JPS63315148A - Catalyst of synthesis of methacrylic acid and preparation thereof showing excellent reproducibility - Google Patents

Abstract

PURPOSE:To enhance methacrylic acid synthesizing activity and mechanical strength, by forming a catalyst having a specific metal oxide composition and having a specific surface area, a pore volume, pore diameter distribution and a pore diameter set to the values within specific ranges. CONSTITUTION:A unbaked catalyst raw material powder is charged in a centrifugal fluidized coating apparatus and granulated into particles having an average diameter of 2-10mm before baking. By this method, a catalyst having a specific surface area of 1.0-10m<2>/g, a pore volume of 0.10-1.0cc/g and pore diameter distributions respectively concentrated to a range of 1-10mum and a range of 0.1- below 1mum is formed. The composition of the catalyst is represented by formula I (wherein A is As, Sb or Ge, B is Cu, Fe, Cr, Ni, Pd or Rh, C is V, W or Nb and D is an alkali metal, an alkaline earth metal or Th).

Description

Detailed Description of the Invention [Industrial Application Field] The present invention provides methacrolein and The present invention relates to an oxidation catalyst suitable for producing methachlorene from isobutyraldehyde and/or isoacetic acid, and a method for producing the same. The present invention has high activity and excellent durability as a catalyst for methachlorene synthesis.
The present invention relates to a method for easily and reproducibly producing a catalyst that has unique physical properties.

[Prior Art] Various catalysts have been proposed for efficiently producing methacrolene through a catalytic gas phase oxidation reaction of methacrolein. These are mainly related to the selection of components constituting the catalyst and their ratios, but some of them are related to regulation of catalyst physical properties and reproducible manufacturing methods. That is,
Although there have been proposals regarding the physical properties of the catalyst itself, such as the surface area, pore volume, and pore diameter, the performance is insufficient, and no product that is at a satisfactory level has yet been found.

For example, JP-A-49-116022, JP-A-50
In the specification of Publication No. 37710, it is stated that the surface area of each catalyst is preferably in the range of 0.01 to 5 m/q10.01 to 50 m2/g. It has a low selectivity and is not necessarily sufficient as an industrial catalyst.

As a report on the surface area and pore volume,
There is a publication No. 3876, in which the surface area is 4 to 20T.
rL 7g, pore volume 0.08-0.5cc/g, catalyst components are phosphorus, molybdenum, and ) as an essential component, and a method of molding using a transfer-type granulator is disclosed. However, as far as the details of this implementation are concerned, the reaction temperature is high and it is unsatisfactory as an industrial catalyst.

[Problems to be Solved by the Invention] The present inventors believe that the optimization of catalyst physical properties is not determined only by the catalyst surface area, pore volume, or pore size distribution alone as in the prior art, but by determining the catalyst surface area, We believe that an industrially superior catalyst can only be obtained if the catalyst is given physical properties that are a combination of three factors: pore volume and pore diameter. By the way, methacrolein,
When carrying out the oxidation or oxidative dehydrogenation reaction of isobutyraldehyde, isoacetic acid, etc., the catalyst is often used in the form of pellets of an appropriate size. Such pellet catalysts are molded using a tablet molding machine, an extrusion molding machine, a round machine, a transfer granulator, etc., but it is often difficult to mold them without reducing the catalyst performance. In most cases, the performance of the resulting catalyst is poor in reproducibility.

Means for Solving Problem U] Therefore, the present inventors conducted extensive studies to find out the cause of the change in catalyst performance that occurs when producing catalyst pellets using various molding machines, and found that Mo, P , Δ, B, C, D, and O (where Mo
is molybdenum, P is phosphorus, △ is at least one element selected from arsenic, antimony, germanium, bismuth, zirconium, and selenium, B is copper, iron, chromium, nickel, manganese, cobalt, tin, silver, zinc, at least one element selected from the group consisting of palladium, rhodium, and tellurium; C is at least one element selected from the group consisting of vanadium, tungsten, and niobium; D is an alkali metal, an alkaline earth metal, Depending on the molding method, catalyst raw material compositions containing at least one element selected from the group consisting of thallium and 0 represents oxygen as component elements may have a large drop in catalytic performance depending on the molding method. It was found that the properties of the catalyst were zero and the physical property values varied.

It has been found that the main reason for this is that molding, particularly the pores of the catalyst, are regulated, and therefore the surface area, pore volume, and pore diameter of the catalyst are regulated. Therefore, in order to obtain a catalyst with excellent performance containing the above components, we investigated the surface area, pore volume, and pore distribution, and found that the surface area was 1.0 to 10.0 TrL2/g.
, the pore volume is 0.10 to 1.0 cc/Cl, and the pore size distribution is 1 to 10 μm and 0.1 to 1 μm in diameter.
It has been found that it is necessary to have physical properties that satisfy the three-row property where the distribution is concentrated in a range of less than m.

Here, regarding the pore size distribution, the volume occupied by pores existing in the range of 0.1 to less than 1 μm is 10% or more of the total pore volume,
Particularly 20% or more, most preferably in the range of 20 to 60%, the volume occupied by pores existing in the range of 1 to 10 μm is 10% or more of the total pore volume, especially 30% or more, most preferably 4
It ranges from 5 to 80%. It has been found that when these conditions are met, this catalyst exhibits high performance in both activity and selectivity. Normally, pores with smaller pore diameters make a large contribution to surface area and pore volume, but when the reaction and catalyst system in the present invention are limited, pores that contribute to activity and selectivity to effective reaction products are It was found that simply increasing the proportion of small pores is not sufficient, and that the coexistence of relatively large pores of 1 to 10 μm improves performance. Based on this knowledge, the inventors conducted extensive research into a method for manufacturing catalysts with specific physical properties, and found that by molding the unfired catalyst powder before granulation using a centrifugal fluid coating device, The present inventors have completed the present invention by discovering that a catalyst can be obtained with extremely high reproducibility and exhibiting excellent catalytic performance compared to conventional catalyst molding methods.

Usually, catalyst molding methods include transfer granulation, Marsurizer molding, fluidized bed granulation, etc. when producing spherical shapes, and extrusion molding and tablet molding when producing cylindrical shapes. law is adopted.

However, when such a molding method is adopted, it is often difficult to mold the catalyst without deteriorating its performance.
There is also a lot of variation in performance, and reproducibility is often poor.

On the other hand, the use of the centrifugal fluid coating apparatus used in the present invention is simple, has good productivity, and can produce spherical or granular catalysts having specific surface areas, pore volumes, and pore size distributions specified in the present invention. It was found that it could be manufactured with good reproducibility. Furthermore, when molded using a centrifugal fluid coating device, a catalyst with a narrow particle size distribution is produced, and the granular or spherical shape of the catalyst provides high mechanical strength, low pressure loss, and high resistance to abrasion, making it suitable for use in reaction equipment. It has the advantage of being easy to fill and remove.

Incidentally, a centrifugal fluid coating apparatus and its method of use are known as a method of granulating powder materials. For example, Japanese Patent Publication No. 46-10878 discloses a method and apparatus for coating pharmaceuticals with sugar coating, and Japanese Patent Publication No. 52-17292 discloses coating of granular cores with a catalyst and/or a centrifugal fluid coating device. Alternatively, a method for producing a granular catalyst or a catalyst carrier characterized by coating it with a carrier is disclosed. The present invention applies this method to the production of oxide catalysts with the physical properties specified above, and can be achieved by simply using water or the like as a binder, or in some cases by burning or volatilizing during calcination to form fine particles in the catalyst. By using a substance that provides pores in combination, it is possible to easily produce a catalyst having a surface area, pore volume, and pore size distribution regulated as described above, and it is also possible to obtain a spherical or granular catalyst with strong physical strength. It is.

As an example of production using this centrifugal fluid coating device, an unfired oxide composition before molding or a powder of a catalyst raw material composition in the previous stage that has not been converted into an oxide is put into the centrifugal fluid coating device, and while blowing hot air, Granulation is carried out without sprinkling a binder such as water, and the particles that have grown to the desired size are taken out in a batch method or a continuous method, and then dried as necessary, at 200 to 600°C. , preferably 300-50
A method is mentioned which consists of firing at a concentration of 0°C.

In the present invention, the catalyst can be used as it is, but it can also be used diluted with an inert carrier or supported on the inert carrier. In granulation molding, it is preferable to use as cores the catalyst itself granulated in advance with a particle size of about 10 times the particle size of the original powder. Of course, an inert carrier can also be used as the core. Examples of the inert carrier include known ones such as silicon carbide, silica, α-alumina, graphite, and other refractory materials. It is preferable that the coating catalyst powder for growing the particle size is adjusted to 100 mesh or less.

In order to reproducibly produce a catalyst having the surface area, pore volume, and pore size distribution defined in the present invention, for example, polyvinyl alcohol, stearic acid, etc. may be added to the catalyst powder during preparation of the catalyst powder, or added to the catalyst powder during molding. Good to add. Depending on the case, if it is desired to further reduce the degree of pulverization of the catalyst, whiskers or glass H&string may be added. Further, water, cellulose, ammonium nitrate, graphite, starch, etc. can be used as a powder binder, and 41 solvents such as alcohol and acetone can also be used.

The catalyst used in the present invention is represented by the following general formula.

No(a) P(b) A(c) B(d) C(e)
D(f) 0(X) (where Mo is molybdenum, P is phosphorus, A is at least one element selected from the group consisting of arsenic, antimony, germanium, bismuth, zirconium, and selenium, and B is copper, iron , chromium, nickel,
At least one element selected from the group consisting of manganese, cobalt, tin, silver, zinc, palladium, rhodium and tellurium; C is at least one element selected from the group consisting of vanadium, tungsten and niobium; D is At least one element selected from the group consisting of alkali metals, alkaline earth metals and thallium and O represent oxygen.

Further, a, b, c, d, e, f, and x are each Mo.

Represents the atomic ratio of P, A, B, C, D and O, a-1
2, b=0.5~4, c=0~5, d-〇~3, e
-O~4, f-0, 01~4 and x are numerical values determined by the oxidation state of each element. ) The catalytic gas phase oxidation reaction according to the present invention has a raw material gas composition of 1
．． A raw material compound such as methacrolein, isobutyraldehyde or isoacetic acid in an amount of 0 to 10% by volume, molecular oxygen in a volume ratio of 1 to 10 with respect to the raw material compound, and an inert gas such as nitrogen, carbon dioxide, or water vapor as a diluent. In particular, the use of steam is advantageous in suppressing the formation of by-products and improving the yield of the desired product.
It is carried out by introducing at a temperature range of 400° C. and a pressure of normal pressure to 10 atmospheres at a space velocity of 100 to 5000 hr −1 (STP). When methacrolein is selected as a raw material, methacrolein does not necessarily have to be pure; methacrolein-containing gas obtained by catalytically reacting isobutylene or tertiary-butanol can also be used. Recommended.

Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. Conversion rate, selectivity and single stream yield in this specification are defined as follows.

Conversion rate (%) - Selectivity (%) - Single flow yield (%) = Example■ (Preparation of catalyst raw material suspension) 40j of heated ion-exchanged water! ammonium paramolybdate 88300 and ammonium metavanadate 53
0Q was added and dissolved with stirring.

Add pyridine 2030G and phosphorus M (85% by weight) to this solution.
5240 was added thereto, 41 nitric acid (specific gravity 1.38), and a solution of 812 g of cesium nitrate dissolved in 51 ion-exchanged water was added and stirred with heating to obtain a suspension (this was referred to as suspension 8).

Example ■-1-1 (Centrifugal fluid coating method) A slurry material obtained by heating and concentrating a part of suspension-A was heated to 250 ml.
The mixture was dried at ℃ for 15 hours and ground into about 100 meshes to obtain a powder.

First, α-alumina particles with an average size of 1 #φ were put into a centrifugal fluid coating device, and then the above powder was put in while passing hot air at 90°C, and while distilled water was added as a binder, the powder was coated with an average diameter of 5 mm. It was granulated into spherical shapes. The spherical particles thus obtained were calcined in a nitrogen stream at 430°C for 3 hours, and then in air at 400°C = 16- for 3 hours. The elemental composition of this catalyst oxide is as follows in atomic ratio (excluding oxygen, the same applies hereinafter): M O12P 1.09 V 1. o9 CS 1.
It was 0.

Example 1-1-2 (centrifugal fluid coating method) side-down l-1-
A catalyst (I-1-2) was prepared in exactly the same manner as in Example 1 except that a 40% by weight aqueous ammonium nitrate solution was used instead of water as the binder.

Examples 1-2-1, 1-2-2 (Tablet molding method) A part of Suspension-A was heat-stirred and evaporated to dryness to form a block shape of 250
The dried block was dried for 15 hours at 0.degree. C. and ground to less than 100 meshes.

Add carbon powder to this powder to make it 2% by weight,
Formed into a 5sφ×5#H tablet and heated at 430°C in a nitrogen stream.
A catalyst (I-1-1) was prepared by calcining at 30° C. for 3 hours and then at 400° C. for 3 hours in an air stream. A catalyst (I-2-2) was prepared by repeating the same operation.

Examples 1-3-1 and 1-3-2 (Extrusion molding method) A slurry material obtained by heating and concentrating a part of the suspension into 2
The mixture was dried at 50° C. for 15 hours, and after pulverization, water was added as a molding aid and extrusion molded to a size of 5 Mφ×5 mm H. This molded product was fired at 430°C for 3 hours in a nitrogen stream,
Subsequently, the catalyst (I-3-
1) was obtained. Repeat the same operation to prepare the catalyst (I-12)
I got it.

Example ■-4 (Marslizer molding method) Heat and concentrate a portion of the suspension, dry the resulting slurry material at 250°C for 15 hours, and add water as a molding aid after crushing to form a 6 mmφ x 4 After molding to ~7 s L, it was placed in a marmerizer to form a spaced shape of 3 mm x 5 tnm.

This was then calcined in a nitrogen stream at 430°C for 3 hours, and then in an air stream at 400°C for 3 hours to obtain a catalyst (I-4).

Example 5-5 (Transfer Granulation Method) A slurry material obtained by heating and concentrating a portion of the suspension was dried at 250° C. for 15 hours and pulverized into about 100 meshes to obtain a powder. First, α in an average of 1 mm is applied to the transfer granulator.
- Pour the alumina particles, then the above powder, 8
The average diameter is 5#φ using 0℃ hot air and distilled water as a binder.
It was granulated into spherical shapes.

This was calcined in a nitrogen stream at 430°C for 3 hours, and then in air at 400°C for 3 hours to obtain catalyst (I-5).

A portion of Example I-6 (@ll washing method suspension) was concentrated by heating to obtain a slurry having a weight of scattered matter of 50% by weight when fired at 400°C.

This slurry material was granulated into a shape with an average diameter of 5#φ using a conventional rounding machine. This spherical material was fired at 430° C. for 3 hours in a nitrogen stream. Next, the catalyst (I-6) was prepared by calcining in air at 400° C. for 3 hours.

Example ■ (Reaction test) The catalyst platform 100 obtained above was
A mixed gas obtained by catalytic gas phase oxidation of isobutylene in the presence of a molybdenum, cobalt, tungsten, and iron oxide multi-component catalyst was introduced into a steel reaction tube of 1.5 mm in diameter at a reaction temperature of 270°C and a space velocity of 1200 hr. The reaction was carried out at −1. The average composition of the mixed gas was as follows.

Methacrolein 3.5% by volume isobutylene
0.04 〃Metachlorolenedecaacetic acid
0.24 horn water steam 20
Oxygen 9.0 Others 67.2 (Inert gas mainly consisting of nitrogen and carbon dioxide) The reaction results and physical property values of each catalyst are summarized in Table-1.

Example ■ (Preparation of catalyst and its reproducibility) A suspension similar to that prepared in Example ■ was prepared and divided into four equal parts.
It was divided into batches. These four batches were used to prepare powder or clay-like materials as raw materials suitable for various molding methods.
They were molded using the same molding method as the 6 series, and their performance was compared, and reproducibility within the same molding method was confirmed. However, regarding the same molding method, four batches of catalysts were independently molded and prepared using exactly the same procedure and under the same conditions. Also, the performance test method is as shown in Example 1-
1-6 was followed. The results are shown in Table-2.

As is clear from Table 2, when molded using the centrifugal fluid coating method, the range of physical properties is small and the catalyst performance is highly active. It can be seen that it is being prepared. on the other hand,
Catalysts molded using other molding methods may not meet the surface area, pore volume, and pore size distribution specified in the present invention depending on the batch, even though they are molded under exactly the same conditions. can. However, as a method for obtaining a catalyst with excellent catalytic performance and good reproducibility, it is found that the molding method using the centrifugal fluid coating method defined in the present invention is the most preferable.

Example ■ (Preparation of catalyst) 18j! of ammonium molybdate 4770Cl! dissolved in water. Separately, add 261Q of 85% orthophosphoric acid to 13% of water.
The mixture was diluted with 50 ml of water, and 162 g of copper nitrate and 171 g of arsenite were dissolved therein, and the mixture was added to the above aqueous ammonium molybdate solution and thoroughly stirred while heating for aging. Separately, 85% Orthorin M261q was diluted in 1350 d of water, 207 q of vanadium pentoxide was added thereto, and water was evaporated while stirring with heating to form a yellow complex. This complex was added to the reaction precipitate of phosphorus, molybdenum, copper and arsenic, and finally 1260 g of potassium hydroxide was added to 13 g of water.
Add the solution dissolved in 50- to make a suspension, which will be referred to as suspension-B. ).

Example (1) (Centrifugal fluid coating method) A portion of suspension-B was treated and catalyzed in the same manner as in Example 1-1-1. However, after drying at 200° C. for 4 hours after granulation, this was calcined at 400° C. for 5 hours under air circulation. The composition of this catalyst is the atomic ratio rMo12P2 CIJo excluding oxygen,
3 KI VI A was 80.5.

This catalyst is designated as lll-1.

Example 111-2'-1, l-2-2 (Tablet Forming Method) A portion of Suspension-B was treated and catalyzed according to the method of Example I-2. However, after drying at 200° C. for 4 hours after molding, this was fired at 400° C. for 5 hours under air circulation. These catalysts are I[r-2
-1, m-2-2.

Example ■ (Reaction test) The reaction was carried out in the same manner as in Example 1, and the performance of each catalyst obtained in Example 1 [[-1-2] was tested. However, the reaction temperature is 290
℃.

Example (Preparation of catalyst) 85% phosphorus M553.2C] was added to an aqueous solution of ammonium molybdate 5088G dissolved in 101 g of pure water, and then 936 q of cesium nitrate was added to 3.6 g of water. i! Then add bismuth nitrate 582Q and antimony pentoxide 194.40 as powder = 27-, and finally add chromic anhydride 120q and selenium dioxide 13
A solution of 3.2 (7) in 3.61 parts of water was added to obtain a suspension (referred to as suspension-C).

Example 1-1 (Centrifugal fluid coating method) A part of suspension-C was treated and catalyzed in the same manner as in Example 1-1-1. However, after granulation, heat treatment was performed at 450°C for 2 hours. The composition of this catalytic Is oxide is Mo12P2B in atomic ratio.
i O,5S bO,5C62,OCro,5S e
It was o, 5. This catalyst is designated as IV-1.

Examples rV-2-1, IV-2-2 (Extrusion process) A portion of suspension-0 was catalyzed according to Example I-3. However, the firing was performed at 450° C. for 2 hours.

These catalysts are designated as IV-2'-1 and IV-2-2.

Example (2) (Reaction test) Each of the catalysts obtained in Example IV-1-2 was subjected to a reaction in the same manner as in Example (2). However, the reaction temperature was 290°C.

Example V (Catalyst Preparation) Molybdenum trioxide 4000q, vanadium pentoxide 252
．． 8Q, copper oxide 4.4. , 2 g, iron oxide 44. lJ,
41.8 g of tin oxide was dispersed in 401 g of ion-exchanged water. After heating and stirring this for about 3 hours, potassium hydroxide 15.6
After adding 0 to this solution, the solution was further refluxed under boiling for about 3 hours to obtain a suspension (referred to as suspension -).

Example v-1 (centrifugal fluid coating method) A portion of the suspension was treated and catalyzed in the same manner as in Example l-1-1. However, the firing was carried out at 350°C for 2 hours under air circulation. The composition of this catalyst oxide is Mo12PI in atomic ratio.
VI Ko, I CLJo, 2 Fe0.2S n
It was o, 1. This catalyst is designated as V-1.

Examples V-2-1, V-2-2 (Marslizer process) A portion of Suspension-D was catalyzed according to Example I-4. However, the firing was carried out at 350°C for 2 hours under air circulation. These catalysts are designated as V-2-1 and V-2-2.

Example V (Reaction Test) Each of the catalysts obtained in Example V-1-2 was subjected to a reaction in the same manner as in Example (2). However, the reaction temperature was 300°C.

Example (2) (Preparation of catalyst) A suspension was obtained in the same manner as in Example (2) except that the catalyst preparation scale was halved and 272 g of barium nitrate was used instead of cesium nitrate (suspension-E). ).

Example ■-1 (Centrifugal flow coating method) A portion of Suspension-E was catalyzed according to Example 1-1-1.

Incidentally, the firing method was also in accordance with Example 1-1-1. The composition of this catalyst oxide is M O12P 1.09 Vl, 09
B a was 0.5. This catalyst is designated as Vl-1.

Example Vr-2-1, Vl-2-2 (transfer granulation method) suspension-
A part of the catalyst was catalyzed according to Example 1-5. These catalysts are designated as Vl-2-1 and Vl-2'-2.

Example (2) (Reaction test) Each catalyst obtained in Example VT-1-2 was subjected to a reaction in the same manner as in Example.

Example ■ (Preparation of catalyst) In Example 1-1-1, germanium oxide, zirconyl nitrate, and cobalt nitrate were added at 130.7°C, 222.7°C] and 121.3°C, respectively, at the time of adding cesium nitrate.
CI was added to make 1 q of suspension (referred to as suspension-F).

Example V'N-1 (Centrifugal Fluid Coating Method) A portion of Suspension-F was treated and catalyzed in the same manner as in Example 1-1-1.

The composition of this catalyst oxide is expressed in atomic ratio (excluding oxygen < ) M
O12P 1.09 V 1.09 Csto Ge
o, 3Z ro, 2Coo, 1. This catalyst is V
Let it be l-1.

Example ■-2-1, ■-2-2 (round machine forming method) Suspension - "
was catalyzed according to Example I-6. These catalysts ■-2
-1, ■-2-2.

Example (2) (Reaction test) Each catalyst obtained in Example (1)-1-2 was subjected to a reaction in the same manner as in Example (2).

Example ■ (Preparation of catalyst) In Example T, tellurium dioxide, manganese nitrate, and nickel nitrate were added at 199.5% each at the time of adding cesium nitrate.
g, 239.20 and 242.3G were added to obtain a suspension (referred to as suspension-G).

Example 1-1 (Centrifugal fluid coating method) A portion of Suspension-G was treated in the same manner as in Example 1-1 to catalyze it. The composition ratio of this catalyst oxide excluding oxygen is the atomic ratio r M O12P 1.09 V 1. o9 C
Sto Teo, s Mno, 2N i 0.2. This catalyst is referred to as Example ①-1.

Examples 1-2-1, 2-2-2 (Tablet forming method) A portion of Suspension-G was catalyzed according to Example I-2. These catalysts
-2-1, ■-2-2.

Example (1) (Reaction test 1~) Using each catalyst obtained in Example (1)-1-2, the reaction was carried out in the same manner as in Example (2).

Example ■ (Preparation of catalyst) In Example ■, when adding cesium nitrate, ammonium tungstate, zinc nitrate, and silver nitrate were added at 561% each.
6Q, 247.9 g and 70. ]J was added to obtain a suspension (referred to as suspension-H).

Example 1-1 (Centrifugal fluid coating method) A part of "Suspension 1" was treated and catalyzed in the same manner as in Example 1-1-1. The composition ratio of this catalyst oxide excluding oxygen is M 012 P 1.09 V 1.09 Cs in atomic ratio
t.

Wo, 5 Z nO, 2A Qo, 1. This catalyst is designated as ■-1.

Examples IX-2-1, IX-2-2 (Extrusion process) A portion of Suspension-H was catalyzed according to Example I-3. These catalysts are referred to as Examples 1-1-1 and 1X-2-2.

Example (2) (Reaction test) Each catalyst obtained in Example-1-2 was subjected to a reaction in the same manner as in Example (2).

Example ■ (Preparation of catalyst) In Example ■, at the time of adding cesium nitrate, 555% of each of thallium nitrate, niobium pentoxide, strontium nitrate, and palladium nitrate was added. Oq, 332.3CI, 440
．． 90 and 96. OQ was added to obtain a suspension (referred to as suspension -■).

Example X-1 (Centrifugal fluid coating method) A portion of Suspension-I was treated and catalyzed in the same manner as in Example 1-1-1. The composition ratio of this catalytic Is oxide excluding oxygen is the atomic ratio TeM O12P 1.09 V 1.09 Cs
t.

Ij! o, s Sro, 5Zso, s PcJo, 1. This catalyst is designated as X-1.

Example>I2-1. X-2-2 (Multalizer method) A portion of suspension-I was catalyzed according to Example I-4. These catalysts are designated as X-11 and X-2-2.

Example X (Reaction test) Each catalyst obtained in Example X-1-2 was subjected to a reaction in the same manner as in Example 2. However, the reaction temperature was 290°C.

EXAMPLE was obtained (referred to as suspension-J).

Example xI-1 (Centrifugal fluid coating device method) Suspension-J
A portion of was treated and catalyzed in the same manner as in Example 1-1-1. The composition ratio of this catalyst oxide excluding oxygen is M O
12P 1.09 V 1.09 CS 1.0Rbo
, 5Cao, 2Kha, and 1. This catalyst is
Set to 1.

Example Xl-1-1, X[-2-2 (Transfer Granulation Method) Suspension-
J was catalyzed according to Example I-5. These catalysts
-2-1 and Xl-2-2.

Example XI (Reaction Test) Using each of the catalysts obtained in Example Xl-1-2, the reaction was carried out in the same manner as in Example (2). However, the reaction temperature was 290°C.

Example Xll (Preparation of catalyst) Molybdenum trioxide 4320G, vanadium pentoxide 228
g and 439.5 Q of 85% orthophosphoric acid to 15 J of water
and heated under reflux for 24 hours. 214.5 g of powdered cerium oxide, 379.5 g of potassium nitrate, and 40.5 g of powdered copper oxide are added thereto to obtain a suspension. ).

Example ■-1 (Centrifugal flow coating method) A portion of the suspension was catalyzed according to Example 1-1-1.

The atomic ratio of the composition of this catalyst oxide excluding oxygen is Mo12V
I Pl, 5 K1.5 CUo, 2 Ceo, 5. This catalyst is designated as X[I-1.

Examples X11-2-1, X11-2-2 (round machine method) Suspension-K was catalyzed according to Example I-6. Korerano Catalyst WoX
[1-2-1, Xll-1-2.

Example (2) (Reaction test) Each of the catalysts obtained in Example X1l-1-2 was subjected to a reaction in the same manner as in Example (2). However, the reaction temperature was 270°C. The above binding is shown in Table 3.

= 37- Example XI (Long Term Reaction Test) A continuous test reaction was carried out for 8000 hours using the catalyst named Example 1-1-1. The reaction test method is the same as in Example T. The reaction temperature at the start of the reaction was 280°C, and after 8000 hours, the reaction temperature was 8°C to obtain almost the same methacrolein conversion rate.
It was enough just to give. The reaction results after 8000 hours were a reaction temperature of 280°C and a methacrolein conversion rate of 82.9%.
, the methachlorene selectivity was 84.0%.

Example W-1 (Reaction Test) The oxidative dehydration reaction of isobutyric acid was carried out using the catalysts of Examples I-1 and I-1. The reaction test was conducted as follows.

Example 1-1-1 A steel reaction tube with a diameter of 25.4 mm was filled with 1,600 m of 1,600 m of isobutyric acid: oxygen: water vapor: nitrogen.
A mixed gas having a near-5 volume ratio of 5,0:10:10 was introduced at a space velocity of 2000 hr', and the reaction was carried out at a reaction temperature of 275°C. The results were an isobutyric acid conversion rate of 100% and a methachlorolene selectivity of 76.2%.

ExampleyI! -2 Example I-2'-1 was used as a catalyst in the summer-1 reaction. As a result, the selectivity of methacrolene was 72.8% at a methacrolein conversion rate of 100%, indicating that the catalyst granulated using a centrifugal fluid coating device had better performance.

V-1 Using the catalyst of Example 1-1-1, oxidative dehydrogenation reaction of isobutyraldehyde was carried out. The reaction test was conducted as follows.

A steel reaction tube with a diameter of 25.4 sφ was filled with 1000 d of the catalyst of Example 1-1-1, and a reaction mixture of isobutyraldehyde:oxygen:
A mixed gas of water vapor:nitrogen-5,0:12.5:10 near 2.5 volume ratio was introduced at a space velocity of 880 hr', and the reaction was carried out at a reaction temperature of 275°C. As a result, the isobutyraldehyde conversion rate was 100% and the methacryl Fli selectivity was 68.9.
%, methacrolein selection -41 = 15.2%.

Example XV-2 Example 1-3-1 was used as catalyst in the reaction of XV-1. As a result, the isobutyraldehyde conversion rate was 100%.
The methacrolene selectivity was 65.1% and the methacrolein selectivity was 14.6%, indicating that the catalyst granulated using a centrifugal fluid coating device had better performance.

Claims (2)

[Claims] (1) Specific surface area is 1.0 to 10.0 m^2/g, pore volume is 0.10 to 1.0 cc/g, and pore size distribution is 1 to 10 μm and 0.1 to less than 1 μm. A catalyst used for producing methacrylic acid by catalytic gas phase oxidation, characterized in that the catalyst has a distribution concentrated in the following range, and the catalytically active substance is represented by the following general formula. Ho(a)P(b)A(c)B(d)C(e)D(f)
O(x) (where Mo is molybdenum, P is phosphorus, A is at least one element selected from the group consisting of arsenic, antimony, germanium, bismuth, zirconium, and selenium, and B is copper, iron, chromium, and nickel. , at least one element selected from the group consisting of manganese, cobalt, tin, silver, zinc, palladium, rhodium and tellurium,
C represents at least one element selected from the group consisting of vanadium, tungsten and niobium; D represents at least one element selected from the group consisting of alkali metals, alkaline earth metals and thallium; and O represents oxygen. Also, a, b, c, d, e, f, x are Mo, P, A, respectively.
, represents the atomic ratio of B, C, D and O, and when a=12, b=0.5-4, c=0-5, d=0-3, e=0-
4, f=0.01 to 4 and x are numerical values determined by the oxidation state of each element. ) (2) When preparing a catalyst having a catalytically active substance represented by the following general formula for producing methacrylic acid from methachlorene and/or isobutyraldehyde and/or isobutyric acid by catalytic gas phase oxidation reaction, unfired catalyst raw materials are used. Pour the powder into a centrifugal fluid coating device and process 2-1.
After granulating it to an average diameter of 0 mm, it is fired, and the specific surface area is 1.0 to 10.0 m^2/g), and the pore volume is 0.10 to 1.0 cc/g. In the pore size distribution, the pore size diameter is 1 to 10 μm and 0.1 to 1
A method for producing a catalyst for producing methacrylic acid with excellent reproducibility, characterized by obtaining a catalyst having a distribution concentrated in a range of less than μm. Ho(a)P(b)A(c)B(d)C(e)D(f)
O(x) (where Mo is molybdenum, P is phosphorus, A is at least one element selected from the group consisting of arsenic, antimony, germanium, bismuth, zirconium, and selenium, and B is copper, iron, chromium, and nickel. , at least one element selected from the group consisting of manganese, cobalt, tin, silver, zinc, palladium, rhodium and tellurium,
C represents at least one element selected from the group consisting of vanadium, tungsten and niobium; D represents at least one element selected from the group consisting of alkali metals, alkaline earth metals and thallium; and O represents oxygen. Also, a, b, c, d, e, f, x are Mo, P, A, respectively.
, represents the atomic ratio of B, C, D and O, and when a=12, b=0.5-4, c=0-5, d=0-3, e=0-
4, f=0.01 to 4 and x are numerical values determined by the oxidation state of each element. )