TWI655180B - Catalyst for manufacturing methanol, method for fabricating thereof and method for manufacturing methanol - Google Patents

Abstract

A catalyst for manufacturing methanol, including copper, zinc oxide, aluminum oxide, hydrophobic silicon dioxide, and chromium trioxide. The weight ratio of copper to zinc oxide is 6/4 to 8/2, the weight ratio of copper to alumina is 6/1 to 8/1, and the weight ratio of copper to anaerobic silica is 6/1 to 8/1. Based on the total weight of copper, zinc oxide, aluminum oxide, anaerobic silicon dioxide, and chromium trioxide, the content is 100 parts by weight, and the content of chromium trioxide is 5 to 10 parts by weight. Therefore, the catalyst for producing methanol of the present invention has higher carbon dioxide conversion rate, methanol selectivity, and methanol yield, which is beneficial to the reuse of carbon dioxide.

Description

Catalyst for producing methanol, preparation method thereof and method for producing methanol

The invention relates to a catalyst, a preparation method and application thereof, and particularly to a catalyst for manufacturing methanol, a preparation method thereof, and a manufacturing method of methanol using the same.

Carbon dioxide (CO ₂ ) is one of the gases that cause the greenhouse effect. It is associated with methane (CH ₄ ), nitrous oxide (N ₂ O), perfluorocarbons (PFCs), and hydrogen fluoride. Carbide (Hydrofluorocarbons, HFCs) and sulfur hexafluoride (SF6) are equivalent to gases that cause greenhouse effects. A study by the Intergovernmental Panel on Climate Change (IPCC) pointed out that when the concentration of carbon dioxide in the atmosphere exceeds 500 ppm, the degree of damage to the environment will increase greatly, so carbon dioxide reduction has become an important international issue.

Carbon dioxide reduction can be achieved by reducing emissions and reducing the concentration in the environment. In terms of mitigation of emissions, improve energy efficiency and save energy Energy-saving measures, resource recovery and reuse, and development of carbon dioxide-free energy are the goals of current research. Reducing the concentration in the environment can use carbon dioxide capture and storage technology, and then cooperate with conversion or other reuse methods to convert carbon dioxide into available resources. Among them, in terms of the reuse of carbon dioxide, carbon dioxide is one of the richest and cheapest carbon resources in the world. If it can be used to produce industrially needed raw materials, it will solve the problem of energy shortage and increase economic benefits.

In the reuse of carbon dioxide, the hydrogenation reaction provided by hydrogen, the electrochemical reaction using a metal electrode to input current, and the photochemical reaction can be regarded as one of the ways to use carbon dioxide for reductive carboxylation to produce raw materials. The reaction of carbon dioxide plus hydrogen to form methanol has attracted the most attention. In the early days, methanol was generated by the reaction of carbon monoxide and hydrogen. Later, it was found that adding a small amount of carbon dioxide to this reaction would greatly increase the production of methanol. However, if pure carbon dioxide can be used to react with hydrogen to generate methanol, it will have considerable development. Potential, the carbon dioxide hydrogenation reaction can be expressed by the following formula (1): CO ₂ +3 H ₂ → CH ₃ OH + H ₂ O (1).

However, from the calculation of thermodynamics, the reaction of carbon dioxide and hydrogen to produce methanol is not more suitable than the reaction of carbon monoxide to produce methanol. Therefore, conventional catalysts such as Cu / ZnO / Al ₂ O ₃ for carbon dioxide and hydrogen to produce methanol are still yielding. Much lower yield than using it for carbon monoxide hydrogenation to produce methanol. In addition, when carbon dioxide and hydrogen are used to generate methanol, a side reaction may occur to generate carbon monoxide and methane, and the product may be a mixture of methanol, carbon monoxide and methane. The foregoing side reaction may be expressed by the following formulas (2) and (3): CO ₂ + H ₂ → CO + H ₂ O (2); CO ₂ +4 H ₂ → CH ₄ +2 H ₂ O (3).

When the product is a mixture of methanol with carbon monoxide and methane, it is not conducive to subsequent applications. For example, when the product is used as a fuel for a fuel cell, the platinum (Pt) catalyst in the fuel cell is poisoned by carbon monoxide and loses its activity.

In view of this, how to develop a suitable catalyst that can increase the carbon dioxide conversion rate and methanol yield, and has a higher methanol selectivity, thereby reducing the content of components other than methanol in the product, are scholars and practitioners in the field The goal of the effort.

An object of the present invention is to provide a catalyst for producing methanol and a preparation method thereof, whereby the catalyst for producing methanol of the present invention can be used as a catalyst for adding carbon dioxide to hydrogen to generate methanol, and is beneficial to carbon dioxide. Reuse. In addition, the catalyst for producing methanol of the present invention has high carbon dioxide conversion rate, methanol selectivity, and methanol yield, which can improve the efficiency of carbon dioxide reuse.

Another object of the present invention is to provide a method for producing methanol, which uses carbon dioxide as a reactant, which is beneficial to the reuse of carbon dioxide. In addition, the method for producing methanol of the present invention has high carbon dioxide conversion rate, methanol selectivity, and methanol yield, and can improve the efficiency of carbon dioxide reuse.

According to an embodiment of the present invention, a catalyst for manufacturing methanol is provided, including copper, zinc oxide, aluminum oxide, hydrophobic silicon dioxide, and chromium trioxide, wherein the weight ratio of copper to zinc oxide is 6/4 to 8/2, copper and oxygen The weight ratio of aluminum oxide is 6/1 to 8/1, and the weight ratio of copper to hydrophobic silicon dioxide is 6/1 to 8/1. Based on copper, zinc oxide, aluminum oxide, hydrophobic silicon dioxide and trioxide. The total weight of dichromium is 100 parts by weight, and the content of chromium trioxide is 5 to 10 parts by weight.

According to the aforementioned catalyst for manufacturing methanol, the catalyst for manufacturing methanol may be in a granular shape, and its average particle diameter may be 100 nm to 10 μm.

According to another embodiment of the present invention, a method for preparing a catalyst for producing methanol is provided, which includes a solution preparation step, a pH adjustment step, a ripening step, a calcination step, and a reduction step. . The solution preparation step is used to mix a plurality of metal salt solutions to obtain a precursor solution, and the metal salt solutions respectively include copper ions, zinc ions, aluminum ions, and chromium ions. The pH adjustment step is used to adjust the pH of the precursor solution to 7 to 9 to obtain a first precipitate. The maturation step is to mature the first precipitate at 60 ° C to 90 ° C and add anaerobic silica to obtain a second precipitate. The calcination step is performed by calcining the second precipitate to obtain a catalyst precursor. The catalyst precursor includes copper oxide, zinc oxide, aluminum oxide, hydrophobic silicon dioxide, and chromium trioxide. The reduction step is to reduce copper oxide in the catalyst precursor to obtain a catalyst for producing methanol. The catalyst for producing methanol includes copper, zinc oxide, aluminum oxide, hydrophobic silicon dioxide, and chromium trioxide. The weight ratio of copper to zinc oxide is 6/4 to 8/2, the weight ratio of copper to alumina is 6/1 to 8/1, and the weight ratio of copper to anaerobic silica is 6/1 to 8 / 1. Based on the weight of copper, zinc oxide, aluminum oxide, hydrophobic silica and chromium trioxide. The total amount is 100 parts by weight, and the content of chromium trioxide is 5 to 10 parts by weight.

According to the aforementioned method for preparing a catalyst for manufacturing methanol, the metal salt solution may be an aqueous metal nitrate solution.

According to the aforementioned method for preparing a catalyst for producing methanol, when the pH value of the current flood solution is less than 7, the pH adjustment step can be completed by adding an aqueous sodium carbonate solution to the precursor solution, and adding sodium carbonate The rate of the aqueous solution may be from 10 mL / min to 100 mL / min. When the pH value of the current flood solution is greater than 9, the pH adjustment step can be completed by adding a nitric acid solution to the precursor solution, and the rate of adding the nitric acid solution can be 5 mL / min to 50 mL / min.

According to the aforementioned method for preparing a catalyst for manufacturing methanol, the time of the aging step may be from 0.5 hours to 2 hours.

According to the aforementioned method for preparing a catalyst for producing methanol, the reduction step can treat the catalyst precursor in an operating environment of hydrogen at a temperature of 1 ° C to 10 ° C to 200 ° C to 400 ° C per minute.

According to the aforementioned method for preparing a catalyst for manufacturing methanol, after the aging step and before the calcining step, it may further include performing a cooling step, performing a purification step, and performing a drying step. The purification step is to filter out and wash the second precipitate, and the drying step is to dry the second precipitate.

According to another embodiment of the present invention, a method for producing methanol is provided, which includes providing a catalyst and performing a hydrogenation reaction. The catalyst includes copper, zinc oxide, aluminum oxide, anaerobic silicon dioxide, and chromium trioxide. The weight ratio of copper to zinc oxide is 6/4 to 8/2, and the weight ratio of copper to aluminum oxide is 6/1 to 8/1, the weight ratio of copper to anaerobic silica is 6/1 to 8/1, based on the total weight of copper, zinc oxide, alumina, anaerobic silica and chromium trioxide, The content of chromium trioxide is 100 parts by weight and 5 to 10 parts by weight. In the hydrogenation reaction, the catalyst is brought into contact with carbon dioxide and hydrogen, and the carbon dioxide is hydrogenated to produce methanol.

According to the aforementioned method for producing methanol, wherein the hydrogenation reaction can be performed at 230 ° C to 300 ° C, the volume ratio of hydrogen to carbon dioxide in the hydrogenation reaction can be 3 to 5, the hydrogenation reaction can be performed in a fixed bed reactor, and the hydrogenation reaction The methanol yield is 900 to 1000 grams of methanol per kilogram of catalyst per hour.

100‧‧‧ Preparation method for catalyst for manufacturing methanol

110, 120, 130, 140, 150‧‧‧ steps

200‧‧‧ Preparation method for catalyst for manufacturing methanol

210, 220, 230, 240, 250, 260, 270, 280‧‧‧ steps

300‧‧‧ Methanol production method

310, 320‧‧‧ steps

In order to make the above and other objects, features, advantages, and embodiments of the present invention more comprehensible, the description of the drawings is as follows: FIG. 1 is a preparation of a catalyst for manufacturing methanol according to an embodiment of the present invention Step flow chart of the method; FIG. 2 is a step flow chart of a method for preparing a catalyst for producing methanol according to another embodiment of the present invention; and FIG. 3 is a method of producing methanol according to another embodiment of the present invention Steps flow chart.

Embodiments of the present invention will be discussed in more detail below. However, this embodiment may be an application of various inventive concepts, and may be specifically implemented in various Different specific ranges. Specific embodiments are for the purpose of illustration only, and are not limited to the scope of the disclosure.

In the present invention, for the sake of brevity and smoothness, a catalyst for producing methanol is sometimes referred to as a catalyst.

<Catalyst for producing methanol>

The invention provides a catalyst for manufacturing methanol, including copper, zinc oxide, aluminum oxide, hydrophobic silicon dioxide and chromium trioxide, wherein the weight ratio of copper to zinc oxide is 6/4 to 8/2. The weight ratio to alumina is 6/1 to 8/1, and the weight ratio of copper to anaerobic silica is 6/1 to 8/1. Based on copper, zinc oxide, alumina, anaerobic silica and three The total weight of the chromium oxide is 100 parts by weight, and the content of the chromium trioxide is 5 to 10 parts by weight. In this way, the catalyst for producing methanol of the present invention can be used as a catalyst for generating carbon dioxide by adding carbon dioxide and hydrogen, which is beneficial to the reuse of carbon dioxide. In addition, the method for producing methanol of the present invention has high carbon dioxide conversion rate, methanol selectivity, and methanol yield, and can improve the efficiency of carbon dioxide reuse.

The aforementioned anaerobic silica refers to the contact angle of water on it is greater than 130 degrees. Therefore, the water (as shown in formula (1)) generated in the carbon dioxide hydrogenation reaction will not accumulate on the surface of the catalyst, but may Break the thermodynamic equilibrium, make the reaction tend to the direction of the product, and then increase the reaction rate. In addition, the particle diameter of the anaerobic silica added in the present invention may be 5 nm to 50 nm, and the specific surface area thereof may be 200 m ² / g to 400 m ² / g, but the present invention is not intended to be limited thereto.

The catalyst for manufacturing methanol of the present invention may be granular, and its average particle diameter may be 100 nm to 10 μm, but the present invention is not intended to be limited thereto.

The chemical formula of the catalyst for producing methanol of the present invention can be expressed by Cu / ZnO / Al ₂ O ₃ / Cr ₂ O ₃ / SiO ₂ , wherein copper has good activity and selectivity and is the activation site of the catalyst. The role of hydrophobic silica is as described above, which is helpful to break the thermodynamic equilibrium, make the reaction tend to the direction of the product and increase the reaction rate. Zinc oxide and chromium trioxide play the role of a tissue promoter to promote synergy, which can increase The dispersibility and stability of copper, while alumina mainly plays the role of a structural accelerator that increases the dispersion and mechanical strength.

<Preparation method of catalyst for producing methanol>

The preparation method of the catalyst for producing methanol according to the present invention can be completed by a coprecipitation method with other steps, which will be described in detail below with reference to FIG. 1. FIG. 1 is a flowchart of steps in a method 100 for preparing a catalyst for producing methanol according to an embodiment of the present invention. As shown in FIG. 1, a method 100 for producing a catalyst for producing methanol includes step 110 and steps. 120, step 130, step 140, and step 150.

Step 110 is a solution preparation step for mixing a plurality of metal salt solutions to obtain a precursor solution, the metal salt solutions respectively including copper ions, zinc ions, aluminum ions, and chromium ions. For example, the metal salt solution may be an aqueous metal nitrate solution. More specifically, the metal salt solution may be a copper nitrate (Cu (NO ₃ ) ₂ ) aqueous solution, a zinc nitrate (Zn (NO ₃ ) ₂ ) aqueous solution, or an aluminum nitrate (Al (NO ₃ ) ₃ ) aqueous solution and chromium nitrate (Cr (NO ₃ ) ₃ ) aqueous solution, but the invention is not limited thereto.

Step 120 is a pH adjustment step, which is used to adjust the pH of one of the precursor solutions (hereinafter referred to as the pH value) to 7 to 9 to obtain a first precipitate. Step 120 may be implemented by adding a basic substance or an acidic substance. The basic substance may be, but is not limited to, an aqueous solution of sodium carbonate (Na ₂ CO ₃ ), and the acidic substance may be, but is not limited to, a nitric acid (HNO ₃ ) solution. For example, when the pH value of the current flood solution is less than 7, the pH adjustment step can be completed by adding an aqueous sodium carbonate solution to the precursor solution, and the rate of adding the aqueous sodium carbonate solution can be 10 mL / min to 100 mL / min. . The concentration of the sodium carbonate aqueous solution may be, but is not limited to, 0.1M to 0.3M. For another example, when the pH value of the current flood solution is greater than 9, the pH adjustment step may be completed by adding a nitric acid solution to the precursor solution, and the rate of adding the nitric acid solution may be 5 mL / min to 50 mL / min. The concentration of the nitric acid solution may be, but is not limited to, 0.1M to 0.3M. More specifically, for example, step 120 may be performed in a titration manner with two solution storage tanks (not shown), a plurality of lines (not shown), and a micro tube pump (not shown). One of the solutions The storage tank stores 0.1M to 0.3M sodium carbonate aqueous solution, and the other solution storage tank stores 0.1M to 0.3M nitric acid solution. When the pH value of the current drive solution is less than 7, the solution can be stored in the solution storage tank by using a micro peristaltic pump. The sodium carbonate aqueous solution is introduced into the precursor solution through a pipeline to adjust the pH value of the precursor solution to fall between 7 and 9. When the pH value of the current precursor solution is greater than 9, the solution can be stored by using a micro-peristaltic pump The nitric acid solution in the tank is introduced into the precursor solution through a pipeline to adjust the pH value of the precursor solution and make it fall between 7 and 9. By controlling the pH value of the precursor solution between 7 and 9, it is beneficial to reduce the particle size of copper in the catalyst of the final product, so that the total surface area of copper can be increased, and the catalytic activity of the catalyst can be improved.

Step 130 is a maturation step, in which the first precipitate is aged at 60 ° C. to 90 ° C. and the anaerobic silica is added to obtain a second precipitate. The time of the aging step may be from 0.5 hours to 2 hours. Specifically, after the pH value of the precursor solution is adjusted to 7 to 9, the temperature can be controlled within the range of 60 ° C to 90 ° C and the solution containing the first precipitate can be continuously stirred for 0.5 to 2 hours, and added Hydrophobic silicon dioxide allows the first precipitate to use the hydrophobic silica as a support to obtain a second precipitate. Hydrophobic silica can be obtained by baking the silica at a high temperature to remove the hydroxyl group (OH) on the surface, but the invention is not intended to be limited thereto.

Step 140 is a calcination step. The second precipitate is calcined to obtain a catalyst precursor. The catalyst precursor includes copper oxide, zinc oxide, aluminum oxide, hydrophobic silicon dioxide, and chromium trioxide. Specifically, in step 140, the second precipitate can be calcined under the condition that the temperature is raised from 1 ° C. to 10 ° C. to 300 ° C. to 500 ° C. per minute, and the foregoing calcination time can be 4 hours to 12 hours.

Step 150 is a reduction step for reducing the copper oxide in the catalyst precursor to obtain a catalyst for producing methanol. The catalyst for producing methanol includes copper, zinc oxide, alumina, and hydrophobic silicon dioxide. And chromium trioxide, where the weight ratio of copper to zinc oxide is 6/4 to 8/2, the weight ratio of copper to alumina is 6/1 to 8/1, and the weight ratio of copper to anaerobic silicon dioxide is 6/1 to 8/1, based on the total weight of copper, zinc oxide, aluminum oxide, hydrophobic silicon dioxide, and chromium trioxide, 100 parts by weight, and the content of chromium trioxide is 5 to 10 parts by weight. Please refer to the above for other details of the catalyst used to make methanol, which will not be repeated here. The reduction step can be from 1 ° C to 10 ° C per minute The catalyst precursor is processed in an operating environment of hydrogen at a temperature of 200 ° C to 400 ° C, and the aforementioned processing time may be 4 hours to 12 hours.

With reference to FIG. 2, it is a flowchart of steps of a method 200 for preparing a catalyst for producing methanol according to another embodiment of the present invention. As shown in FIG. 2, a method 200 for producing a catalyst for producing methanol It includes steps 210, 220, 230, 240, 240, 250, 260, 270, and 280.

Step 210 is a solution preparation step, step 220 is a pH adjustment step, and step 230 is a ripening step. For steps 210, 220, and 230, refer to steps 110, 120, and 120 in FIG. 1 130, no further details.

Step 240 is a cooling step for cooling the solution containing the second precipitate to room temperature. The foregoing room temperature varies according to different seasons and different experimental locations. For example, the foregoing room temperature may be, but is not limited to, 10 ° C to 40 ° C.

Step 250 is a purification step in which the second precipitate is filtered off and washed.

Step 260 is a drying step for drying the second precipitate.

Through steps 240 to 260, the second precipitate can be separated from the solution containing the second precipitate to facilitate the subsequent steps. In addition, steps 240 to 260 are merely examples, and how to separate the precipitate is well known in the art, and the present invention is not limited thereto.

Step 270 is a calcination step, and step 280 is a reduction step. For steps 270 and 280, reference may be made to steps 140 and 150 in FIG. 1, and details are not described herein again.

<Method for producing methanol>

The invention provides a method for producing methanol. Referring to FIG. 3, it is a flowchart of steps of a method 300 for producing methanol according to another embodiment of the present invention. The method 300 for producing methanol includes steps 310 and 320.

Step 310 is to provide a catalyst. The catalyst includes copper, zinc oxide, aluminum oxide, hydrophobic silicon dioxide, and chromium trioxide. The weight ratio of copper to zinc oxide is 6/4 to 8/2, and copper to oxide. The weight ratio of aluminum is 6/1 to 8/1, and the weight ratio of copper to hydrophobic silicon dioxide is 6/1 to 8/1. Based on copper, zinc oxide, aluminum oxide, hydrophobic silicon dioxide, and dioxide The total weight of chromium is 100 parts by weight, and the content of chromium trioxide is 5 to 10 parts by weight. For other details and preparation methods of the catalyst, please refer to the above, which will not be repeated here.

Step 320 is to perform a hydrogenation reaction. The catalyst is brought into contact with carbon dioxide and hydrogen, and the carbon dioxide is hydrogenated to produce methanol. Specifically, the hydrogenation reaction can be performed at 230 ° C to 300 ° C, the volume ratio of hydrogen to carbon dioxide in the hydrogenation reaction can be 3 to 5, the hydrogenation reaction can be performed in a fixed bed reactor, and the methanol yield of the hydrogenation reaction is 900 grams to 1,000 grams of methanol (900g MeOH / kg cat.h ~ 1000g MeOH / kg cat.h) can be obtained per hour of catalyst per kg. Accordingly, the method 300 for producing methanol of the present invention uses carbon dioxide as a reactant, which is advantageous for the reuse of carbon dioxide. In addition, the method 300 for producing methanol of the present invention has high carbon dioxide conversion. Rate, methanol selectivity, and methanol yield can increase the efficiency of carbon dioxide reuse.

In the following, specific examples 1 to 3 and comparative examples 1 to 2 will be further described to explain in detail the catalysts for producing methanol, a method for preparing the same, and a method for producing methanol using the same. Effect.

<Catalysts with different component ratios and their preparation> [Example 1]

First, first prepare a plurality of 0.1M metal salt solutions, wherein an aqueous copper nitrate solution is added 2.562 g of copper nitrate (Cu (NO ₃ ) ₂ ‧2.5H ₂ O) containing 2.5 crystal water to 110 ml of water, and Obtained, zinc nitrate aqueous solution was prepared by adding 1.365 g of zinc nitrate (Zn (NO ₃ ) ₂ ‧ 6H ₂ O) containing six crystal waters to 46 ml of water, and aluminum nitrate aqueous solution was prepared by adding 1.365 g of nine Aluminium nitrate (Al (NO ₃ ) ₃ ‧9H ₂ O) in crystal water was prepared by adding 37 ml of water, and the aqueous chromium nitrate solution was 0.519 g of chromium nitrate (Cr (NO ₃ ) ₃ ‧ 6H ₂ ) Prepared by adding 30 ml of water.

Next, as shown in step 110 in FIG. 1, the foregoing copper nitrate aqueous solution, zinc nitrate aqueous solution, aluminum nitrate aqueous solution, and chromium nitrate aqueous solution are mixed to obtain a precursor solution. Then, as shown in step 120 in FIG. 1, a 0.2 M The first carbonate was co-precipitated by adjusting the pH of the precursor solution to 8 with an aqueous sodium carbonate solution.

Subsequently, as shown in step 130 in FIG. 1, the solution containing the first precipitate is continuously stirred at 80 ° C. for the maturation step for at least 0.5 hours. 0.1 g of anaerobic silica was added to obtain a second precipitate. After standing to cool to room temperature, the second precipitate obtained in the foregoing step was filtered, washed with distilled water, and then dried at 110 ° C. for 12 hours. As shown in step 140 in FIG. 1, the second precipitate is calcined at a temperature of 5 ° C. to 350 ° C. per minute to obtain a catalyst precursor.

Then, as shown in step 150 in FIG. 1, the catalyst precursor is processed at a temperature of 5 ° C. to 300 ° C. per minute in an operating environment of hydrogen to reduce copper oxide to obtain a catalyst. At this time, the components and ratios of the aforementioned catalysts can be further detected, for example, by an inductively coupled plasma mass spectrometry (hereinafter referred to as ICP-MS), and a scanning electron microscope (Scanning electron microscopy) (SEM) to measure the particle size of the catalyst, but the invention is not limited to this.

In Example 1, the concentration of the metal salt solution and the amount of anaerobic silica added subsequently as a support were carried out based on the weight ratio of each component in the product. Each component should be completely precipitated in the co-precipitation step, and after the catalyst prepared in Example 1 was detected by ICP-MS, it was found that the weight ratio of each component contained was substantially the same as the reaction starting material. Specifically, in the catalyst of Example 1, the weight ratio of copper: zinc oxide: alumina: hydrophobic silica was 7: 3: 1: 1, and it was based on copper, zinc oxide, alumina, and anaerobic dioxide. The total weight of silicon and chromium trioxide is 100 parts by weight (that is, the total weight of the catalyst is 100 parts by weight), and the content of chromium trioxide is 5 parts by weight. In other words, in the catalyst of Example 1, three The content of chromium oxide is 5 weight percent (5 wt.%). The average particle diameter of the catalyst in Example 1 was 1.1 μm.

[Example 2]

Different from Example 1, in the catalyst of Example 2, the weight ratio of copper: zinc oxide: alumina: hydrophobic silica is 7: 3: 1: 1, and it is based on copper, zinc oxide, and alumina. The total weight of anaerobic silica and chromium trioxide is 100 parts by weight (that is, the total weight of the catalyst is 100 parts by weight), and the content of chromium trioxide is 8 parts by weight. In other words, in Example 2 In the catalyst, the content of chromium trioxide is 8 weight percent (8 wt.%). The remaining details of the embodiment 2 are substantially the same as those of the embodiment 1, and will not be repeated here. The average particle diameter of the catalyst in Example 2 was 0.82 μm.

[Example 3]

The difference from Example 1 is that in the catalyst of Example 3, the weight ratio of copper: zinc oxide: alumina: hydrophobic silica is 7: 3: 1: 1, and it is based on copper, zinc oxide, and alumina. The total weight of water-soluble silicon dioxide and chromium trioxide is 100 parts by weight (that is, the total weight of the catalyst is 100 parts by weight), and the content of chromium trioxide is 10 parts by weight. In other words, in Example 3, In the catalyst, the content of chromium trioxide is 10 weight percent (10 wt.%). The remaining details of the third embodiment are substantially the same as those of the first embodiment, and details are not described herein again. The average particle diameter of the catalyst in Example 3 was 1.2 μm.

[Comparative Example 1]

In Comparative Example 1, the components of the catalyst include copper, zinc oxide, and aluminum oxide, and the weight ratio thereof is 3: 7: 1. Comparative Example 1 The section is substantially the same as that of Embodiment 1, and is not repeated here. In addition, the average particle diameter of the catalyst of Comparative Example 1 was 0.93 μm.

[Comparative Example 2]

The difference from Example 1 is that in the catalyst of Comparative Example 2, the weight ratio of copper: zinc oxide: alumina: hydrophobic silica is 7: 3: 1: 1, and it is based on copper, zinc oxide, and oxide. The total weight of aluminum, anaerobic silicon dioxide, and chromium trioxide is 100 parts by weight (ie, the total weight of the catalyst is 100 parts by weight), and the content of chromium trioxide is 15 parts by weight. In other words, the comparative examples In the catalyst of 2, the content of chromium trioxide is 15% by weight (15wt.%). The remaining details of Comparative Example 2 are substantially the same as those of Example 1, and are not repeated here. The average particle diameter of the catalyst in Comparative Example 2 was 1.3 μm.

[Activity test]

The following tests were performed using the catalysts of Examples 1 to 3 and Comparative Examples 1 to 2 to make methanol to evaluate the catalyst's activity, and the test results are shown in Table 1. In short, the test method is to evaluate the catalyst using carbon dioxide and hydrogen as the gas source from a fixed-bed reactor to reduce the carbon dioxide to produce methanol. The reaction conditions can be roughly as follows: the amount of catalyst is 2 grams of catalyst, and the pressure It is 50 atm, the gas flow rate is 300 milliliters (300 mL / min) per minute, and the volume ratio of hydrogen gas to carbon dioxide is 3. In addition, the fixed-bed reactor is heated to a preset reaction temperature before the reaction, and the preset reaction temperature is 250 ° C.

In Table 1, the calculation method of the CO ₂ conversion rate is as follows: [(CO ₂ feed weight per hour-CO ₂ reaction outlet weight per hour) / CO ₂ feed weight per hour] x 100%.

In Table 1, the calculation method of methanol selectivity is as follows: (methanol concentration at the reactor outlet / concentration of all products at the reactor outlet) × 100%.

In Table 1, the calculation method of carbon monoxide selectivity is as follows: (carbon monoxide concentration at the reactor outlet / concentration of all products at the reactor outlet) × 100%.

In Table 1, the calculation method of methanol yield is as follows: methanol weight / catalyst weight within one hour from the reactor outlet.

It can be known from Examples 1 to 3 and Comparative Example 1 that the catalyst provided by the present invention contains both chromium trioxide and anaerobic silicon dioxide, which is beneficial to the improvement of carbon dioxide conversion rate, methanol selectivity and methanol production. rate. Furthermore, it can be seen from Comparative Example 2 that when the amount of chromium trioxide added is too high, the carbon dioxide conversion rate, methanol selectivity, and methanol yield will be reduced.

In summary, the present invention provides a catalyst that can be used to produce methanol and a method for preparing the same. Through the combination of the foregoing components and their proportions, the catalytic activity of the catalyst can be improved, which is beneficial to the improvement of carbon dioxide conversion rate and methanol selectivity. And the methanol yield can effectively achieve the purpose of carbon dioxide recovery and reuse.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Any person skilled in the art can make various modifications and retouches without departing from the spirit and scope of the present invention. Therefore, the protection of the present invention The scope shall be determined by the scope of the attached patent application.

Claims (14)

A catalyst for manufacturing methanol, comprising: copper, zinc oxide, aluminum oxide, hydrophobic silicon dioxide, and chromium trioxide, wherein: the weight ratio of the copper to the zinc oxide is 6/4 to 8/2; The weight ratio of the copper to the alumina is 6/1 to 8/1; the weight ratio of the copper to the hydrophobic silicon dioxide is 6/1 to 8/1; and based on the copper, the zinc oxide, the oxide The total weight of aluminum, the hydrophobic silicon dioxide, and the chromium trioxide is 100 parts by weight, and the content of the chromium trioxide is 5 to 10 parts by weight. The catalyst for manufacturing methanol according to item 1 of the scope of the patent application, wherein the catalyst for manufacturing methanol is granular and has an average particle diameter of 100 nm to 10 μm. A preparation method for a catalyst for manufacturing methanol, comprising: performing a solution preparation step for mixing a plurality of metal salt solutions to obtain a precursor solution, the metal salt solutions respectively including copper ions, zinc ions, and aluminum Ions and chromium ions; performing a pH adjustment step for adjusting a pH of a precursor solution between 7 and 9 to obtain a first precipitate; performing a curing step for making the first precipitate A second precipitate is obtained by aging at 60 ° C to 90 ° C and adding anaerobic silica. A calcination step is performed to calcine the second precipitate to obtain a catalyst precursor. The catalyst precursor includes oxidation. Copper, zinc oxide, aluminum oxide, the anaerobic silicon dioxide and chromium trioxide; and performing a reduction step, treating the catalyst precursor in an operating environment of hydrogen at 200 ° C to 400 ° C to make the catalyst The copper oxide in the precursor is reduced to obtain the catalyst for manufacturing methanol. The catalyst for manufacturing methanol includes copper, the zinc oxide, the alumina, the hydrophobic silicon dioxide, and the chromium trioxide. Of which: the copper The weight ratio of the zinc oxide is 6/4 to 8/2; the weight ratio of the copper to the alumina is 6/1 to 8/1; the weight ratio of the copper to the anaerobic silica is 6/1 to 8/1; and based on the total weight of the copper, the zinc oxide, the alumina, the hydrophobic silicon dioxide, and the chromium trioxide is 100 parts by weight, and the content of the chromium trioxide is 5 parts by weight to 10 Parts by weight. The method for preparing a catalyst for producing methanol as described in item 3 of the scope of the patent application, wherein the metal salt solutions are metal nitrate aqueous solutions. The method for preparing a catalyst for producing methanol as described in item 3 of the scope of patent application, wherein when the pH value of the precursor solution is less than 7, the pH value adjustment step is by adding an aqueous solution of sodium carbonate It is completed into the precursor solution, and the sodium carbonate aqueous solution is added at a rate of 10 mL / min to 100 mL / min. The method for preparing a catalyst for manufacturing methanol as described in item 3 of the scope of patent application, wherein when the pH value of the precursor solution is greater than 9, the pH adjustment step is performed by adding a nitric acid solution to The precursor solution is completed, and the rate of adding the nitric acid solution is 5 mL / min to 50 mL / min. The method for preparing a catalyst for producing methanol as described in the third item of the patent application, wherein the time of the ripening step is 0.5 hour to 2 hours. The method for preparing a catalyst for manufacturing methanol as described in item 3 of the scope of patent application, wherein the reduction step is performed in a hydrogen operating environment at a temperature of 1 ° C to 10 ° C to 200 ° C to 400 ° C per minute. The catalyst precursor. According to the method for preparing a catalyst for producing methanol described in item 3 of the scope of patent application, after the aging step and before the calcining step, the method further includes: performing a cooling step to cool the second precipitate to room temperature. Performing a purification step to filter out and wash the second precipitate; and performing a drying step to dry the second precipitate. A method for producing methanol, comprising: providing a catalyst, the catalyst comprising copper, zinc oxide, aluminum oxide, hydrophobic silicon dioxide, and chromium trioxide, wherein a weight ratio of the copper to the zinc oxide is 6 / 4 to 8/2; the weight ratio of the copper to the alumina is 6/1 to 8/1; the weight ratio of the copper to the hydrophobic silicon dioxide is 6/1 to 8/1; and based on the copper, The total weight of the zinc oxide, the alumina, the anaerobic silica, and the chromium trioxide is 100 parts by weight, and the content of the chromium trioxide is 5 to 10 parts by weight; and a hydrogenation reaction is performed, The catalyst is brought into contact with carbon dioxide and hydrogen, and the carbon dioxide is hydrogenated to produce methanol. The method for producing methanol according to item 10 of the scope of patent application, wherein the hydrogenation reaction is performed at 230 ° C to 300 ° C. The method for manufacturing methanol as described in item 10 of the scope of patent application, wherein the volume ratio of the hydrogen to the carbon dioxide in the hydrogenation reaction is 3 to 5. The method for producing methanol according to item 10 of the application, wherein the hydrogenation reaction is performed in a fixed bed reactor. The method for producing methanol according to item 10 of the scope of the patent application, wherein the methanol yield of the hydrogenation reaction is 900 g to 1000 g of methanol per kg of catalyst per hour.