Catalyst suitable for preparing methanol from multi-component mixed gas and preparation method thereof

Abstract

The invention relates to a catalyst suitable for preparing methanol from multi-component mixed gas and a preparation method thereof, the catalyst is of a hydrotalcite-like structure, and the molar ratio of Cu to Zn to Mn to an auxiliary agent in the catalyst suitable for preparing methanol from multi-component mixed gas is (40-65): (15-35): (15-25): (0.5-5). Wherein the auxiliary agent is one or more of Ca, Al, Mg, Sr, La, Ba and Si. The catalyst has efficient catalytic activity in a reaction for preparing methanol through hydrogenation of multi-component mixed gas.

Description

Technical Field

[0001] The present invention relates to the technical field of catalysts, and in particular to a catalyst suitable for producing methanol from a multi-component mixed gas and a preparation method thereof. Background Art

[0002] Carbon dioxide is not only the primary greenhouse gas contributing to global warming, but also a cheap, clean, and abundant natural resource. To fully utilize this resource and promote the development of the chemical industry and a sustainable energy economy, biomass methanol technology utilizes renewable biomass resources to produce green methanol from syngas obtained through biomass gasification. This technology has attracted widespread attention in the industry due to its advantages, such as low carbon emissions throughout its lifecycle, relatively low production costs, and ease of obtaining EU green methanol certification. However, syngas from biomass gasification often contains large amounts of CO₂, with CO₂ content as high as 30-40%. Conventional syngas-to-methanol catalysts are not suitable for feed gases with high CO₂ content. Furthermore, the excessively high CO₂ content in biomass gasification gas makes it unsuitable for commercially available catalysts for the hydrogenation of pure CO₂ to methanol. Therefore, it is necessary to develop a multi-component gas-to-methanol catalyst with high CO₂ and CO₂ tolerance to meet the needs of biomass gasification to methanol.

[0003] Currently, the catalyst used for methanol conversion from syngas is primarily a Cu / ZnO / Al₂O₃ system. Due to the relatively stable chemical properties of CO₂ molecules and the byproduct of water vapor during CO₂ hydrogenation to methanol, water vapor can attack the copper species in the catalyst under high-temperature, high-pressure reaction conditions, causing rapid catalyst deactivation. Consequently, conventional methanol conversion catalysts exhibit low catalytic activity and are susceptible to deactivation in feed gases with high CO₂ content. The CO₂ content in the syngas-to-methanol feedstock typically does not exceed 5%. Furthermore, the currently popular copper-based catalysts for methanol conversion from CO₂ hydrogenation exhibit good catalytic performance and stability in this reaction. However, due to the different activation mechanisms of the catalysts for CO and CO₂, high CO content in the feed gas can alter the chemical state of the catalyst surface, leading to rapid deactivation. Therefore, how to simultaneously improve the activation of copper-based catalysts for both CO and CO₂ in the feed gas and simultaneously enhance the catalyst's tolerance to both CO and CO₂ in the feed gas, and how to develop a methanol conversion catalyst with high CO₂ and CO₂ tolerance for multi-component gas mixtures, remains a key challenge in the development of biomass-to-methanol technology. Summary of the Invention

[0004] The present invention provides a catalyst suitable for preparing methanol from a multi-component mixed gas and a preparation method thereof. The catalyst has high catalytic activity in the reaction of preparing methanol from the multi-component mixed gas by hydrogenation.

[0005] The present invention provides a method for preparing a catalyst suitable for producing methanol from a multi-component mixed gas, the method comprising: Providing a first active metal mixed solution, a second active metal mixed solution and a precipitant solution, wherein the first active metal mixed solution contains a soluble manganese salt and a soluble zinc salt; the second active metal mixed solution contains a soluble copper salt and a soluble zinc salt; and the precipitant solution includes a sodium carbonate solution and a sodium hydroxide solution; Mixing the first active metal mixed solution, the second active metal mixed solution and the precipitant solution to perform a precipitation reaction, and drying and calcining the precipitated product; The second active metal mixed solution and / or the precipitant solution contain an auxiliary agent; the auxiliary agent contains one or more of Ca, Al, Mg, Sr, La, Ba, and Si. In terms of molar amount, the ratio of Cu:Zn:Mn:auxiliary agent is 40-65:15-35:15-25:0.5-5, and the auxiliary agent is one or more of Ca, Al, Mg, Sr, La, Ba, and Si.

[0006] Furthermore, when the auxiliary agent is one or more of Ca, Al, Mg, Sr, La, and Ba, the auxiliary agent is added to the second active metal mixed solution; when the auxiliary agent is Si, the auxiliary agent is added to the precipitant solution.

[0007] Furthermore, in the first active metal mixed solution, the ratio of the zinc salt in the first active metal mixed solution to the total zinc salt used is (0.5-1):1 on a molar basis.

[0008] Furthermore, the concentration of the first active metal mixed solution is 0.5-2 mol / L, and the concentration of the second active metal mixed solution is 0.5-2 mol / L.

[0009] Furthermore, when performing the precipitation reaction, the method further comprises: mixing the first active metal mixed solution with a portion of the precipitant solution; After the first active metal mixed solution is precipitated, a second active metal mixed solution and a portion of the precipitant are added simultaneously to the precipitate obtained by the first active metal mixed solution and the precipitant solution; After the second active metal mixed solution is precipitated, the obtained product is kept warm to age the obtained product; The aged product is filtered, washed, dried and calcined.

[0010] Furthermore, during the precipitation reaction, the reaction temperature is 10-70° C. and the pH of the reaction system is 7-10.

[0011] Furthermore, during the aging process, the aging temperature is 10-70° C., and the aging time is 6-24 hours.

[0012] Furthermore, the calcination temperature is 300-400° C., and the calcination time is 4-12 hours.

[0013] Furthermore, in the precipitant solution, the molar ratio of sodium carbonate to sodium hydroxide is 1-3:1.

[0014] The present invention also provides a catalyst suitable for producing methanol from a multi-component gas mixture. The catalyst has a hydrotalcite-like structure and a molar ratio of Cu:Zn:Mn:additive of 40-65:15-35:15-25:0.5-5. The additive is one or more of Ca, Al, Mg, Sr, La, Ba, and Si.

[0015] In summary, in the present invention, a novel copper-zinc-manganese catalyst system is formed by introducing Mn element into the catalyst to replace the traditional copper-zinc-aluminum system. The Mn element in the catalyst system has the characteristic of adjustable valence state. 2+ to Mn 3+ The electron transfer promotes the formation of abundant oxygen vacancies on the catalyst surface. These oxygen vacancies can adjust the properties of the catalyst surface structure and active sites according to the changes in the reaction atmosphere composition. In addition, the copper-zinc-manganese system catalyst is conducive to the formation of efficient Cu-ZnO and ZnO-MnO x The active interface promotes the non-dissociative adsorption of CO and CO₂, enabling the simultaneous activation and conversion of both CO and CO₂, resulting in a copper-zinc-manganese catalyst with high catalytic activity and good stability in the CO₂ / CO co-hydrogenation to methanol reaction. Furthermore, by sequentially adding multiple active metal mixed solutions and a precipitant, and limiting the precipitant to sodium carbonate and sodium hydroxide, the copper, zinc, and manganese in the catalyst form a hydrotalcite-like structure. The atomically uniform distribution of metal cations within the hydrotalcite-like layer results in a better copper species dispersion after reduction than conventional catalysts. This results in a higher hydrogen activation ability and higher hydrogenation activity compared to conventional copper-based catalysts. The copper species within the hydrotalcite-like structure interact more strongly with ZnO, inhibiting the formation of copper crystals and stabilizing amorphous copper species. This results in better thermal stability than conventional catalysts, inhibiting and enhancing copper species migration and sintering, and exhibiting improved catalytic stability.

[0016] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the following preferred embodiments are specifically cited and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Shown is a comparison chart of the 200h long-term stability of catalyst 3 and reference catalysts 1 to 4. DETAILED DESCRIPTION

[0018] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the present invention is described in detail below with reference to the accompanying drawings and preferred embodiments.

[0019] The present invention provides a catalyst suitable for preparing methanol from a multi-component mixed gas and a preparation method thereof. The catalyst has high catalytic activity in the reaction of preparing methanol from the multi-component mixed gas by hydrogenation.

[0020] The method for preparing a catalyst suitable for producing methanol from a multi-component mixed gas provided by the present invention comprises the following steps: A first active metal mixed solution is provided, wherein the first active metal mixed solution contains a soluble manganese salt and a soluble zinc salt.

[0021] In this embodiment, the concentration of the first active metal mixed solution may be 0.5-2 mol / L, more specifically, it may be 0.6 mol / L, 0.8 mol / L, 1.0 mol / L, 1.3 mol / L, 1.7 mol / L, 1.9 mol / L, etc.

[0022] Preferably, the soluble manganese salt is manganese nitrate, and the soluble zinc salt is zinc nitrate.

[0023] In other embodiments, it may also be a formate or acetate containing manganese or zinc.

[0024] A second active metal mixed solution is provided, wherein the second active metal mixed solution contains a soluble copper salt, a soluble zinc salt and a soluble auxiliary agent.

[0025] In this embodiment, the concentration of the second active metal mixed solution may be 0.5-2 mol / L, more specifically, it may be 0.6 mol / L, 0.8 mol / L, 1.0 mol / L, 1.3 mol / L, 1.7 mol / L, 1.9 mol / L, etc.

[0026] In this embodiment, the auxiliary agent may be a soluble salt containing one or more of Ca, Al, Mg, Sr, La, and Ba.

[0027] A precipitant solution is provided, the precipitant solution comprising sodium carbonate and sodium hydroxide solution.

[0028] In this embodiment, the concentration of the precipitant solution may be 0.5-2 mol / L, more specifically, it may be 0.6 mol / L, 0.8 mol / L, 1.0 mol / L, 1.3 mol / L, 1.7 mol / L, 1.9 mol / L, etc.

[0029] Wherein, the molar ratio of sodium carbonate to sodium hydroxide is 1-3:1.

[0030] It should be noted that, in this embodiment, Si can also be present as an auxiliary agent. When an auxiliary agent containing Si element is used, it can be added to the precipitant in the form of sodium metasilicate.

[0031] Preferably, the soluble copper salt is copper nitrate, and the soluble zinc salt is zinc nitrate.

[0032] In other embodiments, it may also be a formate or acetate containing copper or zinc.

[0033] In this embodiment, the molar ratio of Cu:Zn:Mn:additive is 40-65:15-35:15-25:0.5-5.

[0034] The first active metal mixed solution and the second active metal mixed solution each contain a portion of a soluble zinc salt. In the first active metal mixed solution, the ratio of the added zinc salt to the total zinc salt used, on a molar basis, is (0.5-1):1.

[0035] The first active metal mixed solution, the second active metal mixed solution and the precipitant are mixed to generate a precipitation reaction, and the precipitate is dried and calcined to obtain a catalyst suitable for producing methanol from a multi-component mixed gas.

[0036] More specifically, when performing the precipitation reaction, the method comprises the following steps: A certain liquid level is established in the reactor, and the first active metal mixed solution is mixed with a portion of the precipitant under continuous stirring.

[0037] Preferably, when the first active metal mixed solution and the precipitant are added dropwise, the reaction temperature is 10-70° C., and the pH of the reaction system is 7-10.

[0038] In this step, the amount of the precipitant added is determined according to the amount of the first active metal mixed solution.

[0039] After the precipitation of the first active metal mixed solution is completed, the second active metal mixed solution and the precipitant are added dropwise into the reaction kettle.

[0040] Preferably, when the second active metal mixed solution is added dropwise, the reaction temperature is 10-70° C., and the pH of the reaction system is 7-10.

[0041] After the precipitation of the second active metal mixed solution is completed, the dropwise addition of the precipitant is stopped and the temperature is kept to age the obtained product, thereby obtaining a catalyst precursor slurry.

[0042] The catalyst precursor slurry is filtered and washed until it becomes neutral and no sodium ions remain, then dried and calcined, and then granulated and tableted to obtain a catalyst.

[0043] In this embodiment, the maintaining temperature is 10-70° C., and the aging time is 6-24 hours.

[0044] When the catalyst precursor slurry is dried, the drying temperature is 100-120° C. and the drying time is 12 hours.

[0045] During the calcination, the calcination temperature is 300-400° C. and the calcination time is 4-12 hours.

[0046] In order to facilitate demoulding after tableting, the granulated catalyst can be mixed with graphite during tableting.

[0047] By introducing Mn into the catalyst to replace the traditional copper-zinc-aluminum system, a new copper-zinc-manganese catalyst system is formed. The Mn element in the catalyst system has the characteristic of adjustable valence state. 2+ to Mn 3+ The electron transfer promotes the formation of abundant oxygen vacancies on the catalyst surface. These oxygen vacancies can adjust the properties of the catalyst surface structure and active sites according to the changes in the reaction atmosphere composition. In addition, the copper-zinc-manganese system catalyst is conducive to the formation of efficient Cu-ZnO and ZnO-MnO x The active interface promotes the non-dissociative adsorption of CO and CO₂, enabling the simultaneous activation and conversion of both CO and CO₂, resulting in a copper-zinc-manganese catalyst with high catalytic activity and good stability in the CO₂ / CO co-hydrogenation to methanol reaction. Furthermore, by sequentially adding multiple active metal mixed solutions and a precipitant, and limiting the precipitant to sodium carbonate and sodium hydroxide, the copper, zinc, and manganese in the catalyst form a hydrotalcite-like structure. The atomically uniform distribution of metal cations within the hydrotalcite-like layer results in a better copper species dispersion after reduction than conventional catalysts. This results in a higher hydrogen activation ability and higher hydrogenation activity compared to conventional copper-based catalysts. The copper species within the hydrotalcite-like structure interact more strongly with ZnO, inhibiting the formation of copper crystals and stabilizing amorphous copper species. This results in better thermal stability than conventional catalysts, inhibiting and enhancing copper species migration and sintering, and exhibiting improved catalytic stability.

[0048] The preparation method provided by the present invention is further described below with reference to specific examples: Example 1 1) Dissolve 12.48 g of manganese nitrate tetrahydrate and 11.84 g of zinc nitrate hexahydrate in desalted water to prepare a first active metal mixed solution with a concentration of 1 mol / L; dissolve 28.86 g of copper nitrate trihydrate, 11.84 g of zinc nitrate hexahydrate, and 2.03 g of magnesium nitrate hexahydrate in desalted water to prepare a second active metal mixed solution with a concentration of 1 mol / L; Dissolve 21.46 g of sodium carbonate and 8.1 g of sodium hydroxide in desalted water (the molar ratio of sodium carbonate to sodium hydroxide is 1:1) to prepare a precipitant solution with a Na ion concentration of 1 mol / L. 2) Establishing a certain liquid level in the reactor and controlling the temperature at 70°C, the first active metal mixed solution and the precipitant solution are simultaneously added dropwise to the reactor using a metering pump under continuous stirring. The precipitant addition rate is controlled to maintain the pH of the system at 10 to form a precipitate. 3) After the first active metal mixed solution is precipitated, the second active metal mixed solution and the precipitant solution are added dropwise to the reactor using metering pumps. The precipitant addition rate is controlled to maintain the pH of the system at 10, thereby forming a catalyst precursor precipitate. 4) After the addition of the second active metal mixed solution is complete, the addition of the precipitant solution is stopped, and the temperature is maintained at 70°C for further aging for 6 hours to obtain a catalyst precursor slurry. The catalyst precursor slurry is then filtered and washed until neutral and free of residual sodium ions, dried at 120°C for 12 hours, and then transferred to a calcination furnace and calcined at 400°C for 4 hours. The sample is then granulated, mixed with graphite, and pressed into tablets to obtain Catalyst 1.

[0049] Example 2 1) Dissolve 11.47 g of manganese nitrate tetrahydrate and 9.06 g of zinc nitrate hexahydrate in desalted water to prepare a first active metal mixed solution with a concentration of 2 mol / L; dissolve 37.41 g of copper nitrate trihydrate, 3.02 g of zinc nitrate hexahydrate, 0.9 g of calcium nitrate tetrahydrate, and 1.89 g of aluminum nitrate nonahydrate in desalted water to prepare a second active metal mixed solution with a concentration of 1 mol / L; Dissolve 28.64 g of sodium carbonate, 7.2 g of sodium hydroxide, and 1.42 g of sodium metasilicate nonahydrate in desalted water (the molar ratio of sodium carbonate to sodium hydroxide is 1.5:1) to prepare a precipitant solution with a Na ion concentration of 2 mol / L. 2) Establish a certain liquid level in the reactor and control the temperature at 40°C. Use a metering pump to dropwise add the first active metal mixed solution and the precipitant solution to the reactor simultaneously under continuous stirring. Control the precipitant addition rate to maintain the system pH at 9 to form a precipitate. 3) After the first active metal mixed solution is precipitated, the second active metal mixed solution and the precipitant solution are added dropwise to the reactor using metering pumps. The precipitant addition rate is controlled to maintain the pH of the system at 9, thereby forming a catalyst precursor precipitate. 4) After the addition of the second active metal mixed solution is complete, the addition of the precipitant solution is stopped, and the temperature is maintained at 50°C for further aging for 6 hours to obtain a catalyst precursor slurry. The catalyst precursor slurry is then filtered and washed until neutral and free of residual sodium ions, dried at 120°C for 12 hours, and then transferred to a calcination furnace and calcined at 350°C for 4 hours. The sample is then granulated, mixed with graphite, and pressed into tablets to obtain Catalyst 2.

[0050] Example 3 1) Dissolve 11.25 g of manganese nitrate tetrahydrate and 10.97 g of zinc nitrate hexahydrate in desalted water to prepare a first active metal mixed solution with a concentration of 1.5 mol / L; 32.79 g of copper nitrate trihydrate, 7.31 g of zinc nitrate hexahydrate, and 1.63 g of strontium nitrate were dissolved in desalted water to prepare a second active metal mixed solution with a concentration of 1.5 mol / L; Dissolve 22.5 g of sodium carbonate, 5.66 g of sodium hydroxide, and 2.37 g of sodium metasilicate nonahydrate in desalted water (the molar ratio of sodium carbonate to sodium hydroxide is 1.5:1) to prepare a precipitant solution with a Na ion concentration of 1.5 mol / L. 2) Establish a certain liquid level in the reactor and control the temperature at 50°C. Use a metering pump to dropwise add the first active metal mixed solution and the precipitant solution to the reactor simultaneously under continuous stirring. Control the precipitant addition rate to maintain the system pH at 9 to form a precipitate. 3) After the first active metal mixed solution is precipitated, the second active metal mixed solution and the precipitant solution are added dropwise to the reactor using metering pumps. The precipitant addition rate is controlled to maintain the pH of the system at 9, thereby forming a catalyst precursor precipitate. 4) After the addition of the second active metal mixed solution is complete, the addition of the precipitant solution is stopped, and the temperature is maintained at 50°C for further aging for 6 hours to obtain a catalyst precursor slurry. The catalyst precursor slurry is then filtered and washed until neutral and free of residual sodium ions, dried at 120°C for 12 hours, and then transferred to a calcination furnace and calcined at 350°C for 4 hours. The sample is then granulated, mixed with graphite, and pressed into tablets to obtain Catalyst 3.

[0051] Example 4 1) dissolving 14.38 g of manganese nitrate tetrahydrate and 20.75 g of zinc nitrate hexahydrate in desalted water to prepare a first active metal mixed solution with a concentration of 0.75 mol / L; Dissolve 24.07 g of copper nitrate trihydrate and 5.17 g of zinc nitrate hexahydrate in desalted water to prepare a second active metal mixed solution with a concentration of 0.75 mol / L; Dissolve 26.08 g of sodium carbonate, 4.92 g of sodium hydroxide, and 1.9 g of sodium metasilicate nonahydrate in desalted water (the molar ratio of sodium carbonate to sodium hydroxide is 2:1) to prepare a precipitant solution with a Na ion concentration of 2 mol / L. 2) Establish a certain liquid level in the reactor and control the temperature at 30°C. Use a metering pump to dropwise add the first active metal mixed solution and the precipitant solution to the reactor simultaneously under continuous stirring. Control the precipitant addition rate to maintain the system pH at 9 to form a precipitate. 3) After the first active metal mixed solution is precipitated, the second active metal mixed solution and the precipitant solution are added dropwise to the reactor using metering pumps. The precipitant addition rate is controlled to maintain the pH of the system at 7, thereby forming a catalyst precursor precipitate. 4) After the addition of the second active metal mixed solution is complete, the addition of the precipitant solution is stopped, and the temperature is maintained at 60°C for further aging for 6 hours to obtain a catalyst precursor slurry. The catalyst precursor slurry is then filtered and washed until neutral and free of residual sodium ions, dried at 120°C for 12 hours, and then transferred to a calcination furnace and calcined at 350°C for 4 hours. After granulation and mixing with graphite, tableting is performed to obtain Catalyst 4.

[0052] Example 5 1) dissolving 9.41 g of manganese nitrate tetrahydrate and 19.41 g of zinc nitrate hexahydrate in desalted water to prepare a first active metal mixed solution with a concentration of 0.5 mol / L; 32.02 g of copper nitrate trihydrate, 1.96 g of barium nitrate, and 2.16 g of zinc nitrate hexahydrate were dissolved in desalted water to prepare a second active metal mixed solution with a concentration of 0.5 mol / L; Dissolve 31.79 g of sodium carbonate and 8.0 g of sodium hydroxide in desalted water (the molar ratio of sodium carbonate to sodium hydroxide is 1.5:1) to prepare a precipitant solution with a Na ion concentration of 0.5 mol / L; 2) Establish a certain liquid level in the reactor and control the temperature at 50°C. Use a metering pump to dropwise add the first active metal mixed solution and the precipitant solution to the reactor simultaneously under continuous stirring. Control the precipitant addition rate to maintain the system pH at 8 to form a precipitate. 3) After the first active metal mixed solution is precipitated, the second active metal mixed solution and the precipitant solution are added dropwise to the reactor using metering pumps. The precipitant addition rate is controlled to maintain the pH of the system at 8, thereby forming a catalyst precursor precipitate. 4) After the addition of the second active metal mixed solution is complete, the addition of the precipitant solution is stopped, and the temperature is maintained at 50°C for further aging for 6 hours to obtain a catalyst precursor slurry. The catalyst precursor slurry is then filtered and washed until neutral and free of residual sodium ions, dried at 120°C for 12 hours, and then transferred to a calcination furnace and calcined at 300°C for 4 hours. After granulation and mixing with graphite, the slurry is pressed into tablets to obtain Catalyst 5.

[0053] Example 6 1) Dissolve 10.42 g of manganese nitrate tetrahydrate and 20.34 g of zinc nitrate hexahydrate in desalted water to prepare a first active metal mixed solution with a concentration of 1 mol / L; Dissolve 28.32 g of copper nitrate trihydrate and 5.24 g of zirconium nitrate pentahydrate in desalted water to prepare a second active metal mixed solution with a concentration of 1 mol / L; Dissolve 22.04 g of sodium carbonate, 5.55 g of sodium hydroxide, and 1.9 g of sodium metasilicate nonahydrate in desalted water (the molar ratio of sodium carbonate to sodium hydroxide is 1.5:1) to prepare a precipitant solution with a Na ion concentration of 1.5 mol / L. 2) Establish a certain liquid level in the reactor and control the temperature at 20°C. Use a metering pump to dropwise add the first active metal mixed solution and the precipitant solution to the reactor simultaneously under continuous stirring. Control the precipitant addition rate to maintain the system pH at 8 to form a precipitate. 3) After the first active metal mixed solution is precipitated, the second active metal mixed solution and the precipitant solution are added dropwise to the reactor using metering pumps. The precipitant addition rate is controlled to maintain the pH of the system at 8, thereby forming a catalyst precursor precipitate. 4) After the addition of the second active metal mixed solution is complete, the addition of the precipitant solution is stopped, and the temperature is maintained at 70°C for further aging for 6 hours to obtain a catalyst precursor slurry. The catalyst precursor slurry is then filtered and washed until neutral and free of residual sodium ions, dried at 120°C for 12 hours, and then transferred to a calcination furnace and calcined at 300°C for 4 hours. After granulation and mixing with graphite, the slurry is pressed into tablets to obtain Catalyst 6.

[0054] Comparative Example 1, in Comparative Example 1, it is an oxide structure 1) dissolving 11.25 g of manganese nitrate tetrahydrate and 10.97 g of zinc nitrate hexahydrate in desalted water to prepare a first active metal mixed solution with a concentration of 1.5 mol / L; Dissolve 32.79 g of copper nitrate trihydrate, 7.31 g of zinc nitrate hexahydrate, and 1.63 g of strontium nitrate in desalted water to prepare a second active metal mixed solution with a concentration of 1.5 mol / L; Dissolve 30 g of sodium carbonate and 2.37 g of sodium metasilicate nonahydrate in desalted water to prepare a precipitant solution with a Na ion concentration of 1.5 mol / L; 2) Establish a certain liquid level in the reactor and control the temperature at 50°C. Use a metering pump to dropwise add the first active metal mixed solution and the precipitant solution to the reactor simultaneously under continuous stirring. Control the precipitant addition rate to maintain the system pH at 9 to form a precipitate. 3) After the first active metal mixed solution is precipitated, the second active metal mixed solution and the precipitant solution are added dropwise to the reactor using metering pumps. The precipitant addition rate is controlled to maintain the pH of the system at 9, thereby forming a catalyst precursor precipitate. 4) After the precipitation of the second active metal mixed solution is complete, stop adding the precipitant solution, maintain the temperature within the range of 50°C and continue aging for 6 hours to obtain a catalyst precursor slurry. The catalyst precursor slurry is then filtered and washed until it is neutral and free of sodium ions. It is then dried at 120°C for 12 hours. The sample is then transferred to a calcination furnace and calcined at 350°C for 4 hours. After granulation, the sample is mixed with graphite and pressed into tablets to obtain Reference Catalyst 1.

[0055] Comparative Example 2: In Comparative Example 2, it also has a Cu / Zn / Al hydrotalcite structure, but does not contain the Mn element.

[0056] 1) dissolving 18.19 g of aluminum nitrate nonahydrate and 11.93 g of zinc nitrate hexahydrate in desalted water to prepare a first active metal mixed solution with a concentration of 1.5 mol / L; 35.67 g of copper nitrate trihydrate, 7.95 g of zinc nitrate hexahydrate, and 1.77 g of strontium nitrate hexahydrate were dissolved in desalted water to prepare a second active metal mixed solution with a concentration of 1.5 mol / L; Dissolve 22.5 g of sodium carbonate, 5.66 g of sodium hydroxide, and 2.37 g of sodium metasilicate nonahydrate in desalted water (the molar ratio of sodium carbonate to sodium hydroxide is 1.5:1) to prepare a precipitant solution with a Na ion concentration of 1.5 mol / L. 2) Establish a certain liquid level in the reactor and control the temperature at 50°C. Use a metering pump to dropwise add the first active metal mixed solution and the precipitant solution to the reactor simultaneously under continuous stirring. Control the precipitant addition rate to maintain the system pH at 9 to form a precipitate. 3) After the first active metal mixed solution is precipitated, the second active metal mixed solution and the precipitant solution are added dropwise to the reactor using metering pumps. The precipitant addition rate is controlled to maintain the pH of the system at 9, thereby forming a catalyst precursor precipitate. 4) After the addition of the second active metal mixed solution is complete, the addition of the precipitant solution is stopped, and the temperature is maintained at 50°C for further aging for 6 hours to obtain a catalyst precursor slurry. The catalyst precursor slurry is then filtered and washed until neutral and free of residual sodium ions. The slurry is then dried at 120°C for 12 hours. The sample is then transferred to a calcination furnace and calcined at 350°C for 4 hours. The sample is then granulated, mixed with graphite, and pressed into tablets to obtain Reference Catalyst 2.

[0057] Comparative Example 3: In Comparative Example 3, the Cu / Zn / Ce hydrotalcite-like structure is added with the Ce element which also has adjustable valence state.

[0058] 1) dissolving 16.34 g of cerium nitrate hexahydrate and 9.21 g of zinc nitrate hexahydrate in desalted water to prepare a first active metal mixed solution with a concentration of 1.5 mol / L; 27.54 g of copper nitrate trihydrate, 6.14 g of zinc nitrate hexahydrate, and 1.65 g of strontium nitrate hexahydrate were dissolved in desalted water to prepare a second active metal mixed solution with a concentration of 1.5 mol / L; Dissolve 22.5 g of sodium carbonate, 5.66 g of sodium hydroxide, and 2.37 g of sodium metasilicate nonahydrate in desalted water (the molar ratio of sodium carbonate to sodium hydroxide is 1.5:1) to prepare a precipitant solution with a Na ion concentration of 1.5 mol / L. 2) Establish a certain liquid level in the reactor and control the temperature at 50°C. Use a metering pump to dropwise add the first active metal mixed solution and the precipitant solution to the reactor simultaneously under continuous stirring. Control the precipitant addition rate to maintain the system pH at 9 to form a precipitate. 3) After the first active metal mixed solution is precipitated, the second active metal mixed solution and the precipitant solution are added dropwise to the reactor using metering pumps. The precipitant addition rate is controlled to maintain the pH of the system at 9, thereby forming a catalyst precursor precipitate. 4) After the addition of the second active metal mixed solution is complete, the addition of the precipitant solution is stopped, and the temperature is maintained at 50°C for further aging for 6 hours to obtain a catalyst precursor slurry. The catalyst precursor slurry is then filtered and washed until neutral and free of residual sodium ions. The slurry is then dried at 120°C for 12 hours. The sample is then transferred to a calcination furnace and calcined at 350°C for 4 hours. The sample is then granulated, mixed with graphite, and pressed into tablets to obtain Reference Catalyst 3.

[0059] Comparative Example 4: In Comparative Example 4, the Cu / Zn / Fe hydrotalcite-like structure is added with Fe element which also has valence adjustability.

[0060] 1) dissolving 17.01 g of ferric nitrate nonahydrate and 10.31 g of zinc nitrate hexahydrate in desalted water to prepare a first active metal mixed solution with a concentration of 1.5 mol / L; 30.80 g of copper nitrate trihydrate, 6.87 g of zinc nitrate hexahydrate, and 1.85 g of strontium nitrate hexahydrate were dissolved in desalted water to prepare a second active metal mixed solution with a concentration of 1.5 mol / L; Dissolve 22.5 g of sodium carbonate, 5.66 g of sodium hydroxide, and 2.37 g of sodium metasilicate nonahydrate in desalted water (the molar ratio of sodium carbonate to sodium hydroxide is 1.5:1) to prepare a precipitant solution with a Na ion concentration of 1.5 mol / L. 2) Establish a certain liquid level in the reactor and control the temperature at 50°C. Use a metering pump to dropwise add the first active metal mixed solution and the precipitant solution to the reactor simultaneously under continuous stirring. Control the precipitant addition rate to maintain the system pH at 9 to form a precipitate. 3) After the first active metal mixed solution is precipitated, the second active metal mixed solution and the precipitant solution are added dropwise to the reactor using metering pumps. The precipitant addition rate is controlled to maintain the pH of the system at 9, thereby forming a catalyst precursor precipitate. 4) After the addition of the second active metal mixed solution is complete, the addition of the precipitant solution is stopped, and the temperature is maintained at 50°C for further aging for 6 hours to obtain a catalyst precursor slurry. The catalyst precursor slurry is then filtered and washed until neutral and free of residual sodium ions, dried at 120°C for 12 hours, and then transferred to a calcination furnace and calcined at 350°C for 4 hours. After granulation and mixing with graphite, tableting is performed to obtain Reference Catalyst 4.

[0061] Table 1: Performance of catalysts prepared under different processes for hydrogenation of multi-component gas mixtures to methanol Reaction conditions: 230°C, GHSV = 10000 ml.gcat -1 . h -1 , 5MPa

[0062] The experimental data above demonstrate that the catalyst prepared using the present invention exhibits superior carbon conversion rates for various gas mixtures compared to Reference Catalysts 1 to 4. This demonstrates the catalyst's high catalytic activity in the hydrogenation of multicomponent gas mixtures to produce methanol.

[0063] Further, see Figure 1 In the 200h long-term stability study of the catalyst (reaction conditions: 230℃, GHSV=10000 ml.gcat-1 . h -1 , 5MPa, H2 / CO2 / CO=73:16:11), the stability of reference catalyst 1 and reference catalyst 2 decreased significantly with time, while the stability of comparative example 3 remained stable.

[0064] For further information, see Figure 1 In the 200h stability study of the catalyst, the stability of reference catalyst 3 and reference catalyst 4 to which other elements with adjustable valence states were added was better than that of reference catalyst 1 and reference catalyst 2 to which no elements with adjustable valence states were added, but their stability was lower than that of comparative example 3.

[0065] The present invention also provides a catalyst suitable for methanol production from a multi-component gas mixture, prepared by the above-described catalyst preparation method. The catalyst has a hydrotalcite-like structure and, on a molar basis, a Cu:Zn:Mn:promoter ratio of 40-65:15-35:15-25:0.5-5. The promotor is one or more of Ca, Al, Mg, Sr, La, Ba, and Si.

[0066] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make slight changes or modifications to equivalent embodiments using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a catalyst suitable for producing methanol from a multi-component gas mixture, characterized in that: The method includes: Providing a first active metal mixed solution, a second active metal mixed solution and a precipitant solution, wherein the first active metal mixed solution contains a soluble manganese salt and a soluble zinc salt; the second active metal mixed solution contains a soluble copper salt and a soluble zinc salt; and the precipitant solution includes a sodium carbonate solution and a sodium hydroxide solution; Mixing the first active metal mixed solution, the second active metal mixed solution and the precipitant solution to perform a precipitation reaction, and drying and calcining the precipitated product; The second active metal mixed solution and / or the precipitant solution contain an additive; the additive contains one or more of Ca, Al, Mg, Sr, La, Ba, and Si, and the molar ratio of Cu:Zn:Mn:additive is 40-65:15-35:15-25:0.5-5.

2. The method for preparing a catalyst suitable for producing methanol from a multi-component mixed gas according to claim 1, characterized in that: When the auxiliary agent is one or more of Ca, Al, Mg, Sr, La, and Ba, the auxiliary agent is added to the second active metal mixed solution; when the auxiliary agent is Si, the auxiliary agent is added to the precipitant solution.

3. The method for preparing a catalyst suitable for producing methanol from a multi-component gas mixture according to claim 1, characterized in that: In the first active metal mixed solution, the ratio of the zinc salt in the first active metal mixed solution to the total zinc salt used is (0.5-1):1, calculated on a molar basis.

4. The method for preparing a catalyst suitable for producing methanol from a multi-component mixed gas according to claim 1, characterized in that: The concentration of the first active metal mixed solution is 0.5-2 mol / L, and the concentration of the second active metal mixed solution is 0.5-2 mol / L.

5. The method for preparing a catalyst suitable for producing methanol from a multi-component mixed gas according to claim 1, characterized in that: When performing the precipitation reaction, the method further comprises: mixing the first active metal mixed solution with a portion of the precipitant solution; After the first active metal mixed solution is precipitated, the second active metal mixed solution and a portion of the precipitant are simultaneously added to the precipitate obtained by the first active metal mixed solution and the precipitant solution; After the second active metal mixed solution is precipitated, the obtained product is kept warm to age the obtained product; The aged product is filtered, washed, dried and calcined.

6. The method for preparing a catalyst suitable for producing methanol from a multi-component mixed gas according to claim 1 or 5, characterized in that: During the precipitation reaction, the reaction temperature is 10-70° C. and the pH of the reaction system is 7-10.

7. The method for preparing a catalyst suitable for producing methanol from a multi-component mixed gas according to claim 5, characterized in that: During aging, the aging temperature is 10-70° C. and the aging time is 6-24 hours.

8. The method for preparing a catalyst suitable for producing methanol from a multi-component gas mixture according to claim 1 or 5, characterized in that: The calcination temperature is 300-400° C., and the calcination time is 4-12 hours.

9. The method for preparing a catalyst suitable for producing methanol from a multi-component mixed gas according to claim 1, characterized in that: In the precipitant solution, the molar ratio of sodium carbonate to sodium hydroxide is 1-3:

1.

10. A catalyst suitable for producing methanol from a multi-component gas mixture, characterized by: The catalyst suitable for preparing methanol from a multi-component mixed gas has a hydrotalcite-like structure. In the catalyst suitable for preparing methanol from a multi-component mixed gas, the ratio of Cu:Zn:Mn:additive is 40-65:15-35:15-25:0.5-5 in terms of molar amount, wherein the additive is one or more of Ca, Al, Mg, Sr, La, Ba, and Si.

Images