JP2000024502A - Catalyst for producing methacrylic acid and production thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a catalyst for producing methacrylic acid by subjecting methacrolein to gaseous contact oxidation by molecular oxygen and a method for producing the same. SOLUTION: A methacrylic acid producing catalyst is constituted of formula: MoaVbPcSdXeYf(NH4)gOh [wherein X is at least one element selected from a group consisting of Sb, Si, Cu, Co, Bi and As, Y is at least one element selected from a group consisting of K, Pb, Cs and Tl, a, b, c, d, e, f and g shows atomic ratios of respective element and, when a is 12, b is 0.1-2, c is 1-3, d is 0.01-0.6, e is 0.01-3, f is 0.1-3 and f+g is 2-6 and h is the number of oxygen atoms necessary for satisfying the atomic valencies of respective components. In this catalyst, one wherein pore vol. of pores having a pore size of 1-10 μm is 72% or more of the total pore vol. is pref.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catalyst used for producing methacrylic acid by gas phase catalytic oxidation of methacrolein using molecular oxygen, a method for producing the same, and a method for producing methacrolein in the presence of this catalyst. The present invention relates to a method for producing methacrylic acid by gas-phase catalytic oxidation using oxygen.

[0002]

2. Description of the Related Art Conventionally, with respect to a catalyst used for producing methacrylic acid by subjecting methacrolein to gas-phase catalytic oxidation using molecular oxygen, the physical properties of the catalyst, that is, the specific surface area of the catalyst, the pore volume of the catalyst and the fineness of the catalyst are described. A production method in which the pore diameter and the like are controlled has been proposed. For example, JP-A-49-116022 discloses that the specific surface area of the catalyst is preferably in the range of 0.01 to ⁵ m ² / g. However, it is hard to say that the pore volume and the pore distribution are controlled, and the selectivity of methacrylic acid is low. Japanese Patent Publication No. 54-13876 discloses a catalyst having a specific surface area of 4 to 20 m ² / g and a pore volume of 0.08 to
A method of molding at 0.5 ml / g with a tumbling granulator is described. However, there is no description of the pore distribution, and the results of the examples are not necessarily industrially satisfactory such as a high reaction temperature and a low methacrylic acid selectivity.

[0003] Japanese Patent Application Laid-Open No. 55-73347 describes that the average pore radius is preferably from 2000 to 12000 °. However, there is no description of pore volume and pore distribution, no inorganic fiber is added, and it is hard to say that the pore volume and pore distribution are excellent in control and strength. In addition, sufficient performance has not been obtained with respect to methacrylic acid selectivity. JP-A-63-315148 describes that the catalyst has a specific surface area of 1.0 to 10 m ² / g and a pore volume of 0.1 to 1 m ² / g.
ml / g, the pore volume of pores having a pore diameter in the range of 1 to 10 μm with respect to the total pore volume as a pore diameter distribution is 10% or more,
The pore volume of pores having a pore diameter in the range of 0.1 to 1 μm is 10
% Or more, and water as a binder,
It is stated that cellulose, ammonium nitrate, graphite, starch, alcohol, acetone can be used. The proportion of the pore volume of the pores having a pore diameter in the range of 1 to 10 μm is small, and the proportion of the pore volume of the pores having the pore diameter in the range of 0.1 to 1 μm is large, which is not necessarily sufficient for the methacrylic acid selectivity. Performance has not been obtained. JP-A-3-8
No. 6242 and JP-A-4-90853 describe a catalyst having a specific surface area of 1 to ²⁰ m ² / g and a pore volume of 0.1 to 1 m.
1 / g, the pore volume of pores having a pore diameter in the range of 1 to 10 μm with respect to the total pore volume as a pore diameter distribution is 20 to 70%,
The pore volume of pores having a pore diameter in the range of 0.5 to 1 μm is 3 to
It is described that the pore volume of pores having a pore diameter of 20% and a pore diameter of 0.1 to 0.5 μm is preferably 20 to 70%. In Examples, the pore volume of pores having a pore diameter in the range of 0.1 to 0.5 μm is 40% or more of the total pore volume, and sufficient performance is not necessarily obtained with respect to methacrylic acid selectivity. . U.S. Pat. Nos. 3,959,182, 4
In the specification of Japanese Patent No. 035417, organic compounds such as carboxylic acids having a boiling point of 150 ° C. or higher, such as oxalic acid, alcohols such as glycerol, amines such as diethanolamine, esters such as dioctyl phthalate, and quinones such as hydroquinone. A compound prepared by mixing a compound with an aqueous solution of a catalyst component, drying and calcining the catalyst. In JP-A-51-136615, dibasic carboxylic acids such as oxalic acid and succinic acid, tartaric acid,
Oxycarboxylic acids such as citric acid and lactic acid, mannitol,
A catalyst prepared by adding a polyhydric alcohol such as pyrogallol, a catalyst reduced in glycols such as ethylene glycol and propylene glycol in JP-A-54-19912, and a catalyst prepared in JP-A-57-204230. JP-A-58-6243 discloses a method for producing a catalyst comprising a step of wetting a solidified residue with an anhydrous alcohol having 1 to 5 carbon atoms such as ethanol and then treating the catalyst support material with the wetted residue. Manufacture of a catalyst prepared by mixing and heat-treating an organic reducing substance comprising a group consisting of oxycarboxylic acids such as acids and lactic acids, glycols such as ethylene glycol, propylene glycol and polyalkylene glycol, and saccharides such as dextrin, starch, aldose and lactose. And JP-A-5-28539
In the examples in the specification of No. 0, there is a description that coating is performed using a methanol solution of polyethylene glycol as a binder, but none of the reports describes the pore volume and pore distribution of the catalyst. Or while adding the above organic substance at the stage of preparing the organic substance solution, it is difficult to say that the inorganic fiber is not added and the pore volume and the pore distribution are controlled, and the conversion of methacrolein and the selection of methacrylic acid Both rates are low and are not industrially satisfactory. JP-A-60-48143 reports a method for producing a catalyst in which a carrier is mixed and supported with a lower alcohol such as methanol, ethanol, propanol and butanol. However, it is hard to say that the lower alcohol, which is a gas at 100 ° C. under normal pressure, is mixed with the catalyst and the inorganic fiber is not added, and the pore volume and the pore distribution are controlled. JP-A-5-309293 discloses a method for producing a catalyst by adding and extruding a lower alcohol such as methanol, ethanol, propanol and butanol or acetone. It is difficult to say that pore volume and pore distribution are controlled because lower alcohol or acetone which is gaseous at 100 ° C under normal pressure is used, and because extrusion molding is performed, it is granulated or coated on a carrier. It is considered that the catalyst is not industrially satisfactory in terms of strength as compared with the prepared catalyst.

In Japanese Patent Application Laid-Open No. Hei 5-309274, alcohols such as methanol and ethanol which are liquid at normal temperature are added and shaped, and the shaped catalyst is frozen and heat-treated to produce a catalyst. There is a report that the pores of increase. However, all of them are used for the purpose of increasing the pore volume of pores having a pore diameter in a range different from that of the present invention in addition to using lower alcohol which is a gas at 100 ° C. under normal pressure. The range of pore distribution is wide, and it cannot be said that the pore distribution is sufficiently controlled. JP-A-6
No. 15178, n-propanol, tert
There is a description of a catalyst preparation in which an alcohol having 1 to 6 carbon atoms such as butanol, an aldehyde such as methacrolein, and an organic acid such as methacrylic acid are added to a catalyst component and extruded. However, it is hard to say that the inorganic fiber is not added and the pore distribution is sufficiently controlled. In addition, the catalyst shapes are different, and sufficient performance with respect to strength and methacrylic acid selectivity has not been obtained. JP-A-59-1731
No. 40 describes a catalyst in which 1 to 50% by weight of a whisker having an average fiber diameter of 1 micron or less is added as a supporting agent, and JP-A-59-183832 discloses an average diameter of 5 microns or less and an average length. There are reports of catalyst compositions containing whiskers of 1000 microns or less in heteropolyacid-based compositions. Although it is intended to improve the mechanical strength, it is hard to say that the pore volume and pore distribution are controlled, and sufficient performance is not necessarily obtained with respect to methacrylic acid selectivity.

[0005]

An object of the present invention is to provide a catalyst having excellent catalytic activity and methacrylic acid selectivity.

[0006]

DISCLOSURE OF THE INVENTION The present inventors have developed a catalyst used in the production of methacrylic acid by gas phase catalytic oxidation of methacrolein with molecular oxygen, particularly a heteropolyacid compound containing molybdenum and phosphorus. As for the catalyst, as a result of intensive studies on a catalyst having excellent performance by controlling its physical properties, a catalyst with excellent reproducibility of catalyst performance and improved catalyst performance such as methacrylic acid selectivity was found, and the method of the present invention was developed. It was completed.

Accordingly, the present invention has the general formula _{(1) Mo a V b P} c S d X e Y f (NH 4) g O h (1) [ wherein, X is Sb, Si, Cu, Co, One or more elements selected from the group consisting of Bi and As;
At least one element selected from the group consisting of Rb, Cs, and Tl; a, b, c, d, e, f, and g represent the atomic ratio of each element; = 0.1 ~
2, c = 1-3, d = 0.01-0.6, e = 0.01
3, f = 0.1-3, f + g = 2-6, and h is the number of oxygen atoms necessary to satisfy the valence of each component. ] It is a catalyst for methacrylic acid production characterized by comprising the catalyst composition represented by these, and inorganic fiber. The invention can be represented by the general formula _{(1) Mo a V b P} c S d X e Y f (NH 4) g O h (1) [ wherein, X is Sb, Si, Cu, Co, from Bi and As At least one element selected from the group consisting of
At least one element selected from the group consisting of Rb, Cs, and Tl; a, b, c, d, e, f, and g represent the atomic ratio of each element; = 0.1 ~
2, c = 1-3, d = 0.01-0.6, e = 0.01
3, f = 0.1-3, f + g = 2-6, and h is the number of oxygen atoms necessary to satisfy the valence of each component. Mixing the catalyst composition represented by the formula (I) with inorganic fibers to obtain a mixture, and supplying the mixture under normal pressure,
A method for producing a catalyst for producing methacrylic acid, comprising a step of spraying an aqueous solution of a water-soluble organic compound which is liquid at 100 ° C. to obtain a granulated product, and a step of calcining the granulated product. is there. The invention can be represented by the general formula _{(1) Mo a V b P} c S d X e Y f (NH 4) g O h (1) [ wherein, X is Sb, Si, Cu, Co, from Bi and As At least one element selected from the group consisting of
At least one element selected from the group consisting of Rb, Cs, and Tl; a, b, c, d, e, f, and g represent the atomic ratio of each element; = 0.1 ~
2, c = 1-3, d = 0.01-0.6, e = 0.01
3, f = 0.1-3, f + g = 2-6, and h is the number of oxygen atoms necessary to satisfy the valence of each component. Mixing the catalyst composition represented by the formula (I) with inorganic fibers to obtain a mixture;
A step of spraying an aqueous solution of a water-soluble organic compound which is liquid at 00 ° C. to coat a carrier to obtain a coated product; and a step of calcining the coated product. It is a manufacturing method. The present invention is also a method for producing methacrylic acid, which comprises subjecting methacrolein to gas-phase catalytic oxidation with molecular oxygen in the presence of the above catalyst.

[0008]

DETAILED DESCRIPTION OF THE INVENTION In the present invention, a catalyst composition based on a heteropolyacid compound containing molybdenum and phosphorus is uniformly mixed with inorganic fibers, and the mixture is mixed with a water-soluble organic compound which is liquid at 100 ° C. under normal pressure. The mixture is granulated or coated on a carrier by adding an aqueous solution of the above, and the mixture is calcined, whereby a pore structure in which the pore diameter of each pore is concentrated in the range of 1 to 10 μm can be expressed in the catalyst. . In the present invention, even if the inorganic fibers are mixed, at the time of granulation, or coating the carrier under normal pressure, at 100 ° C., unless adding an aqueous solution of a water-soluble organic compound that is liquid at 100 ° C. A pore configuration in which the pore diameter is concentrated in the range of 1 to 10 μm cannot be obtained. In addition, even if inorganic fibers are not mixed and an aqueous solution of a water-soluble organic compound which is a liquid at normal pressure at 100 ° C. is added and granulated or coated on a carrier, pores are similarly concentrated in the range of 1 to 10 μm in diameter. No pore configuration is obtained.

[0009] Inorganic fibers are uniformly mixed in the catalyst composition,
Only when an aqueous solution of a water-soluble organic compound which is liquid at 100 ° C. is added and granulated, or coated on a carrier, and baked, a pore configuration in which the pore diameter is concentrated in the range of 1 to 10 μm can be obtained. . By using the catalyst obtained by this production method, methacrolein can be oxidized in gas phase with molecular oxygen to produce methacrylic acid with high selectivity.

In the present invention, the catalyst composition is not particularly limited as long as it is a heteropolyacid compound-based catalyst composition containing molybdenum and phosphorus mainly containing molybdophosphoric acid, molybdovanadophosphoric acid and metal salts thereof. As the catalyst composition, the following general formula _{(1) Mo a V b P} c S d X e Y f (NH 4) g O h (1) [ wherein, X is Sb, Si, Cu, Co, One or more elements selected from the group consisting of Bi and As;
At least one element selected from the group consisting of Rb, Cs, and Tl; a, b, c, d, e, f, and g represent the atomic ratio of each element; = 0.1 ~
2, c = 1-3, d = 0.01-0.6, e = 0.01
3, f = 0.1-3, f + g = 2-6, and h is the number of oxygen atoms necessary to satisfy the valence of each component. In the case where a catalyst represented by the above general formula is used, methacrolein is subjected to gas phase catalytic oxidation with molecular oxygen to produce methacrylic acid with a particularly high selectivity. can do. In particular, the S component controls the acidity of the catalyst and improves the selectivity of the catalyst. N
The H ₄ component controls the crystal structure and improves the heat resistance and moisture absorption resistance of the catalyst.

The catalyst composition based on the heteropolyacid compound used in the method of the present invention can be prepared by a conventionally known method. For example, the catalyst composition based on the heteropolyacid compound represented by the general formula shown above can be prepared, for example, by the following method. Molybdenum trioxide,
Mix vanadium pentoxide, copper oxide, sulfuric acid, phosphoric acid and water,
K, Rb, Cs and Tl are added to the homogeneous solution heated and dissolved under reflux.
A catalyst precursor slurry is synthesized by adding a salt of at least one element selected from the group consisting of, for example, a mixed aqueous solution of hydroxide and ammonia. This is 100 ~
The catalyst composition can be obtained by drying at 250 ° C.

The inorganic fibers are glass fibers, ceramic fibers,
It is preferable to use any one of whiskers such as aluminum borate, silicon carbide and potassium titanate, or a mixture thereof. More preferably, glass fibers or whiskers are used, and glass fibers are more preferably used. Average diameter of inorganic fiber is 0.1-20
The average length is preferably from 5 to 200 μm, more preferably from 0.3 to 12 μm, and more preferably from 10 to 120 μm. If the average diameter of the fibers is smaller than 0.1 μm or larger than 20 μm, the desired pore development effect is reduced. The length of the fiber does not particularly affect the appearance of pores, but is preferably from 5 to 200 μm for handling such as mixing. The proportion to be added is preferably 5 to 20 parts by weight, more preferably 7 to 15 parts by weight, per 100 parts by weight of the catalyst composition. If the proportion is less than 5 parts by weight, the effect of the development of pores is small, and if it exceeds 20 parts by weight, the catalyst is too diluted to exhibit sufficient reaction performance. The inorganic fibers can be mixed with the catalyst composition uniformly or by being dispersed in a catalyst precursor slurry and dried by spray drying or the like.

As the water-soluble organic compound, it is preferable to use any of alcohols, diols, polyols and fatty acids, or a mixture thereof. For example, alcohols such as pentanol and hexanol, diols such as ethylene glycol and propanediol, polyols such as glycerin, and fatty acids such as acetic acid, propionic acid, butyric acid, valeric acid, and esters thereof can be used. Among them, diols and polyols are more preferably used, and ethylene glycol and glycerin are more preferably used. The addition ratio is preferably in the range of 0.5 to 10 parts by weight, more preferably in the range of 1 to 5 parts by weight, based on 100 parts by weight of the catalyst composition. When the catalyst is used as a molded body, using a catalyst coated on a granulated or carrier material has a large effect on improving strength, particularly wear loss strength, as compared with a commonly used extruded product or tablet-formed product. . Also, the catalyst coated on the carrier can be expected to have a great effect on improving the methacrylic acid selectivity by suppressing the sequential oxidation reaction. When granulating or coating the carrier, the concentration of the aqueous solution of the water-soluble organic compound is not particularly limited. When using an aqueous solution in the range of 1 to 20 parts by weight per 100 parts by weight of the catalyst composition, the catalyst strength,
It is preferable in terms of reproducibility of catalyst preparation, and it is more preferable to use an aqueous solution in the range of 2 to 10 parts by weight. In the present invention, one of the causes of obtaining a pore configuration in which the pore diameter of each pore is concentrated in a range of 1 to 10 μm is that the water-soluble organic compound has a boiling point of 100 ° C. or more under normal pressure, and until the firing step. This is probably because the catalyst remained in the catalyst. Therefore, when water alone or an aqueous solution of a low boiling point substance such as acetone is used, almost no effect is obtained. If the addition ratio of the water-soluble organic compound is less than 0.5 part by weight, the effect of developing pores cannot be expected.
If the amount exceeds 10 parts by weight, the heteropolyacid dissolves more than necessary, causing agglomeration of granules and the like, making it difficult to granulate or coat the carrier.

The method of adding the aqueous solution of the water-soluble organic compound is not particularly limited, but when granulating or coating the carrier on the mixture of the catalyst composition and the inorganic fibers, the mixture is gradually added by spraying or the like. be able to. When the mixture is coated on a carrier as a catalyst, the carrier is not particularly limited as long as it does not deteriorate the performance by reacting with a catalyst component as a carrier, but silica, alumina, silica alumina, carbon, silicon carbide and the like are generally used. Can be used. Among them, it is more preferable to use silica, alumina, and silica-alumina from the viewpoint of catalyst production cost. For granulation or coating on a carrier, any of a pan type, a tumbling type, a fluid type, or a compound type device using agitation may be used. The calcination method is not particularly limited as long as the heteropolyacid is not decomposed, but usually 250 to 450 ° C, more preferably 300 to 400 ° C.
It is preferable to perform calcination in air or nitrogen under normal pressure from the viewpoint of catalyst production cost. The catalyst obtained by the above method has a pore volume of 72% or more of the total pore volume of pores having a pore diameter in the range of 1 to 10 μm and a pore diameter of less than 1 μm. 0.03ml pore volume
/ G, the total pore volume is controlled to 0.06 ml / g or more. Further, the pore volume of the pores having a pore diameter in the range of 1 to 10 μm is 80% or more of the total pore volume, and the pore volume of the pores having the pore diameter in the range of less than 1 μm is 0.1 μm.
Those having a total pore volume of less than 03 ml / g and controlled to 0.06 ml / g or more are more preferred.

The present invention also relates to a method for producing methacrylic acid, which comprises subjecting methacrolein to gas-phase catalytic oxidation with molecular oxygen in the presence of the above-mentioned catalyst. In the gas phase catalytic oxidation reaction according to the present invention, 1 to 10% by volume
Of methacrolein, 3-20% by volume of molecular oxygen and 7
A mixed gas consisting of a diluent gas of 0 to 90% by volume is used, and the gas is applied onto the catalyst particles under a temperature range of 250 to 450 ° C. and a pressure of 100 to 1100 kPa (normal pressure to 10 atm) at a space velocity of 300 to It is performed by introducing at 5000 / hr. Air is usually used as molecular oxygen, but pure oxygen may be used. As a diluting gas, an inert gas such as nitrogen or carbon dioxide is used. Further, a part of the non-condensable gas contained in the reaction gas may be circulated and used. It is preferable to use water vapor as the diluent gas in order to enhance the activity and selectivity. In that case,
The water vapor in the source gas is usually added up to 60% by volume.
However, the present invention can be practiced by subjecting the catalyst of the present invention to methacrylic acid production by a method other than the above.

[0016]

The present invention will be described in more detail with reference to examples. Note that the present invention is not limited to the embodiments. The conversion and methacrylic acid selectivity are defined as follows.

Conversion (%) = [(number of moles of reacted methacrolein) / (number of moles of supplied methacrolein)]
× 100

Methacrylic acid selectivity (%) = [(moles of methacrylic acid formed) / (moles of reacted methacrolein)] × 100

Example 1 6000 ml of water, 80.1 g of 85% phosphoric acid, 1000 g of molybdenum trioxide, 63 g of vanadium pentoxide, and copper oxide 9.
7 g and 6.5 g of 95% sulfuric acid were mixed and heated under reflux for 7 hours to obtain a uniform solution. This was used as a first raw material solution. 2
135 g of 8% ammonia water and 47.3 g of cesium hydroxide
And 420 ml of water were mixed to obtain a second raw material solution. While stirring the first raw material solution at 15 ° C., the second raw material solution was added dropwise, and the obtained slurry was spray-dried.

Glass powder having an average diameter of 10 μm and an average length of 100 μm is added to the dried catalyst powder in an amount of 15 parts by weight based on 100 parts by weight of the catalyst powder. Powder was obtained. A spherical silica-alumina carrier having a diameter of 3 mm is rolled into a rotating drum, and while heating the drum wall temperature to 95 to 100 ° C, 10 wt%
An ethylene glycol aqueous solution was sprayed on the carrier by spraying, and at the same time, the mixed powder was gradually added so that the loading ratio became 50% by weight to obtain a supported catalyst. The addition amount of ethylene glycol was 5.0 parts by weight based on 100 parts by weight of the catalyst powder. The granulated catalyst supported on the silica alumina was calcined at 360 ° C. for 10 hours in air.

When the pore distribution of the catalyst was measured by a mercury porosimeter, the pore volume of pores having a pore diameter of less than 1 μm was 0.02 ml / g, and the total pore volume was 0.12 m / g.
1 / g, of which the pore volume of the pores having a pore diameter of 1 μm to 10 μm was 82%. 20 ml of the obtained catalyst was added to 1
Filled into an inch reactor, methacrolein 3% by volume, oxygen 9% by volume, steam 20% by volume, nitrogen 68% by volume, raw material gas composition, reactor temperature 300 ° C., space velocity 800 /
hr, reactor outlet pressure 120 kPa (0.2 kgf / cm
^The reaction was performed in ² ), and the performance of the catalyst was evaluated. Table 1 shows the results
It was shown to.

Example 2 A catalyst was prepared in the same manner as in Example 1 except that the concentration of the aqueous ethylene glycol solution was changed from 10% by weight to 2% by weight. The amount of ethylene glycol added was 1.0% by weight based on the catalyst powder. When the pore distribution of this catalyst was measured with a mercury porosimeter, the pore volume of pores having a pore diameter of less than 1 μm was 0.02 ml / g, and the total pore volume was 0.13 m.
1 / g, of which the pore volume of the pores having a pore diameter of 1 μm to 10 μm was 84%. Table 1 shows the performance evaluation results of the catalyst.

Comparative Example 1 In order to clarify the effect of the inorganic fiber on the catalytic performance,
A catalyst was prepared in the same manner as in Example 1 except that no glass fiber was added. The amount of ethylene glycol added was 4.9% by weight based on the catalyst powder. When the pore distribution of this catalyst was measured with a mercury porosimeter, the pore volume of the pores having a pore diameter of less than 1 μm was 0.07 ml / g, and the total pore volume was 0.08 ml / g. Is 1 μm or more
The pore volume of the 10 μm pores was 12%. Table 1 shows the performance evaluation results of the catalyst.

Comparative Example 2 In order to clarify the effect of a water-soluble organic compound which is a liquid at 100 ° C. under normal pressure on catalytic performance, the same procedure as in Example 1 was carried out except that only water was sprayed without ethylene glycol during granulation. Similarly, a catalyst was prepared. When the pore distribution of this catalyst was measured by a mercury porosimeter, the pore volume of the pores having a pore diameter of less than 1 μm was 0.05 ml / g, and the total pore volume was 0.09 ml / g. Is 1 μm to 1
The pore volume of the 0 μm pores was 44%. Table 1 shows the performance evaluation results of the catalyst.

Comparative Example 3 In order to clarify the effect of a water-soluble organic compound which is liquid at 100 ° C. under normal pressure on the catalytic performance, 1% by weight was used during granulation.
A catalyst was prepared in the same manner as in Example 1 except that the aqueous methylcellulose solution was sprayed. The amount of methylcellulose added was 0.6% by weight based on the catalyst powder. When the pore distribution of this catalyst was measured with a mercury porosimeter, the pore diameter was 1
The pore volume of pores smaller than μm is 0.05 ml / g,
The total pore volume is 0.09 ml / g, of which the pore diameter is 1
The pore volume of the pores of μm to 10 μm was 42%. Table 1 shows the performance evaluation results of the catalyst.

Comparative Example 4 In order to clarify the effect of a water-soluble organic compound which is liquid at 100 ° C. under normal pressure on the catalytic performance, the same as in Example 1 except that a 10% by weight aqueous ethanol solution was sprayed during granulation. A catalyst was prepared. The amount of ethanol added was 6% by weight based on the catalyst powder. When the pore distribution of this catalyst was measured with a mercury porosimeter, the pore volume of the pores having a pore diameter of less than 1 μm was 0.04 ml / g, and the total pore volume was 0.08 ml / g. Is 1 μm to 10 μm
The pore volume of the m pores was 49%. Table 1 shows the performance evaluation results of the catalyst.

Comparative Example 5 The same as Example 1 except that a 30% by weight aqueous ethylene glycol solution was sprayed at the time of granulation to clarify the effect of the water-soluble organic compound which is a liquid at 100 ° C. under normal pressure on the catalytic performance. However, the granules agglomerated on the way and coating could not be performed. The addition amount of ethylene glycol was 15% by weight based on the catalyst powder. When the pore distribution of this catalyst was measured by a mercury porosimeter, the pore volume of pores having a pore diameter of less than 1 μm was 0.03 m.
1 / g, the total pore volume is 0.09 ml / g, and the pore volume of pores having a pore diameter of 1 μm to 10 μm is 65 μm.
%Met. Table 1 shows the performance evaluation results of the catalyst.

Example 3 Instead of 2% by weight ethylene glycol aqueous solution, 2% by weight was used.
A catalyst was prepared in the same manner as in Example 2, except that an aqueous glycerin solution was used. The amount of glycerin added was 1.
It was 0% by weight. When the pore distribution of this catalyst was measured with a mercury porosimeter, the pore volume of pores having a pore diameter of less than 1 μm was 0.01 ml / g, and the total pore volume was 0.1 ml / g.
At 13 ml / g, the pore volume of the pores having a pore diameter of 1 μm to 10 μm was 91%. Table 1 shows the performance evaluation results of the catalyst.

Example 4 A catalyst was prepared in the same manner as in Example 3 except that aluminum borate whiskers having an average diameter of 0.7 μm and an average length of 22 μm were added to the catalyst powder in an amount of 10% by weight instead of adding glass fiber. did. The amount of glycerin added was 1.0% by weight based on the catalyst powder. When the pore distribution of this catalyst was measured with a mercury porosimeter, the pore volume of the pores having a pore diameter of less than 1 μm was 0.02 ml / g, and the total pore volume was 0.11 ml / g. Is 1 μm to 10 μm
The pore volume of the m pores was 81%. Table 1 shows the performance evaluation results of the catalyst.

Comparative Example 6 An average length of 22 was used to confirm the effect of the amount of inorganic fiber added.
A catalyst was prepared in the same manner as in Example 4, except that 25 parts by weight of the aluminum borate whisker of 100 μm of the catalyst powder was added. The amount of glycerin added was 1.0 part by weight based on 100 parts by weight of the catalyst powder. When the pore distribution of this catalyst was measured with a mercury porosimeter,
The pore volume of pores having a pore diameter of less than 1 μm is 0.03 ml /
g, the total pore volume was 0.12 ml / g, and the pore volume of pores having a pore diameter of 1 μm to 10 μm was 73%. Table 1 shows the performance evaluation results of the catalyst.

Comparative Example 7 A catalyst was prepared in the same manner as in Example 4 except that aluminum borate whiskers crushed to an average length of 3 μm were used. Glycerin was added in an amount of 1.0 to 100 parts by weight of the catalyst powder.
Parts by weight. When the pore distribution of this catalyst was measured with a mercury porosimeter, the pore volume of pores having a pore diameter of less than 1 μm was 0.03 ml / g, and the total pore volume was 0.03 ml / g.
At 5 ml / g, the pore volume of the pores having a pore diameter of 1 μm to 10 μm was 38%. Table 1 shows the performance evaluation results of the catalyst.

[0032]

[Table 1]

[0033]

The catalyst obtained by the method of the present invention comprises:
The pore volume of the pores having a pore diameter in the range of 1 to 10 μm is 72% or more of the total pore volume, and the pore volume of the pores having the pore diameter in the range of less than 1 μm is 0.03 ml / g. , The total pore volume is controlled to 0.06 ml / g or more. The pore volume of the pores having a pore diameter in the range of 1 to 10 μm is 80% or more of the total pore volume, and the pore volume of the pores having the pore diameter in the range of less than 1 μm is 0.03 ml.
Those having a total pore volume of less than 0.06 ml / g and less than 0.06 ml / g are more preferred. These catalysts show excellent selectivity in the production of methacrylic acid by gas phase catalytic oxidation of methacrolein with molecular oxygen.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toru Nishimura 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture Inside of Tokio Nagayama 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Chemical Co., Ltd. F-term (reference) 4G069 AA03 AA08 BA03B BA13A BA14A BB06A BB06B BB07B BC03A BC05A BC06A BC06B BC16B BC19A BC25A BC26A BC27A BC31A BC31B BC54A BC54B BC59A BC59B BC67A BD02A BD03B0708 BD07 BD07 BD07 BD07 FB09 FB30 FB62 FB63 FC05 FC08 4H006 AA02 AC46 BA02 BA04 BA05 BA09 BA12 BA13 BA14 BA20 BA27 BA30 BA33 BA34 BA35 BA36 BA55 BA56 BA75 BA81 BC13 BC32 BE30 BS10 4H039 CA65 CC30

Claims (10)

[Claims] 1. A general formula _{(1) Mo a V b P} c S d X e Y f (NH 4) g O h (1) [ wherein, X is Sb, Si, Cu, Co, from Bi and As At least one element selected from the group consisting of
At least one element selected from the group consisting of Rb, Cs, and Tl; a, b, c, d, e, f, and g represent the atomic ratio of each element; = 0.1 ~
2, c = 1-3, d = 0.01-0.6, e = 0.01
3, f = 0.1-3, f + g = 2-6, and h is the number of oxygen atoms necessary to satisfy the valence of each component. ] A catalyst for producing methacrylic acid, comprising a catalyst composition represented by the formula: and inorganic fibers. 2. The pore volume of pores having a pore diameter in the range of 1 to 10 μm is 72% or more of the total pore volume, and the pore volume of pores having a pore diameter in the range of less than 1 μm is less than 1 μm. 0.03m
The catalyst for producing methacrylic acid according to claim 1, wherein the catalyst is less than 1 / g and the total pore volume is controlled to 0.06 ml / g or more. 3. The pore volume of a pore having a pore diameter in the range of 1 to 10 μm is 80% or more of the total pore volume, and the pore volume of a pore having a pore diameter in a range of less than 1 μm is less than 1 μm. 0.03m
The catalyst for producing methacrylic acid according to claim 1, wherein the catalyst is less than 1 / g and the total pore volume is controlled to 0.06 ml / g or more. 4. The inorganic fiber is at least one kind of fiber selected from glass fiber, ceramic fiber and whisker, and has a mean diameter of 0.1 to 20 μm and a mean length of 5 to 200 μm. Now, the catalyst composition 10
The catalyst for producing methacrylic acid according to any one of claims 1 to 3, wherein 5 to 20 parts by weight is mixed with respect to 0 part by weight. 5. The inorganic fiber is a glass fiber having an average diameter of 0.1 to 20 μm and an average length of 5 to 200 μm.
μm and 5 to 20 parts by weight per 100 parts by weight of the catalyst composition.
The catalyst for producing methacrylic acid according to any one of claims 1 to 3, wherein the catalyst is mixed in parts by weight. Wherein formula _{(1) Mo a V b P} c S d X e Y f (NH 4) g O h (1) [ wherein, X is Sb, Si, Cu, Co, from Bi and As At least one element selected from the group consisting of
At least one element selected from the group consisting of Rb, Cs, and Tl; a, b, c, d, e, f, and g represent the atomic ratio of each element; = 0.1 ~
2, c = 1-3, d = 0.01-0.6, e = 0.01
3, f = 0.1-3, f + g = 2-6, and h is the number of oxygen atoms necessary to satisfy the valence of each component. Mixing the catalyst composition represented by the formula (1) with inorganic fibers to obtain a mixture, and, while supplying the mixture, spraying an aqueous solution of a water-soluble organic compound which is a liquid at 100 ° C under normal pressure to perform granulation. A method for producing a catalyst for producing methacrylic acid, comprising: a step of obtaining a product; and a step of firing the granulated product. 7. In the general formula _{(1) Mo a V b P} c S d X e Y f (NH 4) g O h (1) [ wherein, X is Sb, Si, Cu, Co, from Bi and As At least one element selected from the group consisting of
At least one element selected from the group consisting of Rb, Cs, and Tl; a, b, c, d, e, f, and g represent the atomic ratio of each element; = 0.1 ~
2, c = 1-3, d = 0.01-0.6, e = 0.01
3, f = 0.1-3, f + g = 2-6, and h is the number of oxygen atoms necessary to satisfy the valence of each component. A step of mixing the catalyst composition represented by the formula (1) and inorganic fibers to obtain a mixture, and, while supplying the mixture, spraying an aqueous solution of a water-soluble organic compound that is liquid at 100 ° C under normal pressure to coat the carrier. A method for producing a catalyst for producing methacrylic acid, comprising: a step of obtaining a coated article by performing the method; and a step of firing the coated article. 8. The water-soluble organic compound is any one of alcohols, diols, polyols, and fatty acids, or a mixture thereof, and is based on 100 parts by weight of the catalyst composition.
The method for producing a catalyst for producing methacrylic acid according to any one of claims 6 to 7, wherein the catalyst is added in an amount of 0.5 to 10 parts by weight. 9. The water-soluble organic compound is ethylene glycol,
Any of glycerin or a mixture thereof,
The method for producing a catalyst for producing methacrylic acid according to any one of claims 6 to 7, wherein the catalyst is added in an amount of 0.5 to 10 parts by weight based on 100 parts by weight of the catalyst composition. 10. A method for producing methacrylic acid, comprising subjecting methacrolein to gas-phase catalytic oxidation with molecular oxygen in the presence of the catalyst according to any one of claims 1 to 5.