Method for producing a catalyst support for hydrolyzing carbonyl sulfide or carbon disulfide, catalyst support, and catalyst containing the catalyst support.

Abstract

To provide a catalyst carrier for hydrolyzing carbonyl sulfide or carbon disulfide difficult to cause cracking even when contacted with water.SOLUTION: A method for manufacturing a catalyst carrier for hydrolyzing carbonyl sulfide or carbon disulfide comprises the steps of: preparing a pseudo-boehmite hydrogel by mixing an aluminum-containing basic aqueous solution and an aluminum-containing acidic aqueous solution; adding silica to the pseudo-boehmite hydrogel to prepare an aging slurry; by spray drying the aging slurry to prepare spray powder; aging the spray powder at a temperature of 150°C, or higher and 350°C. or lower for heat treatment for 0.5 hour or more and 24 hours to prepare a molding precursor; kneading the molding precursor to prepare molding clay; extrusion molding the molding clay to prepare extruded molding; and firing the extruded molding to prepare a catalyst carrier containing γ alumina.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing a catalyst support for hydrolyzing carbonyl sulfide or carbon disulfide, a catalyst support, and a catalyst containing the catalyst support. [Background technology]

[0002] Sulfur compounds are removed in various processes by various methods because they can cause environmental pollution and poison catalysts. In particular, carbonyl sulfides and carbon disulfides, among sulfur compounds, are difficult to remove efficiently by wet methods, unlike hydrogen sulfide and sulfur dioxide. One method for removing them is to hydrolyze them to hydrogen sulfide in the presence of water vapor and a catalyst, and then remove them by a wet method. For example, Patent Document 1 discloses a method for hydrolyzing carbonyl sulfides contained in coal gasification gas or heavy oil gasification gas, etc., using a catalyst consisting of alumina and sodium hydroxide and / or potassium hydroxide.

[0003] As catalysts for hydrolyzing these substances, for example, Patent Document 2 discloses a catalyst for decomposing carbonyl sulfide and hydrogen cyanide in a mixed gas obtained by partial oxidation of heavy oil and / or coal, wherein the catalyst is constructed by supporting chromium oxide on a silica-containing alumina carrier. Furthermore, Patent Document 3 discloses a carbonyl sulfide decomposition apparatus equipped with a catalyst containing alkaline earth metal silicate.

[0004] These catalysts have primarily used gamma-alumina as a support material. However, gamma-alumina-based support materials have the drawback of being prone to cracking when in contact with water. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Special Publication No. 5-70500 [Patent Document 2] Japanese Patent Publication No. 2003-135959 [Patent Document 3] Japanese Patent Publication No. 2021-53619 [Overview of the project] [Problems that the invention aims to solve]

[0006] The present invention aims to provide a method for manufacturing a catalyst support for hydrolyzing carbonyl sulfide or carbon disulfide, which is less prone to cracking even when in contact with water. [Means for solving the problem]

[0007] A method for producing a catalyst support for hydrolyzing carbonyl sulfide or carbon disulfide, comprising the steps of: preparing a pseudoboehmite hydrogel by mixing an aluminum-containing basic aqueous solution and an aluminum-containing acidic aqueous solution; preparing a matured slurry by adding silica to the pseudoboehmite hydrogel; preparing a spray powder by spray-drying the matured slurry; preparing a molding precursor by heat-treating the spray powder at a temperature of 150°C or higher and 350°C or lower for 0.5 hours or higher and 24 hours; preparing a molding clay by kneading the molding precursor; preparing an extruded molded body by extruding the molding clay; and preparing a catalyst support containing γ-alumina by firing the extruded molded body. The above problems can be solved by using the catalyst support obtained by this method for producing a catalyst support. [Effects of the Invention]

[0008] The catalyst support obtained using the manufacturing method of the present invention is less prone to cracking even when in contact with water. [Brief explanation of the drawing]

[0009] [Figure 1] This is a distribution diagram of the integrated pore volume of the catalyst support in Example 1 and Comparative Example 1. [Figure 2]This is a distribution diagram of the log differential pore volume of the molded bodies of Example 1 and Comparative Example 1. [Modes for carrying out the invention]

[0010] The present invention relates to a method for producing a catalyst support for hydrolyzing carbonyl sulfide or carbon disulfide, comprising the steps of: preparing a pseudoboehmite hydrogel by mixing an aluminum-containing basic aqueous solution and an aluminum-containing acidic aqueous solution; preparing a matured slurry by adding silica to the pseudoboehmite hydrogel; preparing a spray powder by spray-drying the matured slurry; preparing a molding precursor by heat-treating the spray powder at a temperature of 150°C or higher and 350°C or lower for 0.5 hours or higher and 24 hours; preparing a molding clay by kneading the molding precursor; preparing an extruded molded body by extruding the molding clay; and preparing a catalyst support containing γ-alumina by firing the extruded molded body. In particular, by heat-treating the spray powder at a temperature of 150°C or higher and 350°C or lower, the number of pores smaller than 10 nm in the final catalyst support is reduced, and the pore distribution becomes broader, making it less prone to cracking even when in contact with water. The present invention relates to a method for producing a catalyst support.

[0011] [Manufacturing method of the present invention] The present invention's manufacturing method includes a step of preparing a pseudoboehmite hydrogel by mixing an aluminum-containing basic aqueous solution with an aluminum-containing acidic aqueous solution. The purpose of this step is to prepare pseudoboehmite, which serves as a raw material for γ-alumina. Pseudoboehmite is one of the crystalline structures of aluminum hydroxide. Here, by using two different aluminum raw materials, differences arise in the properties of the pseudoboehmite gels based on each raw material, and it is thought that these properties affect the pore structure of the final catalyst support.

[0012] Conventional known methods can be used to prepare an aluminum-containing basic aqueous solution, such as dissolving an aluminum-containing compound in a basic aqueous solution or dissolving an alkali salt such as sodium aluminate in water. In this case, the pH of the aluminum-containing basic aqueous solution is preferably 10 or higher, and more preferably 12 or higher. As a method for adjusting the pH, a conventionally known basic aqueous solution such as ammonia water or sodium hydroxide aqueous solution can be added. Furthermore, the aluminum-containing basic aqueous solution may contain a chelating agent such as sodium gluconate to stabilize the dissolved aluminum ions. Moreover, the concentration of aluminum in the aluminum-containing basic aqueous solution is preferably in the range of 1% by mass or more and 10% by mass or less, in terms of Al2O3.

[0013] Conventional known methods can be used to prepare an aluminum-containing acidic aqueous solution, such as dissolving an aluminum-containing compound in an acidic aqueous solution or dissolving aluminum sulfate, aluminum nitrate, etc., in water. In this case, the pH of the aluminum-containing acidic aqueous solution is preferably 5 or less, and more preferably 3 or less. As a method for adjusting the pH, a conventional known acidic aqueous solution containing hydrochloric acid, nitric acid, sulfuric acid, etc., can be added. Furthermore, the concentration of aluminum in the aluminum-containing acidic aqueous solution is preferably in the range of 0.5% by mass or more and 5% by mass or less, in terms of Al2O3.

[0014] When an aluminum-containing basic aqueous solution and an aluminum-containing acidic aqueous solution are mixed, a pseudo-boehmite hydrogel is formed. Preferably, the temperature of both aqueous solutions is 40°C or higher. If the amount of pseudo-boehmite hydrogel produced is small, the pH can be adjusted to a range of 6 to 8 using a conventionally known acid or base. Furthermore, since the pseudo-boehmite hydrogel obtained in this process contains salts derived from the acid or base as impurities, it may be washed with warm water, ammonium sulfate aqueous solution, dilute ammonia water, etc. For example, the pseudo-boehmite hydrogel may be filtered and washed in a flow-through solution.

[0015] The production method of the present invention comprises a step of preparing an aged slurry by adding silica to the pseudo-boehmite hydrogel. This step aims at adding silica to the pseudo-boehmite hydrogel obtained in the preceding step and dispersing the silica in the pseudo-boehmite hydrogel.

[0016] Conventionally known silica can be used as the silica added in this step. For example, silica sol, fumed silica, silica gel and the like can be used. In this case, the average size of the silica is preferably in the range of 1 nm or more and 100 nm or less, more preferably in the range of 1 nm or more and 10 nm or less. By using silica with a small average size, silica can be highly dispersed in the pseudo-boehmite hydrogel. The average size refers to the average (of 50 particles) of the major diameters of primary particles of silica observed with an electron microscope or the like.

[0017] In this step, after adding silica to the pseudo-boehmite hydrogel, aging is carried out for a predetermined time to prepare an aged slurry. In this case, the aging temperature is preferably in the range of 70°C or higher and 100°C or lower, more preferably in the range of 80°C or higher and 100°C or lower. In addition, aging under stirring facilitates high dispersion of silica in the pseudo-boehmite hydrogel. The aging time is preferably in the range of 1 hour or more and 24 hours or less.

[0018] This production method comprises a step of spray-drying the aged slurry to prepare spray powder. This step aims at taking out, as spray powder, the silica-containing pseudo-boehmite hydrogel contained in the aged slurry obtained in the preceding step. In this process, the silica-containing pseudo-boehmite hydrogel is formed into spherical powder through spray drying.

[0019] The spray drying method can be any conventionally known method, as long as it is possible to extract the silica-containing pseudoboehmite hydrogel contained in the aged slurry as a spray powder. For example, a commercially available spray drying apparatus may be used, and droplets of the aged slurry may be sprayed into a drying oven through which hot air flows. In this case, the inlet temperature and outlet temperature of the hot air are adjusted as appropriate according to the desired state of the spray powder.

[0020] This manufacturing method includes a step of preparing a molding precursor by heat-treating the spray powder at a temperature of 150°C to 350°C for 0.5 hours to 24 hours. It is believed that including this step reduces the pore size of the final catalyst support to 10 nm or less, making it less prone to cracking when in contact with water. The reason for this is not clear, but it is thought that the heat treatment promotes the dehydration reaction of the silica-containing pseudoboehmite hydrogel, resulting in less shrinkage of the pseudoboehmite in the subsequent calcination step. It should be noted that although a certain amount of heat is applied in the aforementioned spray drying, the drying time is instantaneous and is therefore not considered sufficient to promote the dehydration reaction.

[0021] Conventional heat treatment methods can be used. For example, the spray powder can be heat-treated using a dryer, muffle furnace, kiln, etc. The heat treatment temperature is preferably in the range of 175°C to 350°C, and more preferably in the range of 200°C to 300°C. By heat-treating the spray powder within this temperature range, the dehydration reaction proceeds appropriately.

[0022] The heat treatment time is preferably in the range of 1 hour to 24 hours, and more preferably in the range of 3 hours to 20 hours. By heat treating the spray powder within this time range, the dehydration reaction proceeds appropriately.

[0023] This manufacturing method includes a step of kneading the molding precursor to prepare molding clay. The purpose of this step is to mold the molding precursor obtained in the previous step into a clay-like form suitable for extrusion molding.

[0024] The molding precursor can be kneaded using conventionally known methods. For example, it can be kneaded with a solvent and at least one molding aid using conventionally known equipment such as a mix maller or kneader. At least one of these solvents and molding aids can be appropriately selected, based on conventionally known methods, to produce a clay that can be extruded.

[0025] This manufacturing method includes a step of firing the extruded molded body to prepare a molded body containing silica-containing γ-alumina. The purpose of this step is to transfer the silica-containing pseudo-boehmite hydrogel contained in the extruded molded body obtained in the previous step to the silica-containing γ-alumina.

[0026] Conventional methods can be used to sinter the extruded body. For example, the extruded body may be sintered using a muffle furnace or the like. The sintering temperature should be above the temperature at which pseudoboehmite transitions to γ-alumina, and is preferably in the range of 500°C to 700°C. If the sintering temperature is too high, the γ-alumina may transition to another phase. Conversely, if the sintering temperature is too low, the transition to γ-alumina will not be promoted. The heat treatment time is preferably in the range of 0.5 hours to 48 hours, and more preferably in the range of 1 hour to 24 hours.

[0027] The catalyst support of the present invention obtained in the above-described process can be used directly as a catalyst for hydrolysis reactions. Furthermore, it is preferable to support at least one component selected from Na, K, and Cr. Supporting these components allows for more efficient hydrolysis of carbonyl sulfides and carbon disulfides, and tends to extend the lifespan. These components can be supported by conventionally known methods using water, such as spray loading and impregnation loading. For example, a salt containing these components can be used as a raw material, and an aqueous solution obtained by dissolving this salt can be supported on the catalyst support using the above-described method. Afterward, the water can be removed by drying using conventionally known methods, and if necessary, it is preferable to calcine it at a temperature of 300°C to 500°C. Furthermore, if a hexavalent Cr compound is used as a raw material, it is preferable to reduce the hexavalent Cr by performing calcination or reduction treatment as necessary. Since hexavalent Cr is a specific hazardous substance, it is preferable to reduce it as much as possible by calcination or reduction treatment. For example, when performing reduction treatment using hydrogen, it is preferable to reduce it at a temperature of 500°C or lower, and more preferably at a temperature of 400°C or lower. Furthermore, it is preferable to gradually reduce hexavalent Cr at these temperatures under a hydrogen concentration of 10 Vol% or less.

[0028] [Catalyst support of the present invention] The catalyst support of the present invention is a catalyst support for hydrolyzing carbonyl sulfide or carbon disulfide, comprising γ-alumina, wherein the Al content is in the range of 70% by mass or more and 99% by mass or less in terms of Al2O3, the Si content is in the range of 1% by mass or more and 30% by mass or less in terms of SiO2, and the pore volume (PV) of the pores is in the range of 5 nm to 5000 nm. 5-5000 The pore volume is 0.5 mL / g or more, the percentage of the integrated pore volume when the pore diameter is 10 nm is 20% or more in the distribution of integrated pore volume, and the maximum value of the log differential pore volume is 3 mL / g or less.

[0029] The catalyst support of the present invention will be described in detail below.

[0030] The catalyst support of the present invention has a cumulative pore volume distribution in which the cumulative pore volume ratio when the pore diameter is 10 nm is 20% or more. The distribution is calculated based on the pore distribution measured by the mercury intrusion method, and is calculated by integrating from the pore volume of the largest pore diameter. Figure 1 is a distribution diagram of the cumulative pore volume of molded bodies obtained by the methods of Comparative Example 1 and Example 1. From this distribution diagram, the cumulative pore volume ratio when the pore diameter is 10 nm is calculated. For example, the dashed line in Figure 1 (Comparative Example 1) has many pores with small pore diameters, so the cumulative pore volume ratio when integrating from pores with large pore diameters to pores with a pore diameter of 10 nm is only 7.3%, and the remaining 92.7% is occupied by pores with a pore diameter of less than 10 nm. On the other hand, the solid line in Figure 1 (Example 1) shows that there are few pores with small pore diameters, so the cumulative pore volume ratio, which is the sum of pores with large pore diameters and pores with a pore diameter of 10 nm, is 57.5%, and the proportion of pores with a pore diameter of less than 10 nm is small. It is believed that having such a pore structure makes the catalyst support of the present invention less prone to cracking even when in contact with water. In the distribution of cumulative pore volume of the catalyst support of the present invention, it is preferable that the cumulative pore volume ratio when the pore diameter is 10 nm is 30% or more, and more preferably 40% or more. Furthermore, the upper limit of the cumulative pore volume ratio is 100%, preferably 90% or less, and more preferably 80% or less. By reducing the number of pores with a pore diameter of less than 10 nm, cracking is less likely to occur when in contact with water, and the yield in the production of catalysts using this support is dramatically improved. In addition, even during hydrolysis reactions in systems where water is present, it is expected that the strength will not decrease easily even after long-term use.

[0031] The catalyst support of the present invention has a maximum Log differential pore volume of 3 mL / g or less. Figure 2 is a distribution diagram of the Log differential pore volume of molded bodies obtained by the methods of Comparative Example 1 and Example 1. The maximum value of the Log differential pore volume is calculated from this distribution diagram. For example, the dashed line in Figure 2 (Comparative Example 1) has a sharp pore distribution, so the maximum value of the Log differential pore volume is a large value of 6.451 mL / g. On the other hand, the solid line in Figure 2 (Example 1) has a broad pore distribution, so the maximum value of the Log differential pore volume is a small value of 1.438 mL / g. It is believed that having such a pore structure makes the catalyst support of the present invention less prone to cracking even when in contact with water. The molded body of the present invention preferably has a maximum Log differential pore volume of 2.5 mL / g or less, and more preferably 2 mL / g or less. The catalyst support of the present invention, with its broad pore distribution, is less prone to pore blockage by by-products and toxic substances, and catalytic activity is easily maintained even when used for a long period of time.

[0032] The catalyst support of the present invention contains γ-alumina. γ-alumina, also known as activated alumina, is widely known as a component of support materials. Because γ-alumina has a large specific surface area and is chemically stable, it is widely used as a support for catalysts or adsorbents. It is also used as a catalyst or adsorbent itself.

[0033] The Al content in the catalyst support of the present invention is in the range of 70% by mass or more and 99% by mass or less, in terms of Al2O3. The catalyst support of the present invention can support more components such as catalysts and adsorbents by containing a larger amount of γ-alumina. Therefore, it is preferable that the Al content is in the range of 80% by mass or more and 99% by mass or less, and more preferably in the range of 90% by mass or more and 99% by mass or less. The Al content can be measured by preparing a solution in which the entire sample is dissolved and using high-frequency inductively coupled plasma atomic emission spectroscopy.

[0034] The catalyst carrier of the present invention contains Si, and the content thereof, in terms of SiO₂, is in the range of 1% by mass or more and 30% by mass or less. Si contained in the catalyst carrier of the present invention exists as silica, which is considered to function as a binder inside the catalyst carrier and increases the physical strength of the catalyst carrier. It also has the function of suppressing the alteration (boehmitization) of γ-alumina in the hydrolysis reaction. However, in the catalyst carrier of the present invention, as the silica content increases, the content of γ-alumina decreases. Therefore, the content of Si contained in the molded body of the present invention is preferably in the range of 1% by mass or more and 20% by mass or less, and particularly preferably in the range of 1% by mass or more and 10% by mass or less. The Si content can be measured by preparing a solution in which the entire sample is dissolved and using high-frequency inductively coupled plasma optical emission spectrometry.

[0035] The catalyst carrier of the present invention has a pore volume (PV 5-5000 ) of pores with a pore diameter in the range of 5 nm to 5000 nm of 0.5 mL / g or more, preferably in the range of 0.55 mL / g or more and 1 mL / g or less, more preferably in the range of 0.55 mL / g or more and 0.9 mL / g or less, and particularly preferably in the range of 0.55 mL / g or more and 0.8 mL / g or less. The PV 5-5000 catalyst carrier of the present invention falling within these ranges has high physical strength and can support a larger amount of the supported component.

[0036] The catalyst carrier of the present invention preferably has a specific surface area of 150 m 2 / g or more, more preferably 200 m 2 / g or more, and particularly preferably 250 m 2 / g or more. The catalyst carrier of the present invention with a large specific surface area can disperse and support the supported component more favorably. The lower limit of the specific surface area is not particularly limited, but it may be 500 m 2 / g or less, 450 m 2 / g or less, or 400 m 2 / g or less.

[0037] The catalyst support of the present invention preferably has a crushing strength of 4 N / mm or more, more preferably 6 N / mm or more, and particularly preferably 8 N / mm or more. Catalyst supports of the present invention with high crushing strength tend to have a longer lifespan when used as catalysts. Furthermore, the upper limit of the crushing strength is not particularly limited, but may be 40 N / mm or less, 30 N / mm or less, or 20 N / mm or less.

[0038] The catalyst support of the present invention is a molded body, not a powder. Its shape is preferably spherical, columnar, or a shape similar to a columnar shape (for example, macaroni-shaped, trefoil-shaped, quadruple-shaped, or spoke-shaped). If it is spherical, its average diameter refers to the diameter and is preferably in the range of 1 mm to 10 mm. If it is columnar or a shape similar to a columnar shape, its average diameter refers to the major axis of the cross-section and is preferably in the range of 1 mm to 10 mm. Furthermore, its average length is preferably 2 mm to 100 mm.

[0039] The catalyst support of the present invention can be used as a hydrolysis catalyst directly by utilizing the chemical properties of γ-alumina, without the need to support specific components. Because the catalyst support of the present invention is resistant to cracking even when in contact with water, it can be suitably used as a support for hydrolysis catalysts used in reactions in the presence of water.

[0040] The catalyst support of the present invention is preferably a catalyst on which at least one supported component selected from Na, K, and Cr is supported. Catalysts on the catalyst support of the present invention that support these components can hydrolyze carbonyl sulfide and carbon disulfide more efficiently and tend to have a longer lifespan. The amount of supported component (in terms of Na2O, K2O, and Cr2O3) is preferably in the range of 1% by mass or more and 30% by mass or less, more preferably in the range of 5% by mass or more and 25% by mass or less, and particularly preferably in the range of 10% by mass or more and 20% by mass or less, relative to the total amount of catalyst. In particular, when Cr is included, the content of hexavalent Cr is preferably 2000 ppm or less, and more preferably 1000 ppm or less. [Examples]

[0041] The manufacturing method and catalyst support of the present invention will be described in detail below using examples. However, the present invention is not limited to the examples.

[0042] [Example 1] To 3.03 kg of an aqueous sodium aluminate solution with an Al2O3 equivalent concentration of 22% by mass, 0.08 kg of sodium gluconate with a concentration of 26.5% by mass and 10.23 kg of pure water were added, and the mixture was heated to 57°C to prepare an aluminum-containing basic aqueous solution. Next, to 4.76 kg of an aqueous aluminum sulfate solution with an Al2O3 equivalent concentration of 7% by mass, 8.57 kg of pure water was added, and the mixture was heated to 57°C to prepare an aluminum-containing acidic aqueous solution. The acidic aqueous solution was added to the basic aqueous solution to prepare a pseudo-boehmite alumina hydrogel.

[0043] This pseudo-boehmite alumina hydrogel was filtered and washed with 0.3% by mass aqueous ammonia to prepare a washing gel. The resulting washing gel contained 0.13% by mass of Na (in terms of Na2O) and 0.48% by mass of S (in terms of SO4).

[0044] This washed gel was added to pure water such that the concentration in terms of Al₂O₃ was 10% by mass. Thereafter, aqueous ammonia with a concentration of 15% by mass was added to adjust the pH to 10.5. Further, silica sol with an average size of 5 nm (product name: SI-550, concentration in terms of SiO₂: 20% by mass, manufactured by JGC Catalysts and Chemicals Ltd.) was added such that the content of silica (in terms of SiO₂) was 1.5% by mass relative to the sum of Al (mass in terms of Al₂O₃) contained in the washed gel and Si (mass in terms of SiO₂) contained in the silica sol. Thereafter, the mixture was heated to 95°C and aged while stirring for 20 hours to prepare an aged slurry.

[0045] This aged slurry was spray-dried to prepare spray powder. The spray powder was heat-treated at 200°C for 12 hours in a dryer to prepare a molding precursor powder. This molding precursor powder was kneaded while adding water in a mix muller to prepare molding clay, which was molded into a 2.6 mmφ cylindrical shape with an extrusion molding machine to prepare an extruded molded body. After drying this extruded molded body, it was fired at 600°C for 3 hours under an air atmosphere to prepare a cylindrical catalyst carrier.

[0046] The following measurements were performed on the obtained catalyst carrier. The results are shown in Table 1.

[0047] The average diameter and average length of the obtained catalyst carrier were measured under the following conditions. <Measurement of Average Diameter and Average Length> · Number of samples: 40 (random sampling) · Diameter measurement: using a micrometer · Length measurement: using a digital vernier caliper

[0048] X-ray diffraction measurement was performed on the obtained catalyst carrier under the following conditions to confirm the presence or absence of γ-alumina. <X-ray Diffraction Measurement> X-ray diffractometer: MineFlex600 (manufactured by Rigaku Corporation) Radiation source: Cu-kα radiation Acceleration voltage, current: 40 KV, 15 mA Scanning speed: 4° / min Step width: 0.02° Measurement range (2θ): 10°~90° <Judgment method> The X-ray diffraction patterns obtained from the above X-ray diffraction measurements were used to confirm the presence or absence of diffraction peaks attributed to γ-alumina, using the integrated powder X-ray analysis software PDXL (manufactured by Rigaku Corporation).

[0049] The pore volume of the obtained catalyst support was measured under the following conditions. From the obtained pore distribution, PV 5-5000 The maximum value of the log differential pore volume and the cumulative pore volume ratio at a pore diameter of 10 nm were also calculated. <Pore volume measurement (Hg intrusion method)> • Pore size distribution analyzer: PM-33GT1LP (manufactured by QUANTA CROME) Pre-treatment: 500℃ for 1 hour • Sample volume: 1 mL • Pore size measurement range: 5nm to 5000nm

[0050] The specific surface area was measured under the following conditions. <Specific surface area measurement> • BET specific surface area measuring device: Macsorb HM Model-1220 (manufactured by Mountec Co., Ltd.) Sample amount: 0.1g Pre-treatment: 500℃ for 1 hour

[0051] The crushing strength was measured under the following conditions. <Measurement of crushing strength> For samples fired at 500°C for 1 hour, the length was measured using a crushing strength measuring device (compressor width 20 mm), and then the load at which the sample was crushed was measured. This measurement was performed for 50 samples, and the Crushing Strength was calculated using the following formula. The arithmetic mean was used as the measured value. Crushing Strength (N / mm) = S / L S: Pressurized load (N) L: Measured length (mm)

[0052] The number of cracks during solvent impregnation was measured under the following conditions. <Number of cracks during solvent impregnation> Fifty randomly sampled samples were immersed in 20 mL of pure water. After 1 hour, the samples were filtered and dried at 50°C for 12 hours. The number of samples after drying was counted, and the number of fractures was calculated using the following formula. Number of cracks = Number of samples after drying - 50

[0053] [Example 2] The catalyst support was prepared in the same manner as in Example 1, except that silica (in SiO2 equivalent) was added to the sum of Al (in Al2O3 equivalent mass) in the washing gel and Si (in SiO2 equivalent mass) in the silica sol so that it was 3% by mass, and a double-arm kneader was used instead of a mixed maller. The obtained catalyst support was measured in the same manner as in Example 1. The results are shown in Table 1.

[0054] [Example 3] A cylindrical catalyst support was prepared in the same manner as in Example 1, except that silica sol was added so that the silica (SiO2 equivalent) amounted to 3% by mass relative to the sum of Al (Al2O3 equivalent mass) contained in the washing gel and Si (SiO2 equivalent mass) contained in the silica sol. The obtained catalyst support was measured in the same manner as in Example 1. The results are shown in Table 1.

[0055] [Example 4] A four-leaf cylindrical catalyst carrier was prepared in the same manner as in Example 3, except that it was extruded into a four-leaf shape with an average diameter of 1.3 mmφ. The obtained catalyst carrier was measured in the same manner as in Example 1. The results are shown in Table 1.

[0056] [Example 5] A cylindrical catalyst support was prepared in the same manner as in Example 1, except that silica (in SiO2 equivalent) was added to the sum of Al (in Al2O3 equivalent mass) contained in the washing gel and Si (in SiO2 equivalent mass) contained in the silica sol so that it amounted to 5% by mass. The obtained catalyst support was measured in the same manner as in Example 1. The results are shown in Table 1.

[0057] [Example 6] A cylindrical catalyst support was prepared in the same manner as in Example 5, except that the spray powder was heat-treated in a dryer at 300°C for 12 hours. The obtained catalyst support was measured in the same manner as in Example 1. The results are shown in Table 1.

[0058] [Comparative Example 1] A cylindrical catalyst support was prepared in the same manner as in Example 1, except that silica sol was not used and the spray powder was not dried in a dryer. The obtained catalyst support was measured in the same manner as in Example 1. The results are shown in Table 1.

[0059] [Comparative Example 2] A cylindrical catalyst support was prepared in the same manner as in Example 2, except that the spray powder was not dried in a dryer. The obtained catalyst support was measured in the same manner as in Example 1. The results are shown in Table 1.

[0060] [Comparative Example 3] A cylindrical catalyst support was prepared in the same manner as in Example 2, except that the spray powder was heat-treated in a dryer at 120°C for 12 hours. The obtained catalyst support was measured in the same manner as in Example 1. The results are shown in Table 1.

[0061] [Table 1]

[0062] [Example 7] An impregnation solution was prepared by dissolving 26.5 g of anhydrous chromic acid (Fujifilm Wako Pure Chemical Industries, Ltd.: 99.5% chromium(VI) oxide) in 130 g of pure water at room temperature. 120 g of the catalyst support from Example 2 was sprayed with the impregnation solution while being fluidized using a blender or the like to uniformly impregnate it with Cr. Afterward, it was dried at 120°C for 3 hours, and then calcined at 400°C for 4 hours. An impregnation solution was prepared by dissolving 6.0 g of potassium carbonate (Fujifilm Wako Pure Chemical Industries, Ltd.: 99.5% potassium carbonate) in 73 g of pure water at room temperature. 100 g of the calcined product was sprayed with the impregnation solution while being fluidized using a blender or the like to uniformly impregnate it with K. It was then dried at 120°C for 3 hours. Furthermore, the obtained catalyst support was gradually reduced at 400°C under a 10 Vol% hydrogen atmosphere to prepare the catalyst. The obtained catalysts were subjected to hydrolysis reaction tests of carbonyl sulfide and carbon disulfide, and their catalytic activity was evaluated.

[0063] <Hydrolysis reaction test> The hydrolysis catalyst obtained as described above was subjected to a hydrolysis reaction test under the following reaction conditions. The results are shown in Table 2. • Reactor: Fixed-bed flow reactor Feed gas composition: COS 2020ppm / H2S 216ppm / CS2 218ppm / CO 5% / H2O 2% / N2 balance Feed gas distribution method: Downflow • GHSV: 4,000h -1 ·Temperature: 160℃ • Pressure: 0.2 MPaG ·Catalyst loading amount: 30mL The carbonyl sulfide conversion rate (%) and carbon disulfide conversion rate (%) were calculated using the following formulas. Carbonyl sulfide conversion rate (%) = [(COS concentration in feed gas - COS concentration in gas after reaction) / COS concentration in feed gas] × 100 Carbon disulfide conversion rate (%) = [(CS2 concentration in feed gas - CS2 concentration in gas after reaction) / CS2 concentration in feed gas] × 100

[0064] Table 2

Claims

1. A method for producing a catalyst support for hydrolyzing carbonyl sulfide or carbon disulfide, comprising the steps of: mixing an aluminum-containing basic aqueous solution with an aluminum-containing acidic aqueous solution to prepare a pseudoboehmite hydrogel; A step of preparing a matured slurry by adding silica to the pseudo-boehmite hydrogel, The process involves spray-drying the aged slurry to prepare a spray powder. A step of preparing a molding precursor by heat-treating the spray powder at a temperature of 150°C or higher and 350°C or lower for 0.5 hours or more and 24 hours. A step of preparing molding clay by kneading the molding precursor, A step of preparing an extruded molded body by extruding the aforementioned molding clay, The process includes a step of preparing a catalyst support containing γ-alumina by firing the extruded body. A method for manufacturing a catalyst support.

2. A catalyst support for hydrolyzing carbonyl sulfide or carbon disulfide, Contains γ-alumina, Al content, ２ O ３ In terms of conversion, it falls within the range of 70% by mass or more and 99% by mass or less. The Si content is SiO ２ In terms of conversion, it is in the range of 1% by mass or more and 30% by mass or less. The volume of pores with a diameter in the range of 5 nm to 5000 nm (PV) ５－５０００ ) is 0.5 mL / g or more, In the distribution of cumulative pore volume, the cumulative pore volume ratio when the pore diameter is 10 nm is 20% or more, and the maximum value of the log differential pore volume is 3 mL / g or less. Catalyst support.

3. The catalyst support according to claim 2, wherein the maximum value of the log differential pore volume is 1.306 mL / g or more and 1.600 mL / g or less.

4. A catalyst for hydrolyzing carbonyl sulfide or carbon disulfide, comprising the catalyst support described in claim 2.

5. The catalyst according to claim 4, comprising Cr.

6. The amount of Cr is ２ O ３ The catalyst according to claim 5, wherein the amount is in the range of 5% by mass or more and 30% by mass or less, when converted.

7. Cr ６＋ The catalyst according to claim 6, wherein the content is 2000 ppm or less.

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