Formaldehyde conversion catalyst preparation method

Abstract

The invention discloses a formaldehyde conversion catalyst preparation method, which belongs to the technical field of catalyst preparation, and comprises the following steps: preparing raw materials, proportioning the raw materials, dissolving the raw materials in deionized water, and stirring for a period of time; according to the method, a normal-temperature catalytic oxidation method is adopted, harsh conditions in the preparation process are eliminated, the difficulty of the production process is greatly reduced, meanwhile, the manganese-based catalyst prepared in the method has the advantages of being high in activity, low in cost, environmentally friendly and the like, the overall preparation cost is greatly reduced, meanwhile, the environment is protected, and the method is suitable for industrial production. Meanwhile, compared with precious metal Pb and Ag which are high in price, non-precious metal such as Co and Ce which are relatively low in price is selected and doped to prepare the catalyst, the application cost of the whole method is further reduced, the catalyst prepared through the method shows good formaldehyde decomposition capacity at the room temperature, and the actual application effect of the method is further improved.

Description

Technical Field

[0001] The invention belongs to the technical field of catalyst preparation, and in particular relates to a method for preparing a formaldehyde conversion catalyst. Background Art

[0002] Formaldehyde is an organic compound. It is a colorless gas with a pungent odor at room temperature and pressure. It is recognized worldwide as the most common pollutant in indoor air pollution and a recognized carcinogen. It is seriously harmful to human health. Long-term exposure to low doses of formaldehyde may lead to chronic respiratory diseases, nasopharyngeal cancer, colon cancer, brain tumors, gene mutations in the cell nucleus, etc. At the same time, formaldehyde is also toxic to the nervous system, immune system, liver, etc. In addition, formaldehyde may also cause chromosomal abnormalities in children and pregnant women and chromosomal abnormalities in newborns. Due to these potential hazards of formaldehyde, many countries and regions have formulated relevant laws and regulations to restrict the use and emission of formaldehyde. Therefore, formaldehyde needs to be treated after it is produced.

[0003] Common methods for removing formaldehyde include room temperature catalytic oxidation, activated carbon adsorption, plasma removal, photocatalysis, etc. A Chinese patent discloses (CN103357399A) a method for coating a nanocatalyst for efficiently converting formaldehyde, comprising the following steps: (1) preparation of a nanocatalyst slurry; (2) mixing and compounding a silicate having a weight equivalent to 0.5-5% of the weight of the nanocatalyst powder and an alkaline compound having a weight equivalent to 1-10% of the weight of the nanocatalyst powder to obtain a binder slurry of a certain concentration; (3) stirring the nanocatalyst powder slurry at a high speed, and slowly dropping the binder slurry during the stirring process to obtain a nanocatalyst composite slurry; (4) drying the treated porous carrier and then immersing it in the nanocatalyst composite slurry, then taking it out and blowing it, repeating the process several times until the porous carrier increases in weight by 10-20% compared with that before immersion, and then drying and calcining it. The advantage of this method is that the nanocatalyst can be evenly and firmly coated on a large surface area porous carrier without affecting the catalytic oxidation performance, and the formaldehyde conversion rate can reach 80%-100%. Although the current formaldehyde conversion catalyst preparation method can also complete the preparation of the catalyst, it uses a large number of high-cost formulas, resulting in a high overall method preparation cost. At the same time, the preparation steps are relatively cumbersome, the fineness of the obtained catalyst is not high, and the actual application effect is not good. There is an urgent need for a formaldehyde conversion catalyst preparation method. Summary of the invention

[0004] The purpose of the present invention is to propose a method for preparing a formaldehyde conversion catalyst in order to solve the problem that although the current method for preparing a formaldehyde conversion catalyst can also complete the preparation of the catalyst, a large number of high-cost formulas are used internally, resulting in a high preparation cost of the overall method. At the same time, the preparation steps are relatively cumbersome, the fineness of the obtained catalyst is not high, and the actual application effect is not good.

[0005] In order to achieve the above object, the present invention adopts the following technical scheme: a method for preparing a formaldehyde conversion catalyst, comprising the following steps:

[0006] S1. Prepare raw materials and mix them according to their proportions;

[0007] S2, dissolving the raw materials in deionized water and stirring for a period of time;

[0008] S3, take a certain concentration of ammonia water and put it into the prepared solution while stirring;

[0009] S4, monitor the pH value in real time until it reaches a suitable pH value;

[0010] S5. Aging the materials for a period of time;

[0011] S6, filtering the aged raw material and taking the filtered precipitate for treatment;

[0012] S7, taking the filter cake and drying it, and then calcining it in a muffle furnace by programmed temperature increase to obtain a catalyst raw powder;

[0013] S8, placing catalyst powder, diaspore and sesbania powder in a mixing device, and adding the mixed liquid to mix;

[0014] S9, placing the mixture in an extrusion device to perform extrusion molding, taking the extruded mixture and drying it;

[0015] S10, finally taking the dried mixed material and placing it in a furnace for calcination at different temperatures;

[0016] S11, obtaining the final product, crushing it in a grinder and then sieving it;

[0017] S12. Collect costs and store them in the warehouse.

[0018] By adopting the above technical scheme and the room temperature catalytic oxidation method, the method eliminates the harsh conditions in the preparation process and greatly reduces the difficulty of the production process. At the same time, the manganese-based catalyst prepared in the method has the characteristics of high activity, low cost, and green environmental protection, which greatly reduces the overall preparation cost and protects the environment. At the same time, compared with the expensive prices of precious metals Pb and Ag, the method selects relatively low-priced non-precious metals such as Co and Ce to prepare catalysts, which further reduces the application cost of the overall method. The catalyst prepared by the method shows good formaldehyde decomposition ability at room temperature, which further improves the practical application effect of the method.

[0019] As a further description of the above technical solution:

[0020] In S1, raw materials are prepared and proportioned. The raw materials include Mn(NO3)2, Co(NO3)2·6H2O, Ce(NO3)3·6H2O, ammonia water, gibbsite and sesbania powder. The proportion of Mn(NO3)2, Co(NO3)2·6H2O and Ce(NO3)3·6H2O is 5:10:3.

[0021] As a further description of the above technical solution:

[0022] In the step S2, the raw material is dissolved in deionized water and stirred for 3-4 hours. In the step S3, 25-28% ammonia water is added to the prepared solution while stirring.

[0023] As a further description of the above technical solution:

[0024] In the step S4, the pH value is monitored in real time until a suitable pH value is reached, and the suitable pH value is 9-10. In the step S5, the material is aged for 12-14 hours.

[0025] As a further description of the above technical solution:

[0026] In S6, the aged raw material is filtered and the filtered precipitate is processed. The specific process of the processing is: the aged raw material is first placed in a cleaning container, and 30-40°C water is added to wash it 3-5 times. After the water is drained, the raw material is washed 4-6 times with 75-80% concentration ethanol solution, and the raw material is drained after washing.

[0027] As a further description of the above technical solution:

[0028] In S7, the filter cake is placed in an oven at 100-120°C for rapid drying. After drying, it is calcined in a muffle furnace using a programmed temperature to obtain a catalyst raw powder. The programmed temperature gradient is five temperature gradients, namely 150°C, 250°C, 350°C, 450°C and 550°C. The first four temperature gradients are calcined for 1 hour each, and the fifth temperature gradient is calcined for 4 hours.

[0029] As a further description of the above technical solution:

[0030] In S8, the catalyst powder, diaspore and sesbania powder are placed in a mixing device, the temperature in the device is increased to 60-80° C., and the mixed liquid is added and mixed for 35-40 minutes.

[0031] As a further description of the above technical solution:

[0032] In the above S9, the mixture is placed in an extruder to be extruded, the extruded mixture is air-dried for 10-12 hours, and after drying, it is placed in a drying furnace and dried at a temperature of 100-120° C. for 4-6 hours.

[0033] As a further description of the above technical solution:

[0034] In the S10, the dried mixture is finally placed in a furnace for calcination at different temperatures. The different temperatures are divided into five temperature gradients, namely 150°C, 250°C, 350°C, 450°C and 550°C. The mixture is calcined for 1 hour in the first four temperature gradients and for 4 hours in the fifth temperature gradient.

[0035] As a further description of the above technical solution:

[0036] In S11, the final product is obtained, crushed in a crusher, and then passed through a 20-40 mesh sieve.

[0037] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0038] In the present invention, the method adopts a room temperature catalytic oxidation method, which eliminates the harsh conditions in the preparation process and greatly reduces the difficulty of the production process. At the same time, the manganese-based catalyst prepared in the method has the characteristics of high activity, low cost, green environmental protection, etc., which greatly reduces the overall preparation cost and protects the environment. At the same time, compared with the expensive prices of precious metals Pb and Ag, the method selects relatively low-priced non-precious metals such as Co and Ce to prepare the catalyst, which further reduces the application cost of the overall method. The catalyst prepared by the method shows good formaldehyde decomposition ability at room temperature, which further improves the practical application effect of the method. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 The present invention is a flow chart of a method for preparing a formaldehyde conversion catalyst. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] Example 1

[0042] See also Figure 1 The present invention provides a technical solution: a method for preparing a formaldehyde conversion catalyst, comprising the following steps:

[0043] S1. Prepare raw materials and mix them. The raw materials include Mn(NO3)2, Co(NO3)2·6H2O, Ce(NO3)3·6H2O, ammonia water, diaspore and sesbania powder. The ratio of Mn(NO3)2, Co(NO3)2·6H2O and Ce(NO3)3·6H2O is 5:10:3.

[0044] S2, dissolve the raw materials in deionized water and stir for 3h;

[0045] S3, take 25% concentration of ammonia water and put it into the prepared solution while stirring;

[0046] S4, real-time monitoring of pH value until reaching a suitable pH value, which is 9;

[0047] S5. Aging the material for 12 hours;

[0048] S6, filtering the aged raw material, and taking the filtered precipitate for treatment, the specific process of the treatment is: taking the aged raw material first into a cleaning container, adding 30°C water to wash 3 times, waiting for the water to drain, using 75% concentration ethanol solution to wash the raw material 4 times, and waiting for the raw material to drain after washing;

[0049] S7, taking the filter cake and placing it in an oven at 100°C for rapid drying, and after drying, calcining it in a muffle furnace using a programmed temperature rise to obtain a catalyst raw powder, the programmed temperature rise gradient is five temperature gradients, namely 150°C, 250°C, 350°C, 450°C and 550°C, calcining for 1 hour in each of the first four temperature gradients, and calcining for 4 hours in the fifth temperature gradient;

[0050] S8, put the catalyst powder, diaspore and sesbania powder into a mixing device, increase the temperature in the device to 60°C, add the mixed solution and mix for 35 minutes;

[0051] S9, placing the mixture in an extruder to perform extrusion molding, taking the extruded mixture and drying it for 10 hours, and then placing it in a drying furnace to dry it at 100° C. for 4 hours;

[0052] S10, finally taking the dried mixed material and placing it in a furnace for calcination at different temperatures, the different temperatures are divided into five temperature gradients, namely 150°C, 250°C, 350°C, 450°C and 550°C, calcining for 1 hour in the first four temperature gradients, and calcining for 4 hours in the fifth temperature gradient;

[0053] S11, obtain the final product, place it in a grinder, grind it, and then pass it through a 20-mesh sieve;

[0054] S12. Collect costs and store them in the warehouse.

[0055] In this embodiment, the method adopts a room temperature catalytic oxidation method, which eliminates the harsh conditions in the preparation process and greatly reduces the difficulty of the production process.

[0056] Example 2

[0057] See also Figure 1 The present invention provides a technical solution: a method for preparing a formaldehyde conversion catalyst, comprising the following steps:

[0058] S1. Prepare raw materials and mix them. The raw materials include Mn(NO3)2, Co(NO3)2·6H2O, Ce(NO3)3·6H2O, ammonia water, diaspore and sesbania powder. The ratio of Mn(NO3)2, Co(NO3)2·6H2O and Ce(NO3)3·6H2O is 5:10:3.

[0059] S2, dissolve the raw materials in deionized water and stir for 3h;

[0060] S3, take 28% concentration of ammonia water and put it into the prepared solution while stirring;

[0061] S4, real-time monitoring of pH value until reaching a suitable pH value, which is 9;

[0062] S5, aging the material for 13 hours;

[0063] S6, filtering the aged raw material, and taking the filtered precipitate for treatment, the specific process of the treatment is: taking the aged raw material first into a cleaning container, adding 30°C water to wash 4 times, waiting for the water to drain, using 78% concentration ethanol solution to wash the raw material 5 times, and waiting for the raw material to drain after washing;

[0064] S7, taking the filter cake and placing it in an oven at 110°C for rapid drying, and after drying, calcining it in a muffle furnace using a programmed temperature rise to obtain a catalyst raw powder, the programmed temperature rise gradient is five temperature gradients, namely 150°C, 250°C, 350°C, 450°C and 550°C, calcining for 1 hour in each of the first four temperature gradients, and calcining for 4 hours in the fifth temperature gradient;

[0065] S8, put the catalyst powder, diaspore and sesbania powder into a mixing device, increase the temperature in the device to 70°C, add the mixed solution and mix for 38 minutes;

[0066] S9, placing the mixture in an extruder to perform extrusion molding, taking the extruded mixture and drying it for 11 hours, and then placing it in a drying furnace and drying it at a temperature of 110° C. for 5 hours;

[0067] S10, finally taking the dried mixed material and placing it in a furnace for calcination at different temperatures, the different temperatures are divided into five temperature gradients, namely 150°C, 250°C, 350°C, 450°C and 550°C, calcining for 1 hour in the first four temperature gradients, and calcining for 4 hours in the fifth temperature gradient;

[0068] S11, obtain the final product, crush it in a grinder and then pass it through a 30-mesh sieve;

[0069] S12. Collect costs and store them in the warehouse.

[0070] In this embodiment, the manganese-based catalyst prepared by the method has the characteristics of high activity, low cost, and green environmental protection, which greatly reduces the overall preparation cost and protects the environment. Compared with the expensive prices of precious metals Pb and Ag, the method selects relatively low-priced non-precious metals such as Co and Ce to prepare catalysts by doping, which further reduces the application cost of the overall method.

[0071] Example 3

[0072] See also Figure 1 The present invention provides a technical solution: a method for preparing a formaldehyde conversion catalyst, comprising the following steps:

[0073] S1. Prepare raw materials and mix them. The raw materials include Mn(NO3)2, Co(NO3)2·6H2O, Ce(NO3)3·6H2O, ammonia water, diaspore and sesbania powder. The ratio of Mn(NO3)2, Co(NO3)2·6H2O and Ce(NO3)3·6H2O is 5:10:3.

[0074] S2, dissolve the raw materials in deionized water and stir for 4h;

[0075] S3, take 28% concentration of ammonia water and put it into the prepared solution while stirring;

[0076] S4, monitor the pH value in real time until it reaches a suitable pH value, which is 10;

[0077] S5. Aging the material for 14 hours;

[0078] S6, filtering the aged raw material, and taking the filtered precipitate for treatment, the specific process of the treatment is: taking the aged raw material first into a cleaning container, adding 40°C water to wash 5 times, waiting for the water to drain, using 80% concentration ethanol solution to wash the raw material 6 times, and waiting for the raw material to drain after washing;

[0079] S7, taking the filter cake and placing it in an oven at 120°C for rapid drying, and after drying, calcining it in a muffle furnace using a programmed temperature rise to obtain a catalyst raw powder, the programmed temperature rise gradient is five temperature gradients, namely 150°C, 250°C, 350°C, 450°C and 550°C, calcining for 1 hour in each of the first four temperature gradients, and calcining for 4 hours in the fifth temperature gradient;

[0080] S8, put the catalyst powder, diaspore and sesbania powder into a mixing device, increase the temperature in the device to 80°C, add the mixed solution and mix for 40 minutes;

[0081] S9, placing the mixture in an extruder to perform extrusion molding, taking the extruded mixture and drying it for 12 hours, and then placing it in a drying furnace and drying it at 120° C. for 6 hours;

[0082] S10, finally taking the dried mixed material and placing it in a furnace for calcination at different temperatures, the different temperatures are divided into five temperature gradients, namely 150°C, 250°C, 350°C, 450°C and 550°C, calcining for 1 hour in the first four temperature gradients, and calcining for 4 hours in the fifth temperature gradient;

[0083] S11, obtain the final product, crush it in a grinder and then pass it through a 40-mesh sieve;

[0084] S12. Collect costs and store them in the warehouse.

[0085] In this embodiment, the catalyst prepared by this method exhibits good formaldehyde decomposition ability at room temperature, further improving the practical application effect of this method.

[0086] Example 4

[0087] See also Figure 1 The present invention provides a technical solution: a method for preparing a formaldehyde conversion catalyst, comprising the following steps:

[0088] S1. Prepare raw materials and mix them. The raw materials include Mn(NO3)2, Co(NO3)2·6H2O, Ce(NO3)3·6H2O, ammonia water, diaspore and sesbania powder. The ratio of Mn(NO3)2, Co(NO3)2·6H2O and Ce(NO3)3·6H2O is 5:10:3.

[0089] S2, dissolve the raw materials in deionized water and stir for 4h;

[0090] S3, take 28% concentration of ammonia water and put it into the prepared solution while stirring;

[0091] S4, monitor the pH value in real time until it reaches a suitable pH value, which is 10;

[0092] S5. Aging the material for 14 hours;

[0093] S6, filtering the aged raw material, and taking the filtered precipitate for treatment, the specific process of the treatment is: taking the aged raw material first into a cleaning container, adding 40°C water to wash 5 times, waiting for the water to drain, using 80% concentration ethanol solution to wash the raw material 5 times, and waiting for the raw material to drain after washing;

[0094] S7, taking the filter cake and placing it in an oven at 120°C for rapid drying, and after drying, calcining it in a muffle furnace using a programmed temperature rise to obtain a catalyst raw powder, the programmed temperature rise gradient is five temperature gradients, namely 150°C, 250°C, 350°C, 450°C and 550°C, calcining for 1 hour in each of the first four temperature gradients, and calcining for 4 hours in the fifth temperature gradient;

[0095] S8, taking the catalyst powder, diaspore and sesbania powder and placing them in a mixing device, raising the temperature in the device to 80°C, adding the mixed solution and mixing for 38 minutes;

[0096] S9, placing the mixture in an extruder to perform extrusion molding, taking the extruded mixture and drying it for 12 hours, and then placing it in a drying furnace and drying it at 120° C. for 5 hours;

[0097] S10, finally taking the dried mixed material and placing it in a furnace for calcination at different temperatures, the different temperatures are divided into five temperature gradients, namely 150°C, 250°C, 350°C, 450°C and 550°C, calcining for 1 hour in the first four temperature gradients, and calcining for 4 hours in the fifth temperature gradient;

[0098] S11, obtain the final product, crush it in a grinder and then pass it through a 35-mesh sieve;

[0099] S12. Collect costs and store them in the warehouse.

[0100] In this embodiment, the method adopts a room temperature catalytic oxidation method. The method eliminates the harsh conditions in the preparation process and greatly reduces the difficulty of the production process. At the same time, the manganese-based catalyst prepared in the method has the characteristics of high activity, low cost, and green environmental protection, which greatly reduces the overall preparation cost and protects the environment. Compared with the expensive prices of precious metals Pb and Ag, the method selects relatively low-priced non-precious metals such as Co and Ce to prepare catalysts, which further reduces the application cost of the overall method. The catalyst prepared by the method exhibits good formaldehyde decomposition ability at room temperature, further improving the practical application effect of the method.

[0101] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for preparing a formaldehyde conversion catalyst, characterized in that: The steps include: S1. Prepare raw materials and mix them according to their proportions; S2, dissolving the raw materials in deionized water and stirring for a period of time; S3, take a certain concentration of ammonia water and put it into the prepared solution while stirring; S4, monitor the pH value in real time until it reaches a suitable pH value; S5. Aging the materials for a period of time; S6, filtering the aged raw material and taking the filtered precipitate for treatment; S7, taking the filter cake and drying it, and then calcining it in a muffle furnace by programmed temperature increase to obtain a catalyst raw powder; S8, placing catalyst powder, diaspore and sesbania powder in a mixing device, and adding the mixed liquid to mix; S9, placing the mixture in an extrusion device to perform extrusion molding, taking the extruded mixture and drying it; S10, finally taking the dried mixed material and placing it in a furnace for calcination at different temperatures; S11, obtaining the final product, crushing it in a grinder and then sieving it; S12. Collect costs and store them in the warehouse.

2. The method for preparing a formaldehyde conversion catalyst according to claim 1, characterized in that: In S1, raw materials are prepared and proportioned. The raw materials include Mn(NO3)2, Co(NO3)2·6H2O, Ce(NO3)3·6H2O, ammonia water, gibbsite and sesbania powder. The proportion of Mn(NO3)2, Co(NO3)2·6H2O and Ce(NO3)3·6H2O is 5:10:

3.

3. The method for preparing a formaldehyde conversion catalyst according to claim 1, characterized in that: In the step S2, the raw material is dissolved in deionized water and stirred for 3-4 hours. In the step S3, 25-28% ammonia water is added to the prepared solution while stirring.

4. The method for preparing a formaldehyde conversion catalyst according to claim 1, characterized in that: In the step S4, the pH value is monitored in real time until a suitable pH value is reached, and the suitable pH value is 9-10. In the step S5, the material is aged for 12-14 hours.

5. The method for preparing a formaldehyde conversion catalyst according to claim 1, characterized in that: In S6, the aged raw material is filtered and the filtered precipitate is processed. The specific process of the processing is: the aged raw material is first placed in a cleaning container, and 30-40°C water is added to wash it 3-5 times. After the water is drained, the raw material is washed 4-6 times with 75-80% concentration ethanol solution, and the raw material is drained after washing.

6. The method for preparing a formaldehyde conversion catalyst according to claim 1, characterized in that: In S7, the filter cake is placed in an oven at 100-120°C for rapid drying. After drying, it is calcined in a muffle furnace using a programmed temperature to obtain a catalyst raw powder. The programmed temperature gradient is five temperature gradients, namely 150°C, 250°C, 350°C, 450°C and 550°C. The first four temperature gradients are calcined for 1 hour each, and the fifth temperature gradient is calcined for 4 hours.

7. The method for preparing a formaldehyde conversion catalyst according to claim 1, characterized in that: In S8, the catalyst powder, diaspore and sesbania powder are placed in a mixing device, the temperature in the device is increased to 60-80° C., and the mixed liquid is added and mixed for 35-40 minutes.

8. The method for preparing a formaldehyde conversion catalyst according to claim 1, characterized in that: In the above S9, the mixture is placed in an extruder to be extruded, the extruded mixture is air-dried for 10-12 hours, and after drying, it is placed in a drying furnace and dried at a temperature of 100-120° C. for 4-6 hours.

9. The method for preparing a formaldehyde conversion catalyst according to claim 1, characterized in that: In the S10, the dried mixture is finally placed in a furnace for calcination at different temperatures. The different temperatures are divided into five temperature gradients, namely 150°C, 250°C, 350°C, 450°C and 550°C. The mixture is calcined for 1 hour in the first four temperature gradients and for 4 hours in the fifth temperature gradient.

10. The method for preparing a formaldehyde conversion catalyst according to claim 1, characterized in that: In S11, the final product is obtained, crushed in a crusher, and then passed through a 20-40 mesh sieve.

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