrier. The needle-punched felt consists of a dust-attracting layer, a base layer, and a dust-backing layer from the inside out. Filamentous activated carbon denitrification catalyst is filled between the base layer and the dust-backing layer. The filter cloth is prepared by needle-punching and connecting the layers. The filamentous activated carbon denitrification catalyst uses activated carbon as a support, CeO2 as the active component, and La2O3 as a co-catalyst. Based on the mass of the support, the mass percentage of the active component is 3-5%, and the mass percentage of the co-catalyst is 1-3%. The steps of this method are as follows: (1) Dissolve the activated carbon precursor, active component precursor and co-catalyst precursor in water, then stir and dry at 80~100℃, and crush the resulting crystalline mixture and screen it into 10~20 mesh fine particles for later use. (2) The fine particles are transferred to a high-temperature centrifuge and centrifuged at 200~250℃ to harvest the filamentous mixture and calcined at 500~600℃ in an inert atmosphere for 2~4h to obtain the filamentous activated carbon denitrification catalyst; (3) Fill the space between the needle-punched felt base layer and the dust-backing layer with filamentous activated carbon denitrification catalyst and fix it by needle-punching hooking method; Among them, the filamentous activated carbon denitrification catalyst uses activated carbon as a support and fructose, glucose, lactose, sucrose or maltose as a precursor; the active component precursor is cerium nitrate, and the co-catalyst precursor is lanthanum nitrate.

2. The preparation method according to claim 1, characterized in that: Step (2) The centrifugation speed is 6000~8000 rad / min.

3. The preparation method according to claim 1, characterized in that: Step (2) The inert atmosphere is at least one of N2, Ar and He.

4. The preparation method according to claim 1, characterized in that: Step (3) The thickness of the filamentous activated carbon denitrification catalyst packing is 2~20mm.

5. The application of the catalyst prepared according to claim 1 in dust removal and denitrification.

6. The application according to claim 5, characterized in that... The catalyst is suitable for temperatures ranging from 150 to 200°C.

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