JP2015054312A - Method for producing catalyst particles for hydrogenation, and catalyst particles for hydrogenation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing catalyst particles for hydrogenation in which there is almost no catalyst particles of the size which cannot be removed or causes clogging and the catalyst particles have a sufficiently large specific surface area, and to provide catalyst particles for hydrogenation.SOLUTION: There is provided a method for producing catalyst particles for hydrogenation, the catalyst particles containing copper oxide. The method comprises the steps of: forming a first slurry including a catalyst precursor by reacting an acidic aqueous solution A containing water-soluble copper compound with a basic aqueous solution B while keeping the pH at 9-14 in an aqueous medium; aging the first slurry; separating a solid component of a catalyst precursor from the first slurry; suspending the separated solid component of the catalyst precursor into an aqueous medium to prepare a second slurry; obtaining a substantially spherical powder by spray drying the second slurry; and calcining the substantially spherical powder.

Description

The present invention relates to a method for producing hydrogenation catalyst particles and hydrogenation catalyst particles.

Many methods are known for producing alcohols by hydrogenating carboxylic acids or esters. Such hydrogenation reaction includes a method using a hydrogenation catalyst. The hydrogenation catalyst generally refers to a catalyst used in a hydrogenation reaction for adding hydrogen to a compound. As such a hydrogenation catalyst, a copper oxide catalyst containing copper oxide as a main component is known.

In a method for producing alcohol or the like using such a hydrogenation catalyst, the hydrogenation catalyst is added to the reaction system. For this reason, it is necessary to remove the hydrogenation catalyst from the product by filtration or the like after completion of the reaction. Usually, the hydrogenation catalyst is composed of catalyst particles having various particle sizes. If catalyst particles having a particle diameter that cannot be removed by filtration are contained, the catalyst particles cannot be sufficiently removed and remain as impurities in the produced alcohol or the like. It is desirable that such impurities do not exist. Even when filtration separation is possible, if there are many fine particles, clogging occurs and the filtration efficiency deteriorates. Therefore, there has been a demand for a hydrogenation catalyst that contains as little catalyst particles that cannot be removed or cause clogging during filtration.
Further, if the average particle diameter of the catalyst particles is increased, the abundance ratio of catalyst particles having a particle diameter that cannot be removed by filtration decreases. In addition, an improvement in filtration efficiency can be expected. However, as the average particle diameter of the catalyst particles increases, the specific surface area of the catalyst particles decreases. When the specific surface area of the catalyst particles is reduced, the chance of contact between the catalyst particles and the reaction raw material is reduced, so that the catalyst activity is reduced. Higher catalyst activity is desirable. Therefore, there has been a demand for catalyst particles having a specific surface area as large as possible.
In summary, there has been a demand for a hydrogenation catalyst that includes catalyst particles that have as few catalyst particles as possible and cannot be removed or cause clogging during filtration and that have as large a specific surface area as possible.

Patent Literature 1 and Patent Literature 2 describe a method for producing a copper-based oxide catalyst.
In these methods, a metal salt aqueous solution in which two or more metal salts containing a copper salt are dissolved and an aqueous solution containing a basic substance are mixed to precipitate a metal hydroxide, A step of aging at a temperature for a predetermined time and a step of drying and baking the precipitate after aging are included, and a copper-based oxide catalyst is produced through these steps. Thus, it is described that a highly uniform catalyst can be obtained by coprecipitation of a plurality of metal ions. Further, it is described that by controlling the type and ratio of the metal salt, it is possible to produce a reproducible copper-based oxide catalyst having good catalytic activity and outstanding durability.
However, in these production methods, when drying the precipitate after aging, no operation is performed to control the particle size and shape of the resulting catalyst particles, so that the shape of the produced catalyst particles must be constant. The particle size distribution is broad. Therefore, a copper-based oxide catalyst having a relatively large number of catalyst particles that cannot be removed or cause clogging during filtration is produced. In addition, the specific surface area was not sufficiently large. Therefore, there is room for improvement in the control of the particle diameter and specific surface area of the catalyst particles.

Japanese Patent Application Laid-Open No. 2012-120979 JP 2010-194421 A

The object of the present invention is to solve the above-mentioned problems, and there are few catalyst particles of a size that cannot be removed or cause clogging during filtration, and a catalyst for hydrogenation having a sufficiently large specific surface area. It is providing the manufacturing method of particle | grains, and the catalyst particle | grains for hydrogenation.

In order to solve the above-mentioned problems, the inventors have intensively studied. As a result, the catalyst particles can be produced by reacting the raw water-soluble copper compound and the basic aqueous solution while maintaining the pH at 9 to 14 during the production of the catalyst particles. The present inventors have found that the specific surface area becomes larger and completed the present invention.

That is, the first aspect of the present invention is a method for producing hydrogenation catalyst particles containing copper oxide, comprising an acidic aqueous solution A containing a water-soluble copper compound and a basic aqueous solution B in an aqueous medium. The step of producing a first slurry containing the catalyst precursor by reacting while maintaining the pH at 9 to 14, the step of aging the first slurry, and the catalyst precursor from the first slurry A step of separating the solid content, a step of suspending the separated catalyst precursor solid content in an aqueous medium to prepare a second slurry, and spray drying the second slurry to obtain a substantially spherical powder. The present invention relates to a production method including a step of obtaining and a step of firing the substantially spherical powder.

In the method for producing the hydrogenation catalyst particles, preferably, the acidic aqueous solution A further contains at least one water-soluble metal compound selected from zirconium, zinc, aluminum, titanium, and iron.

The method for producing the hydrogenation catalyst particles is preferably such that the weight ratio of the water-soluble copper compound to the water-soluble metal compound is copper oxide: metal oxide = 10: 85 in terms of oxide of each metal. 85:10.

In the method for producing the hydrogenation catalyst particles, the aging step is preferably performed at 30 to 100 ° C.

In the method for producing the hydrogenation catalyst particles, the spray drying is preferably performed by using a centrifugal sprayer, the spray drying conditions by the centrifugal sprayer are set to a disk rotational speed of 5000 to 25000 rpm, and the outlet temperature is set to 50 to It is set to 150 ° C.

In the method for producing the hydrogenation catalyst particles, the calcination is preferably performed at a calcination temperature of 250 to 550 ° C. for 1 to 10 hours.

A second aspect of the present invention is a substantially spherical hydrogenation catalyst particle containing copper oxide, wherein in the particle size distribution of the hydrogenation catalyst particle, the proportion of particles having a particle size of 10 to 100 μm is 95 to 95%. The present invention relates to a catalyst particle for hydrogenation that occupies 100%, the proportion of particles having a particle diameter of less than 10 μm is less than 5% of the whole, and the specific surface area is 120 to 200 m ² / g.

The hydrogenation catalyst particles of the present invention preferably further contain at least one component selected from zirconium, zinc, aluminum, titanium and iron.

The hydrogenation catalyst particles of the present invention are preferably obtained by the method for producing hydrogenation catalyst particles of the first aspect of the present invention.

In the method for producing hydrogenation catalyst particles of the present invention, a substantially spherical powder is obtained by spray drying the second slurry. By performing spray drying, the shape of the resulting hydrogenation catalyst particles can be made substantially spherical, and the particle size distribution can be sharpened. That is, the proportion of hydrogenation catalyst particles having a particle size that cannot be removed by filtration can be reduced.
Moreover, in the manufacturing method of the catalyst particle for hydrogenation of this invention, the acidic aqueous solution A containing a water-soluble copper compound and the basic aqueous solution B are made to react, keeping pH at 9-14, of catalyst precursor. The production of the catalyst precursor takes precedence over the particle growth. As a result, catalyst precursor particle growth does not occur, and a large number of small particle catalyst precursors are generated, so that the specific surface area of the catalyst precursor particles increases. Therefore, when the reaction is carried out in the above pH range, the specific surface area of the hydrogenation catalyst particles obtained through the subsequent steps can be increased. The catalytic activity increases in proportion to the specific surface area. That is, in the method for producing hydrogenation catalyst particles of the present invention, highly active hydrogenation catalyst particles can be produced.

FIGS. 1A and 1B are enlarged photographs of a powder obtained by spray drying the second slurry in the method for producing hydrogenation catalyst particles of the present invention, using a scanning electron microscope (SEM). is there. 2 is a graph showing the particle size distribution of the hydrogenation catalyst particles of Example 1 of the present invention and the particle size distribution of the hydrogenation catalyst particles of Comparative Example 1. FIG. FIG. 3 is a diagram showing the relationship between the pH during mixing of the acidic aqueous solution A and the basic aqueous solution B and the specific surface area of the hydrogenation catalyst particles in the method for producing the hydrogenation catalyst particles.

(Formation of first slurry)
In the method for producing hydrogenation catalyst particles of the present invention, a catalyst precursor is prepared by reacting an acidic aqueous solution A containing a water-soluble copper compound with a basic aqueous solution B while maintaining the pH at 9 to 14 in an aqueous medium. A first slurry containing the body is produced.
When the acidic aqueous solution A and the basic aqueous solution B are mixed, a precipitate containing copper hydroxide is generated by the neutralization reaction. This precipitate becomes a catalyst precursor. The first slurry is a precipitate generated by the neutralization reaction and a liquid phase of the reaction solution.
In this step, an organic solvent such as methanol, ethanol, propanol, ethylene glycol, diethylene glycol, or acetone may be added to the aqueous medium for the purpose of improving dispersibility.

In the mixing of the acidic aqueous solution A and the basic aqueous solution B, the addition time of each solution is not particularly limited. For example, the addition time of each solution is preferably 1 to 8 hours.

The mixing of the acidic aqueous solution A and the basic aqueous solution B is not particularly limited as long as the pH in the mixed solution is maintained at 9 to 14, but may be in the range of 10 to 14. Preferably, it is in the range of 12-14. In the method for producing catalyst particles for hydrogenation of the present invention, the specific surface area of the catalyst precursor can be adjusted by adjusting the pH in the solution at the time of mixing. In order to prepare a catalyst precursor having a desired specific surface area, the acidic aqueous solution A and the above-described aqueous solution A are mixed so that the fluctuation of pH during mixing is within a range of −0.5 to +0.5 of a set value. It is preferable to control the addition of the basic aqueous solution B.

Although it does not specifically limit as a water-soluble copper compound contained in acidic aqueous solution A, Copper sulfate (II), Copper nitrate (II), Copper chloride (II) etc. are mentioned, Among these, Reaction by-products Copper (II) sulfate is preferable because of the ease of treatment.
Although the density | concentration in conversion of the oxide of the water-soluble copper compound contained in the acidic aqueous solution A is not specifically limited, It is preferable that it is 10-1000 g / L, and it is more preferable that it is 10-100 g / L.
When the concentration in terms of oxide of the water-soluble copper compound contained in the acidic aqueous solution A is less than 10 g / L, the basic aqueous solution B can be uniformly mixed, but the amount of precipitate generated is small Become. For this reason, it becomes impossible to efficiently produce catalyst particles for hydrogenation.
If the concentration of the water-soluble copper compound contained in the acidic aqueous solution A in terms of oxide is higher than 1000 g / L, the catalytic activity of the hydrogenation catalyst particles obtained through the subsequent steps tends to be lowered.

The acidic aqueous solution A desirably contains at least one water-soluble metal compound selected from zirconium, zinc, aluminum, titanium, and iron in addition to the water-soluble copper compound. Among these, a water-soluble zirconium compound is preferable.
When the acidic aqueous solution A contains a water-soluble metal compound other than the water-soluble copper compound, the weight ratio between the water-soluble copper compound and the water-soluble metal compound is not particularly limited, but is oxidized in terms of oxide of each metal. It is preferable that it is copper: metal oxide = 10: 85-85: 10. When the ratio of copper oxide is lower than the above ratio, the catalytic activity decreases. Moreover, when the ratio of copper oxide is higher than the above ratio, the metal easily aggregates due to heat, and the durability of the catalyst is lowered.

The substance contained in the basic aqueous solution B is not particularly limited, but alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, alkali metal carbonates such as sodium carbonate and potassium carbonate, sodium hydrogen carbonate and the like. Examples thereof include alkali metal hydrogen carbonates such as potassium hydrogen carbonate, amine compounds such as ammonia, methylamine, trimethylamine and alkanolamine, ammonium carbonate, ammonium hydrogencarbonate and the like. Among these, an alkali metal hydroxide having excellent reactivity is preferable, and sodium hydroxide is more preferable. Although the density | concentration of the substance contained in the said basic aqueous solution B is not specifically limited, It is preferable that it is 1-400 g / L, and it is more preferable that it is 1-100 g / L. Further, for the purpose of preventing aggregation of the catalyst particles and controlling the particle diameter, 1 g to 100 g of sodium metasilicate and sodium orthosilicate may be added to 100 g of the catalyst precursor.

Although it does not specifically limit as temperature at the time of mixing acidic aqueous solution A and basic aqueous solution B, It is preferable that it is 30 to 100 degreeC, It is more preferable that it is 50 to 100 degreeC, 80 to 100 degreeC More preferably, the temperature is C.
In the mixing of the acidic aqueous solution A and the basic aqueous solution B, the copper ions contained in the acidic aqueous solution A and the hydroxide ions contained in the basic aqueous solution B react to form copper (II) hydroxide and precipitate. Arise. Copper hydroxide (II) becomes copper oxide (II) by heat. The higher the temperature in this mixing, the faster the production of copper (II) oxide. Conversely, when the temperature is low, the proportion of copper hydroxide (II) increases. That is, when the temperature in mixing is in the above range, the ratio of copper (II) oxide contained in the precipitate is increased.

A first slurry is produced by mixing the acidic aqueous solution A and the basic aqueous solution B. Although a 1st slurry is not specifically limited, It is preferable to contain the deposit of the density | concentration of 5-70 g / L in conversion of the oxide of the metal component contained in the acidic aqueous solution A. If the first slurry contains a precipitate in the above range, the first slurry can be suitably aged as described later.
The amount of the precipitate contained in the first slurry can be controlled by adjusting the concentrations of the acidic aqueous solution A and the basic aqueous solution B.

(Aging of the first slurry)
Next, in the method for producing hydrogenation catalyst particles of the present invention, the first slurry is aged. Aging is a process of reacting unreacted raw materials contained in the first slurry. If the aging is insufficient, the remaining amount of unreacted raw material increases, and the catalytic activity of the hydrogenation catalyst particles obtained through the subsequent steps tends to decrease. By suitably controlling the aging of the first slurry, the catalytic activity of the hydrogenation catalyst particles obtained through the subsequent steps can be improved.

As described above, the first slurry preferably contains a precipitate having a concentration of 5 to 70 g / L in terms of metal oxide contained in the acidic aqueous solution A.
When the content of the precipitate is a concentration of less than 5 g / L in terms of oxide, production efficiency is deteriorated and it is not economical.
If the content of the precipitate is more than 70 g / L in terms of oxide, the viscosity of the slurry becomes high and it becomes difficult to stir uniformly, so the catalyst for hydrogenation obtained through the subsequent steps The catalytic activity of the particles tends to decrease.

Although it does not specifically limit in the manufacturing method of the catalyst particle for hydrogenation of this invention, It is preferable to perform the said aging at 30-100 degreeC, and it is more preferable to carry out at 80-100 degreeC.
When the aging temperature is lower than 30 ° C., the proportion of copper hydroxide (II) contained in the precipitate after aging increases.
When the aging temperature is higher than 100 ° C., the water evaporates, so that the first slurry cannot be maintained at an appropriate concentration.

Although it does not specifically limit in the manufacturing method of the catalyst particle for hydrogenation of this invention, It is preferable to perform the said aging for 30 to 120 minutes, and it is more preferable to perform for 30 to 60 minutes.
When the aging time is shorter than 30 minutes, the remaining amount of unreacted raw material contained in the liquid content of the first slurry increases. Therefore, it becomes impossible to produce the hydrogenation catalyst particles efficiently.
When the aging time is longer than 120 minutes, the specific surface area of the hydrogenation catalyst particles obtained through the subsequent steps becomes small. As a result, the catalytic activity of the hydrogenation catalyst particles tends to decrease. In addition, the production efficiency deteriorates and it is not economical.

(Separation of catalyst precursor solids)
Next, in the method for producing the hydrogenation catalyst particles of the present invention, the catalyst precursor solid content is separated from the first slurry.
The liquid content of the first slurry after aging contains a water-soluble substance derived from the acidic aqueous solution A and the basic aqueous solution B that has not been precipitated by the above-described step. If the hydrogenation catalyst particles are produced with such a water-soluble substance contained, the catalytic activity is lowered. In particular, it is known that the S component contained when a metal sulfate salt is used reduces the catalytic activity. Furthermore, the specific surface area tends to decrease. Therefore, it is important to remove these water-soluble substances in order to improve the catalytic activity.
Therefore, in the method for producing catalyst particles for hydrogenation according to the present invention, the solid content of the catalyst precursor is separated from the first slurry after aging. Thereby, the said water-soluble substance can be prevented from being contained in a catalyst precursor. Whether or not the above substances are removed can be confirmed by measuring the conductivity of the filtrate.
The conductivity of the filtrate is preferably 30 mS / m or less. The method for separating the catalyst precursor solid content is not particularly limited, and an apparatus used for normal catalyst production can be used. For example, when removing suction filtration, filter press, and moisture, cakeless filtration (dynamic filtration) having a scavenging mechanism that prevents the filter cake from becoming thicker as much as possible can be employed. Further, rotary cylindrical cakeless filtration, multi-chamber cylindrical vacuum filtration, centrifugal slurry filtration, or the like may be employed.

(Preparation of second slurry)
Next, in the method for producing hydrogenation catalyst particles of the present invention, the separated catalyst precursor solid content is suspended in an aqueous medium to prepare a second slurry. Thereby, a 2nd slurry can be used suitably for the spray drying performed at a next process.
Although it does not specifically limit as a 2nd slurry, It is preferable that the density | concentration of catalyst precursor solid content is 50-300 g / L in conversion of an oxide, It is more preferable that it is 75-250 g / L, 75 g-200 g More preferably, it is / L.

(Spray drying)
Next, in the method for producing catalyst particles for hydrogenation according to the present invention, a substantially spherical powder is obtained by spray drying the second slurry. Spray drying is a method in which a slurry is sprayed and dried by blowing hot air on the sprayed slurry. When the slurry is sprayed, the droplets become substantially spherical due to surface tension. When such droplets are immediately dried, the resulting powder has a substantially spherical shape. Further, the size of the droplet is proportional to the size of the obtained powder. The droplet size can be adjusted according to the spraying conditions. In particular, when spraying the slurry, if the spraying conditions are constant, the sprayed droplets have a certain size. Further, since the droplets are dried quickly, the particle size distribution of the obtained powder becomes sharp, and a powder having a desired particle size can be obtained.

The method for spray drying is not particularly limited, and examples thereof include centrifugal spray drying using a centrifugal sprayer and pressurized spraying using a pressure nozzle. Among these, a method using a centrifugal sprayer is preferable. Although it does not specifically limit as conditions of the spray drying by a centrifugal sprayer, It is preferable to set it as disc rotation speed 5000-25000rpm, It is more preferable to be 12000-18000rpm, It is further more preferable to be 14000-15000rpm. The outlet temperature is preferably 50 to 150 ° C, more preferably 80 to 120 ° C, and further preferably 90 to 100 ° C.
By spray-drying under such conditions, in the particle size distribution of the hydrogenation catalyst particles obtained through the subsequent steps, the proportion of particles having a particle size of 10 to 100 μm accounts for 95 to 100% of the total particle size, and the particle size is 10 μm. The proportion of less than particles can be less than 5% of the total.

When performing spray drying, a dispersant may be added to the second slurry. Examples of the dispersant include, but are not limited to, polycarboxylic acids and salts thereof, preferably polymaleic acid and salts thereof, polyacrylic acid and salts thereof, substituted acrylic acid polymers, acrylic copolymers, sodium salts of acrylic copolymers, and / or Or an ammonium salt. Representative examples of dispersants derived from acrylic acid include polyacrylic acid and its sodium salt or ammonium salt, and acrylic acid and monomers such as 2-acrylamide, sulfonic acid derivatives such as 2-methylpropanesulfonic acid, and the like. These copolymers are included. A comonomer copolymerizable with acrylic acid or substituted acrylic acid can contain a carboxyl group. Examples of commercialized products include Dispex A-40 (Ciba Specialty Chemicals, Inc.). Other dispersants, such as other types of acrylic dispersants, may be used in forming the compositions of the present invention. It is preferable that the dispersant is added in an amount of 0.1 to 2.0% by weight based on the weight of the solid content of the catalyst precursor contained in the second slurry. When the dispersant is added to the second slurry, the second slurry is less likely to agglomerate, so that it can be suitably sprayed.

(Baking powder)
In the method for producing hydrogenation catalyst particles of the present invention, the substantially spherical powder is calcined.
Firing means heating the powder to convert the metal component contained in the powder into an oxide. Catalytic activity can be obtained by firing.
Firing is not particularly limited, but is preferably performed at a firing temperature of 250 to 550 ° C. and a firing time of 1 to 10 hours, more preferably at a firing temperature of 300 to 500 ° C. and a firing time of 3 to 5 hours. preferable. The firing atmosphere is not particularly limited, and may be performed in an atmosphere of air, carbon dioxide, nitrogen, hydrogen, argon, or the like.

(Catalyst particles for hydrogenation)
Through the above steps, the hydrogenation catalyst particles of the present invention can be obtained.
The hydrogenation catalyst particles of the present invention are substantially spherical hydrogenation catalyst particles containing copper oxide, and in the particle size distribution of the hydrogenation catalyst particles, the ratio of particles having a particle size of 10 to 100 μm is 95% of the total. The proportion of particles having a particle diameter of less than 10 μm is less than 5%, and the specific surface area is 120 to 200 m ² / g.

When the proportion of the hydrogenation catalyst particles having a particle diameter of less than 10 μm is 5% or more of the total hydrogenation catalyst particles, it becomes difficult to sufficiently remove the hydrogenation catalyst particles from the reaction system in which the catalyst is used. Therefore, a lot of impurities are contained in the product obtained by the catalytic reaction. This is not preferred from the standpoint of product purity. Moreover, the filtration efficiency also deteriorates.
When the particle diameter of the hydrogenation catalyst particles exceeds 100 μm, the space between the hydrogenation catalyst particles increases. Therefore, it becomes bulky when storing the hydrogenation catalyst particles. Moreover, since the specific surface area becomes smaller in inverse proportion to the size of the particle diameter, when the particle diameter of the hydrogenation catalyst particles exceeds 100 μm, the catalytic activity tends to decrease.
The particle diameter and particle size distribution of the hydrogenation catalyst particles can be measured by a conventionally known laser diffraction / scattering method.

The catalytic activity is proportional to the specific surface area of the hydrogenation catalyst particles. That is, the larger the specific surface area, the higher the catalytic activity.
The specific surface area of the catalyst particles for hydrogenation of the present invention is 120 to ²⁰⁰ m ² / g. The hydrogenation catalyst particles of the present invention having such a large specific surface area have a sufficiently high catalytic activity.
In this specification, the specific surface area refers to a value measured by a nitrogen adsorption BET one-point method.

The hydrogenation catalyst particles of the present invention preferably further contain at least one component selected from zirconium, zinc, aluminum, titanium, and iron. By including these components, the catalytic activity can be improved. Among these components, it is preferable that zirconium is contained.

The catalyst particles for hydrogenation of the present invention may be used as they are or after being subjected to a reduction treatment. By performing the reduction treatment, the catalytic activity is more strongly expressed.

The present invention will be described below in more detail based on examples, but the present invention is not limited only to these examples.

Example 1
The hydrogenation catalyst particles according to Example 1 were obtained by performing the following operations.

(Preparation of acidic aqueous solution A)
348 g of copper sulfate pentahydrate, 228 g of zirconium oxychloride octahydrate, and 4.8 g of sulfuric acid were added to ion-exchanged water and stirred to obtain an acidic aqueous solution A having a total amount of 1.8 L.

(Preparation of basic aqueous solution B)
260 g of sodium hydroxide and 36 g of sodium metasilicate were added to ion-exchanged water and stirred to obtain a basic aqueous solution B having a total amount of 1.8 L.

(Mixing of acidic aqueous solution A and basic aqueous solution B)
The acidic aqueous solution A and the basic aqueous solution B prepared in the above process were simultaneously added to the reaction tank at a flow rate of 10 mL / min and mixed. The pH during mixing was 12.5 to 13.0. At this time, the liquid temperature during mixing was maintained at 80 ° C.
The solution in which these solutions were mixed became the first slurry, and the pH was 12.9.
The first slurry contains a catalyst precursor which is a precipitate such as copper hydroxide generated by the reaction between the acidic aqueous solution A and the basic aqueous solution B.

(Aging of the first slurry)
After each solution was completely added to the reaction tank, the first slurry was stirred at 80 ° C. for 60 minutes to age the first slurry.

(Separation of catalyst precursor solids)
After aging the catalyst precursor, the first slurry was cooled to room temperature. Next, washing with water was repeated by decanting with water until the filtrate had a conductivity of 30 mS / m to remove water-soluble substances such as sodium ions, sulfate ions and chloride ions in the slurry. The catalyst precursor solids were separated from the first slurry by suction filtration.

(Preparation of second slurry)
The washed catalyst precursor solid was suspended in ion-exchanged water so that the slurry concentration was 75 g / L.

(Spray drying)
The second slurry is spray-dried using a spray dryer (product name: L-12 type, manufactured by Okawahara Chemical Co., Ltd.) with an inlet temperature of 230 ° C., an outlet temperature of 90 ° C., and a disk rotation speed of 15000 rpm. Got the body.
FIGS. 1A and 1B are enlarged photographs of a powder obtained by spray drying the second slurry in the method for producing hydrogenation catalyst particles of the present invention, using a scanning electron microscope (SEM). is there.
FIG. 1A is an enlarged photograph with an observation magnification of 200 times, and FIG. 1B is an enlarged photograph with an observation magnification of 2000 times. As shown in FIGS. 1 (a) and (b), the powder obtained by spray drying was substantially spherical.

(Baking powder)
The powder obtained in the above process was placed in a box-type firing furnace, fired at a firing temperature of 450 ° C. and fired for 5 hours.

The fired particles obtained through the above steps are catalyst particles for hydrogenation according to Example 1.
The particle size distribution of the hydrogenation catalyst particles of Example 1 is shown in FIG.
The particle size and particle size distribution are determined by the transmittance of the dispersion liquid in a sample bath in which pure water is circulated using a laser diffraction / scattering type particle size distribution measuring device (product name: LA-950-V2, manufactured by HORIBA). The sample was added to measure to 85 to 90%. The measurement conditions were a sample refractive index of 2.71, a dispersion medium refractive index of 1.333, and a measurement wavelength of LD655 mm.
The specific surface area was measured using an automatic specific surface area measuring device (product name: GEMINI VII2390, manufactured by Micromeritics) in accordance with the provisions of JIS Z 8830. The sample was heat-treated at 200 ° C. for 60 minutes in a nitrogen atmosphere. .

(Example 2)
The composition of the acidic aqueous solution A was changed to 87 g of copper sulfate pentahydrate, 57 g of zirconium oxychloride octahydrate, 1.2 g of sulfuric acid and the total amount to 450 mL, and the composition of the basic aqueous solution B was changed to 43.4 g of sodium hydroxide. Then, hydrogenation catalyst particles according to Example 2 were obtained in the same manner as in Example 1 except that 9 g of sodium metasilicate and the total amount were changed to 450 mL. In Example 2, the pH during mixing of the acidic aqueous solution A and the basic aqueous solution B was 9.9 to 10.2, and the pH of the first slurry was 10.0. Table 1 shows the specific surface area of the hydrogenation catalyst particles of Example 2.

(Comparative Example 1)
A hydrogenation catalyst particle according to Comparative Example 1 was obtained in the same manner as in Example 1 except that a box dryer was used instead of spray drying, the drying temperature was 120 ° C., and drying was performed for 16 hours. The particle size distribution of the hydrogenation catalyst particle medium of Comparative Example 1 is shown in FIG.

(Comparative Example 2)
The composition of the acidic aqueous solution A was changed to 87 g of copper sulfate pentahydrate, 57 g of zirconium oxychloride octahydrate, 1.2 g of sulfuric acid and the total amount to 450 mL, and the composition of the basic aqueous solution B was changed to 42.3 g of sodium hydroxide. The catalyst particles for hydrogenation according to Comparative Example 2 were obtained in the same manner as in Example 1 except that 9 g of sodium metasilicate and the total amount were changed to 450 mL. In Comparative Example 2, the pH during mixing of the acidic aqueous solution A and the basic aqueous solution B was 8.4 to 8.7, and the pH of the first slurry was 8.5. Table 1 shows the specific surface area of the hydrogenation catalyst particles of Comparative Example 2.

(Comparative Example 3)
The composition of the acidic aqueous solution A was changed to 87 g of copper sulfate pentahydrate, 57 g of zirconium oxychloride octahydrate, 1.2 g of sulfuric acid and the total amount to 450 mL, and the composition of the basic aqueous solution B was changed to 41.6 g of sodium hydroxide. The catalyst particles for hydrogenation according to Comparative Example 3 were obtained in the same manner as in Example 1 except that 9 g of sodium metasilicate and the total amount were changed to 450 mL. In Comparative Example 3, the pH during mixing of the acidic aqueous solution A and the basic aqueous solution B was 7.9 to 8.1, and the pH of the first slurry was 8.0. Table 1 shows the specific surface area of the hydrogenation catalyst particles of Comparative Example 3.

2 is a graph showing the particle size distribution of the hydrogenation catalyst particles of Example 1 of the present invention and the particle size distribution of the hydrogenation catalyst particles of Comparative Example 1. FIG.
As shown in FIG. 2, the particle size distribution of the hydrogenation catalyst particles of Example 1 is sharp. On the other hand, the particle size distribution of the hydrogenation catalyst particles of Comparative Example 1 is broad. In Example 1, the ratio of particles having a particle diameter of less than 10 μm was less than 1%, and such particles were hardly present. On the other hand, in Comparative Example 1, the ratio of particles having a particle diameter of less than 10 μm was 11%, and many such particles were present.

FIG. 3 is a diagram showing the relationship between the pH during mixing of the acidic aqueous solution A and the basic aqueous solution B and the specific surface area of the hydrogenation catalyst particles in the method for producing the hydrogenation catalyst particles.
As shown in FIG. 3, the specific surface area of the hydrogenation catalyst particles correlates with the pH at the time of mixing the acidic aqueous solution A and the basic aqueous solution B, and the specific surface area of the hydrogenation catalyst particles increases as the pH increases. You can see it grows.
In particular, the ratio of the catalyst particles for hydrogenation in Example 1 in which the pH of the first slurry produced by mixing the acidic aqueous solution A and the basic aqueous solution B is 12.9 and in Example 2 in which the pH is 10.0. The surface area was larger than the specific surface area of the hydrogenation catalyst particles of each comparative example.

Claims (9)

A method for producing hydrogenation catalyst particles containing copper oxide,
A step of producing a first slurry containing a catalyst precursor by reacting an acidic aqueous solution A containing a water-soluble copper compound and a basic aqueous solution B while maintaining the pH at 9 to 14 in an aqueous medium. When,
Aging the first slurry;
Separating the catalyst precursor solids from the first slurry;
Suspending the separated catalyst precursor solids in an aqueous medium to prepare a second slurry;
Obtaining a substantially spherical powder by spray drying the second slurry;
And a step of firing the substantially spherical powder. The method for producing catalyst particles for hydrogenation according to claim 1, wherein the acidic aqueous solution A further contains at least one water-soluble metal compound selected from zirconium, zinc, aluminum, titanium, and iron. 3. The hydrogenation according to claim 2, wherein a weight ratio of the water-soluble copper compound to the water-soluble metal compound is copper oxide: metal oxide = 10: 85 to 85:10 in terms of oxide of each metal. Of producing catalyst particles for use. The method for producing catalyst particles for hydrogenation according to any one of claims 1 to 3, wherein the aging step is performed at 30 to 100 ° C. The spray-drying is performed by using a centrifugal sprayer, the conditions of spray-drying by the centrifugal sprayer are set to a disk rotational speed of 5000 to 25000 rpm, and the outlet temperature is set to 50 to 150 ° C. The manufacturing method of the catalyst particle for hydrogenation as described in claim | item. The method for producing catalyst particles for hydrogenation according to any one of claims 1 to 5, wherein the calcination is performed at a calcination temperature of 250 to 550 ° C for 1 to 10 hours. Substantially spherical hydrogenation catalyst particles containing copper oxide,
In the particle size distribution of the catalyst particles for hydrogenation, the proportion of particles having a particle size of 10 to 100 μm accounts for 95 to 100% of the whole, and the proportion of particles having a particle size of less than 10 μm is less than 5% of the whole,
Catalyst particles for hydrogenation having a specific surface area of 120 to 200 m ² / g. The catalyst particles for hydrogenation according to claim 7, wherein the catalyst particles for hydrogenation further contain at least one component selected from zirconium, zinc, aluminum, titanium, and iron. The catalyst particles for hydrogenation according to claim 7 or 8, wherein the catalyst particles for hydrogenation are obtained by the production method according to any one of claims 1 to 6.