JP7098434B2 - Method for producing solid catalysts and aldehydes - Google Patents

Description

The present invention relates to a solid catalyst and a method for producing aldehydes. More specifically, the present invention relates to a solid catalyst for producing aldehydes from carboxylic acids as a raw material, and a method for producing aldehydes from carboxylic acids by hydrogenation using the solid catalyst.

Aldehydes are industrially extremely important compounds as intermediates for various organic chemical syntheses, and are used in large quantities as raw materials for ethyl acetate, peracetic acid, pyridine derivatives, pentaerythritol, crotonaldehyde, paraldehyde, etc. ing.

Currently, aldehydes are industrially produced mainly by oxidation or hydroformylation of ethylene and terminal olefins. However, all of these raw materials are petroleum-derived compounds, and due to the recent soaring prices of petroleum and the problem of resource depletion, a more stable and inexpensively available compound-based production method is desired. Here, focusing on acetaldehyde, which is produced in large quantities industrially, among aldehydes, acetaldehyde has been used as a raw material for producing acetic acid by its oxidation in the past, and acetic acid is inevitably used. It was a more expensive compound than acetaldehyde. However, when the acetic acid production method was changed to the methanol carbonylation method (so-called Monsanto method) in the 1970s, the price order of acetic acid and acetaldehyde was reversed, and the production of acetaldehyde by hydrogen reduction of acetic acid was economically sufficiently established. It became a situation. Furthermore, acetaldehyde is currently produced from ethylene as a raw material as described above, whereas acetic acid is produced from raw materials that can be synthesized from non-petroleum raw materials, such as methanol and carbon monoxide. It can be said that the production of acetaldehyde using acetic acid as a raw material is preferable from the viewpoint of ensuring stability, protecting resources, and protecting the global environment.

From the above situation, some acetaldehyde has already been synthesized by hydrogen reduction of acetic acid. Listed below, Gerald C. Tastin et al. Disclosed a catalyst in which 2.5 to 90% by weight of palladium was added to iron oxide (Patent Document 1). Victor Jay Johnston et al. Disclosed a catalyst in which a carrier composed of silica and carbon was supported with palladium and a metal group composed of iron, copper, gold, and potassium as a second component (Patent Document 2).

In addition, R. Pestman et al. Disclosed that acetaldehyde can be obtained with high selectivity by using a platinum-supported iron oxide catalyst as a method for producing acetaldehyde from acetic acid by hydrogenation (Non-Patent Document 1). In addition, R. Pestman et al. Disclosed that acetaldehyde can be obtained with high selectivity by using an iron oxide catalyst as a method for producing acetaldehyde from acetic acid by hydrogenation (Non-Patent Document 2).

Japanese Unexamined Patent Publication No. 11-322658 Japanese Patent Publication No. 2011-528494

JOURNAL OF CATALYSIS vol.168, 255-264 (1997) JOURNAL OF CATALYSIS vol.148, 261-269 (1994)

Based on the above-mentioned prior art document, the present inventors have conducted verification for industrially producing aldehydes by hydrogenating them in a gas phase using carboxylic acids as raw materials. As a result, the conversion rate of carboxylic acids and aldehydes have been verified. It turned out that the selectivity of the class was not sufficient. Further, the palladium-supported iron oxide catalyst has a drawback that it requires a large amount of palladium in order to obtain good reaction generation, and the catalyst becomes extremely expensive, so that it is not suitable for industrial use.

Therefore, an object of the present invention is that when carboxylic acids are used as a raw material and hydrogenated in a gas phase to produce aldehydes, the conversion rate of the carboxylic acids and / or the selectivity of the aldehydes is high, and the reaction time elapses. It is an object of the present invention to provide a solid catalyst which can suppress a decrease in the yield of aldehydes and is relatively inexpensive and industrially useful. Further, when carboxylic acids are used as a raw material and hydrogenated in a gas phase to produce aldehydes, the conversion rate of carboxylic acids and / or the selectivity of aldehydes is high, and the yield of aldehydes with the passage of reaction time is high. Provided is an industrially useful method for producing aldehydes, which can suppress the decrease.

As a result of diligent studies to solve the above problems, the present inventors have unexpectedly used a specific carrier and a specific inorganic particle as a binder without changing the composition of the catalyst to obtain carboxylic acids. We have found that the conversion rate of carboxylic acids and / or the selectivity of aldehydes in hydrogenation can be improved, and the decrease in the yield of aldehydes with the passage of reaction time can be suppressed, and the present invention has been completed.

That is, the present invention is a carrier-supported solid catalyst for producing aldehydes by hydrogenating in a gas phase using carboxylic acids as a raw material, and the carrier supporting the catalyst component is a sponge-like porous material. And provides a solid catalyst containing at least one inorganic particle selected from the group consisting of alumina, silica, titania, and zirconia as a binder.

In the solid catalyst of the present invention, the content of the inorganic particles in the binder is preferably 0.01 to 20% by weight with respect to the solid catalyst.

In the solid catalyst of the present invention, it is preferable that the catalyst component contains a platinum group metal and iron.

In the solid catalyst of the present invention, the platinum group metal is preferably palladium.

The solid catalyst of the present invention preferably contains molybdenum as the catalyst component.

In the solid catalyst of the present invention, it is preferable that the carrier contains a ceramic or a metal.

The present invention also provides a method for producing aldehydes from carboxylic acids by hydrogenating them in a gas phase using a solid catalyst, and provides a method for producing the aldehydes which are the solid catalysts.

In the method for producing aldehydes of the present invention, it is preferable that the carboxylic acids are acetic acid and the aldehydes are acetaldehyde.

According to the solid catalyst of the present invention, in hydrogenation of carboxylic acids, the conversion rate of carboxylic acids and / or the selectivity of aldehydes can be increased, and the decrease in yield of aldehydes with the lapse of reaction time is suppressed. It is possible to do. Further, according to the method for producing aldehydes of the present invention using the solid catalyst of the present invention, the conversion rate of carboxylic acids and / or the selectivity of aldehydes can be increased, and the aldehydes can be increased with the passage of reaction time. The decrease in yield can be suppressed.

It is a schematic flow chart which shows an example of the manufacturing method of the aldehydes of this invention. 6 is a graph showing the yield of acetaldehyde after a predetermined time has elapsed from the start of the reaction in the reaction of the example.

[Solid catalyst]
The solid catalyst of the present invention is a solid catalyst for producing aldehydes by hydrogenation in a gas phase using carboxylic acids as a raw material (solid catalyst for producing aldehydes), and the carrier supporting the catalyst component is a sponge. It is a porous material in the form of a solid, and contains at least one inorganic particle selected from the group consisting of alumina, silica, titania, and zirconia as a binder. The solid catalyst of the present invention is a substance that works to accelerate the rate of the chemical reaction of hydrogenation when hydrogenating carboxylic acids to produce aldehydes.

(Catalyst component)
The catalyst component in the solid catalyst of the present invention preferably contains a platinum group metal and iron. The platinum group metal may be any material containing a platinum group metal element, and may be an oxide of a platinum group metal or the like. Further, the iron may be any iron containing an iron (Fe) element, and may be an oxide of iron or the like.

The platinum group metal indicates an element located in the 5th and 6th periods, the 8th, 9th, and 10th groups in the periodic table. Specific examples of the platinum group metal include an element group consisting of ruthenium, rhodium, palladium, osmium, iridium, and platinum. Of these, palladium and platinum are preferable from the viewpoint of catalytic activity, but palladium is generally cheaper than platinum, and therefore, industrially, palladium is particularly preferable. These platinum group metals may be used alone or in combination of two or more.

As the platinum group metal, various commercially available catalysts such as a palladium catalyst and a platinum catalyst can also be used. As a raw material for preparing a palladium catalyst, a Pd (NO ₃ ) ₂ aqueous solution, palladium acetate, or the like can be used. Further, as a raw material for preparing a platinum catalyst, H ₂ Pt (OH) ₆ or the like can be used.

The content of the platinum group metal (in terms of elemental element of the metal) is, for example, 0.5 to 45% by weight, preferably 1 to 40% by weight, more preferably 2 to 38% by weight, based on the total amount of the catalyst component (100% by weight). %, More preferably 3 to 35% by weight. When the content of the platinum group metal is in the above range, good catalytic activity can be easily obtained. When palladium is contained as the platinum group metal, the content of palladium (in terms of Pd element) is, for example, 0.5 to 45% by weight, preferably 1 to 40% by weight, based on the total amount of the catalyst component (100% by weight). It is preferably 2 to 38% by weight, more preferably 3 to 35% by weight. The total amount of the catalyst component is a value obtained by subtracting the weight of the carrier from the weight of the entire solid catalyst.

Examples of the raw material for iron include oxides containing an iron (Fe) element, nitrides, and other iron compounds. As the raw material for iron, for example, Fe (NO ₃ ) _{3.9H 2} O, FeSO _{4.7H 2} O, and iron oxide can be used. As the raw material for iron, commercially available ones can be used, and one kind can be used alone or two or more kinds can be used in combination. When a compound having a non-thermally decomposable counterion such as iron sulfate is used as a raw material for iron, the evaporative drying method of an iron salt solution cannot be used. For example, when iron sulfate is used, ammonia or the like can be used. After adding an alkaline precipitate to precipitate as an insoluble iron compound, it is necessary to thoroughly wash the precipitate with water to remove sulfate ions. As will be described later, iron will be present in the catalyst as iron oxide by firing.

The iron content (Fe ₂ O ₃ conversion) is, for example, 30 to 99.5% by weight, preferably 50 to 99% by weight, more preferably 60 to 98% by weight, based on the total amount of catalyst components (100% by weight). , More preferably 70-97% by weight. When the iron content is in the above range, sufficient catalytic activity is maintained and a high selectivity for aldehydes and the like can be easily obtained. The iron content (Fe ₂ O ₃ conversion) can be obtained by calculating the amount of iron (Fe) from elemental analysis and converting it to Fe ₂ O ₃ even in the oxidation form other than Fe ₂ O ₃ . Can be done.

As for the composition ratio of the platinum group metal and iron, for example, 1 to 80 parts by weight, preferably 5 to 60 parts by weight of the platinum group metal (converted to a single element of metal) with respect to 100 parts by weight of iron (converted to Fe ₂ O ₃ ). Parts, more preferably 10 to 50 parts by weight. Generally, the higher the weight ratio of platinum group elements, the higher the catalytic activity (raw material conversion rate), but the price of the catalyst rises, so the composition ratio is determined based on economic rationality.

In addition, platinum group elements and other components other than iron can coexist, and metal oxides such as germanium oxide, tin oxide, vanadium oxide, and zinc oxide can be contained, and copper, gold, potassium, cerium, and the like can be contained. It is also possible to contain 3 metal components. The total weight of the platinum group elements and other components other than iron is, for example, 25% by weight or less, preferably 20% by weight or less, and more preferably 15% by weight or less, based on the total catalyst component (100% by weight).

The total weight of the platinum group metal and iron is, for example, 75% by weight or more, preferably 80% by weight or more, and more preferably 85% by weight or more with respect to the total amount of the catalyst component (100% by weight). When the ratio of the platinum group metal and iron is above a certain level, good catalytic activity can be obtained.

The content of the catalyst component (excluding molybdenum) is, for example, 2 to 500 parts by weight, preferably 2.5 to 300 parts by weight, more preferably 3 to 200 parts by weight, still more preferably 5 with respect to 100 parts by weight of the carrier. ~ 100 parts by weight.

The content of the catalyst component (excluding molybdenum) is, for example, 5 to 80% by weight, preferably 8 to 60% by weight, and more preferably 10 to 50% by weight with respect to the solid catalyst (100% by weight).

The solid catalyst of the present invention may further contain molybdenum as a catalyst component. In the present invention, when molybdenum is contained, the catalytic activity can be easily maintained, the life of the catalyst can be further improved, and the conversion rate of carboxylic acids can be further improved. The molybdenum may be molybdenum oxide, molybdate, or the like as long as it contains a molybdenum element (Mo).

As the molybdenum, various commercially available catalysts such as molybdenum oxide and molybdate can also be used. As a raw material for preparing molybdenum, hexaammonium hexaammonium tetrahydrate heptamolybdate or the like can be used. When molybdenum is supported on a solid catalyst as described later, it is preferable to adjust the solution of the preparation raw material to be alkaline (for example, pH 10 to 14).

When molybdenum is contained, the content of molybdenum (Mo element equivalent) is, for example, 1 to 40 parts by weight, preferably 3 to 35 parts by weight, and more preferably 5 with respect to 100 parts by weight of iron (Fe ₂ O ₃ equivalent). ~ 30 parts by weight. When molybdenum is contained, the content of molybdenum (Mo element equivalent) is, for example, 0.6 to 22% by weight, preferably 1.6 to 20% by weight, based on the total amount of the catalyst component (100% by weight). It is preferably 2.7 to 18% by weight. When the molybdenum content is in the above range, good catalytic activity can be easily obtained, and the conversion rate of carboxylic acids can be further improved.

The content of the total catalyst component including molybdenum is, for example, 2 to 30, preferably 2.5 to 20 parts by weight, more preferably 3 to 15 parts by weight, still more preferably 5 to 100 parts by weight with respect to 100 parts by weight of the carrier. It is a part by weight. The content of all catalyst components including molybdenum is, for example, 2 to 23% by weight, preferably 2.5 to 17% by weight, and more preferably 3.0 to 13% by weight with respect to the solid catalyst (100% by weight). It is% by weight.

(Carrier)
The carrier in the solid catalyst of the present invention is a sponge-like porous material. The sponge-like porous material preferably has a three-dimensional network-like skeleton structure having many communicating pores (continuous pores).

The carrier that supports the catalyst component preferably contains ceramic or metal as the component because it is excellent in heat resistance and durability. The carrier may contain a metal as a component together with the ceramic. As the ceramic or metal, alumina, magnesia, silica, zirconia, silicon carbide, silicon nitride, nickel, and nickel-chromium alloys are preferable. Of these, ceramics (a blend type of cordierite and alumina) composed of three components of alumina, magnesia, and silica, nickel, and a nickel-chromium alloy are particularly preferable. The carrier may contain components other than ceramics and metals such as organic substances as long as the effects of the present application are not impaired.

When the carrier contains ceramic, the proportion of the ceramic is, for example, 30% by weight or more, preferably 50% by weight or more, more preferably 70% by weight or more, still more preferably 70% by weight or more, based on the carrier (100% by weight). It is 80% by weight or more, particularly preferably 90% by weight or more.

When the carrier contains a metal, the proportion of the metal is, for example, 30% by weight or more, preferably 50% by weight or more, more preferably 70% by weight or more, still more preferably 80% by weight or more, based on the carrier (100% by weight). Particularly preferably, it is 90% by weight or more.

When the ceramic and the metal are contained, the total ratio of the ceramic and the metal is, for example, 50% by weight or more, preferably 60% by weight or more, more preferably 70% by weight or more, still more preferable, with respect to the carrier (100% by weight). Is 80% by weight or more, particularly preferably 90% by weight or more.

Examples of the shape of the carrier include a spherical shape, a cylindrical shape, and a cylindrical shape. The size of the carrier is not particularly limited, and when it is spherical, the diameter is, for example, about 0.05 to 20 mm, preferably 0.1 to 15 mm, more preferably 0.5 to 10 mm, and further. It is preferably 1 to 5 mm. In the case of a spherical shape, the average diameter is, for example, about 0.1 to 10 mm, preferably 0.2 to 8 mm, more preferably 0.3 to 5 mm, and further preferably 0.4 to 4 mm. Even if the carrier is spherical, if it is not within the above diameter range, or if it is in the shape of a plate or block of a large size, the carrier is appropriately crushed or sized so as to have an appropriate size (diameter) as the carrier. May be used.

Commercially available carriers can be used, such as sponge-like alumina cordierite (ceramic foam part numbers # 30, # 20, # 13 manufactured by Narita Ceramics Co., Ltd.) and sponge-like metal (manufactured by Sumitomo Electric Industries, Ltd.). , Ceramic part number # 4), etc. can be used. In the present invention, the carrier preferably has many pores per unit volume and has a large surface area. Further, it is preferable to have many communicating pores (continuous pores) from the viewpoint of excellent selectivity of aldehydes.

The porosity (porosity) of the carrier is, for example, 50 to 99%, preferably 60 to 98%, more preferably 70 to 98%, still more preferably 75 to 98%. When the porosity is in the above range, the surface of the carrier to which a sufficient amount of catalyst can be attached can be secured, and the gas can be sufficiently diffused to suppress retention, so that the selectivity of aldehydes is excellent.

The average pore size of the carrier is, for example, 0.1 to 5 mm, preferably 0.2 to 3 mm, more preferably 0.3 to 2 mm, still more preferably 0.5 to 1 mm. If the average pore size is within the above range, the surface of the carrier to which a sufficient amount of catalyst can be attached can be secured, and the gas can be sufficiently diffused to suppress retention, so that the selectivity of aldehydes can be improved. Be done.

The apparent specific gravity of the carrier is, for example, 0.05 to 1.0, preferably 0.1 to 0.98, more preferably 0.15 to 0.97, and even more preferably 0.2 to 0.95.

The ratio of the carrier in the solid catalyst of the present invention is, for example, 50 to 2000 parts by weight, preferably 80 to 900 parts by weight, more preferably 100 to 800 parts by weight, still more preferably 120 to 700 parts by weight with respect to 100 parts by weight of the catalyst component. It is a part by weight.

The content of the carrier is, for example, 30 to 99% by weight, preferably 40 to 97% by weight, and more preferably 50 to 95% by weight with respect to the solid catalyst (100% by weight).

(binder)
The binder (binder; binder) in the solid catalyst of the present invention contains at least one inorganic particle selected from the group consisting of alumina, silica, titania, and zirconia. These inorganic particles as a binder act to bind the catalyst components to each other or the catalyst component and the carrier by drying or firing. By this action, deterioration of the catalyst due to the passage of reaction time can be suppressed, the conversion rate of carboxylic acids can be increased, and a decrease in the yield of aldehydes can be suppressed.

In the solid catalyst of the present invention, the content of the inorganic particles as a binder (when a plurality of them are contained, the total content thereof) is preferably 0.01 to 20% by weight, for example, with respect to the solid catalyst (100% by weight). Is 0.05 to 10% by weight, more preferably 0.1 to 5% by weight, still more preferably 0.15 to 1% by weight. When the content of the inorganic particles is in the above range, the catalyst component and the carrier are firmly bound to each other, and deterioration of the catalyst due to the passage of reaction time can be easily suppressed.

The content of the inorganic particles in the binder is, for example, 0.1 to 50 parts by weight, preferably 0.5 to 40 parts by weight, more preferably 1 to 30 parts by weight, still more preferably, with respect to 100 parts by weight of the total amount of the catalyst component. Is 3 to 20 parts by weight. The content of the inorganic particles in the binder is, for example, 0.1 to 50 parts by weight, preferably 0.3 to 40 parts by weight, more preferably 1 to 30 parts by weight, still more preferably, with respect to 100 parts by weight of the carrier. Is 2 to 20 parts by weight.

The particle size (diameter) of the inorganic particles in the binder is, for example, 1 to 500 nm, preferably 3 to 300 nm, and more preferably 5 to 100 nm. The average particle size (diameter) of the inorganic particles is, for example, 2 to 300 nm, preferably 3 to 200 nm, and more preferably 5 to 100 nm. When the particle size of the inorganic particles is in the above range, the catalyst component and the carrier are bound to each other, and deterioration of the catalyst due to the passage of reaction time can be easily suppressed.

As the binder, a commercially available dispersion (sol) containing inorganic particles can be used. As the dispersion liquid containing alumina as the inorganic particles, product names "AS-200", "AS-520-A" (all manufactured by Nissan Chemical Industries, Ltd.) and the like can be used. As the dispersion liquid containing silica as inorganic particles, Snowtex (registered trademark), product names "ST-NXS", "ST-NS", "ST-N", "ST-N-40" (above, Nissan Chemical Industries) (Made by Co., Ltd.) etc. can be used. As the dispersion liquid containing zirconia as inorganic particles, nanouse (registered trademark) ZR, product names "ZR-30AL", "ZR-20AS", "ZR-30AH" (all manufactured by Nissan Chemical Industries, Ltd.) and the like are used. Can be used. Further, as the dispersion liquid containing titania as the inorganic particles, the product name "CSB" (manufactured by Sakai Chemical Industry Co., Ltd.) can be used.

As the inorganic particles in the binder, other inorganic particles may be contained in addition to the above-mentioned inorganic particles (alumina, silica, titania, and zirconia particles). Other inorganic particles include gold particles, silver particles, copper particles, nickel particles, nickel oxide particles, iron particles, iron oxide particles, tungsten particles, magnesium particles, magnesium oxide particles, zinc particles, zinc oxide particles, and cobalt particles. And particles of these alloys and the like.

The content of the inorganic particles (the total content thereof when a plurality of the particles are contained) is, for example, 80% by weight or more, preferably 90% by weight or more, based on all the inorganic particles (100% by weight) contained as the binder. It is preferably 95% by weight or more. The content of the other inorganic particles (the total content of these particles when a plurality of the particles are contained) is, for example, 20% by weight or less, preferably 10% by weight, based on all the inorganic particles (100% by weight) contained as the binder. Below, it is more preferably 5% by weight or less.

(Catalyst manufacturing method)
The solid catalyst of the present invention is prepared, for example, by adding (1) a step of preparing a solution of a catalyst component or a precursor thereof and a solvent, and (2) a sol of a binder and a solvent to the solution prepared in (1) to prepare a mixed solution. Steps of impregnating the carrier with the mixed solution prepared in (3) and (2), evaporating and drying the solvent impregnated in (4) and (3), and (5) and (4). It can be produced by a method including a step of firing a dried solvent. If necessary, the step of crushing or sizing the carrier used in (3) may be included.

Further, when producing a solid catalyst containing molybdenum as a catalyst component, after the above (5), a molybdenum preparation raw material such as hexaammonium tetrahydrate heptamolybdenum and a solution thereof are prepared, and the above (4) is prepared. ) And (5), it is preferable to produce the product after drying and firing. Molybdenum may be contained in the solid catalyst in an order other than this. When preparing a solution of the preparation raw material and its solvent in the above, it is preferable to add an aqueous ammonia solution or the like to the solution to make the solution alkaline (for example, pH 10 to 14). It is considered that molybdenum becomes mononuclear by making it alkaline and can be added on the catalyst with higher dispersion. When molybdenum is contained, the blending amount of molybdenum (Mo element conversion) is, for example, 1 to 30 parts by weight, preferably 3 to 25 parts by weight, more preferably 5 parts by weight with respect to 100 parts by weight of iron (Fe ₂ O ₃ conversion). ~ 20 parts by weight.

(1) In the step of preparing the catalyst component or a solution of the precursor and the solvent, the solution is prepared by adding the solvent to the catalyst component such as platinum group metal and iron and stirring the mixture. The blending amount of the platinum group metal is, for example, 0.5 to 40% by weight, preferably 1 to 38% by weight, more preferably 2 to 35% by weight, still more preferably 3 with respect to the total amount of the catalyst component (100% by weight). ~ 30% by weight. The amount of iron compounded is, for example, 30 to 99.5% by weight, preferably 40 to 99% by weight, based on the total amount of the catalyst component (100% by weight).

Examples of the solvent include water, alcohol and toluene, and water is preferable. The amount of the solvent used is not particularly limited as long as it can disperse or dissolve the added catalyst component, but is, for example, 100 to 5000 parts by weight, preferably 300 to 1000 parts by weight, based on 100 parts by weight of the total amount of the catalyst component used. Is. Further, since platinum group salts such as palladium are more easily precipitated than iron and other base metal salts, it is also effective to coexist a chelating agent such as citric acid and EDTA in the solution to improve the catalytic activity. be. The blending amount of the chelating agent is, for example, 10 to 1000 parts by weight with respect to 100 parts by weight of the solvent.

(2) In the step of adding the binder and the solvent sol to the solution prepared in (1) to prepare the mixture, the solvent is added to at least one inorganic particle selected from the group consisting of alumina, silica, titania, and zirconia. The added sol is added to the solution prepared in (1) and mixed uniformly to prepare a mixed solution. The solvent used and the amount of the solvent used are the same as in (1) above.

The blending amount of the inorganic particles as a binder is, for example, 0.1 to 50 parts by weight, preferably 1 to 40 parts by weight, more preferably 3 to 30 parts by weight, and further, with respect to 100 parts by weight of the total amount of the added catalyst component. It is preferably 8 to 20 parts by weight.

(3) The step of impregnating the carrier with the mixed solution prepared in (2) is performed, for example, by dropping the mixed solution onto the carrier or adding the carrier to the mixed solution. The carrier may be appropriately stirred or the like so that the mixed solution is uniformly impregnated. When the mixed solution is dropped onto the carrier, the carrier may be appropriately heated in order to evaporate the solvent contained in the catalyst component or its precursor. The heating temperature at that time is, for example, 50 to 100 ° C.

The carrier to be impregnated may be crushed or sized in advance in order to have an appropriate size as a catalyst, and the crushing of the carrier may be cut to an approximately predetermined size with, for example, a ceramic cutter. can. Further, the sizing can be performed using, for example, a sieve. When the carrier after sizing is spherical, the average diameter is, for example, about 0.1 to 10 mm, preferably 0.3 to 8 mm. The blending amount of the carrier is, for example, 50 to 5000 parts by weight, preferably 200 to 2000 parts by weight, based on 100 parts by weight of the total amount of the catalyst component used.

The evaporation to dryness in (4) is carried out at a temperature of, for example, 50 to 150 ° C. for 3 to 48 hours. The drying in (4) is carried out at a temperature of, for example, 50 to 300 ° C. for 1 to 48 hours. Further, the firing in (5) is carried out at a temperature of, for example, 200 to 600 ° C. for 1 to 24 hours. These evaporation to dryness, drying and firing can be performed in an air atmosphere using a general electric furnace or the like. The evaporative drying and drying of (3) may be performed at the same time without being separated. Further, the drying may be performed under reduced pressure.

[Manufacturing method of aldehydes]
The method for producing aldehydes of the present invention is a method for producing aldehydes by hydrogenation using a carboxylic acid as a raw material in a gas phase in the presence of the solid catalyst of the present invention. In the method for producing aldehydes of the present invention, it is preferable to use hydrogen (H ₂ ) gas for hydrogenation.

Carvone acids are organic acids having at least one carboxyl group in the molecule. Examples of carboxylic acids include formic acid, acetic acid, propionic acid, fatty acid, valeric acid, acrylic acid and benzoic acid.

Aldehydes are hydrocarbon compounds having at least one formyl group in the molecule. Examples of aldehydes include formaldehyde, acetaldehyde, propionaldehyde, butanal, pentanal, acrolein, and benzaldehyde. In the method for producing aldehydes of the present invention, aldehydes corresponding to the carboxylic acids as raw materials can be obtained.

In the method for producing aldehydes of the present invention, it is preferable that the carboxylic acid is acetic acid and the aldehyde is acetaldehyde.

FIG. 1 is a schematic flow chart showing an example of the method for producing an aldehyde of the present invention. In the example shown in FIG. 1, the hydrogen gas is supplied from the hydrogen facility P by the line 1, pressurized by the compressor I-1, passes through the buffer tank J-1, and joins the circulating gas of the line 2, and is merged with the circulating gas of the line 2 by the line 3. It is charged in the evaporator A (carboxylic acid evaporator). The carboxylic acids are supplied from the carboxylic acid tank K-1 to the evaporator A from the line 4 using the pump N-1, and the vaporized carboxylic acids are combined with the hydrogen gas in the heat exchangers (heaters) L-1, L-. It is heated in No. 2 and charged into the reactor B filled with the solid catalyst of the present invention from line 5. The evaporator A is provided with a circulation pump N-2. In the reactor B, the carboxylic acids are hydrogenated, and in addition to the main product aldehydes, alcohols such as ethanol, non-condensable methane, ethane, ethylene, carbon dioxide, ketones such as condensable acetone, water, etc. Is generated. In addition, hydrocarbons having 2 or more carbon atoms such as propylene, 1-butene, 1-pentene, and 1-hexene are produced.

Hydrogenation of carboxylic acids can be carried out by a known method. For example, carboxylic acids are reacted with hydrogen in the presence of the solid catalyst of the invention. The solid catalyst of the present invention is preferably subjected to a reduction treatment by contacting with hydrogen in advance before being used for hydrogenation of carboxylic acids. The reduction treatment is carried out, for example, by circulating hydrogen (H ₂ ) gas at 30 to 300 ml / min under the conditions of 50 to 500 ° C. and 0.1 to 5 MPa.

The solid line speed is, for example, 10 to 20000 mm / s, preferably 50 to 10000 mm / s, and more preferably 200 to 3000 mm / s. When the solid linear velocity is in the above range, the selectivity of aldehydes in hydrogenation of carboxylic acids can be improved. The solid linear velocity is the linear velocity in the actual reaction system, and is a value obtained by dividing the volumetric flow rate corrected by the reaction pressure and the reaction temperature by the cross-sectional area of the reaction tube.

The reaction temperature in the reactor is, for example, 250 to 400 ° C, preferably 270 to 350 ° C. If the reaction temperature is too high, the by-product of ketones such as acetone increases, and the selectivity of aldehydes and the like tends to decrease. The reaction pressure in the reactor may be normal pressure, reduced pressure, or under pressure, but is, for example, in the range of 0 to 10 MPa, preferably 0.1 to 3 MPa. The contact time in the reactor is, for example, 0.1 to 1 sec, preferably 0.1 to 0.5 sec.

The supply ratio (molar ratio) of hydrogen and carboxylic acids to the reactor is, for example, hydrogen / carboxylic acids = 0.5 to 50, preferably hydrogen / carboxylic acids = 2 to 25.

The conversion rate of carboxylic acids in the reactor is preferably 80% or less (for example, 5 to 80%). When the conversion rate of carboxylic acids exceeds 80%, by-products (ethyl acetate or the like) are likely to be generated, and the selectivity of aldehydes decreases. Therefore, it is desirable to adjust the residence time and the hydrogen flow rate in the reactor so that the conversion rate of the carboxylic acids is 80% or less.

As described above, the reaction between carboxylic acids and hydrogen mainly causes unconverted carboxylic acids, unconverted hydrogen, aldehydes produced by the reaction, alcohols, water, and other products (such as ethyl acetate). A gaseous reaction product consisting of carboxylic acids, ketones such as acetone) is obtained.

The non-condensable gas and the condensable component can be separated from the gaseous reaction product, and the condensable component can be used as a reaction solution. As a method for separating the non-condensable gas and the condensable component from the gaseous reaction product, for example, a reaction fluid obtained by hydrogenating carboxylic acids is charged in an absorption column, and the condensed component in the reaction fluid is absorbed by the absorption liquid. By doing so, the condensable component and the non-condensable gas can be separated (absorption step). At least a part of the by-produced hydrocarbon having 2 or more carbon atoms is absorbed by the absorbing liquid. In the method for producing aldehydes of the present invention, the condensable component (mixture of the condensable component and the absorbent liquid) absorbed by such an absorbent liquid is also included in the "reaction liquid". In the absorption step, a part of the non-condensable gas is dissolved in the absorbing liquid, but by reducing the pressure of the canned liquid in the absorption tower, the non-condensable gas dissolved in the absorbing liquid is dissipated, and the non-condensable gas is released. By providing a step (dispersion step) of recycling the liquid after gas dissipation in the absorption tower, hydrogen and other non-condensable gas components can be efficiently separated.

In the absorption step, for example, a reaction fluid obtained by hydrogenating carboxylic acids is charged into an absorption column, the condensed components in the reaction fluid are absorbed by the absorption liquid, and the non-condensable gas is dissolved in the absorption liquid. This absorption step is usually carried out by supplying the reaction fluid and the absorption liquid obtained in the reaction step to the absorption tower and bringing them into contact with each other in the absorption tower. The absorption tower is not particularly limited, and a known or well-known gas absorption device, for example, a packed tower, a shelf column, a spray tower, or a wet wall tower can be used.

Further, in the dissipating step, the pressure of the liquid discharged from the can of the absorption tower is reduced to dissipate the non-condensable gas dissolved in the absorbing liquid, and the liquid after the non-condensable gas is dissipated is recycled to the absorbing tower. In this dissipation step, the canned out liquid (condensable component and the absorption liquid after absorbing and dissolving the non-condensable gas) obtained in the absorption step is usually supplied to the dissipative tower in which the pressure is reduced, and the non-condensation is performed. It is done by dissipating sex gas. The dissipating tower is not particularly limited, and a known or well-known gas dissipating device, for example, a packed tower, a shelf column, a spray tower, a wet wall tower, or a gas-liquid separator can be used.

In the example shown in FIG. 1, the reaction fluid flowing out of the reactor B passes through the heat exchanger L-1 by the line 6, is cooled by the heat exchangers (coolers) M-1 and M-2, and is cooled from the line 7. It is charged in the lower part of the absorption tower C. The absorption tower C is charged with the canned liquid of the diffuser tower D (hereinafter, may be referred to as “circulating liquid”) described later from the line 9 as the absorption liquid. The circulating fluid mainly absorbs and dissolves non-condensable gases such as hydrogen, methane, ethane, ethylene and carbon dioxide. Further, as an absorbing liquid other than the circulating liquid (hereinafter, may be referred to as "absorption tower replenishing liquid"), a distillate upper phase liquid containing a large amount of azeotropic solvent (solvent that co-boils with water) is absorbed from line 11. It may be prepared as. The absorption tower replenisher absorbs aldehydes, which are low-boiling condensable components, as well as non-condensable gas. The distillate upper phase liquid is supplied to the line 11 through the line 15 and the cooler M-3. The charging position of the canned out liquid (line 9) (circulating liquid) and the distillate upper phase liquid (line 11) (absorption tower replenisher) of the dissipating tower D into the absorption tower C is to absorb aldehydes and non-condensable gas. Although it can be appropriately selected in consideration of efficiency and the like, it is preferable that the circulating liquid is charged in the middle portion of the absorption tower C and the replenishing liquid in the absorption tower is charged in the upper portion of the absorption tower C.

The canned liquid in the absorption tower C is divided into a line 14 provided in the reaction liquid tank K-2 and a line 8 charged in the diffusion tower D. The canned out liquid of the line 14 is stored in the reaction liquid tank K-2 as the reaction liquid. If necessary, the stored reaction solution may be subjected to a purification step. Line 8 is depressurized by the emission tower D, and hydrogen, methane, ethane, ethylene, and carbon dioxide, which are non-condensable gases dissolved in the absorption liquid, are released from line 10, and the liquid after the non-condensable gas is released is from line 9. It is recycled to absorption tower C. Q-2 is a vent.

The absorption liquid charged in the absorption tower C may be only the canned liquid (circulating liquid) of the absorption tower C, but when the aldehydes are acetaldehyde having a boiling point as low as 20 ° C., in order to improve the recovery rate of acetaldehyde, An absorbent solution containing no acetaldehyde is preferable. For example, as the absorption liquid, in addition to the azeotropic solvent-containing liquid used when separating unreacted carboxylic acids and by-produced water by azeotropic distillation, aldehydes were separated from the canned liquid of the absorption tower C. An aqueous acid solution such as a later liquid is preferable.

When the azeotropic solvent-containing liquid is used as the absorbing liquid, the azeotropic solvent content in the azeotropic solvent-containing liquid is, for example, 10% by weight or more, preferably 30% by weight or more, more preferably 50% by weight or more, still more preferable. Is 75% by weight or more.

The azeotropic solvent forms an azeotropic mixture with water to lower the boiling point, and separates the liquid from water to facilitate the separation of carboxylic acids and water. Examples of co-boiling solvents include isopropyl formate, propyl formate, butyl formate, isoamyl formate, ethyl acetate, isopropyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, methyl butyrate, ethyl butyrate, buty acid. Isopropyl, etc., as ketones, methyl ethyl ketone, methyl propyl ketone, methyl isobutyl ketone, diethyl ketone, ethyl propyl ketone, etc., as aliphatic hydrocarbons, pentane, hexane, heptane, etc., as alicyclic hydrocarbons. , Cyclohexane, methylcyclohexane, dimethylcyclohexane and the like, and examples of aromatic hydrocarbons include benzene and toluene.

Among these, ethyl acetate is preferable as an azeotropic solvent because it tends to exist as a by-product of hydrogenation of carboxylic acids and the recovery step of the azeotropic solvent can be omitted.
In addition, propyl acetate (boiling point 102 ° C), isobutyl acetate (boiling point 117 ° C), sec-butyl acetate (boiling point 112 ° C), isopropyl propionate (boiling point 110 ° C), methyl butyrate (boiling point 102 ° C), ethyl isobutyrate (boiling point). Esters with a boiling point of 100 ° C to 118 ° C at normal pressure, such as 110 ° C), have a higher proportion of water in an azeotropic mixture with water and a lower boiling point than acetic acid, making it easier to separate carboxylic acids and water. To. Further, these esters do not azeotrope with ethanol, or the ratio of ethanol in the azeotropic mixture with ethanol is low, and the separation / recovery of the azeotropic solvent is relatively easy. Therefore, an ester having a boiling point of 100 ° C to 118 ° C at normal pressure is also preferable as the azeotropic solvent.

Further, since methane, which tends to exist as a non-condensable gas, dissolves better in an azeotropic solvent having a lower polarity than a highly polar acetic acid aqueous solution, the azeotropic solvent is suitable as an absorbent liquid for the non-condensable gas.

The ratio (weight ratio) between the supply amount of the absorption tower replenisher (line 11) supplied to the absorption tower C and the supply amount of the reaction fluid (line 7) is, for example, the former / the latter = 0.1 to 10, preferably 0.1 to 10. Is the former / the latter = 0.3 to 2. The ratio (weight ratio) between the amount of the circulating fluid (line 9) supplied to the absorption tower C and the supply amount of the reaction fluid (line 7) is, for example, the former / the latter = 0.05 to 20, preferably the former. / The latter = 0.1 to 10.

The number of stages (theoretical plate) of the absorption tower C is, for example, 1 to 20, preferably 3 to 10. The temperature in the absorption tower C is, for example, 0 to 70 ° C., and the pressure in the absorption tower C is, for example, 0.1 to 5 MPa (absolute pressure).

The temperature in the dissipator D is, for example, 0 to 70 ° C. The pressure in the dissipating column D may be lower than the pressure in the absorbing column C, for example, 0.05 to 4.9 MPa (absolute pressure). The difference between the pressure of the absorption tower C and the pressure of the emission tower D (the former-the latter) can be appropriately selected from the viewpoint of the emission efficiency of the non-condensable gas and the suppression of the loss of aldehydes, and is, for example, 0.05 to 4.9 MPa. It is preferably 0.5 to 2 MPa.

The selectivity of aldehydes in the method for producing aldehydes of the present invention varies depending on the reaction conditions, but is, for example, 30 to 90%, preferably 40 to 90%. The selectivity and yield of aldehydes can be determined by analyzing the reaction solution by gas chromatography or the like.

The purity of aldehydes obtained by the method for producing aldehydes of the present invention is, for example, 90.0% by weight or more, preferably 95.0% by weight or more, and more preferably 98.0% by weight or more. The obtained aldehydes can be further purified by distillation or the like, if necessary, to further increase the purity.

Since the method for producing aldehydes of the present invention uses the solid catalyst of the present invention, it has the effect of suppressing the by-production of the formed hydrocarbons having 2 or more carbon atoms. The selectivity of the hydrocarbon having 2 or more carbon atoms is, for example, 15% or less, preferably 10% or less. In addition, since aldehydes can be selectively produced by adjusting the reaction conditions as described above, ketones such as acetone and gases such as carbon dioxide, carbon monoxide, and methane, which are produced by another side reaction, are generated. Can also be suppressed. The selectivity of ketones such as acetone is, for example, 10% or less, preferably 5% or less. The selectivity of a gas such as carbon dioxide, carbon monoxide, or methane is, for example, 10% or less, preferably 5% or less.

Hereinafter, the present invention will be described in more detail based on Examples, but the present invention is not limited to these Examples.

[Example 1-1]
(Preparation of sponge-like alumina cordierite-supported catalyst containing 2% by weight alumina binder)
First, Pd (NO ₃ ) ₂ aqueous solution (manufactured by Furuya Metal Co., Ltd., 4.5% by weight in terms of Pd) to 12.344 g and Fe (NO ₃ ) _{3.9H 2} O (manufactured by Kanto Chemical Co., Ltd., product No. 16026) -00) 7.330 g and 5.286 g of anhydrous citric acid (manufactured by Wako Pure Chemical Industries, Ltd., product code 030-05525) were added to prepare a solution. Then, a sol in which 0.762 g of an alumina binder (manufactured by Nissan Chemical Industries, Ltd., product name "AS-200", containing 10.3% by weight of Al ₂ O ₃ ) is dispersed in 10 mL of water is added to the solution to make it uniform. It was a mixed solution. Next, a sponge-like alumina cordierite (manufactured by Narita Ceramics Co., Ltd., product number # 30, average pore diameter 0.8 mm, outer diameter 75 mm × 50 mm × 20 mm), which is a carrier, was crushed to open 4.0-. 4.0018 g (which was used after sizing with a 1.00 mm upper and lower sieve) was transferred to an eggplant flask, the above mixed solution was added, and the solvent was distilled off under reduced pressure while warming in a warm water bath at 30-80 ° C. to remove the catalyst particles. Obtained. The obtained catalyst particles were dried at 120 ° C. for 12 hours and then calcined at 400 ° C. for 5 hours to obtain a supported catalyst (solid catalyst). The obtained supported catalyst has a Pd / Fe ₂ O ₃ weight ratio = 40/100 as a catalyst component in terms of Pd and Fe ₂ O ₃ , and the catalyst component (as Pd / Fe ₂ O ₃ ) / alumina in the carrier. The weight ratio was 50/100 (charged amount).

[Example 1-2]
(Preparation of sponge-like alumina cordierite-supported catalyst containing 10% by weight alumina binder)
First, Pd (NO ₃ ) ₂ aqueous solution (manufactured by Furuya Metal Co., Ltd., Pd equivalent 4.5% by weight) to 6.205 g and Fe (NO ₃ ) _{3.9H 2} O (manufactured by Kanto Chemical Co., Ltd., product No. 16026) -00) 3.685 g and 2.634 g of anhydrous citric acid (manufactured by Wako Pure Chemical Industries, Ltd., product code 030-05525) were added to prepare a solution. Then, a sol in which 1.947 g of an alumina binder (manufactured by Nissan Chemical Industries, Ltd., product name "AS-200", containing 10.3% by weight of Al ₂ O ₃ ) is dispersed in 10 mL of water is added to the solution to make it uniform. It was a mixed solution. Next, a sponge-like alumina cordierite (manufactured by Narita Ceramics Co., Ltd., product number # 30, average pore diameter 0.8 mm, outer diameter 75 mm × 50 mm × 20 mm), which is a carrier, was crushed to open 4.0-. Transfer 2.012 g (used by sizing with a 1.00 mm upper and lower sieve) to a eggplant flask, add the above mixed solution, and distill off the solvent under reduced pressure while warming in a warm water bath at 30-80 ° C. to remove the catalyst particles. Obtained. The obtained catalyst particles were dried at 120 ° C. for 12 hours and then calcined at 400 ° C. for 5 hours to obtain a supported catalyst (solid catalyst). The obtained supported catalyst has a Pd / Fe ₂ O ₃ weight ratio = 40/100 as a catalyst component in terms of Pd and Fe ₂ O ₃ , and the catalyst component (as Pd / Fe ₂ O ₃ ) / alumina in the carrier. The weight ratio was 50/100 (charged amount).

[Example 2-1]
(Preparation of sponge-like metal-supported catalyst containing 2% by weight alumina binder)
First, 11.285 g of Pd (NO ₃ ) ₂ aqueous solution (manufactured by Furuya Metal Co., Ltd., 4.5% by weight in terms of Pd) and Fe (NO ₃ ) _{3.9H 2} O (manufactured by Kanto Chemical Co., Ltd., product No. 16026) -00) 6.693 g and 4.813 g of anhydrous citric acid (manufactured by Wako Pure Chemical Industries, Ltd., product code 030-05525) were added to prepare a solution. Then, a sol in which 0.715 g of an alumina binder (manufactured by Nissan Chemical Industries, Ltd., product name "AS-200", containing 10.3% by weight of Al ₂ O ₃ ) is dispersed in 10 mL of water is added to the solution to make it uniform. It was a mixed solution. Next, 3.666 g of a sponge-like metal (Ni—Cr alloy) (manufactured by Sumitomo Electric Industrial Co., Ltd., average pore diameter 0.8 mm, outer diameter 2.5 mm × 2.5 mm × 2.2 mm) as a carrier was put into a eggplant flask. The mixture was transferred, the above mixed solution was added, and the solvent was distilled off under reduced pressure while warming in a warm water bath at 30-80 ° C. to obtain catalyst particles. The obtained catalyst particles were dried at 120 ° C. for 12 hours and then calcined at 400 ° C. for 5 hours to obtain a supported catalyst. Further, 0.037 g of hexaammonium hexaammonium tetrahydrate (manufactured by Wako Pure Chemical Industries, Ltd., product code 018-06901) was placed in a eggplant flask, dissolved in 10 mL of water, and the above-mentioned carrier catalyst was added thereto to warm water. The solvent was distilled off under reduced pressure while warming the bath at 30-80 ° C. to obtain catalyst particles. The obtained catalyst particles were dried at 120 ° C. for 12 hours and then calcined at 300 ° C. for 5 hours to obtain a molybdenum-added supported catalyst. The obtained molybdenum-added carrier catalyst has Pd / Fe ₂ O ₃ weight ratio = 40/100 as a catalyst component in terms of Pd, Mo, and Fe ₂ O ₃ , and is a catalyst component (as Pd / Fe ₂ O ₃ ). ) / Carrier weight ratio = 50/100 (charged amount), Mo / Fe ₂ O ₃ weight ratio = 14/100.

[Example 2-2]
(Preparation of sponge-like metal-supported catalyst containing 0.2 wt% alumina binder)
First, Pd (NO ₃ ) ₂ aqueous solution (manufactured by Furuya Metal Co., Ltd., Pd equivalent 4.5% by weight) to 11.308 g and Fe (NO ₃ ) _{3.9H 2} O (manufactured by Kanto Chemical Co., Ltd., product No. 16026) -00) 6.697 g and 4.820 g of anhydrous citric acid (manufactured by Wako Pure Chemical Industries, Ltd., product code 030-05525) were added to prepare a solution. Then, a sol in which 0.070 g of an alumina binder (manufactured by Nissan Chemical Industries, Ltd., product name "AS-200", containing 10.3% by weight of Al ₂ O ₃ ) is dispersed in 10 mL of water is added to the solution to make it uniform. It was a mixed solution. Next, 3.663 g of a sponge-like metal (Ni—Cr alloy) (manufactured by Sumitomo Electric Industrial Co., Ltd., average pore diameter 0.8 mm, outer diameter 2.5 mm × 2.5 mm × 2.2 mm) as a carrier was put into a eggplant flask. The mixture was transferred, the above mixed solution was added, and the solvent was distilled off under reduced pressure while warming in a warm water bath at 30-80 ° C. to obtain catalyst particles. The obtained catalyst particles were dried at 120 ° C. for 12 hours and then calcined at 400 ° C. for 5 hours to obtain a supported catalyst. Further, 0.030 g of hexaammonium hexaammonium tetrahydrate (manufactured by Wako Pure Chemical Industries, Ltd., product code 018-06901) was placed in a eggplant flask, dissolved in 10 mL of water, and the above-mentioned carrier catalyst was added thereto to warm water. The solvent was distilled off under reduced pressure while warming the bath at 30-80 ° C. to obtain catalyst particles. The obtained catalyst particles were dried at 120 ° C. for 12 hours and then calcined at 300 ° C. for 5 hours to obtain a molybdenum-added supported catalyst. The obtained molybdenum-added carrier catalyst has Pd / Fe ₂ O ₃ weight ratio = 40/100 as a catalyst component in terms of Pd, Mo, and Fe ₂ O ₃ , and is a catalyst component (as Pd / Fe ₂ O ₃ ). ) / Carrier weight ratio = 50/100 (charged amount), Mo / Fe ₂ O ₃ weight ratio = 14/100.

[Example 2-3]
(Preparation of sponge-like metal-supported catalyst containing 4 wt% alumina binder)
First, Pd (NO ₃ ) ₂ aqueous solution (manufactured by Furuya Metal Co., Ltd., Pd equivalent 4.5% by weight) to 11.302 g and Fe (NO ₃ ) _{3.9H 2} O (manufactured by Kanto Chemical Co., Ltd., product No. 16026) -00) 6.700 g and 4.857 g of anhydrous citric acid (manufactured by Wako Pure Chemical Industries, Ltd., product code 030-05525) were added to prepare a solution. Then, a sol in which 1.426 g of an alumina binder (manufactured by Nissan Chemical Industries, Ltd., product name "AS-200", containing 10.3% by weight of Al ₂ O ₃ ) is dispersed in 10 mL of water is added to the solution to make it uniform. It was a mixed solution. Next, 3.663 g of a sponge-like metal (Ni—Cr alloy) (manufactured by Sumitomo Electric Industrial Co., Ltd., average pore diameter 0.8 mm, outer diameter 2.5 mm × 2.5 mm × 2.2 mm) as a carrier was put into a eggplant flask. The mixture was transferred, the above mixed solution was added, and the solvent was distilled off under reduced pressure while warming in a warm water bath at 30-80 ° C. to obtain catalyst particles. The obtained catalyst particles were dried at 120 ° C. for 12 hours and then calcined at 400 ° C. for 5 hours to obtain a supported catalyst. Further, 0.037 g of hexaammonium hexaammonium tetrahydrate (manufactured by Wako Pure Chemical Industries, Ltd., product code 018-06901) was placed in a eggplant flask, dissolved in 10 mL of water, and the above-mentioned carrier catalyst was added thereto to warm water. The solvent was distilled off under reduced pressure while warming the bath at 30-80 ° C. to obtain catalyst particles. The obtained catalyst particles were dried at 120 ° C. for 12 hours and then calcined at 300 ° C. for 5 hours to obtain a molybdenum-added supported catalyst. The obtained molybdenum-added carrier catalyst has Pd / Fe ₂ O ₃ weight ratio = 40/100 as a catalyst component in terms of Pd, Mo, and Fe ₂ O ₃ , and is a catalyst component (as Pd / Fe ₂ O ₃ ). ) / Carrier weight ratio = 50/100 (charged amount), Mo / Fe ₂ O ₃ weight ratio = 14/100.

[Example 2-4]
(Preparation of sponge-like metal-supported catalyst containing 10 wt% alumina binder)
First, 11.348 g of Pd (NO ₃ ) ₂ aqueous solution (manufactured by Furuya Metal Co., Ltd., 4.5% by weight in terms of Pd) and Fe (NO ₃ ) _{3.9H 2} O (manufactured by Kanto Chemical Co., Ltd., product No. 16026) -00) 6.744 g and 4.837 g of anhydrous citric acid (manufactured by Wako Pure Chemical Industries, Ltd., product code 030-05525) were added to prepare a solution. Then, a sol in which 3.544 g of an alumina binder (manufactured by Nissan Chemical Industries, Ltd., product name "AS-200", containing 10.3% by weight of Al ₂ O ₃ ) is dispersed in 10 mL of water is added to the solution to make it uniform. It was a mixed solution. Next, a sponge-like metal (Ni—Cr alloy) as a carrier (manufactured by Sumitomo Electric Industrial Co., Ltd., Celmet product number # 4, average pore diameter 0.8 mm, outer diameter 2.5 mm × 2.5 mm × 2.2 mm) 3. 663 g was transferred to a eggplant flask, the above mixed solution was added, and the solvent was distilled off under reduced pressure while warming in a warm water bath at 30-80 ° C. to obtain catalyst particles. The obtained catalyst particles were dried at 120 ° C. for 12 hours and then calcined at 400 ° C. for 5 hours to obtain a supported catalyst. Further, 0.037 g of hexaammonium hexaammonium tetrahydrate (manufactured by Wako Pure Chemical Industries, Ltd., product code 018-06901) was placed in a eggplant flask, dissolved in 10 mL of water, and the above-mentioned carrier catalyst was added thereto to warm water. The solvent was distilled off under reduced pressure while warming the bath at 30-80 ° C. to obtain catalyst particles. The obtained catalyst particles were dried at 120 ° C. for 12 hours and then calcined at 300 ° C. for 5 hours to obtain a molybdenum-added supported catalyst. The obtained molybdenum-added carrier catalyst has Pd / Fe ₂ O ₃ weight ratio = 40/100 as a catalyst component in terms of Pd, Mo, and Fe ₂ O ₃ , and is a catalyst component (as Pd / Fe ₂ O ₃ ). ) / Carrier weight ratio = 50/100 (charged amount), Mo / Fe ₂ O ₃ weight ratio = 14/100.

[Example 2-5]
(Preparation of sponge-like metal-supported catalyst containing 2% by weight zirconia binder)
First, Pd (NO ₃ ) ₂ aqueous solution (manufactured by Furuya Metal Co., Ltd., Pd equivalent 4.5% by weight) to 11.300 g and Fe (NO ₃ ) _{3.9H 2} O (manufactured by Kanto Chemical Co., Ltd., product No. 16026) -00) 6.690 g and 4.863 g of anhydrous citric acid (manufactured by Wako Pure Chemical Industries, Ltd., product code 030-05525) were added to prepare a solution. Then, 0.242 g of a zirconia binder (manufactured by Nissan Chemical Industries, Ltd., Nanouse (registered trademark) ZR, product name "ZR-30AL", containing 30.6% by weight of ZrO ₂ ) was dispersed in 10 mL of water. The sol was added to obtain a uniform mixed solution. Next, 3.663 g of a sponge-like metal (Ni—Cr alloy) (manufactured by Sumitomo Electric Industrial Co., Ltd., average pore diameter 0.8 mm, outer diameter 2.5 mm × 2.5 mm × 2.2 mm) as a carrier was put into a eggplant flask. The mixture was transferred, the above mixed solution was added, and the solvent was distilled off under reduced pressure while warming in a warm water bath at 30-80 ° C. to obtain catalyst particles. The obtained catalyst particles were dried at 120 ° C. for 12 hours and then calcined at 400 ° C. for 5 hours to obtain a supported catalyst. Further, 0.019 g of hexaammonium hexaammonium tetrahydrate (manufactured by Wako Pure Chemical Industries, Ltd., product code 018-06901) was placed in a eggplant flask, dissolved in 10 mL of water, and the above-mentioned carrier catalyst was added thereto to warm water. The solvent was distilled off under reduced pressure while warming the bath at 30-80 ° C. to obtain catalyst particles. The obtained catalyst particles were dried at 120 ° C. for 12 hours and then calcined at 300 ° C. for 5 hours to obtain a molybdenum-added supported catalyst. The obtained molybdenum-added carrier catalyst has Pd / Fe ₂ O ₃ weight ratio = 40/100 as a catalyst component in terms of Pd, Mo, and Fe ₂ O ₃ , and is a catalyst component (as Pd / Fe ₂ O ₃ ). ) / Carrier weight ratio = 50/100 (charged amount), Mo / Fe ₂ O ₃ weight ratio = 14/100.

[Example 2-6]
(Preparation of sponge-like metal-supported catalyst containing 2% by weight titania binder)
First, Pd (NO ₃ ) ₂ aqueous solution (manufactured by Furuya Metal Co., Ltd., 4.5% by weight in terms of Pd) to 11.309 g and Fe (NO ₃ ) _{3.9H 2} O (manufactured by Kanto Chemical Co., Ltd., product No. 16026) -00) 6.704 g and 4.826 g of anhydrous citric acid (manufactured by Wako Pure Chemical Industries, Ltd., product code 030-05525) were added to prepare a solution. Then, a sol in which 0.187 g of titania binder (titanium oxide, manufactured by Sakai Chemical Industry Co., Ltd., grade "CSB", containing 39.0% by weight of TiO) is dispersed in ₁₀ mL of water is added to the solution to make it uniform. It was a mixed solution. Next, 3.663 g of a sponge-like metal (Ni—Cr alloy) (manufactured by Sumitomo Electric Industrial Co., Ltd., average pore diameter 0.8 mm, outer diameter 2.5 mm × 2.5 mm × 2.2 mm) as a carrier was put into a eggplant flask. The mixture was transferred, the above mixed solution was added, and the solvent was distilled off under reduced pressure while warming in a warm water bath at 30-80 ° C. to obtain catalyst particles. The obtained catalyst particles were dried at 120 ° C. for 12 hours and then calcined at 400 ° C. for 5 hours to obtain a supported catalyst. Further, 0.033 g of hexaammonium hexaammonium tetrahydrate (manufactured by Wako Pure Chemical Industries, Ltd., product code 018-06901) was placed in a eggplant flask, dissolved in 10 mL of water, and the above-mentioned carrier catalyst was added thereto to warm water. The solvent was distilled off under reduced pressure while warming the bath at 30-80 ° C. to obtain catalyst particles. The obtained catalyst particles were dried at 120 ° C. for 12 hours and then calcined at 300 ° C. for 5 hours to obtain a molybdenum-added supported catalyst. The obtained molybdenum-added carrier catalyst has Pd / Fe ₂ O ₃ weight ratio = 40/100 as a catalyst component in terms of Pd, Mo, and Fe ₂ O ₃ , and is a catalyst component (as Pd / Fe ₂ O ₃ ). ) / Carrier weight ratio = 50/100 (charged amount), Mo / Fe ₂ O ₃ weight ratio = 14/100.

[Comparative Example 1]
(Preparation of sponge-like alumina cordierite-supported catalyst)
First, Pd (NO ₃ ) ₂ aqueous solution (manufactured by Furuya Metal Co., Ltd., 4.5% by weight in terms of Pd) to 7.407 g and Fe (NO ₃ ) _{3.9H 2} O (manufactured by Kanto Chemical Co., Ltd., product No. 16026) -00) 4.258 g and 3.070 g of anhydrous citric acid (manufactured by Wako Pure Chemical Industries, Ltd., product code 030-05525) were added to prepare a solution. Next, a sponge-like alumina cordierite (manufactured by Narita Ceramics Co., Ltd., product number # 30, average pore diameter 0.8 mm, outer diameter 75 mm × 50 mm × 20 mm), which is a carrier, was crushed to open 4.0-. 2.333 g (used by sizing with a 1.00 mm upper and lower sieve) was transferred to a eggplant flask, the above mixed solution was added, and the above solution was added dropwise while warming in a warm water bath at 70-80 ° C. The mixture was evaporated to dryness to obtain catalyst particles. The obtained catalyst particles were dried at 120 ° C. for 12 hours and then calcined at 400 ° C. for 5 hours to obtain a supported catalyst (solid catalyst). The obtained supported catalyst has a Pd / Fe ₂ O ₃ weight ratio = 40/100 as a catalyst component in terms of Pd and Fe ₂ O ₃ , and the catalyst component (as Pd / Fe ₂ O ₃ ) / alumina in the carrier. The weight ratio was 50/100 (charged amount).

(Evaluation of catalyst reactivity)
Using the supported catalysts obtained in Examples 1-1 to 2-6 and Comparative Example 1, acetaldehyde was produced by hydrogenation in a gas phase using acetic acid as a raw material by the following method for producing acetaldehyde. The reactivity of the catalyst was evaluated using a reaction system in which acetic acid was vaporized and could be supplied to the reactor as a gas together with hydrogen gas, a catalyst could be attached, and a reaction tube having a heatable reaction tube was used. In Table 1, C2 is the total selectivity of compounds having 2 carbon atoms such as ethane and ethylene. In Table 1, C3 is the total selectivity of compounds having 3 carbon atoms such as propane and propylene. In Table 1, Etc is the total selectivity of other trace by-products. Table 1 below shows the evaluation after 24 hours have passed from the start of the reaction. Further, Table 2 below is an evaluation of Examples 2-1 to 2-4 after a predetermined time has elapsed from the start of the reaction. FIG. 2 is a graph showing the acetaldehyde yield after a predetermined time has elapsed from the start of the reaction for Examples 2-1 to 2-4 (the vertical axis of FIG. 2 is the acetaldehyde yield, and the horizontal axis is the reaction time). .. The straight lines for Examples 2-1 to 2-4 in FIG. 2 indicate linear approximation curves.

(Manufacturing method of acetaldehyde)
The supported catalyst is filled in a 12 mmφ SUS reaction tube connected to a fixed bed type gas phase continuous flow reactor (reactor), and the catalyst layer temperature is set to 300 ° C. by an electric furnace under 100 mL / min hydrogen gas flow. Was heated for 1 hour for pretreatment.
After performing the above pretreatment, hydrogen gas (672 mL / min) and acetic acid solution (0.) so that the contact time is 0.25 sec and the hydrogen / acetic acid charge molar ratio (H ₂ / AC) is 14.0. 124 cc / min) was circulated through the reactor to react. The reactor outlet gas was cooled by a cooler and separated into gas and liquid, and the condensed liquid was collected. Low boiling point components such as acetaldehyde in the non-condensing gas were collected by bubbling in 300 cc of water, and the non-condensed gas components were collected in a gaseous state. During the reaction, the electric furnace and the back pressure valve were adjusted so that the catalyst layer temperature was 330 ° C. and the reaction pressure was 0.4 MPa. After a lapse of a predetermined time from the start of the reaction, the gas passing through the reaction tube was separated from a condenser provided at the outlet of the reaction tube into an off-gas consisting of a condensed liquid and a non-condensed component, and each was analyzed by gas chromatography.

As shown in Table 1, it can be seen that in Example 1-1, the acetic acid conversion rate was clearly higher than that in Comparative Example 1 even though the reaction conditions were the same except that the binder was used. It can be seen that in other examples as well, by using the inorganic particles of alumina, silica, zirconia, or titania as the binder, the acetic acid conversion rate tends to be higher than that of Comparative Example 1. Further, in Example 1-2, the acetic acid conversion rate was clearly higher than that in Example 1-1, despite the same reaction conditions, and the acetic acid conversion rate increased as the amount of the binder used increased. You can see that it is getting higher.

As shown in Table 2 and FIG. 2, in Example 2-4, the decrease in the yield of acetaldehyde with the passage of the reaction time can be suppressed as compared with Example 2-1 and the catalyst deterioration rate is decreased. You can see that there is. From this, it can be seen that the rate of decrease in catalytic activity decreases as the amount of binder used increases.

[Example 3-1]
(Preparation of molybdenum-added sponge-like alumina cordierite-supported catalyst)
First, Pd (NO ₃ ) ₂ aqueous solution (manufactured by Furuya Metal Co., Ltd., Pd equivalent 4.5% by weight) to 12.344 g and Fe (NO ₃ ) _{3.9H 2} O (manufactured by Kanto Chemical Co., Ltd., product No. 16026) -00) 7.330 g and 5.286 g of anhydrous citric acid (manufactured by Wako Pure Chemical Industries, Ltd., product code 030-05525) were added to prepare a solution. Then, in the solution, a solution (sol) in which 0.762 g of an alumina binder (manufactured by Nissan Chemical Industries, Ltd., product name "AS-200", containing 10.3% by weight of Al ₂ O ₃ ) is dispersed in 10 mL of water is added. In addition, a uniform mixed solution was prepared. Next, a sponge-like alumina cordierite (manufactured by Narita Ceramics Co., Ltd., product number # 30, average pore diameter 0.8 mm, outer diameter 75 mm × 50 mm × 20 mm), which is a carrier, was crushed and opened 4.0. 4.0018 g (used by sizing with a -1.00 mm upper and lower sieve) was transferred to an eggplant flask, the above mixed solution was added, and the solvent was distilled off under reduced pressure while warming in a warm water bath at 30-80 ° C., and the catalyst particles were distilled off. Got The obtained catalyst particles were dried at 120 ° C. for 12 hours and then calcined at 400 ° C. for 5 hours to obtain a supported catalyst (solid catalyst). The obtained supported catalyst has a Pd / Fe ₂ O ₃ weight ratio = 40/100 as a catalyst component in terms of Pd and Fe ₂ O ₃ , and the catalyst component (as Pd / Fe ₂ O ₃ ) / alumina in the carrier. The weight ratio was 50/100 (charged amount).
Further, 0.030 g of hexaammonium hexaammonium tetrahydrate (manufactured by Wako Pure Chemical Industries, Ltd., product code 018-06901) was placed in an eggplant flask and dissolved in 10 mL of water. An aqueous ammonia solution was added to this solution to adjust the pH of the solution to 12. The above-mentioned supported catalyst was added thereto, and the solvent was distilled off under reduced pressure while warming in a warm water bath at 30-80 ° C. to obtain catalyst particles. The obtained catalyst particles were dried at 120 ° C. for 12 hours and then calcined at 300 ° C. for 5 hours to obtain a molybdenum-added supported catalyst. The obtained molybdenum-added carrier catalyst has Pd / Fe ₂ O ₃ weight ratio = 40/100 as a catalyst component in terms of Pd, Mo, and Fe ₂ O ₃ , and is a catalyst component (as Pd / Fe ₂ O ₃ ). ) / Carrier = 75/100 (charged amount), alumina binder / catalyst component (as Pd / Fe ₂ O ₃ ) weight ratio = 2/100 (charged amount), Mo / Fe ₂ O ₃ weight ratio = 14/100 there were.

[Comparative Example 2]
First, 11.285 g of Pd (NO ₃ ) ₂ aqueous solution (manufactured by Furuya Metal Co., Ltd., 4.5% by weight in terms of Pd) and Fe (NO ₃ ) _{3.9H 2} O (manufactured by Kanto Chemical Co., Ltd., product No. 16026) -00) 6.693 g and 4.813 g of anhydrous citric acid (manufactured by Wako Pure Chemical Industries, Ltd., product code 030-05525) were added to prepare a solution. Then, in the solution, a solution (sol) in which 0.715 g of an alumina binder (manufactured by Nissan Chemical Industries, Ltd., product name "AS-200", containing 10.3% by weight of Al ₂ O ₃ ) is dispersed in 10 mL of water is added. In addition, a uniform mixed solution was prepared. Next, 3.666 g of a sponge-like metal (Ni—Cr alloy) (manufactured by Sumitomo Electric Industrial Co., Ltd., average pore diameter 0.8 mm, outer diameter 2.5 mm × 2.5 mm × 2.2 mm) as a carrier is put into a eggplant solvent. The above mixed solution was added, and the solvent was distilled off under reduced pressure while warming in a warm water bath at 30-80 ° C. to obtain catalyst particles. The obtained catalyst particles were dried at 120 ° C. for 12 hours and then calcined at 400 ° C. for 5 hours to obtain a supported catalyst. Further, 0.037 g of hexaammonium hexaammonium tetrahydrate (manufactured by Wako Pure Chemical Industries, Ltd., product code 018-06901) was placed in a eggplant flask, dissolved in 10 mL of water, and the above-mentioned carrier catalyst was added thereto to warm water. The solvent was distilled off under reduced pressure while warming the bath at 30-80 ° C. to obtain catalyst particles. The obtained catalyst particles were dried at 120 ° C. for 12 hours and then calcined at 300 ° C. for 5 hours to obtain a molybdenum-added supported catalyst. The obtained molybdenum-added carrier catalyst has Pd / Fe ₂ O ₃ weight ratio = 40/100 as a catalyst component in terms of Pd, Mo, and Fe ₂ O ₃ , and is a catalyst component (as Pd / Fe ₂ O ₃ ). ) / Carrier = 75/100 (charged amount), alumina binder / catalyst component (as Pd / Fe ₂ O ₃ ) weight ratio = 2/100 (charged amount), Mo / Fe ₂ O ₃ weight ratio = 14/100 there were.

(Evaluation of catalyst reactivity)
Using the catalysts obtained in Example 3-1 and Comparative Example 2, acetic acid was used as a raw material in the same manner as described above, and acetaldehyde was produced by hydrogenation in the gas phase. The obtained evaluation results are shown in Tables 3 and 4.

As shown in Table 3, in Example 3-1 the conversion rate of carboxylic acids when producing aldehydes in a gas phase from carboxylic acids is improved as compared with Comparative Example 2. Further, as shown in Table 4, it can be seen that in Example 3-1 the rate of decrease in the conversion rate is lower than that in Comparative Example 2, and the catalyst deterioration can be suppressed. From this, it is considered that molybdenum becomes mononuclear and is added on the catalyst with higher dispersion by using a solution whose pH is adjusted to about 12 when molybdenum is added, which leads to suppression of reduction in catalytic activity. I understood.

A Evaporator B Reactor C Absorption tower D Dissipation tower I-1 to I-2 Compressor J-1 to J-3 Buffer tank K-1 Carvone acid tank K-2 Reaction liquid tank L-1 to L-2 Heater M-1 to M-4 cooler (cooler)
N-1 to N-3 pumps (liquid feed pumps)
P Hydrogen equipment (hydrogen cylinder)
Q-1 to Q-2 Vent 1 to 15 lines

Claims (9)

A carrier-supported solid catalyst for producing aldehydes by hydrogenating in a gas phase using carboxylic acids as a raw material. The carrier supporting the catalyst component is a sponge-like porous material, and alumina is used as a binder. A solid catalyst containing at least one inorganic particle selected from the group consisting of, silica, titania, and zirconia , wherein the inorganic particle binds catalyst components to each other or a catalyst component and a carrier . The solid catalyst according to claim 1, wherein the content of the inorganic particles is 2 to 10 % by weight with respect to the solid catalyst. The solid catalyst according to claim 1, wherein the content of the inorganic particles is 2 to 4% by weight with respect to the solid catalyst. The solid catalyst according to any one of claims 1 to 3 , wherein the catalyst component contains a platinum group metal and iron. The solid catalyst according to claim 4 , wherein the platinum group metal is palladium. The solid catalyst according to any one of claims 1 to 5 , which contains molybdenum as the catalyst component. The solid catalyst according to any one of claims 1 to 6 , wherein the carrier contains a ceramic or a metal. The solid catalyst according to any one of claims 1 to 7 , wherein aldehydes are produced by hydrogenating carboxylic acids as a raw material in a gas phase using a solid catalyst. A method for producing aldehydes. The method for producing an aldehyde according to claim 8 , wherein the carboxylic acid is acetic acid and the aldehyde is acetaldehyde.

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