Water-saving washing method in precipitation method catalyst production process
By using photothermal steam washing technology, microchannels are constructed using modified magnesium sulfate whiskers and magnetic carbon-based photothermal powder to achieve integrated water-saving washing and drying in the production of precipitation catalysts. This solves the problems of high water consumption and low efficiency in traditional washing, improves catalyst purity and production efficiency, and meets the requirements of green chemistry.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- BAIYIN GLENN NEW MATERIALS CO LTD
- Filing Date
- 2025-11-27
- Publication Date
- 2026-04-17
AI Technical Summary
In existing precipitation-based catalyst production, the washing process consumes a large amount of water, is inefficient, and has high energy consumption. Furthermore, it is difficult to effectively remove impurity ions, which affects the catalyst's activity and lifespan.
By combining photothermal filter aids and near-infrared light irradiation, photothermal steam washing technology is used to achieve integrated washing and drying in a small amount of water. Microchannels are constructed using modified magnesium sulfate whiskers and magnetic carbon-based photothermal powder to generate steam that penetrates the filter cake and removes impurities.
It significantly reduces washing water consumption, shortens the process flow, improves production efficiency and catalyst purity, reduces wastewater treatment pressure, and meets the requirements of green chemistry.
Smart Images
Figure CN121869468A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the technical field of precipitation catalyst production, specifically a water-saving washing method in the precipitation catalyst production process. Background Technology
[0002] Coprecipitation is one of the most widely used processes in the industrial production of multi-component catalysts. After the coprecipitation reaction and aging process, the resulting catalyst precipitate slurry is rich in a large number of impurity ions. These residual impurities will cause the active center of the catalyst to sinter, poison, or destroy the pore structure in the subsequent calcination process, which will seriously impair the activity, selectivity and service life of the final catalyst. Therefore, the washing process has become a crucial link in the coprecipitation catalyst production process.
[0003] In existing technologies, the washing methods commonly used in industry mainly include soaking washing and spray washing. These traditional methods rely heavily on the repeated replacement and rinsing of large amounts of ultrapure water, resulting in problems such as high water consumption, low washing efficiency, long process flow, and high energy consumption. Based on this, the present invention proposes a water-saving washing method in the precipitation catalyst production process. Summary of the Invention
[0004] The purpose of this invention is to provide a water-saving washing method in the production process of precipitation catalysts. The photothermal filter aid and supporting process used in this invention can not only reduce the amount of water used for washing to the extreme, but also complete the integrated operation of washing and drying at the same time. This effectively solves the problems of high water consumption, high pollution and high energy consumption in the traditional co-precipitation catalyst production, and significantly improves the green level and economic benefits of the process.
[0005] To achieve the above objectives, the present invention provides the following technical solution: A water-saving washing method for the production process of precipitation catalysts includes the following steps: S1: After the catalyst completes the precipitation reaction and undergoes aging, a catalyst precipitate slurry to be washed is obtained. A photothermal filter aid is added to the catalyst precipitate slurry, and the mixture is stirred for 30-60 minutes. After stirring, the mixture is filtered to obtain a filter cake. S2: Wet the bottom of the filter cake with deionized water, and use near-infrared light to irradiate the surface of the filter cake for photothermal steam washing. When the conductivity value is lower than 50 μS / cm, stop the near-infrared light irradiation to obtain the washed filter cake, thus completing the water-saving washing process in the precipitation catalyst production process.
[0006] The photothermal filter aid comprises the following raw materials in parts by weight: 50-70 parts modified magnesium sulfate whiskers, 30-50 parts magnetic carbon-based photothermal powder, and 5-10 parts dispersant.
[0007] Further, the modified magnesium sulfate whiskers are prepared by the following method: magnesium sulfate whiskers are added to a stearic acid ethanol solution and stirred at 60-80℃ for 1-2 hours. After the reaction is completed, the mixture is filtered to obtain filter residue. The filter residue is washed three times with anhydrous ethanol and dried at 100-120℃ to obtain modified magnesium sulfate whiskers. The concentration of the stearic acid ethanol solution is 5%, and the mass of the stearic acid ethanol solution is 20-30 times the mass of the magnesium sulfate whiskers.
[0008] Furthermore, the magnetic carbon-based photothermal powder is prepared by the following method: magnetic iron oxide nanoparticles are mixed with sucrose at a mass ratio of 1:(3-5), and the resulting product is vacuum dried at 80-100℃ to obtain the magnetic carbon-based photothermal powder.
[0009] Furthermore, the magnetic iron oxide nanoparticles are prepared by the following method: Step 1: Mix ferrous sulfate heptahydrate with deionized water at a mass ratio of 1:(5.0-7.5), stir, and prepare the first solution. Mix sodium hydroxide with deionized water at a mass ratio of 1:(10-16.7), stir, and prepare the second solution. Step 2: Under nitrogen protection, the second solution is quickly poured into the first solution at a volume ratio of 1:1, and reacted at 70-90℃ for 1-2 hours. After the reaction is completed, a third suspension is obtained. The third suspension is placed between the two poles of an electromagnetic separator, and magnetic particles are adsorbed by passing electricity. After separation, the power is turned off to obtain solid magnetic particles. Step 3: Wash the solid magnetic particles with deionized water until neutral, then wash them twice with ethanol, dry them under vacuum at 60-80℃, and grind them to obtain magnetic iron oxide nanopowder.
[0010] Furthermore, the water-saving washing method in the precipitation catalyst production process is characterized in that the dispersant is at least one of polyethylene glycol-4000, polyethylene glycol-6000, and sodium dodecyl sulfate.
[0011] Furthermore, the amount of photothermal filter aid added in S1 is 1-5% of the mass of the catalyst precipitate slurry, and the amount of deionized water used in S2 is 10-20% of the mass of the filter cake.
[0012] Furthermore, the near-infrared light is emitted by a near-infrared laser with a wavelength of 808nm or 980nm and an optical power density of 0.5-1.5 W / cm².
[0013] Furthermore, the photothermal filter aid is prepared by the following method: modified magnesium sulfate whiskers, magnetic carbon-based photothermal powder and dispersant are weighed as needed and mixed in a mixer, and then dry-mixed at room temperature for 30-60 minutes to obtain the photothermal filter aid.
[0014] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention transforms the traditional process, which relies on a large amount of water for physical replacement, into a process that uses a small amount of water to generate steam for penetrating washing through a photothermal steam washing mechanism. This achieves the beneficial effect of significantly reducing the amount of water used for washing, and greatly alleviates the pressure on water resource consumption and wastewater treatment.
[0015] 2. In this invention, the photothermal material can rapidly convert light energy into heat energy under near-infrared light irradiation, generating steam at the interface. The steam carries heat and penetrates the microchannels constructed by whiskers, condensing and washing away impurities, and transferring heat to the entire filter cake. This process continues, and the filter cake gradually changes from wet to dry. This combines the traditional two separate and time-consuming unit operations of washing and drying into one, significantly shortening the overall process time and improving equipment utilization and production efficiency.
[0016] 3. The photothermal steam of the present invention penetrates uniformly in the rigid microchannels constructed by whiskers, achieving deep and uniform purification, ensuring that impurity ions are completely removed, improving the purity of the catalyst precursor, and effectively reducing the redissolution and loss of active components.
[0017] 4. This invention significantly reduces the amount of high-salinity organic wastewater generated at the source, drastically reducing the burden and cost of subsequent wastewater treatment, meeting the requirements of green chemistry and clean production, and yielding significant environmental benefits. Attached Figure Description
[0018] Figure 1 A process flow diagram is provided for a water-saving washing method in the production process of precipitation catalysts. Detailed Implementation
[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0020] Example 1
[0021] A water-saving washing method for the production process of precipitation catalysts includes the following steps: S1: After the catalyst completes the precipitation reaction and undergoes aging, a catalyst precipitate slurry to be washed is obtained. A photothermal filter aid is added to the catalyst precipitate slurry, and the mixture is stirred for 30 minutes. After stirring, the mixture is filtered to obtain a filter cake. The amount of photothermal filter aid added is 1% of the mass of the catalyst precipitate slurry. S2: Wet the bottom of the filter cake with deionized water, and use near-infrared light to irradiate the surface of the filter cake for photothermal steam washing. When the conductivity value is lower than 50 μS / cm, stop the near-infrared light irradiation to obtain the washed filter cake. This completes the water-saving washing process in the precipitation catalyst production process. The amount of deionized water used is 10% of the filter cake mass. The near-infrared light is emitted by a near-infrared laser with a wavelength of 808nm and a light power density of 0.5W / cm².
[0022] Raw material preparation: 50 parts modified magnesium sulfate whiskers, 30 parts magnetic carbon-based photothermal powder, 5 parts polyethylene glycol-4000.
[0023] Preparation of modified magnesium sulfate whiskers: Magnesium sulfate whiskers were added to a stearic acid ethanol solution and stirred at 60°C for 1 hour. After the reaction was completed, the mixture was filtered to obtain a filter residue. The filter residue was washed three times with anhydrous ethanol and dried at 100°C to obtain modified magnesium sulfate whiskers. The concentration of the stearic acid ethanol solution was 5%, and the mass of the stearic acid ethanol solution was 20 times the mass of the magnesium sulfate whiskers.
[0024] Preparation of magnetic iron oxide nanopowder: Step 1: Mix ferrous sulfate heptahydrate with deionized water at a mass ratio of 1:5.0 and stir to obtain the first solution. Mix sodium hydroxide with deionized water at a mass ratio of 1:10 and stir to obtain the second solution. Step 2: Under nitrogen protection, the second solution is quickly poured into the first solution at a volume ratio of 1:1 and reacted at 70°C for 1 hour. After the reaction is completed, a third suspension is obtained. The third suspension is placed between the two poles of an electromagnetic separator, and magnetic particles are adsorbed by passing electricity. After separation, the power is turned off to obtain solid magnetic particles. Step 3: Wash the solid magnetic particles with deionized water until neutral, then wash them twice with ethanol, dry them under vacuum at 60°C, and grind them to obtain magnetic iron oxide nanopowder.
[0025] The magnetic carbon-based photothermal powder is prepared by the following method: magnetic iron oxide nanoparticles are mixed with sucrose at a mass ratio of 1:(3), and the resulting product is vacuum dried at 80°C to obtain the magnetic carbon-based photothermal powder.
[0026] Preparation of photothermal filter aid: Weigh the modified magnesium sulfate whiskers, magnetic carbon-based photothermal powder and polyethylene glycol-4000 as needed and place them in a mixer. Mix them dry at room temperature for 30 minutes to obtain the photothermal filter aid.
[0027] Example 2
[0028] A water-saving washing method for the production process of precipitation catalysts includes the following steps: S1: After the catalyst completes the precipitation reaction and undergoes aging, a catalyst precipitate slurry to be washed is obtained. A photothermal filter aid is added to the catalyst precipitate slurry, and the mixture is stirred for 45 minutes. After stirring, the mixture is filtered to obtain a filter cake. The amount of photothermal filter aid added is 3% of the mass of the catalyst precipitate slurry. S2: Wet the bottom of the filter cake with deionized water, and use near-infrared light to irradiate the surface of the filter cake for photothermal steam washing. When the conductivity value is lower than 50 μS / cm, stop the near-infrared light irradiation to obtain the washed filter cake. This completes the water-saving washing process in the precipitation catalyst production process. The amount of deionized water used is 15% of the filter cake mass. The near-infrared light is emitted by a near-infrared laser with a wavelength of 808nm and a light power density of 1.0 W / cm².
[0029] Raw material preparation: 60 parts modified magnesium sulfate whiskers, 40 parts magnetic carbon-based photothermal powder, 7 parts polyethylene glycol-6000.
[0030] Preparation of modified magnesium sulfate whiskers: Magnesium sulfate whiskers were added to a stearic acid ethanol solution and stirred at 70°C for 1.5 h. After the reaction was completed, the mixture was filtered to obtain a filter residue. The filter residue was washed three times with anhydrous ethanol and dried at 110°C to obtain modified magnesium sulfate whiskers. The concentration of the stearic acid ethanol solution was 5%, and the mass of the stearic acid ethanol solution was 25 times the mass of the magnesium sulfate whiskers.
[0031] Preparation of magnetic iron oxide nanopowder: Step 1: Mix ferrous sulfate heptahydrate with deionized water at a mass ratio of 1:6 and stir to obtain the first solution. Mix sodium hydroxide with deionized water at a mass ratio of 1:13 and stir to obtain the second solution. Step 2: Under nitrogen protection, the second solution is quickly poured into the first solution at a volume ratio of 1:1 and reacted at 80°C for 1.5 hours. After the reaction is completed, a third suspension is obtained. The third suspension is placed between the two poles of an electromagnetic separator, and magnetic particles are adsorbed by electricity. After separation, the power is turned off to obtain solid magnetic particles. Step 3: Wash the solid magnetic particles with deionized water until neutral, then wash them twice with ethanol, dry them under vacuum at 70°C, and grind them to obtain magnetic iron oxide nanopowder.
[0032] The magnetic carbon-based photothermal powder is prepared by the following method: magnetic iron oxide nanoparticles are mixed with sucrose at a mass ratio of 1:(4), and the resulting product is vacuum dried at 90°C to obtain the magnetic carbon-based photothermal powder.
[0033] Preparation of photothermal filter aid: Weigh the modified magnesium sulfate whiskers, magnetic carbon-based photothermal powder and polyethylene glycol-6000 as needed and place them in a mixer. Mix them dry at room temperature for 45 minutes to obtain the photothermal filter aid.
[0034] Example 3
[0035] A water-saving washing method for the production process of precipitation catalysts includes the following steps: S1: After the catalyst completes the precipitation reaction and undergoes aging, a catalyst precipitate slurry to be washed is obtained. A photothermal filter aid is added to the catalyst precipitate slurry, and the mixture is stirred for 60 minutes. After stirring, the mixture is filtered to obtain a filter cake. The amount of photothermal filter aid added is 5% of the mass of the catalyst precipitate slurry. S2: Wet the bottom of the filter cake with deionized water, and use near-infrared light to irradiate the surface of the filter cake for photothermal steam washing. When the conductivity value is lower than 50 μS / cm, stop the near-infrared light irradiation to obtain the washed filter cake. This completes the water-saving washing process in the precipitation catalyst production process. The amount of deionized water used is 20% of the filter cake mass. The near-infrared light is emitted by a near-infrared laser with a wavelength of 980nm and a light power density of 1.5 W / cm².
[0036] Raw material preparation: 70 parts modified magnesium sulfate whiskers, 50 parts magnetic carbon-based photothermal powder, and 10 parts sodium dodecyl sulfate.
[0037] Preparation of modified magnesium sulfate whiskers: Magnesium sulfate whiskers were added to a stearic acid ethanol solution and stirred at 80°C for 2 hours. After the reaction was completed, the mixture was filtered to obtain a filter residue. The filter residue was washed three times with anhydrous ethanol and dried at 120°C to obtain modified magnesium sulfate whiskers. The concentration of the stearic acid ethanol solution was 5%, and the mass of the stearic acid ethanol solution was 30 times the mass of the magnesium sulfate whiskers.
[0038] Preparation of magnetic iron oxide nanopowder: Step 1: Mix ferrous sulfate heptahydrate with deionized water at a mass ratio of 1:7.5 and stir to obtain the first solution. Mix sodium hydroxide with deionized water at a mass ratio of 1:16.7 and stir to obtain the second solution. Step 2: Under nitrogen protection, the second solution is quickly poured into the first solution at a volume ratio of 1:1 and reacted at 90°C for 2 hours. After the reaction is completed, a third suspension is obtained. The third suspension is placed between the two poles of an electromagnetic separator, and magnetic particles are adsorbed by passing electricity. After separation, the power is turned off to obtain solid magnetic particles. Step 3: Wash the solid magnetic particles with deionized water until neutral, then wash them twice with ethanol, dry them under vacuum at 80°C, and grind them to obtain magnetic iron oxide nanopowder.
[0039] The magnetic carbon-based photothermal powder is prepared by the following method: magnetic iron oxide nanoparticles are mixed with sucrose at a mass ratio of 1:(5), and the resulting product is vacuum dried at 100°C to obtain the magnetic carbon-based photothermal powder.
[0040] Preparation of photothermal filter aid: Weigh the modified magnesium sulfate whiskers, magnetic carbon-based photothermal powder and sodium dodecyl sulfate as needed and place them in a mixer. Mix them dry at room temperature for 60 minutes to obtain the photothermal filter aid.
[0041] Comparative Example 1: The difference between this comparative example and Example 1 is that the addition of modified magnesium sulfate whiskers was omitted.
[0042] Comparative Example 2: The difference between this comparative example and Example 1 is that the addition of magnetic carbon-based photothermal powder is omitted.
[0043] Comparative Example 3: The difference between this comparative example and Example 1 is that the dispersant was not added.
[0044] Comparative Example 4: The difference between this comparative example and Example 1 is that it uses a traditional soaking and washing method and does not use photothermal filter aids or near-infrared light irradiation.
[0045] Performance testing: The water-saving washing methods in the precipitation catalyst production process of Examples 1, 2, 3, Comparative Examples 1, 2, 3, and 4 were tested, and the test data are recorded in the table below:
[0046] Test methods: The conductivity of the filter cake after washing is in accordance with GB / T 6908-2018, the specific surface area of the catalyst is in accordance with GB / T 19587-2017, and the catalytic activity of the catalyst is taken as the conversion rate of ammonia oxidation reaction, in accordance with the industry standard "Test Methods for Catalyst Activity".
[0047] The performance test data shows that the catalyst precursors prepared in Examples 1, 2, and 3 have significantly lower electrical conductivity than those in Comparative Examples 1 to 4 after washing. This indicates that the photothermal filter aid achieves efficient removal of impurity ions during washing by constructing microchannels with modified magnesium sulfate whiskers and generating steam with magnetic carbon-based photothermal powder. At the same time, the photothermal effect induced by near-infrared light allows water to penetrate the filter cake in the form of steam, avoiding the loss of active components due to the dissolution of large amounts of water. Compared with the comparative examples, the washing efficiency of the examples is significantly improved. Its mechanism of action is similar to the water transport and transpiration of plant roots in nature. The micro-area fluid migration driven by photothermal light solves the problems of uneven water distribution and serious impurity residue in traditional washing.
[0048] Furthermore, the addition of dispersant ensures the uniform distribution of photothermal materials in the slurry, avoiding local overheating and washing blind spots. Comparative Example 1, lacking modified magnesium sulfate whiskers, has a lack of rigid channels inside the filter cake, resulting in poor steam penetration and high electrical conductivity. Comparative Example 2, lacking magnetic carbon-based photothermal powder, has low photothermal conversion efficiency and cannot form effective steam washing. Comparative Example 3, without dispersant, has material agglomeration leading to uneven heat field distribution and reduced washing effect. Comparative Example 4 uses traditional soaking washing, which relies on a large amount of water resources and cannot avoid the re-adsorption of impurity ions. This indicates that the synergistic effect of the components in the photothermal filter aid is the key to achieving deep washing.
[0049] By comparing and analyzing the data in the table, it can be seen that the water-saving washing method provided by this invention achieves integrated washing and drying operations through the synergistic design of photothermal filter aids and near-infrared irradiation, ensuring the high purity and structural integrity of the catalyst precursor with extremely low water consumption. The surface modification of carbon fibers and the optimization of the curing agent further ensure process stability. Therefore, this invention demonstrates that the water-saving washing method has significant environmental advantages and economic benefits, making it more suitable for widespread use in the green production of catalysts.
[0050] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0051] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.
Claims
1. A water saving washing method in a production process of a precipitated catalyst, characterized by: Includes the following steps: S1: After the catalyst completes the precipitation reaction and undergoes aging, a catalyst precipitate slurry to be washed is obtained. A photothermal filter aid is added to the catalyst precipitate slurry, and the mixture is stirred for 30-60 minutes. After stirring, the mixture is filtered to obtain a filter cake. S2: Wet the bottom of the filter cake with deionized water, and use near-infrared light to irradiate the surface of the filter cake for photothermal steam washing. When the conductivity value is lower than 50μS / cm, stop the near-infrared light irradiation to obtain the washed filter cake, thus completing the water-saving washing process in the precipitation catalyst production process. The photothermal filter aid comprises the following raw materials in parts by weight: 50-70 parts modified magnesium sulfate whiskers, 30-50 parts magnetic carbon-based photothermal powder, and 5-10 parts dispersant.
2. The water-saving washing method in the precipitation catalyst production process according to claim 1, characterized in that, The modified magnesium sulfate whiskers are prepared by the following method: magnesium sulfate whiskers are added to a stearic acid ethanol solution and stirred at 60-80℃ for 1-2 hours. After the reaction is completed, the mixture is filtered to obtain a filter residue. The filter residue is washed three times with anhydrous ethanol and dried at 100-120℃ to obtain modified magnesium sulfate whiskers. The concentration of the stearic acid ethanol solution is 5%, and the mass of the stearic acid ethanol solution is 20-30 times the mass of the magnesium sulfate whiskers.
3. The water-saving washing method in the precipitation catalyst production process according to claim 1, characterized in that, The magnetic carbon-based photothermal powder is prepared by the following method: magnetic iron oxide nanoparticles are mixed with sucrose at a mass ratio of 1:(3-5), and the resulting product is vacuum dried at 80-100℃ to obtain the magnetic carbon-based photothermal powder.
4. The water-saving washing method in the precipitation catalyst production process according to claim 3, characterized in that, The magnetic iron oxide nanopowder is prepared by the following method: Step 1: Mix ferrous sulfate heptahydrate with deionized water at a mass ratio of 1:(5.0-7.5), stir, and prepare the first solution. Mix sodium hydroxide with deionized water at a mass ratio of 1:(10-16.7), stir, and prepare the second solution. Step 2: Under nitrogen protection, the second solution is quickly poured into the first solution at a volume ratio of 1:1, and reacted at 70-90℃ for 1-2 hours. After the reaction is completed, a third suspension is obtained. The third suspension is placed between the two poles of an electromagnetic separator, and magnetic particles are adsorbed by passing electricity. After separation, the power is turned off to obtain solid magnetic particles. Step 3: Wash the solid magnetic particles with deionized water until neutral, then wash them twice with ethanol, dry them under vacuum at 60-80℃, and grind them to obtain magnetic iron oxide nanopowder.
5. The water-saving washing method in the precipitation catalyst production process according to claim 1, characterized in that, The dispersant is at least one of polyethylene glycol-4000, polyethylene glycol-6000, and sodium dodecyl sulfate.
6. The water-saving washing method in the precipitation catalyst production process according to claim 1, characterized in that, The amount of photothermal filter aid added in S1 is 1-5% of the mass of the catalyst precipitate slurry, and the amount of deionized water used in S2 is 10-20% of the mass of the filter cake.
7. The water-saving washing method in the precipitation catalyst production process according to claim 1, characterized in that, The near-infrared light is emitted by a near-infrared laser with a wavelength of 808nm or 980nm and an optical power density of 0.5-1.5 W / cm².
8. The water-saving washing method in the precipitation catalyst production process according to claim 1, characterized in that, The photothermal filter aid is prepared by the following method: Weigh the modified magnesium sulfate whiskers, magnetic carbon-based photothermal powder and dispersant as needed and place them in a mixer. Mix them dry at room temperature for 30-60 minutes to obtain the photothermal filter aid.