Synthesis of methanol catalyst, its preparation method and application

Abstract

The application relates to a synthetic methanol catalyst and a preparation method and application thereof, and belongs to the technical field of catalyst preparation. The preparation method is as follows: a mixed salt aqueous solution containing copper salt, zinc salt and aluminum salt and a precipitant are co-precipitated in parallel to obtain a first mixed material; a mixed salt aqueous solution containing copper salt and zinc salt and a precipitant are co-precipitated in parallel to obtain a second mixed material; the first mixed material and the second mixed material are mixed, stirred, aged, and washed to obtain a first filter cake; under the condition of ultrasonic oscillation, the first filter cake and a high-boiling-point organic aqueous solution are stirred and pulped, and are extracted and filtered to obtain a second filter cake; the second filter cake is dried, is baked in an anaerobic manner, is added with graphite and deionized water, is punched into pieces, and is formed to obtain the synthetic methanol catalyst. The preparation method is simple, nitrogen oxides are not generated in the process, the method is safe and environment-friendly, and has a good industrial prospect; the catalyst prepared by the application has the characteristics of high activity, good sintering resistance and good stability.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of catalyst preparation, and particularly relates to a methanol synthesis catalyst, a preparation method and application thereof. BACKGROUND

[0002] Methanol is an important chemical product and organic chemical raw material. In recent years, the demand and production capacity of methanol continue to grow with the development of industry, and the position of methanol in the national economy is increasingly important. The development and performance improvement of methanol synthesis catalyst greatly affect the development of methanol industry. In industry, methanol is generally synthesized under certain pressure and temperature conditions by using synthesis gas containing H2, CO and CO2. At present, the world generally adopts the medium and low pressure gas phase method to synthesize methanol, and the catalyst used is basically a mixed oxide of copper, zinc and aluminum. The Cu-ZnO-Al2O3 catalyst prepared by the traditional process has high catalytic activity, but since the active metal Cu has a low melting point, it is easy to sinter at high temperature, resulting in poor stability of the catalyst and easy deactivation.

[0003] In order to prevent catalyst sintering and improve the stability of the catalyst, the improvement of copper-based catalyst by those skilled in the art is generally to select and add suitable additives, select suitable carriers, and improve the preparation method of the catalyst, etc.

[0004] CN1660490A adds a small amount of surfactant in the co-precipitation process, which improves the dispersibility of the precipitate, and the catalyst has a large specific surface area and high activity. However, the addition of surfactant will increase the production cost and bring inconvenience to the purification and other treatments of the washing water in the later stage.

[0005] CN103272607A discloses a copper-based catalyst for carbon dioxide hydrogenation synthesis of methanol, a preparation method and application thereof. The preparation method of the catalyst comprises the following steps: first, four solutions are configured, a first solution is prepared by mixing zinc salt, aluminum salt, zirconium salt and stabilizer; a second solution is prepared by mixing zinc salt, aluminum salt and zirconium salt; a third solution is prepared by mixing carbonate and hydroxide; a fourth solution is prepared by mixing copper salt; under the conditions of 20-60℃ and pH=8-11, the solutions are mixed by a step-by-step precipitation method to form a precipitate solution, the precipitate is washed, the precipitate is aged at 50-90℃ for 10-30h, and the copper-based catalyst is obtained by drying and calcining. The stabilizer used includes one or more of polyvinylpyrrolidone and polyethylene glycol. The patent adds a stabilizer in the preparation process of the catalyst, and applies the prepared stabilizer to the carbon dioxide hydrogenation synthesis of methanol, which plays a role in improving the dispersity of the active component and increasing the number of exposed active sites, thereby improving the conversion rate of carbon dioxide and the selectivity of methanol. The highest conversion rate of carbon dioxide can reach 25.2%, and the highest selectivity of methanol can reach 65.6%. However, the catalytic activity of the catalyst, the selectivity of carbon dioxide hydrogenation synthesis of methanol and the conversion rate of CO2 still need to be improved. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the present invention aims to provide a method for preparing a methanol synthesis catalyst, which has a simple preparation process, does not generate nitrogen oxides during the process, is safe and environmentally friendly, and has good industrial prospects; the present invention also provides a methanol synthesis catalyst with the characteristics of high activity, good sintering resistance and good stability.

[0007] In order to achieve the above object, according to one aspect of the present invention, a method for preparing a catalyst for synthesizing methanol is provided, comprising the following steps:

[0008] (1) co-precipitating a mixed salt solution containing a soluble copper salt, a soluble zinc salt, and a soluble aluminum salt and a precipitant aqueous solution in parallel to obtain a first mixed material;

[0009] (2) co-precipitating a mixed salt solution containing a soluble copper salt and a soluble zinc salt and an aqueous solution of a precipitant to obtain a second mixed material;

[0010] (3) Mix the first mixed material and the second mixed material, stir, let stand for aging, and wash until there is no Na + Detect and obtain the first filter cake;

[0011] (4) Under ultrasonic vibration conditions, the first filter cake and a high-boiling point organic aqueous solution with a concentration of 40 g / L-115 g / L were stirred and slurried, and filtered to obtain a second filter cake;

[0012] (5) Drying the second filter cake, calcining it in an oxygen-free state, adding graphite and deionized water, and forming it into tablets to obtain the methanol synthesis catalyst.

[0013] In some embodiments, the soluble copper salts in step (1) and step (2) are independently selected from one or more of copper nitrate, copper oxalate, and copper acetate.

[0014] In some embodiments, the soluble zinc salts in step (1) and step (2) are independently selected from one or more of zinc nitrate, zinc oxalate, and zinc acetate.

[0015] In some embodiments, in step (1), the soluble aluminum salt is aluminum nitrate.

[0016] In some embodiments, the precipitating agents in step (1) and step (2) are independently selected from one or more of sodium hydroxide, sodium carbonate, and sodium bicarbonate.

[0017] In some embodiments, in step (1), the molar ratio of copper ions to zinc ions in the mixed salt solution is (0.2-5):1.

[0018] In some embodiments, in step (1), the ratio of the total moles of copper ions and zinc ions to the moles of aluminum ions in the mixed salt aqueous solution is (0.2-8):1.

[0019] In some embodiments, in step (1), the concentration of the precipitant aqueous solution is 1 mol / L-5 mol / L.

[0020] In some embodiments, in step (1), the co-precipitation reaction conditions are: under stirring, the reaction temperature is controlled to be 30℃-80℃, and the pH is controlled to be 7.0-9.0.

[0021] In some embodiments, in step (2), the molar ratio of copper ions to zinc ions in the mixed salt aqueous solution is (0.5-5):1.

[0022] In some embodiments, in step (2), the concentration of the precipitant aqueous solution is 1 mol / L-5 mol / L.

[0023] In some embodiments, in step (2), the co-precipitation reaction conditions are: under stirring, the reaction temperature is controlled to be 60℃-95℃, and the pH is controlled to be 7.0-9.0.

[0024] In some embodiments, in step (3), the mass moisture content of the first filter cake is 150%-200%.

[0025] In some embodiments, in step (4), the mass moisture content of the second filter cake is 140%-150%.

[0026] In some embodiments, in step (4), the high-boiling-point organic matter includes one or more of carbohydrates, polyhydroxy organic matter.

[0027] In some embodiments, the carbohydrates include one or more of glucose, sucrose, lactose, soluble starch, and the polyhydroxy organic matter includes one or more of ethylene glycol, glycerol, and polyethylene glycol.

[0028] In some embodiments, in step (4), the frequency of the ultrasonic oscillation is 25 kHz-40 kHz.

[0029] In some embodiments, in step (5), the drying temperature is 100℃-150℃, and the drying time is 8h-24h.

[0030] In some embodiments, in step (5), the anaerobic roasting temperature is 350℃-450℃, and the anaerobic roasting time is 2h-5h.

[0031] According to another aspect of the present invention, there is also provided a methanol synthesis catalyst prepared according to the above preparation method, which comprises the following components in percentage by mass based on the total amount:

[0032] CuO35%-60%;

[0033] ZnO25%-40%;

[0034] Al2O34%-15%;

[0035] 3%-6% of the carbon component is generated by the decomposition of high-boiling point organic matter; and the balance is graphite.

[0036] According to another aspect of the present invention, the present invention also provides a catalyst prepared according to the above preparation method or the use of the above catalyst in a methanol synthesis process.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] (1) The preparation method of the present invention controls the concentration and addition method of the high-boiling-point organic matter so that the carbon components generated by the dehydrated carbonized high-boiling-point organic matter are more evenly distributed in the catalyst, forming a "carbon fence" that effectively separates the active metal grains in the catalyst and prevents them from rapidly agglomerating and growing during use; by controlling the content of the carbon components generated by the high-boiling-point organic matter in the catalyst, the carbon components can not only effectively separate the active metal grains, but also prevent excessive carbon components from covering the active metal surface; if the content of the carbon components generated by the high-boiling-point organic matter is too low, the separation effect is not obvious; if the content of the carbon components generated by the high-boiling-point organic matter is too high, excessive carbon particles will shield the surface of the active metal ions and affect the activity of the catalyst. The generated carbon components are stable under normal use conditions of the methanol synthesis catalyst and have no adverse effects on the catalyst. Therefore, the catalyst prepared according to the preparation method of the present invention has the characteristics of high activity, good sintering resistance and good stability.

[0039] (2) The preparation method of the methanol synthesis catalyst of the present invention is simple to operate, has wide adaptability, requires little process change, is low in cost, does not generate nitrogen oxides during the preparation process, and is environmentally friendly and pollution-free. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings, wherein:

[0041] Figure 1 (a) and (b) are SEM images of the catalyst cat-1 prepared in Example 1 of the present invention before and after the catalytic reaction, respectively.

[0042] Figure 2(a), (b) are SEM images of the catalyst D-cat-1 prepared in the present application comparative example 1 before and after catalyzing reaction, respectively.

[0043] Figure 3 (a), (b) are SEM images of the catalyst D-cat-2 prepared in the present application comparative example 2 before and after catalyzing reaction, respectively.

[0044] Figure 4 (a), (b) are SEM images of the catalyst D-cat-3 prepared in the present application comparative example 3 before and after catalyzing reaction, respectively.

[0045] Figure 5 (a), (b) are SEM images of the catalyst D-cat-4 prepared in the present application comparative example 4 before and after catalyzing reaction, respectively.

[0046] Figure 6 (a), (b) are SEM images of the catalyst D-cat-5 prepared in the present application comparative example 5 before and after catalyzing reaction, respectively.

[0047] Figure 7 (a), (b) are SEM images of the catalyst D-cat-6 prepared in the present application comparative example 6 before and after catalyzing reaction, respectively. DETAILED DESCRIPTION

[0048] To enable persons skilled in the art to understand the features and effects of the present application, the following is a general description and definition of the terms and phrases mentioned in the specification and claims. Unless otherwise specified, all technical and scientific words used in the text are of the usual meaning understood by those skilled in the art of the present application, and in the event of conflict, the definition in the specification shall prevail.

[0049] Theories or mechanisms described and disclosed herein, whether or not correct, should not be construed as limiting the scope of the present application, i.e., the present application can be practiced without relying on any particular theory or mechanism.

[0050] Herein, when describing embodiments or examples, it should be understood that they are not intended to limit the present application to these embodiments or examples. Rather, all alternatives, modifications, and equivalents of the methods and materials described herein, which are within the scope of the claims, are to be included.

[0051] Herein, for the sake of brevity, not all possible combinations of the various technical features described in the various embodiments or examples are described. Therefore, any combination of the various technical features described in the various embodiments or examples can be made, as long as the combination does not result in a contradiction, and all possible combinations are to be considered as being within the scope of the present specification.

[0052] The present invention provides a method for preparing a methanol synthesis catalyst, comprising the following steps:

[0053] (1) co-precipitating a mixed salt solution containing a soluble copper salt, a soluble zinc salt, and a soluble aluminum salt and a precipitant aqueous solution in parallel to obtain a first mixed material;

[0054] (2) co-precipitating a mixed salt solution containing a soluble copper salt and a soluble zinc salt and an aqueous solution of a precipitant to obtain a second mixed material;

[0055] (3) Mix the first mixed material and the second mixed material, stir, let stand for aging, and wash until there is no Na + Detect and obtain the first filter cake;

[0056] (4) Under ultrasonic vibration conditions, the first filter cake and a high-boiling point organic aqueous solution with a concentration of 40 g / L-115 g / L were stirred and slurried, and filtered to obtain a second filter cake;

[0057] (5) Drying the second filter cake, calcining it in an oxygen-free state, adding graphite and deionized water, and forming it into tablets to obtain the methanol synthesis catalyst.

[0058] According to the preparation method provided by the present invention, in some embodiments, the soluble copper salt in step (1) and step (2) is independently selected from one or more of copper nitrate, copper oxalate, and copper acetate. Preferably, the soluble copper salt is copper nitrate.

[0059] According to the preparation method provided by the present invention, in some embodiments, the soluble zinc salt in step (1) and step (2) is independently selected from one or more of zinc nitrate, zinc oxalate, and zinc acetate. Preferably, the soluble zinc salt is zinc nitrate.

[0060] According to the preparation method provided by the present invention, in some embodiments, in step (1), the soluble aluminum salt is aluminum nitrate.

[0061] According to the preparation method provided by the present invention, in some embodiments, the precipitant in step (1) and step (2) is independently selected from one or more of sodium hydroxide, sodium carbonate, and sodium bicarbonate. Preferably, the precipitant is sodium carbonate.

[0062] According to the preparation method provided by the application, in some embodiments, in step (1), the molar ratio of copper ions to zinc ions in the mixed salt aqueous solution is (0.2-5):1, and it can be understood that the molar ratio can be any specific value of 0.2:1, 0.4:1, 0.6:1, 0.8:1, 1:1, 1.2:1, 1.4:1, 1.6:1, 1.8:1, 2:1, 2.2:1, 2.4:1, 2.6:1, 2.8:1, 3:1, 3.2:1, 3.4:1, 3.6:1, 3.8:1, 4:1, 4.2:1, 4.4:1, 4.6:1, 4.8:1, 5:1 or any value within the range of (0.2-5):1.

[0063] According to the preparation method provided by the application, in some embodiments, in step (1), the ratio of the total moles of copper ions and zinc ions to the moles of aluminum ions in the mixed salt aqueous solution is (0.2-8):1, and it can be understood that the molar ratio can be any specific value of 0.2:1, 0.4:1, 0.6:1, 0.8:1, 1:1, 1.2:1, 1.4:1, 1.6:1, 1.8:1, 2:1, 2.2:1, 2.4:1, 2.6:1, 2.8:1, 3:1, 3.2:1, 3.4:1, 3.6:1, 3.8:1, 4:1, 4.2:1, 4.4:1, 4.6:1, 4.8:1, 5:1, 5.2:1, 5.4:1, 5.6:1, 5.8:1, 6:1, 6.2:1, 6.4:1, 6.6:1, 6.8:1, 7:1, 7.2:1, 7.4:1, 7.6:1, 7.8:1, 8:1 or any value within the range of (0.2-8):1.

[0064] In the application, the molar ratio of copper ions to zinc ions in the mixed salt aqueous solution in step (1) is controlled to be (0.2-5):1, and the ratio of the total moles of copper ions and zinc ions to the moles of aluminum ions is (0.2-8):1. Under this ratio, CuO in the catalyst can be fully refined and highly dispersed, forming a eutectic with ZnO and Al2O3, thereby improving the activity and heat resistance of the catalyst.

[0065] According to the preparation method provided by the application, in some embodiments, in step (1), the concentration of the precipitant aqueous solution is 1 mol / L-5 mol / L, and it can be understood that the concentration of the precipitant aqueous solution can be any specific value of 1 mol / L, 1.5 mol / L, 2 mol / L, 2.5 mol / L, 3 mol / L, 3.5 mol / L, 4 mol / L, 4.5 mol / L, 5 mol / L or any value within the range of 1 mol / L-5 mol / L.

[0066] According to the preparation method provided by the application, in some embodiments, in step (1), the coprecipitation reaction conditions are: under stirring, the reaction temperature is controlled to be 30-80 DEG C, and the pH is 7.0-9.0; it can be understood that the reaction temperature can be any specific value in 30 DEG C, 35 DEG C, 40 DEG C, 45 DEG C, 50 DEG C, 55 DEG C, 60 DEG C, 65 DEG C, 70 DEG C, 75 DEG C, 80 DEG C or any value in the range of 30 DEG C-80 DEG C; the pH can be any specific value in 7.0, 7.2, 7.4, 7.6, 7.8, 8.0, 8.2, 8.4, 8.6, 8.8, 9.0 or any value in the range of 7.0-9.0.

[0067] According to the preparation method provided by the application, in some embodiments, in step (2), the molar ratio of copper ions to zinc ions in the mixed salt aqueous solution is (0.5-5):1, it can be understood that the molar ratio can be any specific value in 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, 2:1, 2.1:1, 2.2:1, 2.3:1, 2.4:1, 2.5:1, 2.6:1, 2.7:1, 2.8:1, 2.9:1, 3:1, 3.1:1, 3.2:1, 3.3:1, 3.4:1, 3.5:1, 3.6:1, 3.7:1, 3.8:1, 3.9:1, 4:1, 4.1:1, 4.2:1, 4.3:1, 4.4:1, 4.5:1, 4.6:1, 4.7:1, 4.8:1, 4.9:1, 5:1 or any value in the range of (0.5-5):1.

[0068] In the application, the molar ratio of copper ions to zinc ions in the mixed salt aqueous solution in step (2) is controlled to be (0.5-5):1. Too low copper ions will result in low content of active component copper in the final catalyst, reducing the catalyst activity; too high copper ions will result in that copper and zinc cannot form a complete eutectic, and a large amount of free copper ions appear in the catalyst, which is easy to sinter in use, affecting the heat resistance of the catalyst.

[0069] According to the preparation method provided by the application, in some embodiments, in step (2), the concentration of the precipitant aqueous solution is 1-5 mol / L, it can be understood that the concentration of the precipitant aqueous solution can be any specific value in 1 mol / L, 1.5 mol / L, 2 mol / L, 2.5 mol / L, 3 mol / L, 3.5 mol / L, 4 mol / L, 4.5 mol / L, 5 mol / L or any value in the range of 1-5 mol / L.

[0070] In some embodiments of the preparation method, in step (2), the co-precipitation reaction conditions are: under stirring, the reaction temperature is controlled to be 60-95 DEG C, and the pH is controlled to be 7.0-9.0. It can be understood that the reaction temperature can be any specific value in the range of 60 DEG C, 65 DEG C, 70 DEG C, 75 DEG C, 80 DEG C, 85 DEG C, 90 DEG C, 95 DEG C or any value in the range of 60 DEG C-95 DEG C; and the pH can be any specific value in the range of 7.0, 7.2, 7.4, 7.6, 7.8, 8.0, 8.2, 8.4, 8.6, 8.8, 9.0 or any value in the range of 7.0-9.0.

[0071] The co-precipitation reaction refers to that two or more cations are contained in a solution, and exist in the solution in a homogeneous phase; after a precipitant is added and a precipitation reaction is performed, uniform precipitates of various components can be obtained. In the present application, the co-precipitation refers to a method in which the precipitant solution and the solution containing metal cations are simultaneously added into a reactor in a proportion.

[0072] In some embodiments of the preparation method, in step (3), the washing is performed by using deionized water, and the specific washing method can be pressure filtration or suction filtration.

[0073] Further, the temperature of the deionized water is 60 DEG C-75 DEG C. It can be understood that the temperature of the deionized water can be any specific value in the range of 60 DEG C, 61 DEG C, 62 DEG C, 63 DEG C, 64 DEG C, 65 DEG C, 66 DEG C, 67 DEG C, 68 DEG C, 69 DEG C, 70 DEG C, 71 DEG C, 72 DEG C, 73 DEG C, 74 DEG C, 75 DEG C or any value in the range of 60 DEG C-75 DEG C.

[0074] In some embodiments of the preparation method, the mass moisture content of the first filter cake is controlled to be 150%-200%. It can be understood that the mass moisture content of the first filter cake can be any specific value in the range of 150%, 155%, 160%, 165%, 170%, 175%, 180%, 185%, 190%, 195%, 200% or any value in the range of 150%-200%. If the moisture content of the first filter cake is too low, the filter cake is dry and hard, and a large number of spherical balls with different sizes are formed in the beating process of the high-boiling-point organic water solution, the slurry is not uniform, and the low moisture content leads to a longer suction filtration time; if the moisture content of the first filter cake is too high, the filter cake is soft and not conducive to transfer, and the concentration of the high-boiling-point organic water solution is not easy to control.

[0075] In the present application, the high-boiling-point organic matter refers to an organic matter with a boiling point higher than 150 DEG C under normal pressure.

[0076] According to the preparation method provided by the present application, in some embodiments, in step (4), the high-boiling organic matter comprises one or more of a carbohydrate, a polyhydroxy organic matter.

[0077] Further, the carbohydrate comprises one or more of glucose, sucrose, lactose, soluble starch.

[0078] Further, the polyhydroxy organic matter comprises one or more of ethylene glycol, glycerol, polyethylene glycol.

[0079] Further, the high-boiling organic matter is polyethylene glycol with an average molecular weight of 4000.

[0080] According to the preparation method provided by the present application, in some embodiments, the concentration of the high-boiling organic matter aqueous solution is 40 g / L-115 g / L, and the concentration of the high-boiling organic matter aqueous solution can be calculated individually according to its carbon content, for example, the concentration of polyethylene glycol aqueous solution is 40 g / L-80 g / L, and it can be understood that the concentration of polyethylene glycol aqueous solution can be any specific value of 40 g / L, 45 g / L, 50 g / L, 55 g / L, 60 g / L, 65 g / L, 70 g / L, 75 g / L, 80 g / L or any value within the range of 40 g / L-80 g / L; the concentration of glucose, sucrose, lactose, soluble starch, ethylene glycol, glycerol aqueous solution is 55 g / L-115 g / L, and it can be understood that the concentration of glucose, sucrose, lactose, soluble starch, ethylene glycol, glycerol aqueous solution can be any specific value of 55 g / L, 60 g / L, 65 g / L, 70 g / L, 75 g / L, 80 g / L, 85 g / L, 90 g / L, 95 g / L, 100 g / L, 105 g / L, 110 g / L, 115 g / L or any value within the range of 55 g / L-115 g / L.

[0081] According to the preparation method provided by the present application, in some embodiments, in step (4), the frequency of the ultrasonic oscillation is 25 kHz-40 kHz, and it can be understood that the frequency of the ultrasonic oscillation can be any specific value of 25 kHz, 26 kHz, 27 kHz, 28 kHz, 29 kHz, 30 kHz, 31 kHz, 32 kHz, 33 kHz, 34 kHz, 35 kHz, 36 kHz, 37 kHz, 38 kHz, 39 kHz, 40 kHz or any value within the range of 25 kHz-40 kHz.

[0082] According to the preparation method provided by the present invention, in some embodiments, in step (4), the mass moisture content of the second filter cake is controlled to be 140%-150%. It is understood that the mass moisture content of the second filter cake can be any specific value of 140%, 141%, 142%, 143%, 144%, 145%, 146%, 147%, 148%, 149%, 150%, or any value within the range of 140%-150%. If the moisture content of the second filter cake is too high, the drying process will cause the organic matter in the filter cake to migrate and locally aggregate, resulting in uneven distribution of the carbon components. If the moisture content of the second filter cake is too low, the filtration time will be longer.

[0083] In the present invention, the calculation formula of the filter cake mass moisture content is:

[0084] Filter cake mass moisture content (%) = (wet filter cake weight - dry filter cake weight) / dry filter cake weight × 100%

[0085] The wet filter cake is the filter cake taken out immediately after washing, and the dry filter cake is the filter cake dried in a blast drying oven under ventilation conditions at 120°C for 24 hours.

[0086] In the present invention, high-boiling-point organic matter is introduced into a first filter cake having a specific water content and subjected to ultrasonic oscillation, thereby breaking the copper, zinc, and aluminum precipitate particles into fine particles, allowing the high-boiling-point organic matter in the solution to be fully mixed with the precipitate fine particles. By controlling the water content of the first filter cake and the second filter cake obtained after the co-precipitation reaction, the amount of high-boiling-point organic matter solution adsorbed by the filter cake is controlled, thereby controlling the content of carbon produced by the decomposition of the high-boiling-point organic matter in the final product.

[0087] According to the preparation method provided by the present invention, in some embodiments, in step (5), the drying temperature is 100°C-150°C, and the drying time is 8h-24h; it can be understood that the drying temperature can be any specific value among 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, or any value within the range of 100°C-150°C; the drying time can be any specific value among 8h, 9h, 10h, 11h, 12h, 13h, 14h, 15h, 16h, 17h, 18h, 19h, 20h, 21h, 22h, 23h, 24h, or any value within the range of 8h-24h.

[0088] In some embodiments of the preparation method, the anaerobic roasting temperature in step (5) is 350-450 DEG C, and the anaerobic roasting time is 2-5 h. It can be understood that the anaerobic roasting temperature can be any specific value in the range of 350 DEG C-450 DEG C, or any value in the range of 350 DEG C-450 DEG C; the anaerobic roasting time can be any specific value in the range of 2 h-5 h, or any value in the range of 2 h-5 h.

[0089] In the present application, the anaerobic roasting refers to roasting in an oxygen-free state, and the purpose of the anaerobic roasting is to promote the carbonization of the high-boiling-point organic matter adsorbed in the filter cake to form carbon components. The temperature of the anaerobic roasting is controlled in the range of 350 DEG C-450 DEG C, which can ensure the complete carbonization of the high-boiling-point organic matter and ensure that the carbon components generated by the carbonization do not affect the activity of the catalyst. If the roasting temperature is lower than 350 DEG C, the high-boiling-point organic matter is not completely carbonized, and the metal precipitate is not completely decomposed; if the roasting temperature is higher than 450 DEG C, the carbon components generated by the carbonization of the high-boiling-point organic matter form hot spots in the catalyst, which promotes the sintering and growth of the copper grains near the hot spots, thereby reducing the activity of the catalyst.

[0090] In some embodiments of the preparation method, the addition amount of the graphite in step (5) is 2%-6% of the mass of the second filter cake after roasting; and the addition amount of the deionized water is 10%-15% of the mass of the second filter cake after roasting.

[0091] The tablet forming, also referred to as the tablet compression, is not specifically limited in the present application, and the conventional tablet forming method in the art can be used, including but not limited to the use of a tablet press to compress into a tablet shape or a ring shape.

[0092] In the present application, the carbon components generated by the carbonization of the high-boiling-point organic matter are more uniformly distributed in the catalyst, which can more effectively separate the active metal grains in the catalyst and prevent the growth of the active metal grains during use. The generated carbon components are stable in nature under the normal use conditions of the synthetic methanol catalyst and have no adverse effect on the activity of the catalyst.

[0093] The present application also provides a synthetic methanol catalyst prepared according to the above method, which comprises the following components: CuO, ZnO, Al2O3, carbon components generated by the decomposition of high-boiling-point organic matter, and graphite.

[0094] In the present invention, the mass percentage of the CuO is 35%-60% based on the total amount of the catalyst. It can be understood that its content can be any specific value of 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, or 60%, or any value within the range of 35%-60%.

[0095] In the present invention, the mass percentage of ZnO is 25%-40% based on the total amount of catalyst. It can be understood that its content can be any specific value among 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, and 50%, or any value within the range of 25%-40%.

[0096] In the present invention, the mass percentage of Al2O3 is 4%-15% based on the total amount of catalyst. It can be understood that its content can be any specific value of 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15% or any value within the range of 4%-15%.

[0097] In the present invention, the mass percentage of the carbon component generated by the decomposition of the high-boiling point organic matter is 3%-6% based on the total amount of the catalyst. It can be understood that its content can be any specific value of 3%, 3.2%, 3.4%, 3.6%, 3.8%, 4%, 4.2%, 4.4%, 4.6%, 4.8%, 5%, 5.2%, 5.4%, 5.6%, 5.8%, or 6%, or any value within the range of 3%-6%.

[0098] In the present invention, the content of the carbon component generated by the decomposition of the high-boiling-point organic matter in the catalyst is controlled to 3%-6% by weight of the catalyst. The stable carbon particles can separate the active metal ions and prevent them from agglomerating and growing. If the mass content of the carbon component generated by the decomposition of the high-boiling-point organic matter is lower than 3%, the separation effect is not obvious. If the mass content of the carbon component generated by the decomposition of the high-boiling-point organic matter is higher than 6%, excessive carbon particles will shield the surface of the active metal ions and affect the activity of the catalyst.

[0099] The present invention also provides a catalyst prepared according to the above preparation method or the use of the above catalyst in a methanol synthesis process. The present invention has no specific restrictions on the process conditions for synthesizing methanol, and conventional processes for synthesizing methanol in the art can be used.

[0100] The present application will be described in detail below by way of examples. It should be understood that the following examples are only used to exemplarily further explain and illustrate the content of the present application, and are not used to limit the present application.

[0101] The chemical additives used in the examples and comparative examples of the present application are commercially available. The content of each component in the catalyst prepared in the examples and comparative examples is determined by using the method for analyzing the chemical components of methanol synthesis catalysts in HG / T 4198-2011, and the carbon content is determined by using a carbon-sulfur analyzer.

[0102] Example 1

[0103] The preparation method of the synthetic methanol catalyst described in the present example comprises the following steps:

[0104] (1) 10 g of Cu(NO3)2·3H2O, 30 g of Zn(NO3)2·6H2O and 15 g of Al(NO3)3·9H2O are weighed and dissolved in 150 mL of deionized water, 40 g of Na2CO3 is weighed and dissolved in 100 mL of deionized water, and the two solutions are subjected to a parallel flow co-precipitation reaction at 45°C, with the pH value of the reaction being controlled at 7.0, to obtain a first mixture;

[0105] (2) 60 g of Cu(NO3)2·3H2O and 20 g of Zn(NO3)2·6H2O are weighed and dissolved in 200 mL of deionized water, 48 g of Na2CO3 is weighed and dissolved in 150 mL of deionized water, and the two solutions are subjected to a parallel flow co-precipitation reaction at 75°C, with the pH value of the reaction being controlled at 7.5, and after the reaction is completed, the stirring is continued for 30 min, and after the material changes from blue to blue-green, a second mixture is obtained;

[0106] (3) The first mixture and the second mixture are mixed, and the stirring is continued for 30 min, and the material is aged for 5 h, and after being washed with deionized water until no Na + is detected, a first filter cake is obtained, and the water content of the first filter cake is controlled at 170%;

[0107] (4) 800 mL of a polyethylene glycol 4000 aqueous solution with a concentration of 40 g / L is added to a reactor, the first filter cake is transferred to the reactor, and the stirring is performed under ultrasonic oscillation at 25-40 kHz to form a slurry, and the excess solution is removed by suction filtration to obtain a second filter cake, and the water content of the second filter cake is controlled at 150%;

[0108] (5) The second filter cake is dried in an oven at 150°C for 10 h, is crushed to 10 mesh, and is calcined in a muffle furnace under an oxygen-free condition at 350°C for 4 h; after cooling, 5 wt% of graphite and 10 wt% of deionized water are added, the mixture is uniformly mixed, and is formed into a tablet to obtain a catalyst cat-1.

[0109] After testing, in the synthetic methanol catalyst cat-1 prepared in this embodiment, the mass proportion of CuO is 54.5%, the mass proportion of ZnO is 32.4%, the mass proportion of Al2O3 is 4.8%, the mass proportion of carbon components generated by decomposition of high-boiling point organic matter is 3.5%, and the balance is graphite.

[0110] Example 2

[0111] The preparation method of the methanol synthesis catalyst described in this embodiment comprises the following steps:

[0112] (1) Weigh 30 g of Cu(NO3)2·3H2O, 40 g of Zn(NO3)2·6H2O, and 45 g of Al(NO3)3·9H2O and dissolve them in 150 mL of deionized water. Weigh 120 g of Na2CO3 and dissolve it in 200 mL of deionized water. The two solutions are subjected to a co-current coprecipitation reaction at 45°C. The reaction pH is controlled to 7.0 to obtain a first mixed material.

[0113] (2) Weigh 20 g of Cu(NO3)2·3H2O and 25 g of Zn(NO3)2·6H2O and dissolve them in 200 mL of deionized water. Weigh 40 g of Na2CO3 and dissolve them in 150 mL of deionized water. The two solutions are subjected to a co-current coprecipitation reaction at 75 °C. The pH value of the reaction is controlled to be 7.5. After the reaction is completed, continue stirring for 30 min. When the material changes from blue to blue-green, a second mixed material is obtained.

[0114] (3) Mix the first mixed material with the second mixed material, continue stirring for 30 minutes, let it stand for aging for 8 hours, and wash it with deionized water until there is no Na + Detect and obtain the first filter cake, and control the moisture content of the first filter cake to be 200%;

[0115] (4) Add 280 mL of 80 g / L polyethylene glycol 4000 aqueous solution to the reactor, transfer the first filter cake to the reactor, stir and slurry under 25-40 kHz ultrasonic vibration, and remove excess solution by filtration to obtain a second filter cake. The mass moisture content of the second filter cake is controlled to be 140%;

[0116] (5) The second filter cake was dried in an oven at 150°C for 10 h, crushed to 10 mesh, and calcined in a muffle furnace at 450°C in an oxygen-free environment for 4 h; after cooling, 2 wt% graphite and 10 wt% deionized water were added, mixed, and formed into tablets to obtain catalyst cat-2.

[0117] After testing, in the synthetic methanol catalyst cat-2 prepared in this embodiment, the mass proportion of CuO is 36.4%, the mass proportion of ZnO is 39.3%, the mass proportion of Al2O3 is 13.5%, the mass proportion of carbon components generated by decomposition of high-boiling point organic matter is 6%, and the balance is graphite.

[0118] Example 3

[0119] The preparation method of the synthetic methanol catalyst described in this embodiment comprises the following steps:

[0120] (1) 8.26 g of Cu(CH3COOH)2·H2O, 22.13 g of Zn(CH3COOH)2·2H2O, and 15 g of Al(NO3)3·9H2O were weighed and dissolved in 150 mL of deionized water, 40 g of Na2CO3 was weighed and dissolved in 100 mL of deionized water, and the two solutions were subjected to a parallel flow co-precipitation reaction at 45°C, with the reaction pH value controlled at 7.0, to obtain a first mixture;

[0121] (2) 49.58 g of Cu(CH3COOH)2·H2O and 22.14 g of Zn(CH3COOH)2·2H2O were weighed and dissolved in 200 mL of deionized water, 50 g of Na2CO3 was weighed and dissolved in 150 mL of deionized water, and the two solutions were subjected to a parallel flow co-precipitation reaction at 75°C, with the reaction pH value controlled at 7.5, and after the reaction was completed, stirring was continued for 30 min, and after the material changed from blue to blue-green, a second mixture was obtained;

[0122] (3) The first mixture and the second mixture were mixed and stirred for 30 min, and then aged for 2 h, and then washed with deionized water until no Na + was detected, to obtain a first filter cake, and the water content of the first filter cake was controlled at 170%;

[0123] (4) 450 mL of a glucose aqueous solution with a concentration of 55 g / L was added to the reactor, and the first filter cake was transferred to the reactor, and was stirred and pulped under ultrasonic oscillation at 25-40 kHz, and then excess solution was removed by suction filtration to obtain a second filter cake, and the water content of the second filter cake was controlled at 140%;

[0124] (5) The second filter cake was dried in an oven at 150°C for 10 h, crushed to 10 mesh, and then calcined in a muffle furnace at 450°C under anaerobic conditions for 4 h; after cooling, 6 wt% of graphite and 15 wt% of deionized water were added, mixed, and then formed into a sheet to obtain the catalyst cat-3.

[0125] It was detected that in the synthetic methanol catalyst cat-3 prepared in this embodiment, the mass fraction of CuO was 50.7%, the mass fraction of ZnO was 36.1%, the mass fraction of Al2O3 was 4.5%, the mass fraction of carbon components generated by the decomposition of high-boiling organic matter was 3%, and the balance was graphite.

[0126] Comparative Example 1

[0127] The preparation method of the synthetic methanol catalyst in the comparative example is the same as that in Example 1, except that the anaerobic calcination in step (5) is replaced by calcination under an air atmosphere at 350°C, to obtain a synthetic methanol catalyst D-cat-1.

[0128] It is detected that the mass fraction of the carbon component generated by the decomposition of high-boiling organic matter in the synthetic methanol catalyst cat-1 prepared in the comparative example is 0.2%.

[0129] Comparative Example 2

[0130] The preparation method of the synthetic methanol catalyst in the comparative example is the same as that in Example 1, except that the ultrasonic oscillation is not used in step (4), to obtain a synthetic methanol catalyst D-cat-2.

[0131] It is detected that the mass fraction of the carbon component generated by the decomposition of high-boiling organic matter in the synthetic methanol catalyst D-cat-2 prepared in the comparative example is 3.5%.

[0132] Comparative Example 3

[0133] The preparation method of the synthetic methanol catalyst in the comparative example comprises the following steps:

[0134] (1) 10 g of Cu(NO3)2·3H2O, 30 g of Zn(NO3)2·6H2O and 15 g of Al(NO 3)3 ·9H2O were weighed and dissolved in 150 mL of deionized water, 40 g of NaCO3 was weighed and dissolved in 100 mL of deionized water, and the two solutions were subjected to a parallel flow co-precipitation reaction under the condition of 45°C, with the reaction pH value controlled at 7.0, to obtain a first mixture;

[0135] (2) 60 g of Cu(NO3)2·3H2O and 20 g of Zn(NO3)2·6H2O were weighed and dissolved in 200 mL of deionized water, 48 g of Na2CO3 was weighed and dissolved in 150 mL of deionized water, and the two solutions were subjected to a parallel flow co-precipitation reaction under the condition of 75°C, with the reaction pH value controlled at 7.5; after the reaction was completed, stirring was continued for 30 min, and after the material changed from blue to blue-green, a second mixture was obtained.

[0136] (3) The first mixture and the second mixture were mixed and stirred for 30 min, and then aged for 5 h; after washing with deionized water until no Na + was detected, a first filter cake was obtained, and the water content of the first filter cake was controlled at 170%;

[0137] (4) The first filter cake obtained in step (3) was washed with a 50 g / L aqueous solution of polyethylene glycol 4000, and the excess solution was removed by suction filtration to obtain a second filter cake, and the water content of the second filter cake was controlled at 150%;

[0138] (5) The second filter cake was dried in an oven at 150°C for 10h, crushed to 10 mesh, and calcined in a muffle furnace at 350°C under anaerobic conditions for 4h. After cooling, 5wt% graphite and 10wt% deionized water were added, mixed, and then formed into tablets to obtain the catalyst D-cat-3.

[0139] It was detected that the mass fraction of the carbon component generated by the decomposition of high-boiling organic matter in the synthetic methanol catalyst D-cat-3 prepared in this example was 3.5%.

[0140] Example 4

[0141] The preparation method of the synthetic methanol catalyst described in this example comprises the following steps:

[0142] (1) 10g of Cu(NO3)2·3H2O, 30g of Zn(NO3)2·6H2O, and 15g of Al(NO3)3·9H2O were weighed and dissolved in 150mL of deionized water, 40g of Na2CO3 was weighed and dissolved in 100mL of deionized water, and the two solutions were subjected to a parallel flow co-precipitation reaction at 45°C, with the reaction pH value controlled at 7.0, to obtain a first mixture;

[0143] (2) 60g of Cu(NO3)2·3H2O and 10g of Zn(NO3)2·6H2O were weighed and dissolved in 200mL of deionized water, 45g of Na2CO3 was weighed and dissolved in 150mL of deionized water, and the two solutions were subjected to a parallel flow co-precipitation reaction at 75°C, with the reaction pH value controlled at 7.5. After the reaction was completed, stirring was continued for 30min, and after the material changed from blue to blue-green, a second mixture was obtained;

[0144] (3) The first mixture and the second mixture were mixed and stirred for another 30min, and then aged for 5h. After washing with deionized water until no Na + was detected, a filter cake was obtained, and the moisture content of the filter cake was controlled at 170%;

[0145] (4) The filter cake of step (3) was dried in an oven at 150°C for 10h, 3.3g of polyethylene glycol 4000 powder was added, and the mixture was crushed to 200 mesh, calcined in a muffle furnace at 350°C under anaerobic conditions for 4h, and then cooled. After adding 5wt% graphite and 10wt% deionized water, the mixture was mixed, granulated, and formed into tablets to obtain the catalyst D-cat-4.

[0146] It was detected that the mass fraction of the carbon component generated by the decomposition of high-boiling organic matter in the synthetic methanol catalyst D-cat-4 prepared in this example was 3.5%.

[0147] Example 5

[0148] The preparation method of the synthetic methanol catalyst described in this example comprises the following steps:

[0149] (1) Weigh 10 g of Cu(NO3)2·3H2O, 30 g of Zn(NO3)2·6H2O, and 15 g of Al(NO3)3·9H2O and dissolve them in 150 mL of deionized water. Weigh 40 g of Na2CO3 and dissolve it in 100 mL of deionized water. The two solutions are subjected to a co-current coprecipitation reaction at 45°C. The reaction pH is controlled to be 7.0 to obtain a first mixed material.

[0150] (2) Weigh 60 g of Cu(NO3)2·3H2O and 20 g of Zn(NO3)2·6H2O and dissolve them in 200 mL of deionized water. Weigh 48 g of Na2CO3 and dissolve them in 150 mL of deionized water. The two solutions are subjected to a co-current co-precipitation reaction at 75 °C. The pH value of the reaction is controlled to be 7.5. After the reaction is completed, continue stirring for 30 min. When the material changes from blue to blue-green, a second mixed material is obtained.

[0151] (3) Mix the first mixed material with the second mixed material, continue stirring for 30 minutes, let it stand for 5 hours, and wash it with deionized water until there is no Na + Detect and obtain filter cake;

[0152] (4) The filter cake of step (3) was dried in an oven at 150°C for 10 h, mixed evenly with a mixed solution prepared by adjusting 10 g of deionized water and 3.3 g of polyethylene glycol 4000, crushed to 10 mesh, and calcined in a muffle furnace at 350°C in anoxic conditions for 4 h; after cooling, 5 wt% of graphite and 10 wt% of deionized water were added, mixed evenly, and formed into tablets to obtain catalyst D-cat-5.

[0153] According to testing, the mass of carbon components generated by decomposition of high-boiling-point organic matter in the synthetic methanol catalyst D-cat-5 prepared in this comparative example accounts for 3.5%.

[0154] Comparative Example 6

[0155] The preparation method of the synthetic methanol catalyst described in this comparative example has the same preparation steps as Example 1, except that the concentration of the polyethylene glycol 4000 aqueous solution in step (4) is 120 g / L, and the synthetic methanol catalyst D-cat-6 is prepared.

[0156] According to testing, the mass of carbon components generated by decomposition of high-boiling-point organic matter in the synthetic methanol catalyst D-cat-6 prepared in this comparative example accounts for 7.5%.

[0157] Comparative Example 7

[0158] The preparation method of the synthetic methanol catalyst in the comparative example is the same as that in Example 1, except that the concentration of the aqueous polyethylene glycol 4000 solution in step (4) is 30 g / L, and the synthetic methanol catalyst D-cat-7 is prepared.

[0159] It is detected that the mass percentage of the carbon component generated by the decomposition of high-boiling organic matter in the synthetic methanol catalyst D-cat-7 prepared in the comparative example is 2.6%.

[0160] Comparative Example 8

[0161] The preparation method of the synthetic methanol catalyst in the comparative example is the same as that in Example 1, except that the calcination condition in step (4) is replaced by 300°C absolute oxygen-free calcination, and the synthetic methanol catalyst D-cat-8 is prepared.

[0162] It is detected that the mass percentage of the carbon component generated by the decomposition of high-boiling organic matter in the synthetic methanol catalyst D-cat-8 prepared in the comparative example is 2.3%.

[0163] Comparative Example 9

[0164] The preparation method of the synthetic methanol catalyst in the comparative example is the same as that in Example 1, except that the calcination condition in step (4) is replaced by 500°C absolute oxygen-free calcination, and the synthetic methanol catalyst D-cat-9 is prepared.

[0165] It is detected that the mass percentage of the carbon component generated by the decomposition of high-boiling organic matter in the synthetic methanol catalyst D-cat-9 prepared in the comparative example is 3.5%.

[0166] Comparative Example 10

[0167] The preparation method of the synthetic methanol catalyst in the comparative example includes the following steps:

[0168] (1) 10 g of Cu(NO3)2·3H2O, 30 g of Zn(NO3)2·6H2O, 15 g of Al(NO3)3·9H2O and 3.4 g of polyethylene glycol 4000 are dissolved in 150 mL of deionized water, 40 g of Na2CO3 is dissolved in 100 mL of deionized water, and the two solutions are subjected to a parallel flow co-precipitation reaction under the condition of 45°C, and the pH value of the reaction is controlled at 7.0, to obtain a first mixture;

[0169] (2) 60 g of Cu(NO3)2·3H2O and 20 g of Zn(NO3)2·6H2O are dissolved in 200 mL of deionized water, 48 g of Na2CO3 is dissolved in 150 mL of deionized water, and the two solutions are subjected to a parallel flow co-precipitation reaction under the condition of 75°C, and the pH value of the reaction is controlled at 7.5, after the reaction is completed, the stirring is continued for 30 min, and after the material changes from blue to blue-green, a second mixture is obtained;

[0170] (3) Mix the first mixed material with the second mixed material, continue stirring for 30 minutes, let it stand for 5 hours, and wash it with deionized water until there is no Na + Detect and obtain filter cake;

[0171] (4) The filter cake was dried in an oven at 150°C for 10 h, crushed to 10 mesh, and calcined in a muffle furnace at 350°C for 4 h. After cooling, 2 wt% graphite and 10 wt% deionized water were added, mixed, and formed into tablets to obtain catalyst D-cat-10.

[0172] According to the test, the mass of the carbon components generated by decomposition of high-boiling-point organic matter in the synthetic methanol catalyst D-cat-10 prepared in this comparative example accounts for 0.3%.

[0173] Comparative Example 11

[0174] The preparation method of the methanol synthesis catalyst described in this comparative example comprises the following steps:

[0175] (1) Weigh 10 g of Cu(NO3)2·3H2O, 30 g of Zn(NO3)2·6H2O, and 15 g of Al(NO3)3·9H2O and dissolve them in 150 mL of deionized water. Weigh 40 g of Na2CO3 and dissolve it in 100 mL of deionized water. The two solutions are subjected to a co-current coprecipitation reaction at 45°C. The reaction pH is controlled to be 7.0 to obtain a first mixed material.

[0176] (2) Weigh 60 g of Cu(NO3)2·3H2O and 20 g of Zn(NO3)2·6H2O and dissolve them in 200 mL of deionized water. Weigh 48 g of Na2CO3 and dissolve them in 150 mL of deionized water. The two solutions are subjected to a co-current co-precipitation reaction at 75 °C. The pH value of the reaction is controlled to be 7.5. After the reaction is completed, continue stirring for 30 min. When the material changes from blue to blue-green, a second mixed material is obtained.

[0177] (3) Mix the first mixed material with the second mixed material, continue stirring for 30 minutes, let it stand for 5 hours, and wash it with deionized water until there is no Na + Detect and obtain filter cake;

[0178] (4) The filter cake was dried in an oven at 150°C for 10 h, crushed to 10 mesh, and calcined in a muffle furnace at 350°C for 4 h. After cooling, 5 wt% graphite and 10 wt% deionized water were added, mixed, and formed into tablets to obtain catalyst D-cat-11.

[0179] The reaction activity and heat resistance of the methanol synthesis catalysts prepared in the above examples and comparative examples were evaluated using a pressurized evaluation device. The specific steps are as follows:

[0180] The catalyst sample was first crushed to 40-60 mesh, 5 mL of the sample was mixed with quartz sand at a ratio of 1:1; reduction was carried out by using N2containing 3% (volume percentage) H2, and the temperature was raised to 230°C at a rate of 20°C / h; the raw gas composition (volume percentage) was CO 15%, CO2 5%, N2 15%, and H2 65%; the compositions of the raw gas and the reaction tail gas were analyzed by using gas chromatography, and the CO conversion rate was calculated;

[0181] The activity evaluation test conditions were as follows: reaction temperature 240°C, pressure 5.0 MPa, and space velocity 10000 h-1. -1 ;

[0182] The heat treatment resistance conditions were as follows: treatment at 400°C for 20 h in a N2atmosphere.

[0183] The activity retention rate of the catalyst was calculated by the following formula, and the specific performance test results of the catalyst are shown in Table 1.

[0184] Catalyst activity retention rate (%) = CO conversion rate (%) after 20 h of reaction / initial CO conversion rate (%) x 100%

[0185] Table 1: Catalyst performance test results of examples and comparative examples

[0186] .

[0187] As can be seen from the examples and comparative examples, the activity retention rates of the catalysts prepared in the examples are all above 93%, which are obviously superior to the catalysts prepared by the methods of the comparative examples. In Comparative Example 1, the catalyst was calcined in an air atmosphere, and the mass ratio of the carbon component generated by the decomposition of high-boiling organic matter in the catalyst was 0.2%, and the activity retention rate of the catalyst was low. In Comparative Example 2, the slurry process did not include ultrasonic oscillation, although the mass ratio of the carbon component generated by the decomposition of high-boiling organic matter in the catalyst was 3.5%, the high-boiling organic matter could not be fully mixed with the precipitate particles, and the activity retention rate of the catalyst was only about 90%. In Comparative Examples 3-5 and 10, the high-boiling organic matter was added in different ways, and the activity retention rates of the final catalysts were all lower than those of the examples. In Comparative Examples 6 and 7, the concentrations of the high-boiling organic matter were outside the application, and the activity retention rates of the obtained catalysts were both low, which indicated that the control of the concentration of the high-boiling organic matter was very important, and the effect was not ideal when the concentration was too high or too low. In Comparative Example 8, the temperature of the anaerobic calcination was too low, and in Comparative Example 9, the temperature of the anaerobic calcination was too high, and the initial activity of the catalysts was obviously low. In Comparative Example 11, the high-boiling organic matter was not used, and the activity retention rate of the catalyst was lower than 90%.

[0188] From Figure 1 (a), Figure 1(b) It can be seen that the catalyst prepared in Example 1 of the present invention has a uniformly distributed granular morphology before and after the reaction, and the active components have no obvious sintering phenomenon, indicating that the catalyst has good stability; while the catalyst prepared in the comparative example has a uniformly distributed granular morphology before the reaction, and the catalyst morphology changes greatly after the reaction, showing a flaky, flocculent, rod-like or layered structure, indicating that the active components of the catalyst have sintered after the reaction, which is also the reason for the decrease in catalyst activity stability.

[0189] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection of the present invention.

Claims

1. A method for preparing a catalyst for synthesizing methanol, characterized in that: The steps include: (1) co-precipitating a mixed salt solution containing a soluble copper salt, a soluble zinc salt, and a soluble aluminum salt and a precipitant aqueous solution in parallel to obtain a first mixed material; (2) co-precipitating a mixed salt solution containing a soluble copper salt and a soluble zinc salt and an aqueous solution of a precipitant to obtain a second mixed material; (3) Mix the first mixed material and the second mixed material, stir, let stand for aging, and wash until there is no Na + Detect and obtain the first filter cake; (4) Under ultrasonic vibration conditions, the first filter cake and a high-boiling point organic aqueous solution with a concentration of 40 g / L-115 g / L were stirred and slurried, and filtered to obtain a second filter cake; (5) drying the second filter cake, calcining it in an oxygen-free state, adding graphite and deionized water, and forming it into tablets to obtain the methanol synthesis catalyst; In step (3), the mass moisture content of the first filter cake is 150%-200%; in step (4), the mass moisture content of the second filter cake is 140%-150%; In step (4), the high-boiling-point organic matter includes one or more of carbohydrates and polyhydroxy organic matter; the carbohydrates include one or more of glucose, sucrose, lactose, and soluble starch; the polyhydroxy organic matter includes one or more of ethylene glycol, glycerol, and polyethylene glycol; In step (5), the anaerobic roasting temperature is 350°C-450°C, and the anaerobic roasting time is 2h-5h; The methanol synthesis catalyst comprises the following components in total weight percentage: CuO35%-60%; ZnO25%-40%; Al2O34%-15%; 3%-6% of the carbon component is generated by the decomposition of high-boiling point organic matter; and the balance is graphite.

2. The method for preparing a methanol synthesis catalyst according to claim 1, characterized in that The method has one or more of the following characteristics: The soluble copper salts in step (1) and step (2) are independently selected from one or more of copper nitrate, copper oxalate, and copper acetate; The soluble zinc salts in step (1) and step (2) are independently selected from one or more of zinc nitrate, zinc oxalate, and zinc acetate; In step (1), the soluble aluminum salt is aluminum nitrate; The precipitating agents in step (1) and step (2) are independently selected from one or more of sodium hydroxide, sodium carbonate, and sodium bicarbonate.

3. The method for preparing the methanol synthesis catalyst according to claim 1, characterized in that The method has one or more of the following characteristics: In step (1), the molar ratio of copper ions to zinc ions in the mixed salt solution is (0.2-5):1; In step (1), the ratio of the total molar number of copper ions and zinc ions to the molar number of aluminum ions in the mixed salt solution is (0.2-8):1; In step (1), the concentration of the precipitant aqueous solution is 1 mol / L-5 mol / L; In step (1), the coprecipitation reaction conditions are: under stirring, the reaction temperature is controlled at 30°C-80°C, and the pH is 7.0-9.

0.

4. The method for preparing the methanol synthesis catalyst according to claim 1, wherein The method has one or more of the following characteristics: In step (2), the molar ratio of copper ions to zinc ions in the mixed salt solution is (0.5-5):1; In step (2), the concentration of the precipitant aqueous solution is 1 mol / L-5 mol / L; In step (2), the coprecipitation reaction conditions are: under stirring, the reaction temperature is controlled at 60°C-95°C, and the pH is 7.0-9.

0.

5. The method for preparing the methanol synthesis catalyst according to claim 1, characterized in that The method has one or more of the following characteristics: In step (4), the frequency of the ultrasonic oscillation is 25kHz-40kHz; In step (5), the drying temperature is 100°C-150°C, and the drying time is 8h-24h.

6. Use of the catalyst prepared according to the preparation method according to any one of claims 1 to 5 in a methanol synthesis process.

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