JP2013188669A - Method for producing catalyst for production of unsaturated aldehyde and/or unsaturated carboxylic acid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for the production of a catalyst used for the production of an unsaturated aldehyde and/or an unsaturated carboxylic acid excellent in mechanical strength and a method for the production of an unsaturated aldehyde and/or an unsaturated carboxylic acid by using the catalyst obtained by this production method.SOLUTION: There are provided a method for the production of a catalyst for the production of an unsaturated aldehyde and/or an unsaturated carboxylic acid, comprising a complex oxide containing molybdenum, bismuth, iron, and antimony, the method comprising steps (1) to (4), wherein the catalyst is obtained by mixing at least one member selected from a mixture B obtained by mixing a bismuth compound and an iron compound with water, and a mixture C obtained by mixing a mixture A obtained by mixing a molybdenum compound with water with the mixture B, further with an antimony compound, and a method for the production of an unsaturated aldehyde and/or an unsaturated carboxylic acid by using the catalyst obtained by this production method.

Description

  The present invention relates to a method for producing a catalyst used for producing an unsaturated aldehyde and / or an unsaturated carboxylic acid. Moreover, this invention relates to the method of manufacturing unsaturated aldehyde and / or unsaturated carboxylic acid using the catalyst obtained by this manufacturing method.

  Conventionally, a catalyst made of a composite oxide containing molybdenum, bismuth, iron and antimony is known. This catalyst is effective as a catalyst for producing acrolein and / or acrylic acid by vapor-phase catalytic oxidation of propylene with molecular oxygen. This catalyst is also effective as a catalyst for producing methacrolein and / or methacrylic acid by vapor-phase catalytic oxidation of isobutylene or tertiary butyl alcohol with molecular oxygen.

  This catalyst is generally obtained by drying and calcining an aqueous solution or / an aqueous slurry containing a catalyst component. When used in the oxidation reaction described above, the catalyst is usually packed in a fixed bed reactor as a molded body or a support. And use it. Therefore, if the mechanical strength of the catalyst is low, the catalyst is crushed during filling, and a pressure loss occurs in the reactor during the reaction. Therefore, such a catalyst is required to have high mechanical strength.

As a method for increasing the mechanical strength of the catalyst, Patent Document 1 discloses that after drying an aqueous solution or an aqueous slurry containing a catalyst raw material, first-stage calcination is performed in an atmosphere of molecular oxygen-containing gas. Heat treatment is performed in the presence of a reducing substance to obtain a reductant having a mass reduction rate of 0.05 to 6%, and then the obtained reductant is second-stage fired in an atmosphere of molecular oxygen-containing gas. A method is described.
However, even if the method described in Patent Document 1 is adopted, the mechanical strength of the obtained catalyst is not always sufficient.

JP 2009-274034 A

  The subject of the present invention is a method for producing an unsaturated aldehyde and / or unsaturated carboxylic acid production catalyst having excellent mechanical strength, and is selected from propylene, isobutylene and tertiary butyl alcohol in the presence of the catalyst produced by the method. And a method for producing an unsaturated aldehyde and / or an unsaturated carboxylic acid, wherein the compound obtained is vapor-phase catalytically oxidized with molecular oxygen.

（式中、Ｍｏ、Ｂｉ、Ｆｅ及びＳｂはそれぞれモリブデン、ビスマス、鉄及びアンチモンを表し、Ａはニッケル及び／又はコバルトを表し、Ｂはマンガン、亜鉛、カルシウム、マグネシウム、スズ及び鉛から選ばれる元素を表し、Ｃはリン、ホウ素、ヒ素、テルル、タングステン、ケイ素、アルミニウム、チタン、ジルコニウム及びセリウムから選ばれる元素を表し、Ｄはカリウム、ルビジウム、セシウム及びタリウムから選ばれる元素を表し、Ｏは酸素を表し、ａ＝１２としたとき、０＜ｂ≦１０、０＜ｃ≦１０、０．１≦ｄ≦５．０、１≦ｅ≦１０、０≦ｆ≦１０、０≦ｇ≦１０、０＜ｈ≦２であり、ｘは各元素の酸化状態により定まる値である。）で示されるものである前記（１）〜（３）のいずれかに記載の製造方法。
（５）前記（１）〜（４）のいずれかに記載の製造方法により触媒を製造し、この触媒の存在下、プロピレン、イソブチレン及びターシャリーブチルアルコールから選ばれる化合物を分子状酸素により気相接触酸化する不飽和アルデヒド及び／又は不飽和カルボン酸の製造方法。 As a result of intensive studies to solve the above-mentioned problems, the present inventors have found a solution means having the following constitution and have completed the present invention.
(1) A method for producing an unsaturated aldehyde and / or unsaturated carboxylic acid production catalyst comprising a composite oxide containing molybdenum, bismuth, iron and antimony, comprising the following steps (1) to (4): And a method for producing an unsaturated aldehyde and / or unsaturated carboxylic acid production catalyst, wherein at least one selected from the following mixture B and mixture C is obtained by further mixing an antimony compound.
Step (1): A step of obtaining a mixture A by mixing a molybdenum compound with water.
Step (2): A step of obtaining a mixture B by mixing a bismuth compound and an iron compound with water.
Step (3): A step of obtaining the mixture C by mixing the mixture A obtained in the step (1) and the mixture B obtained in the step (2).
Step (4): A step of drying the mixture C obtained in the step (3), followed by firing in an oxidizing gas atmosphere.
(2) The manufacturing method as described in said (1) which heat-processes the said mixture C at 50-75 degreeC before the said drying.
(3) The production method according to (1) or (2), wherein at least one selected from the mixture B and the mixture C is the mixture B.
(4) The composite oxide has the following general formula (I)

(Wherein Mo, Bi, Fe and Sb represent molybdenum, bismuth, iron and antimony, A represents nickel and / or cobalt, and B represents an element selected from manganese, zinc, calcium, magnesium, tin and lead, respectively) C represents an element selected from phosphorus, boron, arsenic, tellurium, tungsten, silicon, aluminum, titanium, zirconium and cerium, D represents an element selected from potassium, rubidium, cesium and thallium, and O represents oxygen When a = 12, 0 <b ≦ 10, 0 <c ≦ 10, 0.1 ≦ d ≦ 5.0, 1 ≦ e ≦ 10, 0 ≦ f ≦ 10, 0 ≦ g ≦ 10, 0 <h ≦ 2, and x is a value determined by the oxidation state of each element.) The production method according to any one of the above (1) to (3).
(5) A catalyst is produced by the production method according to any one of (1) to (4), and in the presence of this catalyst, a compound selected from propylene, isobutylene and tertiary butyl alcohol is vapor-phased with molecular oxygen. A method for producing an unsaturated aldehyde and / or an unsaturated carboxylic acid which undergoes catalytic oxidation.

  ADVANTAGE OF THE INVENTION According to this invention, there exists an effect that the catalyst for unsaturated aldehyde and / or unsaturated carboxylic acid manufacture which is excellent in mechanical strength can be manufactured. Moreover, unsaturated aldehyde and / or unsaturated carboxylic acid can be manufactured with a high yield by using the catalyst for unsaturated aldehyde and / or unsaturated carboxylic acid manufacturing obtained by this manufacturing method.

It is a schematic explanatory drawing which shows the manufacturing method of the catalyst for unsaturated aldehyde and / or unsaturated carboxylic acid manufacture which concerns on one Embodiment of this invention.

  Hereinafter, a method for producing an unsaturated aldehyde and / or unsaturated carboxylic acid production catalyst (hereinafter sometimes referred to as “catalyst”) according to an embodiment of the present invention will be described in detail with reference to FIG. . The catalyst of this embodiment is used when producing an unsaturated aldehyde and / or an unsaturated carboxylic acid.

  The catalyst of this embodiment may be referred to as molybdenum (hereinafter may be referred to as “Mo”), bismuth (hereinafter also referred to as “Bi”), or iron (hereinafter referred to as “Fe”). ) And antimony (hereinafter sometimes referred to as “Sb”) as a necessary component.

  The composite oxide of this embodiment may contain elements other than essential components. Examples of other elements include nickel, cobalt (hereinafter sometimes referred to as “Co”), manganese, zinc, calcium, magnesium, tin, lead, phosphorus, boron, arsenic, tellurium, tungsten, silicon, aluminum, Examples thereof include titanium, zirconium, cerium, potassium, rubidium, cesium (hereinafter sometimes referred to as “Cs”), thallium and the like. Among those exemplified, at least selected from nickel, cobalt, potassium, rubidium, cesium and thallium. One type is preferred.

  As the composite oxide of the present embodiment, the compound represented by the general formula (I) described above is preferable. Specific examples of the composite oxide represented by the general formula (I) include those represented by the following general formula (IA).

（式中、Ｏ及びｘは、前記と同じである。）

(In the formula, O and x are the same as described above.)

The manufacturing method of the catalyst of this embodiment which consists of such a complex oxide includes the following steps (1) to (4).
<Steps (1) and (2)>
As shown in FIG. 1, first, in the step (1), the molybdenum compound is mixed with water to obtain a mixture A, and in the step (2), the bismuth compound and the iron compound are mixed with water to obtain a mixture B.

  Examples of each compound of molybdenum, bismuth and iron include oxides, nitrates, sulfates, carbonates, bicarbonates, hydroxides, oxo acids and ammonium salts thereof, halides and the like. Specific examples of the molybdenum compound include molybdenum trioxide, molybdic acid, ammonium molybdate, and the like. Specific examples of the bismuth compound include bismuth oxide, bismuth nitrate, bismuth sulfate, and the like. Specific examples of the iron compound. Includes iron nitrate (III), iron sulfate (III), iron chloride (III) and the like.

  Here, when the composite oxide constituting the catalyst of the present embodiment contains other elements described above, the other elements are mixed when obtaining the mixtures A and B in the form of the above-described compounds. preferable. Specific examples of the compound of other elements include cobalt nitrate and cesium nitrate.

  The order of mixing each compound and water in obtaining the mixtures A and B, the mixing temperature, the stirring conditions, the amount of water used, etc. are not particularly limited, and may be set as appropriate. The mixing ratio of the bismuth compound and the iron compound when obtaining the mixture B, and the mixing ratio of the compound of other elements when obtaining the mixtures A and B are such that each element contained in the catalyst satisfies the desired atomic ratio. You can do it. When the temperature of water is 20 to 60 ° C., preferably about 30 to 60 ° C., and each compound is added to this water, each compound is easily dissolved, so that the workability in obtaining the mixtures A and B is improved. Can do. Each of the mixtures A and B obtained through the steps (1) and (2) may be an aqueous solution or a slurry.

<Step (3)>
Next, as shown in FIG. 1, the mixture A obtained in the step (1) and the mixture B obtained in the step (2) are mixed to obtain a mixture C.

  The mixing order, the mixing temperature, the stirring conditions, and the like of the mixtures A and B when obtaining the mixture C are not particularly limited and may be set as appropriate. As a specific example, the mixture A may be in a stirring state, and the mixture B may be added to the stirring mixture A. On the contrary, the mixture A may be added to the stirred mixture B. The mixing ratio of the mixtures A and B may be set so that each element included in the catalyst satisfies a desired atomic ratio. The mixture C obtained through the step (3) may be an aqueous solution or a slurry.

<Process (4)>
Next, as shown in FIG. 1, the mixture C obtained in the step (3) is dried and then baked. The mixture C can be dried using, for example, a kneader, a box-type dryer, a drum-type aeration dryer, a spray dryer, an air dryer, or the like.

  Firing of the dried mixture C is performed in an oxidizing gas atmosphere. An oxidizing gas means a gas containing an oxidizing substance. Specific examples of the oxidizing gas include molecular oxygen-containing gas. The molecular oxygen concentration in the gas is usually 1 to 30% by volume, and preferably 10 to 25% by volume. As the molecular oxygen source, air, pure oxygen, or the like is usually used, and these are diluted with, for example, nitrogen, carbon dioxide, water, helium, argon or the like as necessary, and used as the molecular oxygen-containing gas.

  As a calcination temperature, it is 300-600 degreeC normally, and it is preferable that it is 400-550 degreeC. The firing time is usually 5 minutes to 100 hours, and preferably 1 hour to 60 hours.

  As shown in FIG. 1, the mixture C is preferably heat-treated at 40 to 100 ° C., preferably 50 to 75 ° C., more preferably 60 to 70 ° C. before drying as described above. Thereby, the mechanical strength of the catalyst can be further increased.

  Although it does not restrict | limit especially as a method of heat processing, For example, the method of accommodating the mixture C in a mixing container and stirring the mixture C on the specific temperature conditions mentioned above etc. are mentioned. The heat treatment time is usually 0.1 hour or longer, preferably 1 hour or longer, and preferably 20 hours or shorter from the viewpoint of productivity.

  Here, in the present embodiment, at least one selected from the mixture B and the mixture C described above is obtained by further mixing an antimony compound. That is, in this embodiment, as shown in FIG. 1, when obtaining the mixture B and / or the mixture C, an antimony compound is mixed. Thereby, the catalyst excellent in mechanical strength can be obtained.

  In particular, at least one selected from the mixture B and the mixture C is preferably the mixture B. That is, when obtaining the mixture B, it is preferable to mix an antimony compound. Thereby, it is possible to obtain a catalyst having excellent mechanical strength and high catalytic activity. By using such a catalyst, an unsaturated aldehyde and / or an unsaturated carboxylic acid can be produced in a high yield.

  The mixing order of the antimony compound and the other compound when obtaining the mixture B and / or the mixture C is not particularly limited, and may be set as appropriate. The mixing ratio of the antimony compound may be set so that antimony contained in the catalyst satisfies a desired atomic ratio. Examples of the antimony compound include antimony trioxide, antimony trichloride, antimony trifluoride, antimony triacetate, antimony tartrate, antimony pentoxide, and the like.

The catalyst of this embodiment which is excellent in mechanical strength is manufactured through the above steps.
The catalyst obtained by calcination may be heat-treated in the presence of a reducing substance. Thereby, the catalyst which is more excellent in mechanical strength can be obtained. Examples of the reducing substance include hydrogen, ammonia, carbon monoxide, hydrocarbon, alcohol, aldehyde, amine, and the like, and two or more of them may be used as necessary. Each of the hydrocarbon, alcohol, aldehyde and amine preferably has about 1 to 6 carbon atoms.

  Specific examples of hydrocarbons include saturated aliphatic hydrocarbons such as methane, ethane, propane, n-butane and isobutane; unsaturated aliphatic hydrocarbons such as ethylene, propylene, α-butylene, β-butylene and isobutylene; benzene Specific examples of alcohols include saturated aliphatic alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, secondary butyl alcohol, and tertiary butyl alcohol; Unsaturated aliphatic alcohols such as alcohol, crotyl alcohol, methallyl alcohol; phenols and the like. Specific examples of aldehydes include formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde, isoform Saturated aliphatic aldehydes such as butyraldehyde; unsaturated aliphatic aldehydes such as acrolein, crotonaldehyde, methacrolein, etc. Saturated aliphatic amines; unsaturated aliphatic amines such as allylamine and diallylamine; and anilines.

  The heat treatment in the presence of the reducing substance is usually performed by heat-treating the baked catalyst in an atmosphere of a gas containing the reducing substance. The concentration of the reducing substance in the gas is usually from 0.1 to 50% by volume, preferably from 3 to 30% by volume, and the reducing substance is used so that the reducing substance has such a concentration. The substance may be diluted with, for example, nitrogen, carbon dioxide, water, helium, argon or the like.

  As temperature of the heat processing performed in presence of a reducing substance, it is 200-600 degreeC normally, and it is preferable that it is 300-500 degreeC. The heat treatment time is usually 5 minutes to 20 hours, and preferably 30 minutes to 10 hours.

  The heat treatment performed in the presence of the reducing substance is preferably performed, for example, by storing the baked catalyst in a tube-type or box-type container and circulating a gas containing the reducing substance in the container. . The gas discharged from the container may be circulated in the container and reused as necessary.

  The catalyst heat-treated in the presence of the reducing substance may be further calcined in an oxidizing gas atmosphere. Thereby, the catalyst which is more excellent in mechanical strength can be obtained. Examples of the oxidizing gas include the same oxidizing gas as exemplified in the firing of the mixture C described above. As a calcination temperature, it is 200-600 degreeC normally, and it is preferable that it is 350-550 degreeC. The firing time is usually 5 minutes to 20 hours, and preferably 30 minutes to 10 hours.

  The usage form of the catalyst of the present embodiment is not particularly limited. For example, the catalyst may be molded into a desired shape and used as a molded body, or the catalyst component is supported on a carrier and used as a carrier. May be.

  Examples of the molding method when the catalyst is used as a molded body include a tableting molding method and an extrusion molding method. Examples of the molded shape include a ring shape, a pellet shape, a spherical shape, and a cylindrical shape.

  As the molding time, the following time is preferable. That is, in this embodiment, when the mixture B and / or mixture C described above is obtained, the antimony compound is mixed to increase the mechanical strength of the catalyst. Therefore, the molding is preferably performed after mixing the antimony compound. . Specifically, it is preferable to mold the mixture C after drying it, or mold the mixture C after drying and baking it.

  Further, when molding the catalyst, it is preferable to add, for example, an inorganic fiber in order to improve the mechanical strength of the catalyst. The inorganic fiber is not particularly limited as long as it is substantially inert to the target oxidation reaction, and examples thereof include alumina fiber, silica fiber, glass fiber, and silica-alumina fiber.

  The addition amount of the inorganic fiber is preferably about 1 to 15 parts by mass with respect to 100 parts by mass of the catalyst component. A more detailed description of the inorganic fiber is described in, for example, JP-A-9-52053.

  Examples of the carrier when the catalyst is used as a carrier include silica, alumina, silicon carbide, silicon nitride and the like.

  Since the catalyst of this embodiment described above is excellent in mechanical strength, when used in the production of unsaturated aldehyde and / or unsaturated carboxylic acid, crushing of the catalyst due to filling into the reactor is well suppressed. Therefore, the pressure loss during the reaction can be reduced, and the compound selected from propylene, isobutylene and tertiary butyl alcohol can be stably vapor-phase-oxidized with molecular oxygen to produce unsaturated aldehyde and / or Alternatively, an unsaturated carboxylic acid can be produced.

  In the gas phase catalytic oxidation reaction, a fixed bed multitubular reactor is usually filled with the catalyst of this embodiment, and a raw material compound selected from propylene, isobutylene and tertiary butyl alcohol, molecular oxygen, and the like are contained in the reactor. By supplying a source gas containing

  Air is usually used as the molecular oxygen source, and the raw material gas may contain, for example, nitrogen, carbon dioxide, carbon monoxide, water vapor, etc. as components other than the raw material compound and molecular oxygen. .

  The reaction temperature is usually 250 to 400 ° C., and the reaction pressure can be reduced, but is usually 100 to 500 kPa. The amount of molecular oxygen with respect to the raw material compound is usually 1 to 3 mol times. The space velocity SV of the raw material gas is usually 500 to 5000 / h on the basis of STP (standard temperature and pressure).

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited by these Examples. In the following examples, ml / min representing the gas flow rate is based on STP unless otherwise specified. Moreover, the evaluation method of each physical property is as follows.

<Catalyst drop strength test>
A stainless steel net having a mesh opening of 4.76 mm was fixed to the bottom of a metal tube having an inner diameter of 30 mm and a length of 5 m installed substantially perpendicular to the horizontal direction so that the surface thereof was almost horizontal.

  The catalyst was introduced and dropped from the top of the metal tube. The catalyst after dropping was collected, placed on a sieve having an opening of 4.76 mm, the sieve was vibrated, and the mass of the catalyst remaining on the sieve was measured.

  The measured value is applied to the formula: [mass of catalyst remaining on the sieve (g) / mass of catalyst charged from the top of the metal tube] × 100 to calculate the drop strength (%) of the catalyst. did.

<Oxidation reaction of isobutylene>
First, 3 g of catalyst was diluted and filled with 30 g of silicon carbide (“Shinano Random GC F16” manufactured by Shinano Denki Co., Ltd.) on the raw material gas inlet side of a glass reaction tube having an inner diameter of 18 mm.

  Next, a mixed gas of isobutylene / oxygen / nitrogen / steam = 1.0 / 2.2 / 6.2 / 2.0 (molar ratio) from the raw material gas inlet side into this reaction tube was 87.6 ml / min. It was supplied at a flow rate and an oxidation reaction was carried out at a reaction temperature of 370 ° C. And the conversion and yield of isobutylene were computed. The calculation method of the conversion rate and yield of isobutylene is as follows.

(Conversion rate of isobutylene)
The conversion rate (%) of isobutylene (hereinafter sometimes referred to as “IB”) is expressed by the formula: [(number of moles of supplied isobutylene) − (number of moles of unreacted isobutylene)] / (number of moles of supplied isobutylene) Calculated from x100.

(yield)
The yield (%) of methacrolein (hereinafter sometimes referred to as “MACR”) was calculated from the formula: [(number of moles of methacrolein) / (number of moles of supplied isobutylene)] × 100.
The yield (%) of methacrylic acid (hereinafter sometimes referred to as “MAA”) was calculated from the formula: [(mol number of methacrylic acid) / (mol number of supplied isobutylene)] × 100.
The yield (%) of methacrolein and methacrylic acid was calculated from the formula: yield (%) of methacrolein + yield (%) of methacrylic acid.

<Preparation of catalyst>
First, 2207 g of ammonium molybdate [(NH ₄ ) ₆ Mo ₇ O ₂₄ · 4H ₂ O] was dissolved in 2500 g of hot water at 50 ° C. to obtain a mixture A as an aqueous solution.

Meanwhile, 1010 g of iron (III) nitrate [Fe (NO ₃ ) ₃ .9H ₂ O], 2183 g of cobalt nitrate [Co (NO ₃ ) ₂ .6H ₂ O], 97 g of cesium nitrate [CsNO ₃ ] and antimony trioxide [Sb ₂ O ₃ ] 43 g was dissolved in hot water 1000 g at 30 to 40 ° C., and then bismuth nitrate [Bi (NO ₃ ) ₃ .5H ₂ O] 485 g was dissolved to obtain a mixture B as an aqueous solution.

  Next, the mixture A was stirred, and the mixture B was added to the stirred mixture A to obtain a mixture C as a slurry. The obtained mixture C was heat-treated by stirring at 65 ° C. for 80 minutes, and then dried by an air dryer.

  To this dried mixture C, silica alumina fiber “RFC400-SL” manufactured by Saint-Gobain TM was added. The addition amount of silica alumina fiber was 9 parts by mass with respect to 100 parts by mass of the dried mixture C.

  Next, the mixture C to which the silica alumina fiber was added was molded into a ring shape having an outer diameter of 6.3 mm, an inner diameter of 2.5 mm, and a length of 6 mm, and then calcined at 545 ° C. for 6 hours in an air stream to form a catalyst (Ia ) This catalyst (Ia) contains 0.96 atoms of bismuth, 2.4 atoms of iron, 7.2 atoms of cobalt, 0.48 atoms of cesium and 0.48 atoms of antimony with respect to 12 atoms of molybdenum. The value of each atom is a value calculated from the charged amount.

<Evaluation>
As a result of performing a test based on the above-described catalyst drop strength test using 30 g of the obtained catalyst (Ia), the catalyst drop strength was 97.6%.

  Moreover, as a result of performing an oxidation reaction based on the above-described oxidation reaction of isobutylene using the obtained catalyst (Ia), the conversion of isobutylene was 84.0%, the yield of methacrolein was 69.9%, The yield of methacrylic acid was 2.3%, and the yields of methacrolein and methacrylic acid were 72.2%.

<Preparation of catalyst>
First, the mixture A was obtained as an aqueous solution in the same manner as in Example 1, and the mixture B was obtained as an aqueous solution in the same manner as in Example 1 except that antimony trioxide was not mixed.

  Next, the mixture A was stirred, and the mixture B was added to the stirred mixture A. After stirring at 65 ° C. for 80 minutes, 43 g of antimony trioxide was added to obtain a mixture C as a slurry.

  Then, except that the heat treatment of the obtained mixture C was performed by stirring at 65 ° C. for 60 minutes, it was dried in the same manner as in Example 1, and after adding silica alumina fiber, it was molded into a ring shape and baked. Catalyst (Ib) was obtained. This catalyst (Ib) contains 0.96 atoms of bismuth, 2.4 atoms of iron, 7.2 atoms of cobalt, 0.48 atoms of cesium and 0.48 atoms of antimony with respect to 12 atoms of molybdenum.

<Evaluation>
As a result of conducting a test based on the above-described catalyst drop strength test using 30 g of the obtained catalyst (Ib), the catalyst drop strength was 97.0%.

  Further, as a result of performing an oxidation reaction based on the above-described oxidation reaction of isobutylene using the obtained catalyst (Ib), the conversion of isobutylene was 76.0%, the yield of methacrolein was 64.0%, The yield of methacrylic acid was 2.1%, and the yields of methacrolein and methacrylic acid were 66.1%.

[Comparative Example 1]
<Preparation of catalyst>
First, the mixture A was obtained as an aqueous solution in the same manner as in Example 1, and the mixture B was obtained as an aqueous solution in the same manner as in Example 1 except that antimony trioxide was not mixed. In the same manner as in No. 1, the mixture C was obtained as a slurry.

  Next, the obtained mixture C was heat-treated and dried in the same manner as in Example 1, and silica alumina fiber was added and antimony trioxide was added. The amount of antimony trioxide added was 2.5 parts by mass with respect to 100 parts by mass of the dried mixture C.

  The mixture C was heat-treated and dried, and then the mixture obtained by adding silica alumina fiber and antimony trioxide was molded into a ring shape and calcined in the same manner as in Example 1 to obtain catalyst (II). The catalyst (II) contains bismuth 0.96 atoms, iron 2.4 atoms, cobalt 7.2 atoms, cesium 0.48 atoms, and antimony 0.48 atoms with respect to 12 atoms of molybdenum.

<Evaluation>
As a result of performing a test based on the above-described catalyst drop strength test using 30 g of the obtained catalyst (II), the catalyst drop strength was 88.0%.

  Further, as a result of performing an oxidation reaction based on the above-described oxidation reaction of isobutylene using the obtained catalyst (II), the conversion of isobutylene was 74.0%, the yield of methacrolein was 63.1%, The yield of methacrylic acid was 2.0%, and the yields of methacrolein and methacrylic acid were 65.1%.

Table 1 shows the results of Examples 1 and 2 and Comparative Example 1 described above.

  As is clear from Table 1, Examples 1 and 2 in which at least one selected from the mixture B and the mixture C is obtained by further mixing an antimony compound are formed, that is, after the mixture C is dried. Since the drop strength is higher than that of Comparative Example 1 in which the antimony compound is mixed, it can be seen that the mechanical strength is excellent. And Example 1, 2 showed the result higher than the comparative example 1 in the conversion of isobutylene and the yield of methacrolein and methacrylic acid. In particular, Example 1 in which the mixture B obtained by further mixing the antimony compound among the mixture B and the mixture C showed excellent results in the conversion of isobutylene and the yield of methacrolein and methacrylic acid.

Claims (5)

A method for producing an unsaturated aldehyde and / or unsaturated carboxylic acid production catalyst comprising a composite oxide containing molybdenum, bismuth, iron and antimony, comprising the following steps (1) to (4), and A method for producing an unsaturated aldehyde and / or unsaturated carboxylic acid production catalyst, wherein at least one selected from the mixture B and the mixture C is obtained by further mixing an antimony compound.
Step (1): A step of obtaining a mixture A by mixing a molybdenum compound with water.
Step (2): A step of obtaining a mixture B by mixing a bismuth compound and an iron compound with water.
Step (3): A step of obtaining the mixture C by mixing the mixture A obtained in the step (1) and the mixture B obtained in the step (2).
Step (4): A step of drying the mixture C obtained in the step (3), followed by firing in an oxidizing gas atmosphere.   The manufacturing method of Claim 1 which heat-processes the said mixture C at 50-75 degreeC before the said drying.   The production method according to claim 1 or 2, wherein at least one selected from the mixture B and the mixture C is the mixture B. The composite oxide has the following general formula (I)

(Wherein Mo, Bi, Fe and Sb represent molybdenum, bismuth, iron and antimony, A represents nickel and / or cobalt, and B represents an element selected from manganese, zinc, calcium, magnesium, tin and lead, respectively) C represents an element selected from phosphorus, boron, arsenic, tellurium, tungsten, silicon, aluminum, titanium, zirconium and cerium, D represents an element selected from potassium, rubidium, cesium and thallium, and O represents oxygen When a = 12, 0 <b ≦ 10, 0 <c ≦ 10, 0.1 ≦ d ≦ 5.0, 1 ≦ e ≦ 10, 0 ≦ f ≦ 10, 0 ≦ g ≦ 10, (0 <h ≦ 2, and x is a value determined by the oxidation state of each element.)
The method according to any one of claims 1 to 3, wherein   An unsaturated aldehyde which produces a catalyst by the production method according to any one of claims 1 to 4, and in the presence of the catalyst, gas phase catalytically oxidizes a compound selected from propylene, isobutylene and tertiary butyl alcohol with molecular oxygen. And / or a method for producing an unsaturated carboxylic acid.

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