3D gaseous molecular sieve filter screen for removing ammonia gas and preparation method of 3D gaseous molecular sieve filter screen

Abstract

The invention provides a 3D gaseous molecular sieve filter screen for removing ammonia gas and a preparation method thereof, and belongs to the technical field of ammonia gas purification. The method comprises the following steps: mixing 10-30 parts of an adsorption material, 10-40 parts of a catalytic material, 10-30 parts of an additive and 30-40 parts of an adhesive, pulping, spraying on a 3D fiber material, and curing to finally obtain the 3D gaseous molecular sieve filter screen. By utilizing an oxygen vacancy defect catalytic mechanism, the catalyst is suitable for realizing efficient removal of industrial high-concentration ammonia gas and indoor low-concentration ammonia odor at normal temperature, is adaptive to air purification system integration, and is simple and convenient in preparation process and easily available in raw materials.

Description

Technical Field

[0001] The present application belongs to the technical field of ammonia purification, and in particular relates to a 3D gaseous molecular sieve filter for removing ammonia and a preparation method thereof. Background Art

[0002] Liquid ammonia, a clean energy source, is gradually replacing traditional fossil fuels because it contains no carbon molecules and produces only nitrogen and water upon combustion. However, liquid ammonia is prone to leakage or volatilization during use and storage, releasing ammonia gas with a pungent odor. Ammonia is not only highly irritating to the human respiratory system, eyes, and skin, but also forms secondary pollutants in the air, causing long-term environmental damage. Therefore, the treatment of ammonia emissions has become a key issue in the application of clean energy.

[0003] Currently, ammonia treatment technologies primarily include physical adsorption and chemical spraying. Physical adsorption typically utilizes porous materials such as activated carbon and coconut shell charcoal, but its adsorption capacity is limited, making it particularly inefficient for treating high-concentration ammonia. Furthermore, after saturation, the adsorbent requires frequent replacement or regeneration, resulting in high operating costs. Chemical spraying neutralizes ammonia with an acidic solution, such as dilute sulfuric acid, to produce salts such as ammonium sulfate. While this method is highly efficient, it produces large amounts of saline wastewater, requiring additional treatment to prevent secondary contamination. Furthermore, the equipment requires significant floor space and consumes high amounts of energy.

[0004] Therefore, there is an urgent need for a new material and method that is efficient, energy-saving, low-cost and adaptable to the treatment of ammonia at different concentrations. Summary of the Invention

[0005] The purpose of this application is to provide a 3D gaseous molecular sieve filter for removing ammonia and a preparation method thereof, so as to solve the above-mentioned problems existing in the prior art.

[0006] The embodiments of the present application can be implemented through the following technical solutions:

[0007] On the one hand, the present application provides a method for preparing a 3D gaseous molecular sieve filter for removing ammonia, comprising the following steps: S1, preparing a slurry, the slurry comprising the following raw material components in parts by weight: 10-30 parts of an adsorbent, 10-40 parts of a catalytic material, 10-30 parts of an additive and 30-40 parts of an adhesive; S2, spraying the slurry prepared in S1 on a 3D fiber material and curing it.

[0008] Furthermore, the adsorbent is selected from at least two of diatomaceous earth, porous silicon, activated alumina, bentonite, zeolite, activated carbon, and nanoporous active silicon.

[0009] Furthermore, the catalytic material includes a transition metal oxide or a rare earth metal oxide having the ability to form oxygen vacancies, a noble metal nitrate, and lanthanum nitrate.

[0010] Furthermore, the transition metal oxide or rare earth metal oxide having the ability to form oxygen vacancies is selected from any one or a combination of tungsten oxide, cerium oxide, yttrium oxide, titanium dioxide, and manganese oxide; and the noble metal nitrate is selected from any one or a combination of platinum nitrate, rhodium nitrate, and palladium nitrate.

[0011] Furthermore, the additives include gas-phase metal oxides, cellulose ether compounds and solvents.

[0012] Furthermore, the fumed metal oxide is selected from any one or a combination of fumed silicon oxide, fumed titanium oxide, and fumed aluminum oxide; the cellulose ether compound is selected from any one or a combination of hydroxypropyl methylcellulose and sodium carboxymethyl cellulose; and the solvent is deionized water.

[0013] Furthermore, the adhesive is selected from any one of styrene acrylic emulsion, pure acrylic emulsion, acrylic acid emulsion, silicone acrylic emulsion, polyvinyl acetate emulsion, and polyvinyl alcohol, or a combination of several of them.

[0014] Furthermore, the S1 specifically includes the following steps: S11, weighing the adsorbent and the additive according to the weight ratio, mixing and stirring, heating to 60-80°C and stirring until it becomes a homogeneous slurry; S12, adding the catalyst material in the weight ratio to the homogeneous slurry of S11, continuing to stir for 30 minutes, then cooling to 30-40°C and filtering; S13, weighing the binder according to the weight ratio, adding the slurry filtered in S12 thereto, mixing and stirring for 20 minutes, and filtering to obtain the final slurry for spraying.

[0015] Furthermore, the 3D fiber material is a flexible material with a three-dimensional hollow structure, the upper and lower surface meshes are breathable on six sides, and the middle layer is supported by polyester fiber in X-90 form; the 3D fiber material includes front and back materials made of short-fiber polyester fiber with a specification of 75D×2, and an intermediate support material composed of a mixture of polyolefin elastomer and polyester.

[0016] On the other hand, the present application provides a 3D gaseous molecular sieve filter for removing ammonia, which is prepared by any of the preparation methods described above.

[0017] The embodiments of the present application provide a 3D gaseous molecular sieve filter for removing ammonia and a preparation method thereof, which have at least the following beneficial effects:

[0018] This application forms a functional slurry that can be sprayed on 3D fiber materials by compounding a catalytic material that can generate oxygen vacancies with an adsorbent, a three-dimensional network additive, and an adhesive. The slurry uses the mechanism by which oxygen vacancies attack oxygen molecules to generate oxygen ions or ozone and reduce the bond energy of ammonia, thereby catalytically decomposing ammonia at low or room temperature. The slurry can achieve an ammonia removal rate of up to 92.8% within 150 seconds.

[0019] By using 3D fiber materials with porosity, density diversity, low wind resistance, light weight, and large specific surface area as the base material, it has strong capture ability and can decompose ammonia at room temperature without the help of electricity and light energy;

[0020] The 3D gaseous molecular sieve filter of the present application has readily available raw materials and a simple preparation process. It is not only suitable for treating high-concentration ammonia emitted from industrial production, but also for treating low-concentration ammonia odor indoors, and is easy to integrate with air purification systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a scanning electron microscope image of the unprocessed 3D fiber material of this application;

[0022] Figure 2 This is a scanning electron microscope image of the 3D gaseous molecular sieve filter prepared in this application; DETAILED DESCRIPTION

[0023] Hereinafter, the present application will be further described based on preferred embodiments with reference to the accompanying drawings.

[0024] The chemical reagents used in this manual are all commercially available products.

[0025] The present application provides a 3D gaseous molecular sieve filter for removing ammonia and a preparation method thereof, the method specifically comprising the following steps:

[0026] S1, preparing slurry;

[0027] The slurry is prepared from the following raw material components in parts by weight: 10-30 parts of adsorbent, 10-40 parts of catalytic material, 10-30 parts of additive and 30-40 parts of adhesive;

[0028] Specifically, the adsorbent is selected from at least two of diatomaceous earth, porous silicon, activated alumina, bentonite, zeolite, activated carbon, and nanoporous active silicon; the adsorbent has a rich pore structure, provides a large number of adsorption sites, and can initially capture ammonia molecules.

[0029] Specifically, the catalyst material includes a transition metal oxide or a rare earth metal oxide having the ability to form oxygen vacancies, a noble metal nitrate, and lanthanum nitrate; wherein the transition metal oxide or the rare earth metal oxide having the ability to form oxygen vacancies is easy to form oxygen vacancies (i.e., a defect formed after the lattice oxygen removes an oxygen atom), and the oxygen vacancies can attack oxygen molecules in the air, turning them into oxygen ions (O 2- ) or ozone (O3), on the other hand, can also attack ammonia molecules, reduce the bond energy of ammonia molecules, and make them more likely to react; with oxygen ions (O 2-) as an example, it undergoes an oxidation reaction as shown in formula (1) with the ammonia molecules whose bond energy is reduced after being catalyzed, generating nitrogen and water; in addition, the noble metal (noble metal nitrate) and rare earth material (lanthanum nitrate) in the catalyst material can synergistically act with oxygen vacancies, thereby achieving the decomposition of ammonia under low temperature or room temperature conditions;

[0030] 2NH3+3O 2- =N2+3H2O (1).

[0031] Furthermore, the transition metal oxide or rare earth metal oxide having the ability to form oxygen vacancies is selected from any one or a combination of tungsten oxide, cerium oxide, yttrium oxide, titanium dioxide, and manganese oxide; and the noble metal nitrate is selected from any one or a combination of platinum nitrate, rhodium nitrate, and palladium nitrate.

[0032] Specifically, the additives include a gas-phase metal oxide, a cellulose ether compound, and a solvent; wherein the gas-phase metal oxide can construct a microporous structure with porous gaps, increase the specific surface area, increase the reaction sites with ammonia, and enhance the ability to capture ammonia; the cellulose ether compound plays the role of bonding the gas-phase metal oxide, making the structure more stable.

[0033] Furthermore, the fumed metal oxide is selected from any one or a combination of fumed silicon oxide, fumed titanium oxide, and fumed aluminum oxide; the cellulose ether compound is selected from any one or a combination of hydroxypropyl methylcellulose and sodium carboxymethyl cellulose; and the solvent is deionized water.

[0034] Furthermore, step S1 includes the following specific steps:

[0035] S11, weighing the adsorbent and the additive according to the weight ratio, mixing and stirring, heating to 60-80°C and stirring until a homogeneous slurry is formed; preferably, the heating rate is 1°C / min.

[0036] S12, adding the catalyst material by weight to the homogenous slurry of S11, continuing stirring for 30 minutes, cooling to 30-40°C, and filtering;

[0037] S13, weighing the binder according to the weight ratio, adding the slurry filtered in S12 thereto, mixing and stirring for 20 minutes, and filtering to obtain the final slurry for spraying.

[0038] S2, spraying the slurry prepared in S1 onto the 3D fiber material and curing it;

[0039] Specifically, the 3D fiber material is a flexible material with a three-dimensional hollow structure. The upper and lower surface meshes are breathable on six sides, and the middle layer is supported by polyester fibers in X-90 form. Furthermore, the 3D fiber material includes front and back materials made of short-fiber polyester fibers with a specification of 75D×2, and an intermediate support material composed of a mixture of polyolefin elastomer (POE) and polyester (PET).

[0040] This structure gives the 3D fiber material the characteristics of high ventilation volume, low wind resistance and light weight, providing a good support skeleton for the slurry, so that the formed filter net can be in full contact with the air, facilitating the capture and decomposition of ammonia. In addition, it is also easier to cut in subsequent use and has a better fit.

[0041] Specifically, the spraying specifically refers to pouring the slurry configured in S1 into a spray tank, selecting a suitable spray gun caliber, and evenly spraying the 3D fiber material; wherein, the spraying adopts the equipment commonly used in this field, and the parameters such as the spray gun caliber can be adjusted according to the actual spraying effect, and are not specifically limited here.

[0042] Specifically, the curing includes the following steps: first, the 3D fiber material sprayed with the slurry is placed in a room temperature environment, ventilated and dried to evaporate most of the solvent (deionized water) in the slurry, and preliminarily fix the morphology of the slurry on the surface of the 3D fiber material; then, the dried filter is placed in an oven for curing to further optimize the mechanical properties, catalytic stability and pore structure of the 3D gaseous molecular sieve filter.

[0043] Example 1

[0044] S1, preparing slurry;

[0045] Weigh the following raw materials:

[0046] Adsorbent: 100g diatomaceous earth, 50g nanoporous active silica, 50g activated alumina;

[0047] Catalyst material: 60g lanthanum nitrate, 10g platinum nitrate, 30g nano titanium dioxide, 50g cerium oxide;

[0048] Additives: fumed silicon oxide 10g, fumed titanium oxide 10g, hydroxypropyl methylcellulose 10g, deionized water 270g;

[0049] Adhesive: 300g acrylic emulsion, 50g polyvinyl alcohol.

[0050] S11, pour the weighed adsorbent (100 g of diatomaceous earth, 50 g of nanoporous active silicon, 50 g of activated alumina) and additives (10 g of fumed silica, 10 g of fumed titanium oxide, 10 g of hydroxypropyl methylcellulose, 270 g of deionized water) into a stirring barrel, start the stirrer at low speed, raise the temperature to 80°C at a rate of 1°C per minute, and maintain stirring at 80°C for 30 minutes until the barrel becomes a homogeneous slurry;

[0051] S12, adding a catalyst (60 g of lanthanum nitrate, 10 g of platinum nitrate, 30 g of nano-titanium dioxide, and 50 g of cerium oxide) to the homogeneous slurry, continuing stirring for 30 minutes to evenly disperse the catalyst in the slurry, then cooling the slurry to 30-40° C., pouring the slurry into a filter bag and filtering it to remove any impurities and unevenly dispersed particles;

[0052] S13, pour the weighed adhesive (300g of acrylic emulsion, 50g of polyvinyl alcohol) into the bucket and stir at a low speed, then slowly add the slurry filtered in step S12 into the bucket, continue stirring for 20 minutes to fully mix the adhesive and slurry, then pour the prepared slurry in the bucket into the filter bag again for filtration to obtain the final fine slurry for spraying.

[0053] S2, spraying and curing;

[0054] Pour the slurry prepared in S1 into the spray can and spray the 3D fiber material evenly.

[0055] Among them, 3D fiber materials are such as Figure 1 The flexible material with a three-dimensional hollow structure shown has upper and lower surface layers made of short-fiber polyester fibers with a specification of 75D×2, and the middle support material is a mixture of polyolefin elastomer (POE) and polyester (PET), with the overall support being X-90.

[0056] The sprayed 3D gaseous molecular sieve filter is first dried at room temperature to volatilize the solvent in the slurry, and then placed in an oven for curing to completely cross-link and cure the adhesive, finally forming a Figure 2 The stable 3D gaseous molecular sieve filter shown.

[0057] Example 2

[0058] The difference between this embodiment and embodiment 1 is only the ratio of raw materials. Other details are the same as those in embodiment 1 and will not be described again here.

[0059] Adsorbent: 60g diatomaceous earth, 40g activated alumina;

[0060] Catalyst material: 35g lanthanum nitrate, 5g platinum nitrate, 60g cerium oxide;

[0061] Additives: fumed silica 20g, hydroxypropyl methylcellulose 10g, deionized water 170g;

[0062] Adhesive: 250g acrylic emulsion, 50g polyvinyl alcohol.

[0063] Example 3

[0064] The difference between this embodiment and embodiment 1 is only the ratio of raw materials. Other details are the same as those in embodiment 1 and will not be described again here.

[0065] Adsorbent: 100g diatomaceous earth, 100g nanoporous active silica, 100g activated alumina;

[0066] Catalyst material: 230g lanthanum nitrate, 20g platinum nitrate, 150g cerium oxide;

[0067] Additives: fumed silicon oxide 10g, fumed titanium oxide 10g, hydroxypropyl methylcellulose 10g, deionized water 270g;

[0068] Adhesive: 300g acrylic emulsion, 100g polyvinyl alcohol.

[0069] Comparative Example 1

[0070] This comparative example is a 3D fiber material that has not been sprayed. The 3D fiber material used is the same as that in Example 1 and will not be described again here.

[0071] Ammonia removal performance test:

[0072] The ammonia removal performance of the prepared material was tested according to the following method. The specific operations are as follows:

[0073] A piece of 3D gaseous molecular sieve filter for removing ammonia prepared according to the embodiment with a length × width × thickness of 100 mm × 100 mm × 8 mm is prepared for standby use;

[0074] Pour 10 ml of 0.5% ammonia solution into a glass container and place it in a 20-liter odor test chamber. The indoor temperature is controlled at 25°C. A fan and an ammonia concentration detector are set in the odor test chamber. The range of the ammonia concentration detector is: 0-100ppm;

[0075] Turn on the fan and ammonia detector to allow the ammonia in the glassware to evaporate to 95ppm;

[0076] Take out the glass container containing ammonia water and continue to use the fan to stir the air containing ammonia in the test chamber for 5 minutes, so that the value on the ammonia detector is controlled at 90ppm±3;

[0077] Place the cut spare 3D gas molecular sieve filter into the odor test chamber, use 150 seconds as the standard test time, record the value on the ammonia detector dropping from 90ppm to the value during this time period, calculate the ammonia removal rate, and repeat three times to take the average value.

[0078] The ammonia removal efficiency performance of Example 1 and Comparative Example 1 was tested according to the above method, and the results are shown in Table 1.

[0079] Table 1

[0080]

[0081] The above is a detailed introduction to the specific implementation methods of the present application. For those skilled in the art, several improvements and modifications can be made to the present application without departing from the principles of the present application. These improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. A method for preparing a 3D gaseous molecular sieve filter for removing ammonia, characterized in that: The following steps are involved: S1, preparing a slurry, wherein the slurry comprises the following raw material components in parts by weight: 10-30 parts of an adsorbent, 10-40 parts of a catalytic material, 10-30 parts of an additive, and 30-40 parts of a binder; S2, spraying the slurry prepared in S1 onto the 3D fiber material and curing it.

2. The preparation method according to claim 1, characterized in that The adsorbent is selected from at least two of diatomaceous earth, porous silicon, activated alumina, bentonite, zeolite, activated carbon, and nano-microporous active silicon.

3. The preparation method according to claim 1, characterized in that The catalytic material includes a transition metal oxide or a rare earth metal oxide having the ability to form oxygen vacancies, a noble metal nitrate and lanthanum nitrate.

4. The preparation method according to claim 3, characterized in that The transition metal oxide or rare earth metal oxide having the ability to form oxygen vacancies is selected from any one or a combination of tungsten oxide, cerium oxide, yttrium oxide, titanium dioxide, and manganese oxide; The noble metal nitrate is selected from any one of platinum nitrate, rhodium nitrate and palladium nitrate or a combination thereof.

5. The preparation method according to claim 1, characterized in that The additives include gas-phase metal oxides, cellulose ether compounds and solvents.

6. The preparation method according to claim 5, characterized in that The fumed metal oxide is selected from any one or a combination of fumed silicon oxide, fumed titanium oxide, and fumed aluminum oxide; The cellulose ether compound is selected from any one or a combination of hydroxypropyl methylcellulose and sodium carboxymethyl cellulose; The solvent is deionized water.

7. The preparation method according to claim 1, characterized in that The adhesive is selected from any one of styrene acrylic emulsion, pure acrylic emulsion, acrylic acid emulsion, silicone acrylic emulsion, polyvinyl acetate emulsion, and polyvinyl alcohol, or a combination of several of them.

8. The preparation method according to claim 1, characterized in that The S1 specifically includes the following steps: S11, weighing the adsorbent and the additive according to the weight ratio, mixing and stirring, heating to 60-80° C. and stirring until a homogeneous slurry is formed; S12, adding the catalyst material by weight to the homogenous slurry of S11, continuing stirring for 30 minutes, cooling to 30-40°C, and filtering; S13, weighing the binder according to the weight ratio, adding the slurry filtered in S12 thereto, mixing and stirring for 20 minutes, and filtering to obtain the final slurry for spraying.

9. The preparation method according to claim 1, characterized in that The 3D fiber material is a flexible material with a three-dimensional hollow structure. The upper and lower surface meshes are breathable on six sides, and the middle layer is supported by polyester fibers in an X-90 pattern. The 3D fiber material includes front and back materials made of short-fiber polyester fibers with a specification of 75D×2, and an intermediate supporting material composed of a mixture of polyolefin elastomer and polyester.

10. A 3D gaseous molecular sieve filter for removing ammonia, characterized in that: Prepared by the preparation method according to any one of claims 1 to 9.

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