Methanol catalyst forming method, methanol catalyst and application
By adding uncalcined raw powder and controlling the weight loss on ignition and calcination conditions during the preparation of methanol catalysts, the problem of easy deformation of catalyst channels was solved, higher hydrogenation activity and stability were achieved, and costs were reduced.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ZHEJIANG INTELLIGENT TRANSPORTATION TECHNOLOGY INNOVATION CENTER
- Filing Date
- 2025-07-18
- Publication Date
- 2026-07-07
AI Technical Summary
During the tableting process, the pore structure of methanol catalysts is prone to deformation and collapse, resulting in a decrease in specific surface area and pore volume, which affects the hydrogenation performance of the catalyst. In addition, conventional methods, such as adding pore-forming agents and secondary calcination, lead to larger copper active species particles and decreased activity.
By adding uncalcined catalyst powder as a pore-forming agent during the catalyst preparation process, controlling the weight loss on ignition and calcination temperature, and avoiding the addition of additional binders and pore-forming agents, the gas generated by the decomposition of uncalcined powder is used to expand the pore size, and the calcination conditions are optimized to improve the pore volume and copper particle dispersibility.
This improved the hydrogenation activity and stability of the catalyst, reduced the preparation cost, avoided the use of additional additives, and enhanced the diffusion performance of reactants and products.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of catalyst preparation, and more particularly to a method for forming a methanol catalyst, a methanol catalyst, and its applications. Background Technology
[0002] Solid catalysts, in industrial applications, need to be adapted to catalytic reactors in specific shapes and sizes. For solid powder molding, methods such as flake molding, extrusion molding, ball forming, spray molding, and oil column molding are generally used to obtain catalysts of specific shapes and sizes. These molding processes typically require the addition of auxiliary materials such as binders and pore-forming agents. The molding processing methods and formulations of catalysts are closely related to their activity and stability; therefore, the molding formulations and processing methods are particularly important in catalyst preparation.
[0003] Methanol catalysts are typically produced using a pelletizing process. During pelletizing, the catalyst's pore structure deforms or even collapses, leading to a decrease in specific surface area and pore volume, thus reducing the catalyst's hydrogenation performance. Conventional methods increase the specific surface area and pore volume by adding pore-forming agents, but this requires secondary calcination. However, prolonged calcination causes the copper active species particles to enlarge, further reducing the catalyst's hydrogenation activity. Summary of the Invention
[0004] To address the aforementioned problems, this invention provides a method for forming a methanol catalyst, a methanol catalyst, and its application. By adding a small amount of uncalcined catalyst powder as a pore-forming agent, the pore size can be expanded more uniformly, improving the diffusion of reactants and products, thus achieving the effect of a pore-forming agent. This can enhance the hydrogenation activity of the catalyst, reduce the use of additives, and lower the catalyst preparation cost.
[0005] The present invention provides a method for forming a methanol catalyst, comprising the following steps: preparing catalyst raw powder; calcining a portion of the catalyst raw powder to form a calcined catalyst; mixing the catalyst raw powder, the calcined catalyst raw powder, and a release agent; granulating the mixed material in a granulator and screening it with a screen; and granulating the screened catalyst particles in a tableting machine to obtain a formed catalyst.
[0006] In one embodiment of the present invention, the catalyst powder is prepared by a co-precipitation method, specifically including: weighing zinc nitrate hexahydrate and aluminum nitrate nonahydrate, adding them to deionized water, stirring and dissolving, denoted as solution A; weighing copper nitrate trihydrate and zirconium nitrate and dissolving them in deionized water, denoted as solution B; weighing anhydrous sodium carbonate, adding it to deionized water, stirring and dissolving to form a precipitant solution, denoted as solution C; simultaneously adding solutions A and C dropwise to a container containing deionized water, controlling the pH value of the suspension in the container; after solution A has been added dropwise, adding solutions B and C dropwise to the suspension, maintaining the pH value of the suspension; after the addition is completed, aging the suspension; washing and drying the aged slurry for later use, the dried sample being the catalyst powder.
[0007] In one embodiment of the present invention, the mesh size of the screen is 20-60 mesh.
[0008] In one embodiment of the present invention, the catalyst powder needs to be controlled for weight loss on ignition during the calcination process, and the weight loss on ignition is controlled at 2%-12%. In the mixed material, the amount of catalyst powder added is 2%-10%.
[0009] In one embodiment of the present invention, the dimensions of the shaped catalyst include 3*3mm, 4*4mm, 4*5mm, 5*5mm, 6*5mm, and 6*6mm.
[0010] In one embodiment of the present invention, the catalyst powder contains 50-70% copper by mass, 20-30% zinc oxide by mass, and 10-20% aluminum oxide by mass.
[0011] In one embodiment of the present invention, the release agent includes one or more of graphite, talc and carbon black, and the mass percentage of the release agent in the mixed material is 1%-6%.
[0012] In one embodiment of the present invention, the calcination temperature is 300-500°C and the calcination time is 2-5 hours.
[0013] The present invention also provides a methanol catalyst prepared according to the methanol catalyst forming method described above.
[0014] The present invention also provides an application of a methanol catalyst prepared according to the methanol catalyst forming method described above, or the methanol catalyst described above, in the reaction of preparing methanol by hydrogenation of carbon dioxide.
[0015] Compared with existing technologies, the present invention has the following beneficial technical effects:
[0016] This invention provides a method for forming a methanol catalyst, the methanol catalyst itself, and its application. In the catalyst forming process, no additional binders or pore-forming agents are required. By controlling the catalyst's weight loss on ignition and adding uncalcined catalyst powder during catalyst preparation and synthesis, and using a lower calcination temperature and shorter calcination time, the particle size of active copper species can be minimized, thereby improving catalytic hydrogenation activity. Furthermore, the gas generated during the decomposition of the uncalcined catalyst powder can expand the pore structure, promoting the diffusion of reactants and products, further enhancing the catalyst's hydrogenation activity and stability, and reducing catalyst costs. Detailed Implementation
[0017] The specific embodiments of the present invention will be described in further detail below with reference to the examples. These examples are for illustrative purposes only and are not intended to limit the scope of the invention.
[0018] This invention discloses a method for forming a methanol catalyst, comprising the following steps:
[0019] The process involves preparing catalyst raw powder; calcining a portion of the catalyst raw powder; mixing the catalyst raw powder, the calcined catalyst, and a release agent; granulating the mixture using a dry granulator and screening it with a screen; and then feeding the screened catalyst particles into a tableting machine for tableting. This invention provides a method that eliminates the need for additional binders and pore-forming agents during catalyst forming. Instead, by adding uncalcined catalyst raw powder during catalyst preparation and synthesis, the pore size and volume of the catalyst are increased through the self-decomposition of the catalyst raw powder, thereby improving the hydrogenation activity and stability of the catalyst and reducing catalyst costs.
[0020] On the one hand, the incompletely decomposed original catalyst powder acts as a pore-forming agent during the decomposition process, which can more uniformly expand the pore size and improve the diffusion of reactants and products, thereby improving the hydrogenation activity of the catalyst. In addition, the expansion of the catalyst pore size is conducive to the diffusion of product water vapor, which can inhibit the oxidation and sintering of the catalyst by water vapor.
[0021] On the other hand, during the calcination process, the catalyst powder also needs to undergo weight loss on ignition testing, temperature control, and reduction of calcination time. Controlling weight loss on ignition can improve the dispersion of copper species and reduce the size of copper particles, eliminating the need for secondary calcination of the catalyst, thereby further improving hydrogenation activity and reducing the catalyst preparation cost. Furthermore, optimizing the calcination temperature and time can improve the dispersion of copper species in the catalyst. Uniform dispersion of copper particles is beneficial for inhibiting Ostwald rinsing, thus further improving the stability of the catalyst.
[0022] In one embodiment of the present invention, the catalyst powder is prepared by co-precipitation, specifically including:
[0023] Weigh zinc nitrate hexahydrate and aluminum nitrate nonahydrate, add them to deionized water, stir and dissolve, and label this as solution A; weigh copper nitrate trihydrate and zirconium nitrate, dissolve them in deionized water, and label this as solution B; weigh anhydrous sodium carbonate, add it to deionized water, stir and dissolve to form a precipitant solution, and label this as solution C; simultaneously add solutions A and C dropwise to a container containing deionized water, controlling the pH value of the suspension in the container; after solution A has been added, add solutions B and C dropwise to the suspension, maintaining the pH value of the suspension; after the addition is complete, age the suspension; wash and dry the aged slurry for later use, and the dried sample is the original catalyst powder.
[0024] In one embodiment of the present invention, the co-precipitation method is as follows:
[0025] Weigh 8.29g of zinc nitrate hexahydrate and 5.82g of aluminum nitrate nonahydrate, add 90mL of deionized water, stir and dissolve in a 200mL beaker, and label this solution A. Weigh 18.04g of copper nitrate trihydrate and 0.51g of zirconium nitrate, dissolve in 153mL of deionized water, and label this solution B. Weigh 41.6g of anhydrous sodium carbonate, add 400mL of deionized water, stir and dissolve to form a 1mol / L precipitant solution, and label this solution C. Add solutions A and C simultaneously dropwise to a three-necked flask containing 100mL of deionized water, maintaining the pH of the suspension in the three-necked flask at 7. After solution A has been added, add solutions B and C dropwise to the suspension, maintaining the pH of the suspension at 7. After the addition is complete, age the suspension at 60℃ for 3 hours. Wash and dry the aged slurry for later use. The dried sample is the original catalyst powder.
[0026] In one embodiment of the present invention, the mesh size of the screen is 20-60 mesh.
[0027] In one embodiment of the present invention, the loss on ignition of the catalyst powder is controlled at 2%-12%, for example, 2%, 4%, 5%, 10%, 12%, and the amount of catalyst powder added is 2%-10%, for example, 2%, 4%, 6%, 10%.
[0028] In one embodiment of the present invention, the dimensions of the shaped catalyst include 3*3mm, 4*4mm, 4*5mm, 5*5mm, 6*5mm, and 6*6mm.
[0029] In one embodiment of the present invention, the mass percentage of copper in the catalyst powder is 50-70%, for example, 50%, 60%, 70%; the mass percentage of zinc oxide is 20-30%, for example, 20%, 25%, 30%; and the mass percentage of aluminum oxide is 10-20%, for example, 10%, 15%, 20%.
[0030] In one embodiment of the present invention, the release agent includes one or more of graphite, talc and carbon black, and the mass percentage of the release agent is 1%-6%, for example, 1%, 3%, 5% and 6%.
[0031] In one embodiment of the present invention, the calcination temperature is 300-500℃, for example, 300℃, 400℃, 500℃, and the calcination time is 2-5 hours, for example, 2 hours, 3 hours, 4 hours, 5 hours.
[0032] The present invention also provides a methanol catalyst prepared according to the methanol catalyst forming method described above.
[0033] The present invention also provides an application of a methanol catalyst prepared according to the methanol catalyst forming method described above, or the methanol catalyst described above, for use in the reaction of producing methanol by hydrogenation of carbon dioxide.
[0034] The present invention will be further illustrated below with reference to the embodiments.
[0035] Example 1
[0036] Uncalcined catalyst powder was calcined in a muffle furnace at 300℃ for 3 hours, and the resulting catalyst was labeled as Catalyst 1. A portion of Catalyst 1 was subjected to a loss on ignition test. 100g of Catalyst 1, 3g of uncalcined catalyst powder, and 2g of graphite were mixed evenly in a mixer. The mixed material was then poured into a dry granulator for granulation and screened through a 20-60 mesh sieve. The screened catalyst particles were then poured into the feed inlet of a tableting machine for tableting and labeled as Formed Catalyst 1.
[0037] Example 2
[0038] Uncalcined catalyst powder was calcined in a muffle furnace at 400℃ for 4 hours, and the resulting catalyst was labeled as catalyst 2. A portion of catalyst 2 was subjected to a loss on ignition test. 100g of catalyst 2, 5g of uncalcined catalyst powder, and 2g of talc powder were mixed evenly in a mixer. The mixed material was then poured into a dry granulator for granulation and screened through a 20-60 mesh sieve. The sieved catalyst particles were then poured into the feed inlet of a tableting machine for tableting and labeled as tableted catalyst 2.
[0039] Example 3
[0040] Uncalcined catalyst powder was calcined in a muffle furnace at 350℃ for 3 hours, and the resulting catalyst was labeled as catalyst 3. A portion of catalyst 3 was subjected to a loss on ignition test. 100g of catalyst 3, 2g of uncalcined catalyst powder, and 1g of graphite were mixed evenly in a mixer. The mixed material was poured into a dry granulator for granulation and screened through a 20-60 mesh sieve. The screened catalyst particles were then poured into the feed inlet of a tableting machine for tableting and labeled as tableted catalyst 3.
[0041] Example 4
[0042] Uncalcined catalyst powder was calcined in a muffle furnace at 500℃ for 3 hours, and the resulting catalyst was labeled as catalyst 4. A portion of catalyst 4 was subjected to a loss on ignition test. 100g of catalyst 4, 8g of uncalcined catalyst powder, and 5g of carbon black were mixed evenly in a mixer. The mixed material was poured into a dry granulator for granulation and screened through a 20-60 mesh sieve. The screened catalyst particles were then poured into the feed inlet of a tableting machine for tableting and labeled as tableted catalyst 4.
[0043] Example 5
[0044] Uncalcined catalyst powder was calcined in a muffle furnace at 450℃ for 5 hours, and the resulting catalyst was labeled as catalyst 5. A portion of catalyst 5 was subjected to a loss on ignition test. 100g of catalyst 5, 6g of uncalcined catalyst powder, and 4g of graphite were mixed evenly in a mixer. The mixed material was poured into a dry granulator for granulation and screened through a 20-60 mesh sieve. The screened catalyst particles were then poured into the feed inlet of a tableting machine for tableting and labeled as tableted catalyst 5.
[0045] Example 6
[0046] Uncalcined catalyst powder was calcined in a muffle furnace at 350℃ for 4 hours, and the resulting catalyst was labeled as catalyst 6. A portion of catalyst 6 was subjected to a loss on ignition test. 100g of catalyst 6, 5g of uncalcined catalyst powder, and 3g of graphite were mixed evenly in a mixer. The mixed material was poured into a dry granulator for granulation and screened through a 20-60 mesh sieve. The screened catalyst particles were then poured into the feed inlet of a tableting machine for tableting and labeled as tableted catalyst 6.
[0047] Comparative Example 1
[0048] Uncalcined catalyst powder was calcined in a muffle furnace at 500℃ for 4 hours, and the resulting catalyst was labeled as Catalyst 7. A portion of Catalyst 7 was subjected to a loss on ignition test. 100g of Catalyst 7 and 4g of graphite were mixed evenly in a mixer. The mixture was then poured into a dry granulator for granulation and screened through a 20-60 mesh sieve. The sieved catalyst particles were then poured into the feed inlet of a tableting machine for tableting and labeled as Formed Catalyst 7.
[0049] Loss on ignition test method: Take 10g of calcined catalyst powder and place it in a muffle furnace at 500℃ for the first calcination for 30 minutes. After the muffle furnace temperature drops to room temperature, remove the sample and place it in a desiccator to cool. Weigh the cooled sample in an analytical balance and record the catalyst mass as m1. Then place the sample in a muffle furnace at 500℃ for the second calcination for 30 minutes and weigh the cooled sample as m2. Repeat the above operation until m1 = mn (n times). The loss on ignition of the catalyst is w = (10 - mn) / 10.
[0050] The catalysts in the above examples and comparative examples were applied to the reaction of carbon dioxide hydrogenation to methanol, and their performance was tested under the following conditions: reaction temperature 250°C, reaction pressure 5 MPa, and reaction space velocity 10000 mL∙h. -1 ∙g cat -1 The H2 to CO2 flow rate ratio was 3:1, and the test results are shown in Table 1.
[0051] Table 1. Catalyst performance test results in Examples 1-6 and Comparative Example 1
[0052]
[0053] As shown in Table 1, comparing Examples 1-6 with Comparative Example 1, the catalysts in Examples 1-6 were prepared by controlling the ignition weight loss index of the catalyst itself and adding uncalcined catalyst powder during the molding process. In Comparative Example 1, only the ignition weight loss test was performed during the molding process, without adding uncalcined catalyst powder. The methanol space-time yields in Examples 1-6 were all higher than those in Comparative Example 1, the deactivation rates were all lower than those in Comparative Example 1, and the molding strengths were all higher than those in Comparative Example 1. It can be seen that controlling the ignition weight loss index of the catalyst itself and adding uncalcined catalyst powder during the catalyst molding process, thereby improving the pore size and pore volume of the catalyst through catalyst self-decomposition, can better improve the hydrogenation activity and stability of the catalyst.
[0054] As described above, the methanol catalyst forming method, methanol catalyst, and application provided by this invention do not require the addition of additional binders and pore-forming agents during the catalyst forming process. Instead, by controlling the catalyst's weight loss on ignition and adding uncalcined catalyst powder during catalyst preparation and synthesis, the catalyst's pore size and volume are increased through self-decomposition. Using a lower calcination temperature and shorter calcination time minimizes the particle size of active copper species, thereby enhancing catalytic hydrogenation activity. Furthermore, the gas generated during the decomposition of the uncalcined catalyst powder expands the pore structure, promoting the diffusion of reactants and products, further improving the catalyst's hydrogenation activity and stability, and reducing catalyst costs.
[0055] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.
Claims
1. A method for forming a methanol catalyst, characterized in that, Includes the following steps: Preparation of catalyst raw powder; A portion of the original catalyst powder was calcined; The catalyst powder, the calcined catalyst powder, and the release agent are mixed together; The mixed materials are poured into a granulator for granulation and then screened using a mesh screen. The sieved catalyst particles are poured into a tableting machine for tableting and forming to obtain the formed catalyst; The catalyst powder needs to undergo weight loss on ignition control during the calcination process, and the weight loss on ignition is controlled at 2%-12%. In the mixed material, the amount of catalyst powder added is 2%-10%, and the mass percentage of the release agent in the mixed material is 1%-6%. The roasting temperature is 300-500℃, and the roasting time is 2-5 hours; The catalyst powder is prepared by co-precipitation, including the following steps: Weigh out zinc nitrate hexahydrate and aluminum nitrate nonahydrate, add them to deionized water, stir to dissolve, and record this as solution A; Weigh out copper nitrate trihydrate and zirconium nitrate and dissolve them in deionized water, and denote this as solution B; Weigh out anhydrous sodium carbonate, add deionized water, stir to dissolve, and form a precipitant solution, denoted as solution C; Solution A and solution C are simultaneously added dropwise to a container containing deionized water, and the pH value of the suspension in the container is controlled. After solution A has been added dropwise, solution B and solution C are added dropwise to the suspension, and the pH value of the suspension is maintained. After the addition is complete, the suspension is aged. The aged slurry was washed, dried, and then kept for later use. The dried sample was the original catalyst powder.
2. The methanol catalyst forming method according to claim 1, characterized in that, The mesh size of the screen is 20-60 mesh.
3. The methanol catalyst forming method according to claim 1, characterized in that: The dimensions of the molded catalyst include 3*3mm, 4*4mm, 4*5mm, 5*5mm, 6*5mm, and 6*6mm.
4. The methanol catalyst forming method according to claim 1, characterized in that: The catalyst powder contains 50-70% copper, 20-30% zinc oxide, and 10-20% aluminum oxide by mass.
5. The method for forming a methanol catalyst according to claim 1, characterized in that, The release agent includes one or more of graphite, talc, and carbon black.
6. A methanol catalyst, characterized in that: The methanol catalyst is prepared by the molding method according to any one of claims 1-5.
7. The application of a methanol catalyst prepared by the methanol catalyst forming method according to any one of claims 1-5, or the methanol catalyst according to claim 6, characterized in that, It is used in the reaction of hydrogenating carbon dioxide to produce methanol.