A deodorizing catalyst for a vehicle-mounted incineration toilet, a preparation method thereof, and use thereof

Abstract

The present application relates to a kind of deodorization catalysts suitable for vehicle-mounted incineration toilet and its preparation method and use, the preparation method includes the following steps: providing aluminum-based carrier;- copper compound, nickel compound, iron compound and manganese compound are sequentially loaded on the aluminum-based carrier, and the deodorization catalyst is prepared.The deodorization catalyst includes aluminum-based carrier and copper compound, nickel compound, iron compound and manganese compound loaded on the aluminum-based carrier.The deodorization catalyst of the present application is stable in nature, can be mass-produced in industrialized batch, has integrated structure, is suitable for vehicle-mounted scene, can effectively catalyze degradation of substance with irritating odor at lower temperature, realizes the effective removal of odor of excrement combustion tail gas.

Description

Technical Field

[0001] This invention relates to the field of catalysts, and in particular to a deodorizing catalyst, its preparation method, and its uses. Background Technology

[0002] The way people travel is becoming increasingly diversified. With independent travel becoming a significant part of tourism, RV travel is poised to become a focal point. Comfort and convenience in enclosed environments are key concerns for RV manufacturers both domestically and internationally. Surveys indicate that 87% of users do not want to handle their own RV toilet waste, leading to the development of various RV toilets that do not require manual cleaning. These include biodegradable toilets, incinerators, pulverizers, and microbial biodegradable toilets. Incinerators offer the most thorough and rapid waste treatment, but they produce large amounts of harmful odors during combustion, easily polluting the surrounding environment. Furthermore, the backflow into the enclosed space of the RV can cause discomfort and harm to health. Therefore, the exhaust fumes from incinerators require catalysts to remove their distinctive odors. The odor of human feces is complex, containing volatile fatty acids, sulfur compounds, skatole, and amines. Developing a catalyst capable of effectively degrading these complex substances has become a significant challenge.

[0003] CN 114555136 A discloses a deodorizing catalyst comprising a copper-manganese composite oxide, zeolite, and activated carbon, which can effectively remove odors containing sulfur compounds and amine compounds, and is particularly suitable for odors containing methanethiol and trimethylamine. CN 115551634 A discloses a deodorizing catalyst for refrigerators comprising a Cu-Mn composite oxide and zeolite with a silica / alumina molar ratio of more than 100, used to remove methanethiol and inhibit the release of dimethyl disulfide. The above patents target two odor components in residences and refrigerators, but do not test the removal effect on acids and skatole, and are not applicable to exhaust gas treatment from excrement combustion.

[0004] CN 116966901 A discloses a deodorizing catalyst comprising a support and 0.05%-2% of an active component (the main active component being platinum), which can catalytically treat odors without special conditions. The catalyst in this patent must contain platinum, a precious metal, and is only suitable for toilet overflow odors, not for fecal incineration.

[0005] CN 116984026 A discloses a modified mesoporous metal oxide with an amino-containing trimethoxysilane surface, used to effectively remove harmful gases such as formaldehyde and methanethiol. The thermally stable layer formed on the catalyst surface extends its service life and achieves efficient deodorization while removing formaldehyde. However, the catalyst used in this patent is granular, resulting in a large pressure drop, making it unsuitable for situations involving the combustion of large volumes of waste.

[0006] CN 116832530 A discloses a fiber filter material supported on an aldehyde and odor removal catalyst. The catalyst uses a mesoporous metal oxide as the active support and is grafted with an amino-containing trimethylsiloxane on its surface, exhibiting excellent aldehyde and odor removal performance. Through in-situ loading technology, the catalyst can be loaded onto the inner and outer surfaces of the modified polypropylene fiber during the synthesis process, avoiding the covering of active sites and preserving catalytic performance. However, the polypropylene fiber material used in this patent has poor heat transfer properties and is not suitable for applications requiring high temperatures for the catalytic removal of skatole and acetic acid. Summary of the Invention

[0007] To address the challenges of industrial-scale preparation and application of deodorizing catalysts for incinerated toilets in vehicles, this invention provides a deodorizing catalyst, its preparation method, and its uses. Utilizing the advantages of an integral alumina support layer and the resistance of the active material to detachment, this invention successfully prepares a deodorizing catalyst for incinerated toilets in vehicles, providing a reference for the industrial-scale preparation of deodorizing catalysts and their widespread application in efficiently removing odors generated from the combustion of excrement.

[0008] To achieve the above objectives, the present invention provides the following technical solution: One of the technical solutions of the present invention is to provide a method for preparing a deodorizing catalyst, comprising the following steps: - Provides aluminum-based carriers; - The deodorizing catalyst is prepared by loading copper compounds, nickel compounds, iron compounds and manganese compounds onto the aluminum-based support.

[0009] According to a preferred embodiment, the deodorizing catalyst is prepared by first loading copper, nickel, and iron compounds onto the aluminum-based support, followed by loading a manganese compound. The loading order of the copper, nickel, and iron compounds is not specified.

[0010] According to a preferred embodiment, the aluminum-based support comprises a γ-Al₂O₃ / Al aluminum-based support.

[0011] According to a preferred embodiment, the step of providing an aluminum-based carrier includes: - Anodize the aluminum substrate; - The anodized aluminum substrate is subjected to a single firing process; - A hot water fusion reaction is carried out on an aluminum substrate that has undergone one firing. - The aluminum substrate that has undergone hot water sintering reaction is then subjected to secondary calcination.

[0012] According to a preferred embodiment, the aluminum substrate is selected from one or more of aluminum corrugated mesh, aluminum flat mesh, aluminum corrugated plate, or aluminum flat plate.

[0013] According to a preferred embodiment, before anodizing, the aluminum substrate is pretreated with 5-15 wt% (preferably 6-14 wt%, 7-13 wt%, 8-12 wt%, 9-11 wt%) NaOH solution and 5-15 wt% (preferably 6-14 wt%, 7-13 wt%, 8-12 wt%, 9-11 wt%) HNO3 solution for 1-5 min (preferably 2-4 min).

[0014] According to a preferred embodiment, the method for preparing the deodorizing catalyst of the present invention satisfies the following conditions: The conditions for anodic oxidation are as follows: the electrolyte is an oxalic acid solution of 0.1-0.8 mol / L (preferably 0.2-0.7 mol / L, 0.3-0.6 mol / L, or 0.4-0.5 mol / L), the temperature is 15-25℃ (preferably 16-24℃, 17-23℃, 18-22℃, or 19-21℃), and the current density is 25-50 A / m. 2 (Preferred 27-48 A / m) 2 29-46 A / m 2 31-44 A / m 2 33-42A / m 2 35-40 A / m 2 37-38 A / m 2 The time is 8-16 h (preferably 7-15 h, 8-14 h, 9-13 h, 10-12 h). - The temperature of the first roasting is 350-550 ℃ (preferably 370-530 ℃, 390-510 ℃, 410-490 ℃, 430-470 ℃, 450-460 ℃), and the time is 1-3 h (preferably 1.5-2.5 h); - The temperature of the hot water hydration reaction is 30-95 ℃ (preferably 40-90 ℃, 50-80 ℃, 60-70 ℃), and the time is 60-120 min (preferably 70-110 min, 80-100 min). - The secondary roasting temperature is 350-550 ℃ (preferably 370-530 ℃, 390-510 ℃, 410-490 ℃, 430-470 ℃, 450-460 ℃), and the time is 3-6 h (preferably 4-5 h).

[0015] According to a preferred embodiment, the copper compound includes copper oxide, the nickel compound includes nickel oxide, the iron compound includes iron oxide, and the manganese compound includes manganese dioxide and manganese carbonate.

[0016] According to a preferred embodiment, the step of loading the copper compound includes: - Immerse the aluminum-based support in a copper nitrate solution with a concentration of 1-2 mol / L (preferably 1.2-1.8 mol / L, 1.4-1.6 mol / L) for 8-20 h (preferably 9-19 h, 10-18 h, 11-17 h, 12-16 h, 13-15 h) at an immersion temperature of 10-35 ℃ (preferably 12-33 ℃, 14-31 ℃, 16-29 ℃, 18-27 ℃, 20-25 ℃). - Calcination at 400-550 ℃ (preferably 420-530 ℃, 440-510 ℃, 460-490 ℃, 470-480 ℃) for 3-6 h (preferably 4-5 h).

[0017] According to a preferred embodiment, the step of loading a nickel compound includes: - Immerse the aluminum-based support in a nickel nitrate solution with a concentration of 0.5-1.5 mol / L (preferably 0.7-1.3 mol / L, 0.9-1.1 mol / L) for 8-20 h (preferably 9-19 h, 10-18 h, 11-17 h, 12-16 h, 13-15 h) at an immersion temperature of 10-35 ℃ (preferably 12-33 ℃, 14-31 ℃, 16-29 ℃, 18-27 ℃, 20-25 ℃). - Calcination at 400-550 ℃ (preferably 420-530 ℃, 440-510 ℃, 460-490 ℃, 470-480 ℃) for 3-6 h (preferably 4-5 h).

[0018] According to a preferred embodiment, the step of loading the iron compound includes: - Immerse the aluminum-based support in a ferric nitrate solution with a concentration of 0.02-0.08 mol / L (preferably 0.03-0.07 mol / L, 0.04-0.06 mol / L) for 6-22 h (preferably 8-20 h, 9-19 h, 10-18 h, 11-17 h, 12-16 h, 13-15 h) at an immersion temperature of 10-35 ℃ (preferably 12-33 ℃, 14-31 ℃, 16-29 ℃, 18-27 ℃, 20-25 ℃). - Calcination at 250-500 ℃ (preferably 270-480 ℃, 290-460 ℃, 310-440 ℃, 330-420 ℃, 350-400 ℃, 370-380 ℃) for 3-6 h (preferably 4-5 h).

[0019] According to a preferred embodiment, the step of loading the manganese compound includes: - An aluminum-based support loaded with copper, nickel, and iron compounds is immersed in a solution of manganese acetate at a concentration of 0.02-0.08 mol / L (preferably 0.03-0.07 mol / L, 0.04-0.06 mol / L) and urea at a concentration of 0.2-0.8 mol / L (preferably 0.3-0.7 mol / L, 0.4-0.6 mol / L) for 8-24 h (preferably 10-22 h, 12-20 h, 14-18 h, 16-17 h) at an immersion temperature of 80-95 ℃ (preferably 82-93 ℃, 84-91 ℃, 86-89 ℃, 87-88 ℃). - Calcination at 250-500 ℃ (preferably 270-480 ℃, 290-460 ℃, 310-440 ℃, 330-420 ℃, 350-400 ℃, 370-380 ℃) for 3-6 h (preferably 4-5 h).

[0020] Another aspect of the present invention relates to a deodorizing catalyst comprising an aluminum-based support and copper, nickel, iron and manganese compounds supported on the aluminum-based support.

[0021] According to a preferred embodiment, copper compounds, nickel compounds, and iron compounds are first loaded onto the aluminum-based carrier, followed by manganese compounds.

[0022] According to a preferred embodiment, the aluminum-based support comprises a γ-Al₂O₃ / Al aluminum-based support.

[0023] According to a preferred embodiment, the copper compound includes copper oxide, the nickel compound includes nickel oxide, the iron compound includes iron oxide, and the manganese compound includes manganese dioxide and manganese carbonate.

[0024] According to a preferred embodiment, based on the aluminum-based carrier, the copper loading is 1.6-5.3 wt% (preferably 2-5 wt%, 3-4 wt%), the nickel loading is 0.9-4.7 wt% (preferably 1-4 wt%, 2-3 wt%), the iron loading is 4.9-8.4 wt% (preferably 5-8 wt%, 6-7 wt%), and the manganese loading is 5.7-14.3 wt% (preferably 6-14 wt%, 7-13 wt%, 8-12 wt%, 9-11 wt%).

[0025] According to a preferred embodiment, the aluminum-based carrier is obtained from an aluminum substrate, which is selected from one or more of aluminum corrugated mesh, aluminum flat mesh, aluminum corrugated plate, or aluminum flat plate.

[0026] Another aspect of the present invention relates to the use of the deodorizing catalyst in the deodorization of exhaust gas from excrement combustion.

[0027] The beneficial technical effects of the present invention are as follows: This invention utilizes a stable, structured metal support to prepare a multi-component catalyst, which is less prone to detachment of various active components and is suitable for automotive applications. By leveraging the interactions between copper, nickel, iron, and manganese, it effectively catalyzes the degradation of substances with irritating odors such as ammonia, skatole, acetic acid, and hydrogen sulfide at lower temperatures, achieving effective removal of odors from exhaust gases after waste combustion.

[0028] The catalyst preparation process disclosed in this invention is safe, can be mass-produced industrially, and its integrated structure makes it easy to replace, making it more suitable for automotive applications. The copper-nickel-iron-manganese catalyst can efficiently reduce ammonia, skatole, acetic acid, hydrogen sulfide, and other substances in odorous gases, achieving a 100% conversion rate for 2600 ppm ammonia at 150 °C. Attached Figure Description

[0029] Figure 1 This is a flowchart of a method for preparing a deodorizing catalyst according to a preferred embodiment of the present invention.

[0030] Figure 2 Scanning electron microscope images of the CuNiFeMn / γ-Al2O3 / Al (a) prepared in Example 1, Cu / γ-Al2O3 / Al (b) prepared in Comparative Example 1, Ni / γ-Al2O3 / Al (c) prepared in Comparative Example 2, Fe / γ-Al2O3 / Al (d) prepared in Comparative Example 3, and Mn / γ-Al2O3 / Al (e) prepared in Comparative Example 4.

[0031] Figure 3 The images show the CuNiFeMn / γ-Al2O3 / Al flat mesh catalyst prepared in Example 1 (a), the CuNiFeMn / γ-Al2O3 / Al corrugated mesh catalyst prepared in Example 2 (b), the CuNiFeMn / γ-Al2O3 / Al plate catalyst prepared in Example 3 arranged in a regular flow channel (c), and the CuNiFeMn / γ-Al2O3 / Al plate catalyst prepared in Example 4 rolled up into a static mixer shape (d).

[0032] Figure 4 The XRD patterns of the catalysts prepared in Example 1 and Comparative Examples 1-4 and their γ-Al2O3 / Al supports are shown.

[0033] Figure 5 This is a schematic diagram illustrating the degradation effect of the catalysts prepared in Comparative Examples 1-4 on ammonia.

[0034] Figure 6 This is a schematic diagram illustrating the degradation effect of the catalysts prepared in Comparative Examples 1-4 on acetic acid.

[0035] Figure 7 The diagram illustrates the degradation effect of the catalysts prepared in Comparative Examples 1-4 on skatole.

[0036] Figure 8 This is a schematic diagram illustrating the degradation effect of the catalysts prepared in Comparative Examples 5-7 on ammonia.

[0037] Figure 9 This is a schematic diagram illustrating the degradation effect of the catalysts prepared for comparative examples 8-9 on ammonia.

[0038] Figure 10 This is a schematic diagram illustrating the degradation effect of the catalysts prepared in Examples 1-5 on ammonia.

[0039] Figure 11 This is a schematic diagram illustrating the degradation effect of the catalysts prepared in Examples 1-5 on acetic acid.

[0040] Figure 12 This is a schematic diagram illustrating the degradation effect of the catalysts prepared in Examples 1-5 on skatole.

[0041] Figure 13 The catalyst prepared in Example 6 is used to treat the exhaust gas from actual waste combustion, and the condensate after treatment is compared with the condensate without catalyst treatment.

[0042] Figure 14 The catalyst prepared in Example 6 was used to treat the exhaust gas from the combustion of actual waste, and the concentrations of hydrogen sulfide, formaldehyde, and TVOC (total volatile organic compounds) at the outlet changed over time.

[0043] Figure 15 This is a schematic diagram illustrating the degradation effect of the catalyst prepared in Example 7 on ammonia.

[0044] Figure 16 This is a schematic diagram illustrating the degradation effect of the catalyst prepared in Example 8 on ammonia.

[0045] Figure 17 This is a schematic diagram illustrating the degradation effect of the catalyst prepared in Example 9 on ammonia.

[0046] Figure 18 This is a schematic diagram illustrating the degradation effect of the catalyst prepared in Example 10 on ammonia.

[0047] Figure 19 This is a schematic diagram illustrating the degradation effect of the catalyst prepared in Example 11 on ammonia. Detailed Implementation

[0048] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention. It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the present invention.

[0049] Furthermore, regarding the numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included within this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0050] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar to or equivalent to those described herein may be used in the implementation or testing of this invention.

[0051] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0052] Figure 1 The flowchart below illustrates a method for preparing a deodorizing catalyst according to a preferred embodiment of the present invention. The method includes: aluminum substrate pretreatment, aluminum substrate anodizing, primary calcination of the aluminum substrate, thermal annealing reaction of the aluminum substrate, secondary calcination of the aluminum substrate, and loading with copper, nickel, iron, and manganese compounds. The various steps in the preparation method will be described in detail below with the aid of examples.

[0053] To demonstrate the technical effects achieved by this invention, the catalysts obtained in the examples and comparative examples were evaluated for their degradation effects on acetic acid, ammonia, and skatole using the following activity evaluation methods: - In the ammonia removal activity evaluation, ammonia gas at a flow rate of 44.4 ml / min and air at a flow rate of 400 ml / min were introduced into a reaction tube packed with catalyst. After stabilization for 20 min at different reaction temperatures, the outlet ammonia concentration was measured using gas chromatography.

[0054] In the evaluation of acetic acid combustion activity, acetic acid solution was pumped into the vaporization chamber and then introduced into the reaction tube packed with catalyst at a flow rate of 800 mL / min. After stabilizing for 20 min at different reaction temperatures, the condensate at the outlet was collected, and the concentration of acetic acid at the outlet was measured using gas chromatography.

[0055] - In the evaluation of skatole removal activity, a 10 mg / L skatole solution was evaporated and introduced into a reaction tube packed with catalyst, and air was introduced at a flow rate of 400 ml / min. After stabilizing for 20 min at different reaction temperatures, the outlet condensate was collected, and the odor intensity of the outlet exhaust gas and condensate was determined by olfactory identification.

[0056] Example 1 The aluminum mesh was pretreated with 10 wt% NaOH solution for 4 min and 10 wt% HNO3 solution for 2 min, respectively, and then placed in an anodizing bath at 20 ℃ and a current density of 30 A / m. 2 The 0.4 mol / L oxalic acid solution was anoly oxidized for 12 h, and after natural drying, it was calcined at 350 °C for 1 h; then hydrated in deionized water at 80 °C for 60 min, and after natural drying, it was calcined again at 500 °C for 4 h to obtain the network γ-Al2O3 / Al support.

[0057] The mesh-like γ-Al₂O₃ / Al support was immersed in a 1.5 mol / L copper nitrate solution at 25 °C for 12 h, then rinsed with deionized water and air-dried. The dried sample was calcined in a muffle furnace at 500 °C for 4 h, and the resulting sample was designated Cu / γ-Al₂O₃ / Al. The Cu / γ-Al₂O₃ / Al support was immersed in a 1.0 mol / L nickel nitrate solution at 25 °C for 12 h, then rinsed with deionized water and air-dried. The dried sample was calcined in a muffle furnace at 500 °C for 4 h, and the resulting sample was designated CuNi / γ-Al₂O₃ / Al. The CuNi / γ-Al₂O₃ / Al support was immersed in a 0.05 mol / L ferric nitrate solution at 25 °C for 10 h, then rinsed with deionized water and air-dried. The dried sample was calcined in a muffle furnace at 500 °C for 4 h, and the resulting sample was designated CuNiFe / γ-Al₂O₃ / Al. The CuNiFe / γ-Al₂O₃ / Al sample was then placed in a solution of 0.05 mol / L manganese acetate and 0.5 mol / L urea and kept at 90 °C for 12 h. The surface was then rinsed with deionized water to remove any remaining solution. After air drying, the sample was calcined at 400 °C for 4 h to obtain the network-like CuNiFeMn / γ-Al₂O₃ / Al catalyst. Figure 2 Image (a) shows a scanning electron microscope image of the network CuNiFeMn / γ-Al2O3 / Al catalyst prepared in Example 1. It can be seen that active metal compounds of Cu, Ni, Fe, and Mn can all be successfully loaded onto the surface of the γ-Al2O3 / Al support. Repeated impregnation and loading do not damage the porous structure of the catalyst, allowing gas to reach the active sites through the gaps between surface particles. Figure 2(d) shows that the irregular cubic structures on the surface are manganese compounds. XRD analysis revealed that the composition of the network CuNiFeMn / γ-Al2O3 / Al catalyst is CuO, NiO, Fe2O3, MnCO3, MnO2, and γ-Al2O3. The loadings of Cu, Ni, Fe, and Mn are 2.8, 2.1, 5.8, and 7.4 wt%, respectively (see [reference]). Figure 4 ).

[0058] The obtained mesh-like CuNiFeMn / γ-Al2O3 / Al catalyst was cut into 10 circular discs, totaling 2.5 g, with each disc weighing 0.25 g. These discs were then packed into a fixed-bed reactor with a diameter of 25 mm. Figure 3 As shown in (a) above, the ammonia removal activity evaluation, acetic acid combustion activity evaluation and skatole removal activity evaluation described above were then performed.

[0059] Example 2 Compared to Example 1, the aluminum substrate is an aluminum corrugated mesh, and other conditions are the same as in Example 1.

[0060] Example 3 Compared to Example 1, the aluminum substrate is an aluminum plate, and the anodizing current density is 50 A / m. 2 The obtained plate-shaped CuNiFeMn / γ-Al2O3 / Al catalyst was cut into 11 rectangles, each 60 mm long, 19 mm wide, and 0.4 mm thick, and arranged into regular flow channels with a spacing of 0.8 mm for activity evaluation. Other conditions were the same as in Example 1.

[0061] Example 4 Compared to Example 1, the aluminum substrate is an aluminum plate, and the anodizing current density is 50 A / m. 2 The obtained plate-shaped CuNiFeMn / γ-Al2O3 / Al catalyst was cut into strips 10 cm long and 2.5 cm wide and twisted into the shape of a static mixer for activity evaluation. Other conditions were the same as in Example 1.

[0062] Example 5 Compared with Example 4, the aluminum substrate is a corrugated aluminum plate, and other conditions are the same as in Example 4.

[0063] Example 6 Compared to Example 3, tests were conducted in a real excrement combustion scenario using 600 g of feces and 1400 g of urine. Forty-five rectangular flat catalyst plates, each 260 mm long, 26 mm wide, and 0.8 mm thick, were arranged in a regular flow channel with a 1 mm spacing. The combustion was carried out at 240-300 °C for 4-18 m... 3 The test was conducted at an airflow rate of / h, with other conditions being the same as in Example 3.

[0064] Example 7 Compared with Example 1, the anodizing time was changed to 14 h and the current density was changed to 25 A / m. 2 Alternatively, the anodizing time can be changed to 8 hours, and the current density to 35 A / m. 2 Other conditions were the same as in Example 1. The compositions of the two catalysts obtained were CuO, NiO, Fe2O3, MnCO3, MnO2, and γ-Al2O3, respectively. The loadings of Cu, Ni, Fe, and Mn were close to 2.8, 2.1, 5.8, and 7.4 wt% in Example 1.

[0065] Example 8 Compared with Example 1, the impregnation time of Cu was changed to 8, 16, and 20 h, the anodizing time was changed to 14 h, and the current density was changed to 25 A / m. 2 Other conditions were the same as in Example 1. XRD analysis showed that the three catalysts obtained in Example 8 all contained CuO, NiO, Fe2O3, MnCO3, MnO2, and γ-Al2O3. The Cu loadings were 1.6, 4.1, and 5.3 wt%, respectively.

[0066] Example 9 Compared with Example 1, the impregnation time of Ni was changed to 8, 16, and 20 h, the anodizing time was changed to 14 h, and the current density was changed to 25 A / m. 2 Other conditions were the same as in Example 1. XRD analysis showed that the three catalysts obtained in Example 9 all contained CuO, NiO, Fe2O3, MnCO3, MnO2, and γ-Al2O3. The Ni loadings were 0.9, 3.3, and 4.7 wt%, respectively.

[0067] Example 10 Compared with Example 1, the impregnation time of Fe was changed to 6, 14, 18 and 22 h, the anodizing time was changed to 14 h, and the current density was changed to 25 A / m. 2 Other conditions were the same as in Example 1. XRD analysis showed that the four catalysts obtained in Example 10 all contained CuO, NiO, Fe2O3, MnCO3, MnO2, and γ-Al2O3. The Fe loadings were 4.9, 6.6, 7.5, and 8.4 wt%, respectively.

[0068] Example 11 Compared with Example 1, the impregnation time of Mn was changed to 8, 16, 20 and 24 h, the anodizing time was changed to 14 h, and the current density was changed to 25 A / m. 2Other conditions were the same as in Example 1. XRD analysis showed that the four catalysts obtained in Example 11 all contained CuO, NiO, Fe2O3, MnCO3, MnO2, and γ-Al2O3. The Mn loadings were 5.7, 9.1, 11.0, and 14.3 wt%, respectively.

[0069] Comparative Example 1 Compared to Example 1, a Cu / γ-Al2O3 / Al single-component catalyst was used, and other conditions were the same as in Example 1.

[0070] Comparative Example 2 Compared to Example 1, a Ni / γ-Al2O3 / Al single-component catalyst was used, while other conditions were the same as in Example 1.

[0071] Comparative Example 3 Compared to Example 1, a Fe / γ-Al2O3 / Al single-component catalyst was used, while other conditions were the same as in Example 1.

[0072] Comparative Example 4 Compared to Example 1, a single-component Mn / γ-Al2O3 / Al catalyst was used, while other conditions remained the same as in Example 1.

[0073] Comparative Example 5 Compared to Example 1, a CuMn / γ-Al2O3 / Al bicomponent catalyst was used, while other conditions remained the same as in Example 1.

[0074] Comparative Example 6 Compared to Example 1, a NiMn / γ-Al2O3 / Al bicomponent catalyst was used, while other conditions remained the same as in Example 1.

[0075] Comparative Example 7 Compared to Example 1, a FeMn / γ-Al2O3 / Al bicomponent catalyst was used, while other conditions remained the same as in Example 1.

[0076] Comparative Example 8 Compared to Example 1, a CuFeMn / γ-Al2O3 / Al three-component catalyst was used, and other conditions were the same as in Example 1.

[0077] Comparative Example 9 Compared to Example 1, a NiFeMn / γ-Al2O3 / Al three-component catalyst was used, and other conditions were the same as in Example 1.

[0078] Figure 5 , Figure 6 , Figure 7 The diagrams show the degradation effects of the catalysts prepared in Comparative Examples 1-4 on ammonia, acetic acid, and skatole, respectively. Figure 8The diagram shows the degradation effect of the catalysts prepared in Comparative Examples 5-7 on ammonia. Figure 9 The diagram shows the degradation effect of the catalysts prepared in Comparative Examples 8-9 on ammonia. Figure 10 , Figure 11 and Figure 12 The figures show schematic diagrams illustrating the degradation effects of the catalysts prepared in Examples 1-5 on ammonia, acetic acid, and skatole. A comparison of these figures reveals that, compared to catalysts not present in this invention, the catalyst of this invention can not only effectively catalyze the degradation of substances with irritating odors such as ammonia, acetic acid, and skatole at lower temperatures, but also exhibits a significantly higher catalytic degradation rate at the same temperature, effectively removing the odor from exhaust gases from the combustion of excrement.

[0079] Figure 13 The image shows a comparison between the outlet condensate after treating actual exhaust gas with the catalyst prepared in Example 6 and the condensate without catalyst treatment. Figure 14 The figure shows the changes in the concentrations of hydrogen sulfide, formaldehyde, and TVOC at the outlet after treating the exhaust gas from actual excrement combustion with the catalyst prepared in Example 6. As shown in the figure, the outlet condensate treated with the catalyst of this invention is colorless and transparent, and the concentrations of hydrogen sulfide and formaldehyde in the outlet exhaust gas are essentially zero. The sample combustion is divided into two stages: the first stage (0-25 min) is the evaporation of water in urine and feces, and the odor source in this process is mainly ammonia. Under the action of the catalyst of this invention, there is no odor at the outlet. The second stage (25-80 min) is the rapid combustion stage of the solid after water loss, so the combustion produces a small amount of TVOC, which is maintained below 8 ppm.

[0080] Figures 15 to 19 The figures show schematic diagrams illustrating the degradation effects of catalysts with different loadings prepared in Examples 7-11 on ammonia. As shown, the catalysts meeting the loading requirements of this invention can not only effectively catalyze the degradation of ammonia at lower temperatures, but also exhibit significantly higher catalytic degradation rates at the same temperatures, thus achieving effective removal of odors from exhaust gas from waste combustion.

[0081] Although the invention has been specifically shown and described with reference to embodiments thereof, those skilled in the art will understand that various changes in form and detail may be made without departing from the scope of the invention as defined by the claims.

Claims

1. A method for preparing a deodorizing catalyst, characterized in that, Includes the following steps: - Provides aluminum-based carriers; - The deodorizing catalyst is prepared by loading copper compounds, nickel compounds, iron compounds and manganese compounds onto the aluminum-based support.

2. The method for preparing the deodorizing catalyst according to claim 1, characterized in that, The deodorizing catalyst was prepared by first loading copper compounds, nickel compounds, and iron compounds onto the aluminum-based support, and then loading manganese compounds.

3. The method for preparing the deodorizing catalyst according to claim 1, characterized in that, The aluminum-based support includes γ-Al2O3 / Al aluminum-based support.

4. The method for preparing the deodorizing catalyst according to claim 3, characterized in that, The steps for providing an aluminum-based carrier include: - Anodize the aluminum substrate; - The anodized aluminum substrate is subjected to a single firing process; - A hot water fusion reaction is carried out on an aluminum substrate that has undergone one firing. - The aluminum substrate that has undergone hot water sintering reaction is then subjected to secondary calcination.

5. The method for preparing the deodorizing catalyst according to claim 4, characterized in that, The aluminum substrate is selected from one or more of aluminum corrugated mesh, aluminum flat mesh, aluminum corrugated plate, or aluminum flat plate.

6. The method for preparing the deodorizing catalyst according to claim 4, characterized in that, Before anodizing, the aluminum substrate was pretreated with 5-15 wt% NaOH solution and 5-15 wt% HNO3 solution for 1-5 min respectively.

7. The method for preparing the deodorizing catalyst according to claim 4, characterized in that, The conditions for anodic oxidation are as follows: the electrolyte is a 0.1-0.8 mol / L oxalic acid solution, the temperature is 15-25 ℃, and the current density is 25-50 A / m. 2 The time is 8-16 hours; - The temperature of the first roasting is 350-550 ℃, and the time is 1-3 h; - The temperature of the hot water hydration reaction is 30-95 ℃, and the time is 60-120 min; - The secondary roasting temperature is 350-550 ℃, and the time is 3-6 h.

8. The method for preparing the deodorizing catalyst according to claim 1, characterized in that, The copper compound includes copper oxide, the nickel compound includes nickel oxide, the iron compound includes iron oxide, and the manganese compound includes manganese dioxide and manganese carbonate.

9. The method for preparing the deodorizing catalyst according to claim 1, characterized in that, The steps for loading copper compounds include: - Immerse the aluminum-based support in a copper nitrate solution with a concentration of 1-2 mol / L for 8-20 h at an immersion temperature of 10-35℃; - Calcination at 400-550 ℃ for 3-6 h.

10. The method for preparing the deodorizing catalyst according to claim 1, characterized in that, The steps of loading nickel compounds include: - Immerse the aluminum-based support in a nickel nitrate solution with a concentration of 0.5-1.5 mol / L for 8-20 h at an immersion temperature of 10-35 ℃; - Calcination at 400-550 ℃ for 3-6 h.

11. The method for preparing the deodorizing catalyst according to claim 1, characterized in that, The steps of loading iron compounds include: - Immerse the aluminum-based support in a ferric nitrate solution with a concentration of 0.02-0.08 mol / L for 6-22 h at an immersion temperature of 10-35 ℃; - Calcination at 250-500 ℃ for 3-6 h.

12. The method for preparing the deodorizing catalyst according to claim 1, characterized in that, The steps of loading manganese compounds include: - The aluminum-based support loaded with copper, nickel and iron compounds was immersed in a solution of manganese acetate (0.02-0.08 mol / L) and urea (0.2-0.8 mol / L) for 8-24 h at an immersion temperature of 80-95 °C. - Calcination at 250-500 ℃ for 3-6 h.

13. A deodorizing catalyst, characterized in that, The deodorizing catalyst comprises an aluminum-based support and copper, nickel, iron, and manganese compounds supported on the aluminum-based support.

14. The deodorizing catalyst according to claim 13, characterized in that, The aluminum-based carrier is first loaded with copper compounds, nickel compounds, and iron compounds, and then loaded with manganese compounds.

15. The deodorizing catalyst according to claim 13, characterized in that, The aluminum-based support includes γ-Al2O3 / Al aluminum-based support.

16. The deodorizing catalyst according to claim 13, characterized in that, The copper compound includes copper oxide, the nickel compound includes nickel oxide, the iron compound includes iron oxide, and the manganese compound includes manganese dioxide and manganese carbonate.

17. The deodorizing catalyst according to claim 13, characterized in that, Based on the aluminum-based carrier, the copper loading is 1.6-5.3 wt%, the nickel loading is 0.9-4.7 wt%, the iron loading is 4.9-8.4 wt%, and the manganese loading is 5.7-14.3 wt%.

18. The deodorizing catalyst according to claim 13, characterized in that, The aluminum-based carrier is obtained from an aluminum substrate, which is selected from one or more of aluminum corrugated mesh, aluminum flat mesh, aluminum corrugated plate, or aluminum flat plate.

19. Use of the deodorizing catalyst according to any one of claims 12 to 18 in the deodorization of exhaust gas from excrement combustion.

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