Catalyst and method for producing methanol using catalyst

Abstract

The present invention suppresses damage and wear of a catalyst. A catalyst according to one embodiment of the present disclosure is used in a reaction in which a source material includes a carbon oxide. The catalyst includes a copper oxide, zinc oxide, and an aluminum oxide, and is pellets having a cylinder-like shape. The BET specific surface area of the catalyst as measured by a nitrogen adsorption method is 90-107 m2 / g, the total pore volume is 0.25-0.40 cm3 / g, and the average pore diameter is in the range of 11-15 nm. The pellets each have a body section and a protruding section, the body section has a cylindrical shape having a circular first surface, the protruding section protrudes from the first surface along the direction of extension of the center axis of the body section, and in a cross-section of the pellet including the center axis, (i) a line segment that connects the intersection of an imaginary line and an upper surface of the pellet, said imaginary line resulting from extending the center axis, and an upper end corner section of the body section, and (ii) said imaginary line form an angle of less than 90°.

Description

Catalyst, and method for producing methanol using the catalyst

[0001] This disclosure relates to a catalyst used in a reaction containing carbon oxides as a raw material, and to a method for producing methanol using the catalyst.

[0002] One example of a reaction that uses carbon oxides as raw materials is the synthesis of methanol. Methanol is an industrially important basic raw material. Therefore, there has been a demand for increased efficiency in the manufacturing process for reasons such as energy conservation and economic efficiency. A typical methanol synthesis process uses carbon oxides (carbon oxides) derived from synthesis gas, which is the carbon source, and hydrogen as the main raw materials. In this synthesis process, it is known that a catalyst consisting of copper and zinc oxide (Cu-ZnO catalyst) is used.

[0003] As a catalyst for promoting methanol synthesis, for example, Patent Document 1 discloses a catalyst in which the molar ratio of zinc to copper is 0.5 to 0.7.

[0004] International Publication No. 2013 / 183577 brochure

[0005] In such catalysts, it is desirable to reduce catalyst damage, breakage, and / or wear.

[0006] A catalyst according to one aspect of this disclosure is a catalyst used in a reaction involving carbon oxides as raw materials, comprising copper oxide, zinc oxide, and aluminum oxide, and having a cylindrical pellet shape, with a BET specific surface area of ​​90 to 107 m² as measured by nitrogen adsorption. ２ The value is / g, and the total pore volume is 0.25 to 0.40 cm³. ３ The density is / g, and the average pore diameter is in the range of 11-15 nm.

[0007] A method for producing methanol according to one aspect of this disclosure includes the step of contacting a raw material gas containing carbon oxides and hydrogen with the catalyst to obtain methanol.

[0008] According to one aspect of this disclosure, damage, breakage, and / or wear of the catalyst can be reduced.

[0009] This is a perspective view of an exemplary catalyst of the present disclosure. This is a cross-sectional view taken along the line II-II in Figure 1. This is a cross-sectional view of a catalyst of another embodiment. This is a cross-sectional view of a catalyst of another embodiment. This is a log differential pore volume distribution graph of the examples and comparative examples.

[0010] [Embodiment 1] The catalyst relating to this disclosure will be described in detail below. Hereinafter, the catalyst within the scope of this disclosure will be referred to as the catalyst. Unless otherwise specified in this specification, "A to B" representing a numerical range means "A or greater, B or less".

[0011] This catalyst is used in reactions that involve carbon oxides as raw materials. This catalyst is made from copper oxide (CuO), zinc oxide (ZnO), and aluminum oxide (Al ２ O ３ ) includes.

[0012] In this catalyst, the copper oxide content may be 50 to 80% by mass, preferably 55 to 80% by mass, and more preferably 60 to 79% by mass. By setting the copper oxide content to 50 to 80% by mass, the methanol yield can be improved.

[0013] Furthermore, in this catalyst, the mass content ratio of zinc oxide to copper oxide may be 0.10 to 0.52, preferably 0.15 to 0.50, and more preferably 0.18 to 0.45. The mass content ratio of zinc oxide to copper oxide can be determined by dividing the mass of zinc oxide contained in this catalyst by the mass of copper oxide. If the content ratio is too low, aggregation of Cu crystals is likely to occur, and the activity may decrease rapidly. If the content ratio is too high, the amount of Cu, which is the active component, will decrease, and the activity may decrease. By setting the mass content ratio of zinc oxide to copper oxide to 0.10 to 0.52, a catalyst with high catalytic activity can be realized.

[0014] This catalyst may further contain doping elements. The doping elements contained in this catalyst may be rare earth elements, alkali metals, alkaline earth metals, transition metals, or metal oxides. The elements used as doping elements may be samarium, gallium, tantalum, palladium, zirconium, magnesium, silicon, boron, cerium, lanthanum, neodymium, europium, or erbium. For example, the doping elements contained in this catalyst may be rare earth elements. The content of rare earth elements in this catalyst may be 100 wt ppm or more, preferably 1000 wt ppm or more, and more preferably 5000 wt ppm or more. The rare earth element contained in this catalyst may also be samarium.

[0015] Furthermore, in this catalyst, the elemental ratio (molar ratio) of the doped element to copper may be less than 0.01, preferably 0.005 or less, and more preferably 0.003 to 0.005. Also, in this catalyst, the elemental ratio (molar ratio) of the doped element to zinc may be less than 0.022. Furthermore, in this catalyst, the elemental ratio (molar ratio) of the doped element to aluminum may be less than 0.25, preferably less than 0.1, and more preferably 0.015 to 0.090.

[0016] This catalyst is a cylindrical pellet with a BET specific surface area of ​​90 to 107 m² as measured by nitrogen adsorption. ２ The value is / g, and the total pore volume is 0.25 to 0.40 cm³. ３ The density is / g, and the average pore diameter is in the range of 11-15 nm.

[0017] Because this catalyst possesses the above-mentioned characteristics, it is possible to reduce damage, breakage, and / or wear of the catalyst.

[0018] Reactions that use carbon oxides as raw materials include, for example, carbon monoxide (CO) and / or carbon dioxide (CO2). ２ The catalytic reaction may include a raw material. More specifically, it may be a methanol synthesis reaction in which a raw material containing a carbon oxide and hydrogen is brought into contact with a catalyst to obtain methanol.

[0019] In this disclosure, the BET specific surface area (m²) ２ / g), total pore volume (cm ３ / g) and average pore diameter (nm) are obtained based on measurement using a nitrogen adsorption method. Specifically, the specific surface area and pore size distribution of the catalyst can be measured using an automatic specific surface area / pore size distribution measuring apparatus "BELSORP-mini X" (manufactured by MicrotracBEL Corp.). The surface area measurement in said measurement is performed using the BET method. A sample that has been subjected to constant temperature vacuum drying at 120°C for 2 hours is used as the catalyst subjected to the measurement. Nitrogen gas is used as the treatment gas, and liquid nitrogen temperature is used as the treatment temperature.

[0020] BET specific surface area (m ２ / g) is a value obtained by analysis in the relative pressure range of p / p0 = 0.1000 to 0.2500. Total pore volume (cm ３ / g) is a value obtained from the nitrogen adsorption capacity up to a relative pressure of p / p0 = 0.9900. Pore diameter (nm) is a pore diameter calculated from the values of BET specific surface area and total pore volume, assuming cylindrical pores.

[0021] The constituent components of the present catalyst are not limited to only the above components, and may contain other elements. For example, the present catalyst may contain 0.1% by mass or more of graphite. Said graphite can function as a lubricant.

[0022] Further, when the pore distribution of the present catalyst is measured by mercury porosimetry and the pore distribution is represented by a Log differential pore volume distribution graph, the peak top of the graph may be located in the range of 0.0054 to 0.0080 µm, more preferably 0.0055 to 0.0075 µm. The pore distribution in the present disclosure can be measured using mercury porosimetry. Specifically, the pore distribution can be measured using a mercury porosimeter "Autopore V9620" manufactured by Micromeritics. Further, the measurement target range may be a pore radius range from 0.0018 µm to 100 µm. A sample that has been subjected to constant temperature drying at 120°C for 4 hours is used as the catalyst subjected to the measurement.

[0023] Furthermore, in the present catalyst, the ratio of the total volume of pores having a pore radius of 0.056 to 100 µm to the total pore volume measured by mercury porosimetry may be 3% or less, more preferably 1.5% or less. The pore volume of pores having a predetermined pore radius can be measured using a mercury porosimeter "Autopore V9620" manufactured by Micromeritics. The total pore volume may be the total pore volume of pores having a pore radius of 0.0018 µm to 100 µm.

[0024] Next, the shape of the catalyst will be described with reference to FIGS. 1 to 3. FIG. 1 is a perspective view of a catalyst 100 as an example of the present catalyst. FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1. The catalyst 100 is a pellet having a cylindrical shape. The diameter D of the present catalyst may be 2 mm or more and 6 mm or less, more preferably 3 mm or more and 5 mm or less. Further, the height H of the present catalyst may be 2 mm or more and 6 mm or less, more preferably 3 mm or more and 5 mm or less. In the present catalyst, the aspect ratio calculated as diameter / height may be 0.3 or more and 3.0 or less, more preferably 0.5 or more and 2.0 or less.

[0025] Specifically, the catalyst 100 includes a main body portion 2 and a protruding portion 3. The main body portion 2 may have a cylindrical shape having a circular first surface 2A. The protruding portion 3 protrudes from the first surface 2A along the extending direction of the central axis of the main body portion 2. In a cross-section of the catalyst 100 including the central axis of the main body portion 2 as shown in FIG. 2, an angle θ formed by (i) a line segment L2 connecting an intersection point P1 between an imaginary line L1 extending the central axis and the upper surface of the catalyst 100 and an upper corner P2 of the main body portion 2, and (ii) the imaginary line L1 is smaller than 90°. For example, the angle θ may be in the range of 50° or more and 99° or less, preferably 60° or more and 95° or less, and more preferably 70° or more and 90° or less.

[0026] For example, in the catalyst 100 shown in FIGS. 1 and 2, the main body 2 has a cylindrical shape with a circular first surface 2A. The protruding portion 3 is located on the first surface 2A and protrudes from the first surface 2A along the extending direction of the central axis of the main body 2. In a cross-section of the catalyst 100 that includes the central axis of the main body 2, the protruding portion 3 has a trapezoidal shape. In other words, the protruding portion 3 has a surface parallel to the first surface 2A and an inclined surface connecting the parallel surface and the first surface 2A. When the catalyst 100 is viewed from above, the outer edge of the protruding portion 3 is located inward of the outer edge of the main body 2.

[0027] In the present specification, the shape as shown in FIGS. 1 and 2, in which the protruding portion 3 has a flat surface and an angle formed by the flat surface and an inclined surface at an edge of the flat surface, is referred to as a corner flat shape.

[0028] The diameter D of the main body 2 of the present catalyst may be 2 mm or more and 6 mm or less, for example, 3 mm or more and 5 mm or less. Further, the height H of the present catalyst may be 2 mm or more and 6 mm or less, for example, 3 mm or more and 5 mm or less. In the present catalyst, the aspect ratio calculated as diameter / height may be 0.3 or more and 3.0 or less, for example, 0.5 or more and 2.0 or less.

[0029] FIG. 3 is a cross-sectional view of a catalyst 100A showing another embodiment of the present catalyst. The catalyst 100A is a pellet having a cylindrical-like shape. The catalyst 100A includes a main body 2 and a protruding portion 3. The main body 2 has a cylindrical shape with a circular first surface 2A. The protruding portion 3 protrudes from the first surface 2A along the extending direction of the central axis of the main body 2. In a cross-section of the catalyst 100A that includes the central axis of the main body 2 as shown in FIG. 3, an angle θ formed by (i) a line segment L2 connecting an intersection point P1 between an imaginary line L1 extending the central axis and the upper surface of the catalyst 100, and an upper end corner P2 of the main body 2, and (ii) the imaginary line L1 is smaller than 90°. For example, the angle θ may be in a range of 50° or more and 99° or less, preferably 60° or more and 95° or less, more preferably 70° or more and 90° or less.

[0030] Furthermore, in the catalyst 100A shown in Figure 3, the main body 2 is cylindrical in shape with a circular first surface 2A. The projection 3 is located on the first surface 2A and protrudes from the first surface 2A along the extension direction of the central axis of the main body 2. In a cross-section of the catalyst 100 including the central axis of the main body 2, the outer edge of the projection 3 has an arc. In other words, the projection 3 has a dome shape. When the catalyst 100 is viewed from above, the outer edge of the projection 3 is located overlapping with the outer edge of the main body 2. Such a catalyst 100A is also within the scope of this disclosure.

[0031] <Method for Manufacturing the Catalyst> Next, a method for manufacturing the catalyst will be described. The method for manufacturing the catalyst according to this disclosure is not particularly limited and may be a known method. For example, it may be manufactured by precipitating an aqueous solution of an acidic salt of each metal element constituting the catalyst with a precipitating agent, followed by drying and calcination (see Japanese Patent Application Publication No. 2010-194421).

[0032] More specifically, the method for producing the catalyst may include the following steps (1) to (5): (1) Coprecipitation step: A step in which a precipitating agent is added to a solution or suspension of an acidic salt of each metal element constituting the catalyst or a metal compound, and the complex salt (mainly carbonate) is precipitated. In the coprecipitation step, maturation for a predetermined time may be performed in order to obtain a highly active catalyst precursor. (2) Washing step: A step in which the complex salt is filtered and washed. (3) Drying step: A step in which the cake obtained by filtration is dried. (4) Calcination step: A step in which the complex salt is calcined and converted into an oxide. (5) Molding step: A step in which the powder oxide obtained after the calcination step is compressed into tablets.

[0033] In the coprecipitation step described in (1) above, an acidic solution and a precipitating agent may be added simultaneously to a solution or suspension of one or more acidic salts or metal compounds to precipitate the complex salt. The solution or suspension of the acidic salt or metal compound and the acidic solution may contain copper, zinc, aluminum, and doped elements. The acidic salt of each metal element may be one or more selected from the group consisting of nitrates, sulfates, acetates, formates, oxalates, phosphates, aluminates, and halides, and is preferably a nitrate or sulfate.

[0034] The metal compound of each metal element may be one or more selected from the group consisting of oxides and carbonates, preferably an oxide, and more preferably an alumina sol. The precipitating agent may be one or more selected from the group consisting of sodium carbonate, sodium bicarbonate, and sodium hydroxide, and is preferably sodium carbonate. In the above (1) coprecipitation step, the solvent may be one or more selected from the group consisting of water, methanol, ethanol, isopropanol, ethyl acetate, tetrahydrofuran, and dichloromethane, preferably water and ethanol, and more preferably water.

[0035] In the molding process (5), the catalyst may be compressed into tablets by applying a load of 2.5 kN to 5.5 kN in order to form pellets with a diameter of 5 mm.

[0036] <Method for Producing Methanol> The following describes a method for producing methanol using this catalyst. A methanol production method according to one embodiment of this disclosure includes the step of contacting a raw material gas containing carbon oxides and hydrogen with the catalyst according to this disclosure to obtain methanol. As described above, this catalyst has the characteristics described above and can improve the methanol production efficiency.

[0037] The reaction conditions in this process may be, for example, a reaction temperature of 150 to 300°C and a reaction pressure (gauge pressure) of 0.5 to 10 MPaG.

[0038] An example of a reactor used in this process is a fixed-bed reactor. Alternatively, an internal condensation reactor may be used, which has a condensation surface and allows the methanol synthesis reaction to proceed by condensing the high-boiling components, including methanol and water, produced within the reactor.

[0039] <Raw Material Gas> The raw material gas contains carbon oxides and hydrogen. In the methanol production method according to this embodiment, the raw material gas may contain carbon dioxide and hydrogen. Alternatively, carbon monoxide and carbon dioxide may be included as carbon oxides. When both carbon monoxide and carbon dioxide are used as carbon oxides, they may be included in any ratio.

[0040] The molar ratio of hydrogen to carbon oxides in the raw material gas is not particularly limited. The raw material gas may contain components other than carbon oxides and hydrogen, as long as they do not affect methanol production. Examples of such components include third components such as nitrogen and impurities such as by-products associated with carbon oxide production. The raw material gas may also contain water.

[0041] Carbon oxides, hydrogen, and water vapor may be introduced into the reactor separately, or they may be introduced into the reactor as a mixed gas in any combination.

[0042] [Use of Catalyst] When this catalyst is used in reactions that include carbon oxides as raw materials, such as methanol production methods, the catalyst may be used after being reduced with a reducing gas (hydrogen, a mixture of hydrogen and nitrogen, a gas containing carbon monoxide, etc.). By contacting this catalyst containing copper oxide with a reducing gas, CuO can be reduced to Cu, which has catalytic activity.

[0043] Furthermore, after the reaction using this catalyst is complete, the catalyst may be subjected to an inert treatment by oxidation with an oxidizing gas such as oxygen. By contacting the used catalyst with an oxidizing gas, the Cu can be oxidized back to CuO, which has low reaction activity.

[0044] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. In the following, the examples are catalysts within the scope of the present disclosure (the present catalyst), and the comparative examples are catalysts outside the scope of the present disclosure.

[0045] <Measurement> (Measurement of BET specific surface area, total pore volume, and average pore diameter) BET specific surface area (m²) of the examples and comparative examples ２ ( / g), total pore volume (cm³) ３The specific surface area ( / g) and average pore diameter (nm) were obtained from measurements using the nitrogen adsorption method. Specifically, the specific surface area and pore diameter distribution of the catalyst were measured using the automatic specific surface area / pore diameter distribution analyzer "BELSORP-mini X" (Microtrac-Bel). Surface area measurement in this measurement was performed using the BET method. The catalyst used for measurement was a sample that had been vacuum-dried at 120°C for 2 hours. Nitrogen gas was used as the processing gas, and the processing temperature was the liquid nitrogen temperature.

[0046] BET specific surface area (m ２ The total pore volume (cm³ / g) was determined by analysis over the relative pressure range p / p0 = 0.1000 to 0.2500. ３ The nitrogen adsorption capacity ( / g) was determined from the nitrogen adsorption capacity up to a relative pressure p / p0 = 0.9900. The pore diameter (nm) was calculated from the BET specific surface area and total pore volume, assuming cylindrical pores.

[0047] (Measurement of pore distribution and pore volume) The pore distribution and pore volume of the examples and comparative examples were measured using the mercury intrusion method. Specifically, the pore distribution and pore volume were measured using the Micrometrics Autopore V9620 mercury porosimeter. The measurement range was set to a pore radius of 0.0018 μm to 100 μm. The ratio of the total volume of pores with a pore radius of 0.056 to 100 μm was calculated by taking the total volume of pores in the range of 0.0018 μm to 100 μm as the total pore volume. Specifically, this ratio was calculated as the ratio of the cumulative amount of mercury intruded into pores with a pore radius of 0.056 to 100 μm to the cumulative amount of mercury intruded into pores with a pore radius of 0.0018 μm to 100 μm. The catalyst used for the measurement was a sample that had been dried at a constant temperature of 120°C for 4 hours.

[0048] (Pellet Preparation) For pellet preparation, a manual, simple tablet molding machine "HANDTAB-100R" manufactured by Ichihashi Seiki Co., Ltd. was used. Tablets were formed using a mortar and pestle in this machine. The tablet-forming surface of the pestle was either a corner-shaped plane or a flat plane. For the corner-shaped plane type, the dimensions shown in Figure 1 were such that the lower base diameter d1 of the frustum was 4.800 mm, the upper base diameter d2 was 4.108 mm, and the height h was 0.200 mm. Figure 4 is a perspective view of the catalyst 200 when a flat-type pestle was used. The catalyst 200 has a cylindrical shape with flat top and bottom surfaces. The angle θ was derived based on the dimensions of the mortar and pestle. The angle θ may also be measured using an X-ray CT scanner.

[0049] (Pellet size measurement) For cylindrical pellets, the maximum height H and maximum diameter D of 30 pellets were measured using calipers, and the average value was calculated.

[0050] The shape of the cylindrical pellets described herein is determined by the shape of the dies and punches used for tableting. The shape can also be determined by an X-ray CT scanner. From the determined shape, the maximum angle θ formed by the line segment connecting a point on the outermost circumference of the cylinder to the upper or lower end on the centerline was calculated.

[0051] (Measurement of Crushing Rate) The crushing rate of the pellets was measured as follows. First, five pellets were placed on a stainless steel wire mesh with a mesh opening of 1.7 mm and a wire diameter of 0.80 mm, and vibrated for 30 minutes at an amplitude of 1.5 mm using an electromagnetic vibration type sieve divider "MA-200" manufactured by Ito Seisakusho Co., Ltd. After vibration, the crushing rate of the pellets was derived by dividing the difference between the weight of the pellets that did not pass through a sieve with a mesh opening of 3.35 mm and the weight of the pellets before vibration by the weight of the pellets before vibration. This crushing rate of the pellets is an evaluation index for the ease with which fine powder and granules are generated due to damage and abrasion caused by vibration.

[0052] <Preparation and Measurement Results of Catalysts> (Example 1 - Catalyst E1) The component content of catalyst E1 was 61.7% by mass of copper oxide, 24.3% by mass of zinc oxide, 9.8% by mass of aluminum oxide, 1.3% by mass of samarium oxide, and 2.9% by mass of graphite.

[0053] The specific surface area of ​​the catalyst E1 sample before tableting, as determined by nitrogen gas adsorption, was 127.58 m². ２ The total pore volume is 0.63 cm³ / g. ２ The average pore diameter was 19.63 nm. Using a corner-angled flat pestle with a diameter D = 5 mm, a cylindrical catalyst E1 with a height H = 4 mm was fabricated from the sample under a load of 5 kN. The average maximum height H was 4.04 mm, and the average maximum diameter D was 5.03 mm. The maximum angle θ was 85.426°. The BET specific surface area of ​​the obtained catalyst E1 was 94.89 m². ２ The total pore volume is 0.27 cm³ / g. ２ The average pore diameter was 11.30 nm per g. The peak in the log differential pore volume distribution graph measured by the mercury intrusion method was 0.0056 μm, and pores with pore radii between 0.056 and 100 μm accounted for 1.3% of the total pore volume. The pellet crushing rate due to vibration was 0.33 mass%.

[0054] (Example 2 - Catalyst E2) Catalyst E2 was prepared under the same conditions as in Example 1, except that the load during tableting was changed to 4 kN. The average value of the maximum height H was 3.96 mm, and the average value of the maximum diameter D was 5.03 mm. The maximum value of the angle θ was 85.426°. The BET specific surface area of ​​the obtained catalyst E2 was 98.14 m². ２ / g, total pore volume is 0.30 cm³ ２ The average pore diameter was 12.10 nm per g. The peak in the log differential pore volume distribution graph measured by the mercury intrusion method was 0.0059 μm, and pores with pore radii of 0.056 to 100 μm accounted for 0.8% of the total pore volume. The pellet crushing rate due to vibration was 0.49 mass%.

[0055] (Example 3 - Catalyst E3) A cylindrical catalyst E3 was fabricated under the same conditions as in Example 1, except that the load during tableting was changed to 3 kN. The average value of the maximum height H was 4.02 mm, and the average value of the maximum diameter D was 5.04 mm. The maximum value of the angle θ was 85.426°. The BET specific surface area of ​​the obtained catalyst E3 was 106.45 m². ２ The total pore volume is 0.35 cm³ / g. ２The average pore diameter was 12.98 nm per g. The peak in the log differential pore volume distribution graph measured by the mercury intrusion method was 0.0072 μm, and pores with pore radii of 0.056 to 100 μm accounted for 2.6% of the total pore volume. The pellet crushing rate due to vibration was 0.76 mass%.

[0056] (Example 4 - Catalyst E4) A cylindrical catalyst E4 was prepared under the same conditions as in Example 2, except that a flat pestle with a diameter of 5 mm was used. The average value of the maximum height H was 4.04 mm, and the average value of the maximum diameter D was 5.03 mm. The maximum value of the angle θ was 90.000°. The BET specific surface area of ​​the obtained catalyst C4 was 96.35 m². ２ / g, total pore volume is 0.30 cm³ ２ The average pore diameter was 12.41 nm per g. The peak in the log differential pore volume distribution graph measured by the mercury intrusion method was 0.0059 μm, and pores with pore radii of 0.056 to 100 μm accounted for 1.2% of the total pore volume. The pellet crushing rate due to vibration was 1.07% by mass.

[0057] (Comparative Example 1 - Catalyst C1) A cylindrical catalyst C1 was prepared under the same conditions as in Example 1, except that the load during tableting was changed to 1 kN. The average value of the maximum height H was 4.12 mm, and the average value of the maximum diameter D was 5.06 mm. The maximum value of the angle θ was 85.426°. The BET specific surface area of ​​the obtained catalyst C1 was 113.47 m². ２ The total pore volume is 0.46 cm³ / g. ２ The average pore diameter was 16.29 nm per g. The peak in the log differential pore volume distribution graph measured by the mercury intrusion method was 0.0090 μm, and pores with pore radii of 0.056 to 100 μm accounted for 23.7% of the total pore volume. The pellet crushing rate due to vibration was 4.66 mass%.

[0058] (Comparative Example 2 - Catalyst C2) A cylindrical catalyst C2 was prepared under the same conditions as in Example 1, except that the load during tableting was changed to 2 kN. The average value of the maximum height H was 4.10 mm, and the average value of the maximum diameter D was 5.04 mm. The maximum value of the angle θ was 85.426°. The BET specific surface area of ​​the obtained catalyst C2 was 108.37 m². ２ The total pore volume is 0.41 cm³ / g. ２ The average pore diameter was 15.27 nm per g. The peak in the log differential pore volume distribution graph measured by the mercury intrusion method was 0.0081 μm, and pores with pore radii of 0.056 to 100 μm accounted for 8.1% of the total pore volume. The pellet crushing rate due to vibration was 1.24 mass%.

[0059] (Comparative Example 3 - Catalyst C3) A cylindrical catalyst C3 was prepared under the same conditions as in Example 1, except that the load during tableting was changed to 6 kN. The average value of the maximum height H was 4.01 mm, and the average value of the maximum diameter D was 5.05 mm. The maximum value of the angle θ was 85.426°. The BET specific surface area of ​​the obtained catalyst C3 was 89.98 m². ２ The total pore volume is 0.24 cm³ / g. ２ The average pore diameter was 10.70 nm. In the log differential pore volume distribution graph measured by the mercury intrusion method, the peak was 0.0053 μm, and pores with pore radii of 0.056 to 100 μm accounted for 1.8% of the total pore volume. The pellet fragmentation rate due to vibration was 20.5% by mass. The fragmentation rate at this time was mainly due to the occurrence of internal cracks.

[0060] (Comparative Example 4 - Catalyst C4) A cylindrical catalyst C4 was prepared under the same conditions as in Example 4, except that a flat pestle with a diameter of 5 mm was used. The average value of the maximum height H was 4.04 mm, and the average value of the maximum diameter D was 5.03 mm. The maximum value of the angle θ was 90.000°. The BET specific surface area of ​​the obtained catalyst C5 was 108.33 m². ２ The total pore volume is 0.42 cm³ / g. ２The average pore diameter was 15.33 nm per g. The peak in the log differential pore volume distribution graph measured by the mercury intrusion method was 0.0081 μm, and pores with pore radii of 0.056 to 100 μm accounted for 7.8% of the total pore volume. The pellet crushing rate due to vibration was 1.36 mass%.

[0061] Table 1 below summarizes the tableting conditions, pellet analysis values, and weight loss rates for the above-described examples and comparative examples. In Table 1, "Pore Volume Percentage (%)" refers to the total pore volume (m³). ２ The total volume of pores with a pore radius of 0.056 to 100 μm (m³) relative to / g ２ This shows the percentage (%) of the amount per g.

[0062]

[0063] Furthermore, Figure 5 shows the pore distribution measured by the mercury intrusion method for the examples and comparative examples, and the pore distribution is represented by a log differential pore volume distribution graph.

[0064] From the results of the above examples and comparative examples, it was determined that the pellets contain copper oxide, zinc oxide, and aluminum oxide, have a cylindrical shape, and have a BET specific surface area of ​​90 to 107 m² as measured by the nitrogen adsorption method. ２ The value is / g, and the total pore volume is 0.25 to 0.40 cm³. ３ The BET specific surface area measured by nitrogen adsorption method, where the concentration is 1 / g and the average pore diameter is in the range of 11–15 nm, is 90–107 m². ２ The value is / g, and the total pore volume is 0.25 to 0.40 cm³. ３ Catalysts with a concentration of 1 / g and an average pore diameter in the range of 11–15 nm have been demonstrated to reduce catalyst damage, breakage, and / or wear.

[0065] Furthermore, the results from the examples of catalyst E1 and catalyst E4 demonstrate that catalysts having the following characteristic A can further reduce catalyst damage, breakage, and / or wear.

[0066] Feature A: The cylindrical pellet has a main body and a protruding portion, the main body has a cylindrical shape with a circular first surface, the protruding portion protrudes from the first surface along the extension direction of the central axis of the main body, and in the cross-section of the pellet including the central axis, (i) the angle between the line segment connecting the intersection point of the imaginary line extending the central axis and the upper surface of the pellet and the upper end corner of the main body, and (ii) the imaginary line, is less than 90°.

[0067] [Additional Notes] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

[0068] [Summary] (1) The catalyst according to Embodiment 1 of the present disclosure is a catalyst used in a reaction that includes carbon oxide as a raw material, and comprises copper oxide, zinc oxide, and aluminum oxide, and is a cylindrical pellet, with a BET specific surface area of ​​90 to 107 m² as measured by the nitrogen adsorption method. ２ The value is / g, and the total pore volume is 0.25 to 0.40 cm³. ３ The density is / g, and the average pore diameter is in the range of 11-15 nm.

[0069] (2) The catalyst according to embodiment 2 of the present disclosure, in embodiment 1 above, wherein the pellet has a main body and a protruding portion, the main body has a cylindrical shape with a circular first surface, the protruding portion protrudes from the first surface along the direction of extension of the central axis of the main body, and in a cross-section of the pellet including the central axis, the angle between (i) a line segment connecting the intersection point of a virtual line extending the central axis and the upper surface of the pellet and the upper end corner of the main body, and (ii) the virtual line is less than 90°.

[0070] (3) In the catalyst according to embodiment 3 of the present disclosure, the pore distribution is measured by the mercury intrusion method in embodiment 1 or 2, and when the pore distribution is represented by a log differential pore volume distribution graph, the peak top of the graph is located in the range of 0.0054 to 0.0080 μm.

[0071] (4) In any of the embodiments 1 to 3 described above, the catalyst according to embodiment 4 of the present disclosure has a ratio of 3% or less of the total pore volume of pores with a pore radius of 0.056 to 100 μm to the total pore volume measured by the mercury intrusion method.

[0072] (5) The catalyst according to embodiment 5 of the present disclosure contains 0.1% by mass or more of graphite in any of embodiments 1 to 4 above.

[0073] (6) A method for producing methanol according to embodiment 6 of the present disclosure includes the step of contacting a raw material gas containing carbon oxide and hydrogen with any of the catalysts of embodiments 1 to 5 above to obtain methanol.

[0074] (7) The methanol production method according to Embodiment 7 of the present disclosure is wherein, in Embodiment 6, the carbon oxide is carbon dioxide.

Claims

1. A catalyst for use in reactions involving carbon oxides as raw materials, comprising copper oxide, zinc oxide, and aluminum oxide, in the form of cylindrical pellets, with a BET specific surface area of ​​90 to 107 m² as measured by nitrogen adsorption. ２ The concentration is per gram, and the total pore volume is 0.25 to 0.40 cm³. ３ A catalyst with a concentration of / g and an average pore diameter in the range of 11–15 nm.

2. The catalyst according to claim 1, wherein the pellet has a main body and a projection, the main body has a cylindrical shape with a circular first surface, the projection protrudes from the first surface along the direction of extension of the central axis of the main body, and in a cross-section of the pellet including the central axis, the angle between (i) a line segment connecting the intersection point of a virtual line extending the central axis and the upper surface of the pellet and the upper end corner of the main body, and (ii) the virtual line is less than 90°.

3. The catalyst according to claim 1, wherein the pore distribution is measured by the mercury intrusion method, and when the pore distribution is represented by a log differential pore volume distribution graph, the peak top of the graph is located in the range of 0.0054 to 0.0080 μm.

4. The catalyst according to claim 1, wherein the ratio of the total volume of pores with a pore radius of 0.056 to 100 μm to the total pore volume measured by the mercury intrusion method is 3% or less.

5. The catalyst according to claim 1, comprising 0.1% by mass or more of graphite.

6. A method for producing methanol, comprising the step of contacting a raw material gas containing carbon oxides and hydrogen with a catalyst according to any one of claims 1 to 5 to obtain methanol.

7. The method for producing methanol according to claim 6, wherein the carbon oxide is carbon dioxide.

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