JP3370548B2 - Method for producing catalyst for synthesis of unsaturated aldehyde and unsaturated carboxylic acid - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to propylene, isobutylene, tertiary butyl alcohol (hereinafter abbreviated as TBA) or methyl tertiary butyl ether (hereinafter MT).
Abbreviated as BE. The present invention relates to a process for producing a catalyst for use in the synthesis of unsaturated aldehydes and unsaturated carboxylic acids corresponding to each of them by vapor-phase catalytic oxidation of (1) with molecular oxygen.

[0002]

2. Description of the Related Art Conventionally, a catalyst used in the vapor phase catalytic oxidation of propylene to produce acrolein and acrylic acid, and a vapor phase catalytic oxidation of isobutylene, TBA or MTBE to produce methacrolein and methacrylic acid. Many proposals have been made for catalysts used in. For example, Japanese Unexamined Patent Publication No. 7-289902 discloses a method in which a slurry containing a catalyst component is atomized and then heat treated. However, it has been difficult to say that the catalysts known so far are sufficient in terms of yield, and it is desired to develop a method for producing a catalyst capable of obtaining unsaturated aldehydes and unsaturated carboxylic acids in high yields. Is the current situation.

[0003]

DISCLOSURE OF THE INVENTION According to the present invention, propylene, isobutylene, TBA or MTBE is subjected to gas phase catalytic oxidation with molecular oxygen to obtain a high yield of unsaturated aldehyde and unsaturated carboxylic acid corresponding to each. The purpose is to provide a method for producing a catalyst that can be produced at a high rate.

[0004]

The present invention is directed to propylene,
In the production of a catalyst containing at least molybdenum, bismuth and iron, which is used in the gas phase catalytic oxidation of isobutylene, TBA or MTBE with molecular oxygen to synthesize the corresponding unsaturated aldehyde and unsaturated carboxylic acid. After heat-treating the aqueous slurry containing the catalyst component, the particles of the aqueous slurry are treated to have an average particle diameter of 0.5 to 10 μm.
The method for producing a catalyst for synthesizing unsaturated aldehydes and unsaturated carboxylic acids is characterized in that the catalyst is pulverized to m, and then spherical particles having an average particle diameter of 10 to 250 μm are formed using a spray dryer, followed by firing and molding.

Further, the present invention is characterized in that, before the heat treatment of the aqueous slurry containing the catalyst component in the above invention, the particles of the aqueous slurry are previously atomized to an average particle size of 0.5 to 10 μm. And a method for producing a catalyst for synthesizing unsaturated carboxylic acid.

The present invention also provides at least molybdenum used in the gas phase catalytic oxidation of propylene, isobutylene, TBA or MTBE with molecular oxygen to synthesize the corresponding unsaturated aldehyde and unsaturated carboxylic acid. In producing a catalyst containing bismuth and iron, the particles of the aqueous slurry containing the catalyst component are heat-treated while being atomized to an average particle size of 0.5 to 10 μm, and then using a spray dryer, the average particle size of 10 to 250 μm. It is a process for producing a catalyst for synthesizing unsaturated aldehydes and unsaturated carboxylic acids, which is characterized in that it is made into spherical particles, followed by firing and molding.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The catalyst produced by the present invention is obtained by subjecting propylene, isobutylene, TBA or MTBE to gas-phase catalytic oxidation with molecular oxygen to obtain a corresponding unsaturated aldehyde and unsaturated carboxylic acid, that is, It is used for synthesizing acrolein and acrylic acid from propylene and methacrolein and methacrylic acid from other than propylene, and contains at least molybdenum, bismuth and iron as components constituting the catalyst.

In the present invention, the method for producing the aqueous slurry containing the catalyst component does not need to be limited to a special method, and as long as there is no significant uneven distribution of the components, the well-known precipitation method and oxidation method are well known. Various methods such as a material mixing method can be used.

In the present invention, the heat treatment conditions for the aqueous slurry containing the catalyst component are 100 to 110 under normal pressure.
The temperature is 0.1 to 10 hours at 100 ° C., and the pressure is 100 to 200 ° C. for 0.1 to 10 hours. When the heat treatment temperature is lower than 100 ° C, the catalyst yield improving effect is small, and when the heat treatment temperature is higher than 200 ° C, the design and structure of the industrial catalyst manufacturing apparatus are complicated, which is not practical.

In the present invention, as a method for atomizing the particles of the aqueous slurry containing the catalyst component to an average particle size of 0.5 to 10 μm, a means having a high atomization efficiency such as a homogenizer, a bead mill or ultrasonic irradiation is used. It is practical to use.

According to the present invention, the average particle size of the aqueous slurry containing the finely-divided catalyst component after and / or before the heat treatment or simultaneously with the heat treatment is 0.5 to 10 μm,
It is preferably 0.7 to 8 μm. If the average particle size of the aqueous slurry is made smaller than 0.5 μm, the basic particles forming the catalyst component may be destroyed, and the desired catalyst performance may not be obtained, which is not preferable. Also,
If the average particle size exceeds 10 μm, the uniformity of the aqueous slurry containing the catalyst component cannot be maintained, so that the catalyst component may be separated during the spray drying step, and as a result, the catalyst performance may decrease, which is not preferable. . The average particle diameter as used herein refers to the median diameter in the volume-based particle size distribution.

In the present invention, the heat treatment conditions and atomization conditions of the aqueous slurry containing the catalyst component are as described above, but prior to the spray drying described below, the aqueous slurry is treated by any of the following methods. (1) Atomization is performed after heat treatment. (2) The material that has been atomized in advance is heat-treated and then atomized. (3) Heat treatment while atomizing. As described above, the feature of the present invention is that atomization is always performed immediately before spray drying.

The above-mentioned aqueous slurry containing the catalyst component atomized to a size of 0.5 to 10 μm is then dried with a spray dryer. In this case, the average particle diameter of the spherical particles dried by a spray dryer is 10 to 250 μm, preferably 2
It is set to 0 to 150 μm.

The average particle diameter of the spray-dried spherical particles can be determined by the Ceramic Society of Japan, "Ceramic Manufacturing Process-Preparation and Molding of Powder-" p37, and Kagaku Kogyo Co., Ltd. Industrial operation series No. 2, p. It can be adjusted by the method described in 99, etc.

The spherical particles obtained by spray drying are then calcined. The firing conditions are not particularly limited, and known firing conditions can be applied. Firing is usually 200-6
It is carried out in the temperature range of 00 ° C., and the firing time is appropriately selected depending on the target catalyst.

The calcined product is then molded. There is no particular limitation on the molding method and shape, and using a general powder molding machine such as a tablet molding machine, an extrusion molding machine, or a rolling granulator, a spherical shape, a ring shape, a cylindrical shape, a star shape, or the like can be obtained. Mold into any shape. The catalyst calcined product can also be used by supporting it on a carrier.

As the raw material of the catalyst component, a combination of oxides, sulfates, nitrates, carbonates, hydroxides, ammonium salts, halides and the like of each element can be used. For example, as a molybdenum raw material, ammonium paramolybdate, molybdenum trioxide, or the like can be used.

When producing the catalyst, known additives such as organic compounds such as polyvinyl alcohol and carboxymethyl cellulose may be added. Furthermore, inorganic compounds such as graphite and diatomaceous earth, glass fibers, inorganic fibers such as ceramic fibers and carbon fibers may be added. In addition, examples of the component of the carrier used when carrying the carrier include silica, alumina, silica-alumina, magnesia, and titania.

The catalyst obtained as described above may be calcined again. Firing is usually performed in the temperature range of 200 to 600 ° C.

The production method of the present invention is particularly applicable to the general formula Mo _a Bi _b Fe _c A _d X _e Y _f Z _g Si _h O _i (wherein Mo, Bi, Fe, Si and O are molybdenum, bismuth and iron, respectively). , Silicon and oxygen, A represents at least one element selected from the group consisting of cobalt and nickel, and X represents chromium, lead, manganese, calcium, magnesium, niobium, silver, barium, tin, tantalum and zinc. At least 1 selected from the group consisting of
And Y represents at least one element selected from the group consisting of phosphorus, boron, sulfur, selenium, tellurium, cerium, tungsten, antimony and titanium.
Z represents at least one element selected from the group consisting of lithium, sodium, potassium, rubidium, cesium and thallium. a, b, c, d, e, f, g, h
And i represent the atomic ratio of each element, and when a = 12, b
= 0.01 to 3, c = 0.01 to 5, d = 1 to 12, e
= 0 to 8, f = 0 to 5, g = 0.001 to 2, h = 0
20 and i is the number of oxygen atoms required to satisfy the valence of each component. When used for a catalyst having a composition represented by (4), preferable results are obtained.

In the presence of the catalyst produced by the method of the present invention, the raw material propylene, isobutylene, TBA or M is used.
An unsaturated aldehyde and an unsaturated carboxylic acid are obtained by carrying out a gas phase catalytic oxidation reaction using molecular oxygen for TBE. Propylene, isobutylene, TBA in raw material gas
Alternatively, the molar ratio of MTBE to molecular oxygen is 1: 0.5-3.
Is preferred. The raw material gas is preferably diluted with an inert gas before use. It is economical to use air as the molecular oxygen source, but pure oxygen-enriched air can be used if necessary. The reaction pressure is preferably atmospheric pressure to several atmospheres. The reaction temperature can be selected in the range of 200 to 450 ° C, but the range of 250 to 400 ° C is particularly preferable. The catalyst in the reactor may be diluted with an inert material such as silica, alumina, silica-alumina, silicon carbide, ceramic balls or stainless steel.

[0022]

EXAMPLES Examples of producing a catalyst by the method of the present invention and reaction examples using the catalyst will be specifically described below. In the description, parts are parts by weight, and the analysis of the raw material gas and the product was by gas chromatography. In addition, the reaction rates of the raw material olefin, TBA or MTBE in the Examples and Comparative Examples, the selectivity of the unsaturated aldehyde and unsaturated carboxylic acid to be produced, the total yield of the unsaturated aldehyde and unsaturated carboxylic acid to be produced (hereinafter, Abbreviated as total yield) was calculated by the following definition. As a dryer used for spray drying, a spray dryer manufactured by "NIRO JAPAN" (drying room SD-12.5 type sprayer rotating disk wheel type SL-24-120) was used. The average particle diameters of the slurry and the dry spherical particles were measured with PRO-7000S manufactured by "Seishin Enterprise Co., Ltd."

[0023]

[Equation 1]

[0024]

[Equation 2]

[0025]

[Equation 3]

[0026]

[Equation 4]

[Example 1] 500 parts of ammonium paramolybdate, 6.2 parts of ammonium paratungstate, 1.4 parts of potassium nitrate, 27.5 parts of antimony trioxide and 55.0 parts of bismuth trioxide in 1000 parts of pure water. Was added and stirred with heating (A-1 solution). Separately, to 1000 parts of pure water, 114.4 parts of ferric nitrate, 274.7 parts of cobalt nitrate and 35.1 parts of zinc nitrate were sequentially added and dissolved (B-1).
liquid). Solution B-1 was added to solution A-1 to form an aqueous slurry, which was then heated to 103 ° C. and heat-treated at 103 ° C. for 1.5 hours with stirring, and then "Clearmix" manufactured by M Technique Co., Ltd. ( Hereinafter, the particles of the aqueous slurry are atomized to have an average particle diameter of 3.5 μm by simply using Clearmix. Then, the finely divided aqueous slurry was used to obtain dry spherical particles having an average particle diameter of 76.6 μm using a spray dryer.

The dried spherical particles thus obtained were calcined in a rotary kiln in an air atmosphere at 300 ° C. for 1 hour to obtain a catalyst calcined powder, which was then pressure-molded. Then, it was fired again at 500 ° C. for 6 hours in an air atmosphere. The composition of elements other than oxygen in the obtained catalyst (the same applies hereinafter) was as shown in the following formula. Mo ₁₂ W _0.1 Bi ₁ Fe _1.2 Sb _0.8 Co ₄ Zn _0.5 K
_0.06

A stainless steel reaction tube was filled with this catalyst,
A raw material gas of propylene 5%, oxygen 12%, water vapor 10% and nitrogen 73% (volume%) was passed through the catalyst layer at a contact time of 3.6 seconds and reacted at 310 ° C. As a result, the reaction rate of propylene was 99.5% and the selectivity of acrolein was 9
1.4%, selectivity of acrylic acid 6.7%, total yield 9
It was 7.6%.

[Example 2] In Example 1, the aqueous slurry obtained by adding the solution B-1 to the solution A-1 was subjected to atomization treatment using "CLEARMIX" to an average particle size of 3.2 µm. The temperature was raised to 103 ° C., and 1.5 at 103 ° C. with stirring and holding.
After heat treatment for 7 hours, 74.6 μm using a spray dryer
Of dry spherical particles were obtained. A catalyst was produced from the dried spherical particles thus obtained in the same manner as in Example 1, and the reaction was carried out under the same conditions. As a result, the reaction rate of propylene was 99.
The selectivity was 6%, the selectivity for acrolein was 91.5%, the selectivity for acrylic acid was 6.7%, and the total yield was 97.8%.

Example 3 In Example 1, the aqueous slurry obtained by adding the solution B-1 to the solution A-1 was subjected to atomization treatment using "CLEARMIX" to an average particle size of 3.5 μm. After that, the temperature is raised to 103 ° C., and the temperature is maintained at 103 ° C. with stirring and 1.5
Heat treated for hours. After that, the particles of the aqueous slurry were atomized to an average particle diameter of 3.0 μm again using “CLEARMIX”. Next, the atomized aqueous slurry was used to obtain 75.9 μm dry spherical particles using a spray dryer. A catalyst was produced from the dried spherical particles thus obtained in the same manner as in Example 1, and the reaction was carried out under the same conditions. As a result, the reaction rate of propylene was 99.5%, the selectivity of acrolein was 91.7%, the selectivity of acrylic acid was 6.5%, and the total yield was 97.7%.

Example 4 Example 1 was repeated except that the aqueous slurry was heat-treated at 135 ° C. for 1.5 hours under a pressure of 4 kgf / cm ² using an autoclave.
A catalyst was produced in the same manner as in, and the reaction was performed under the same conditions. As a result, the conversion of propylene was 99.5%, the selectivity of acrolein was 91.6%, and the selectivity of acrylic acid was 6.5.
%, The total yield was 97.6%. The average particle size of the spherical particles after spray drying in this example was 78.1 μm.

Comparative Example 1 A catalyst was prepared in the same manner as in Example 1 except that the atomization treatment of the aqueous slurry after adding the solution B-1 to the solution A-1 was not carried out. It was produced and reacted under the same conditions. As a result, the reaction rate of propylene was 98.5% and the selectivity of acrolein was 89.6.
%, Acrylic acid selectivity 6.3%, total yield 94.5%
Met. The average particle size of the spherical particles after spray drying in this example was 76.3 μm.

[Comparative Example 2] In Example 1, the particles of the aqueous slurry obtained by adding the solution B-1 to the solution A-1 in Example 1 were subjected to atomization treatment to an average particle diameter of 12.5 µm. A catalyst was produced in the same manner as in Example 1 except that the reaction was performed, and the reaction was performed under the same conditions. As a result, the reaction rate of propylene was 99.3% and the selectivity of acrolein was 90.
9%, acrylic acid selectivity 6.8%, total yield 97.0
%Met. The average particle size of the spherical particles after spray drying in this example was 78.5 μm.

[Comparative Example 3] In Example 1, the particles of the aqueous slurry obtained by adding the solution B-1 to the solution A-1 using a general high-pressure homogenizer were atomized to an average particle size of 0.2 µm. A catalyst was produced in the same manner as in Example 1 except that the above was performed, and the reaction was performed under the same conditions. As a result, the reaction rate of propylene was 99.5% and the selectivity of acrolein was 9
0.8%, acrylic acid selectivity 6.5%, total yield 9
It was 6.8%. The average particle size of the spherical particles after spray drying in this example was 72.1 μm.

[Example 5] 500 parts of ammonium paramolybdate, 6.2 parts of ammonium paratungstate, 23.0 parts of cesium nitrate, 27.5 parts of antimony trioxide and 33.0 parts of bismuth trioxide in 1000 parts of pure water. Parts were added and the mixture was heated and stirred (A-2 liquid). Separately, in 1000 parts of pure water, 190.7 parts of ferric nitrate, 68.6 parts of nickel nitrate, 446.4 parts of cobalt nitrate and 30.
3 parts were sequentially added and dissolved (solution B-2). Liquid A-2 to B-
After adding 2 liquids to make an aqueous slurry, the temperature is raised to 103 ° C.,
After heat treatment for 1.5 hours while maintaining stirring, the particles of the aqueous slurry were atomized to an average particle diameter of 3.5 μm using “CLEARMIX”. The atomized slurry was dried using a spray dryer to obtain dry spherical particles having an average particle size of 76.0 μm.

The dried spherical particles thus obtained were calcined in a rotary kiln in an air atmosphere at 300 ° C. for 1 hour to obtain a catalyst calcined powder, which was pressure-molded. Then, it was fired again at 500 ° C. for 6 hours in an air atmosphere. The elemental composition of the resulting catalyst was as follows. Mo ₁₂ W _0.1 Bi _0.6 Fe ₂ Sb _0.8 Ni ₁ Co _6.5 M
g _0.5 Cs _0.5

This catalyst was filled in a stainless steel reaction tube,
A raw material mixed gas of 5% isobutylene, 12% oxygen, 10% steam and 73% (volume%) nitrogen was passed through the catalyst layer for a contact time of 3.6 seconds to react at 340 ° C. As a result, the conversion of isobutylene is 98.8%, the selectivity of methacrolein is 90.3%, the selectivity of methacrylic acid is 3.6%,
The total yield was 92.8%.

[Example 6] In Example 5, while the solution A-2 was added with the solution B-2, the aqueous slurry was subjected to atomization treatment using "CLEARMIX" to an average particle diameter of 3.2 µm. The temperature was raised to 103 ° C., and 1.5 at 103 ° C. with stirring and holding.
After heat treatment for a period of time, the aqueous slurry was used to obtain dry spherical particles having an average particle size of 75.0 μm using a spray dryer. A catalyst was produced from the dry spherical particles thus obtained in the same manner as in Example 5, and the reaction was performed under the same conditions. As a result, the conversion of isobutylene is 98.8%, the selectivity of methacrolein is 90.4%, the selectivity of methacrylic acid is 3.6%,
The total yield was 92.9%.

[Example 7] In Example 5, the aqueous slurry obtained by adding the solution B-2 to the solution A-2 was subjected to atomization treatment using "CLEARMIX" to an average particle diameter of 3.5 µm. After that, the temperature is raised to 103 ° C., and the mixture is kept at 103 ° C. for 1.5 while stirring.
Heat treated for hours. After that, the particles of the aqueous slurry were atomized to an average particle diameter of 3.0 μm again using “CLEARMIX”. Next, the atomized aqueous slurry was used to obtain dry spherical particles having an average particle diameter of 77.6 μm using a spray dryer. Example 5 was obtained from the dry spherical particles thus obtained.
A catalyst was produced in the same manner as in, and the reaction was performed under the same conditions. As a result, the conversion of isobutylene was 98.7%, the selectivity of methacrolein was 90.7%, the selectivity of methacrylic acid was 3.4%, and the total yield was 92.9%.

Example 8 Example 5 was repeated except that the aqueous slurry was heat-treated at 135 ° C. for 1.5 hours under a pressure of 4 kgf / cm ² using an autoclave.
A catalyst was produced in the same manner as in, and the reaction was performed under the same conditions. As a result, the conversion of isobutylene was 98.8%, the selectivity of methacrolein was 90.5%, the selectivity of methacrylic acid was 3.4%, and the total yield was 92.8%. The average particle size of the spherical particles after spray drying in this example is 77.5 μm.
Met.

[Comparative Example 4] A catalyst was prepared in the same manner as in Example 5 except that the water-based slurry was not atomized after the solution B-2 was added to the solution A-2. It was produced and reacted under the same conditions. As a result, the conversion of isobutylene was 98.0% and the selectivity of methacrolein was 89.
3%, methacrylic acid selectivity 3.3%, total yield 90.
It was 7%. The average particle size of the spherical particles after spray drying in this example was 75.4 μm.

[Comparative Example 5] In Example 5, the particles of the aqueous slurry obtained by adding the solution B-2 to the solution A-2 in Example 5 were subjected to atomization treatment to an average particle size of 12.5 µm. A catalyst was produced in the same manner as in Example 5 except that the reaction was performed, and the reaction was performed under the same conditions. As a result, the reaction rate of isobutylene was 98.2% and the selectivity of methacrolein was 9
0.4%, methacrylic acid selectivity 3.5%, total yield 9
It was 2.2%. The average particle size of the spherical particles after spray drying in this example was 76.8 μm.

[Comparative Example 6] In Example 5, the particles of the aqueous slurry obtained by adding the solution B-2 to the solution A-2 using a general high-pressure homogenizer were atomized to an average particle size of 0.2 µm. A catalyst was produced in the same manner as in Example 5 except that the above was performed, and the reaction was performed under the same conditions. As a result, the conversion of isobutylene was 98.1%, the selectivity of methacrolein was 90.3%, the selectivity of methacrylic acid was 3.6%, and the total yield was 92.1%. The average particle size of the spherical particles after spray drying in this example was 72.1 μm.

[Comparative Example 7] In Example 5, the aqueous slurry obtained by adding the solution B-2 to the solution A-2 was "clear mix".
The average particle diameter of the particles of the aqueous slurry is 3.5 μm
After being atomized, the temperature was raised to 103 ° C., heat treatment was performed for 1.5 hours while maintaining stirring, and the heat-treated slurry was used to obtain dry particles having an average particle diameter of 78.1 μm using a spray dryer. A catalyst was produced in the same manner as in Example 5, and the reaction was performed under the same conditions. As a result, the conversion of isobutylene was 98.4%, the selectivity of methacrolein was 90.3%, the selectivity of methacrylic acid was 3.3%, and the total yield was 92.1%.

[Example 9] Using the catalyst of Example 5, the reaction was carried out under the same conditions as in Example 5 except that TBA was used as the raw material. As a result, the reaction rate of TBA was 100%, the selectivity of methacrolein was 88.4%, the selectivity of methacrylic acid was 3.2%, and the total yield was 91.6%.

[Comparative Example 8] A catalyst was prepared in the same manner as in Example 5 except that the water-based slurry was not atomized after the solution B-2 was added to the solution A-2. Manufactured. As a result of carrying out the reaction under the same conditions as in Example 9, TB
A reaction rate of 100%, methacrolein selectivity of 86.5
%, Methacrylic acid selectivity 3.1%, total yield 89.6
%Met.

[0048]

EFFECT OF THE INVENTION Using the catalyst produced by the method of the present invention, propylene, isobutylene, TBA or MTB is obtained.
When E is vapor-phase catalytically oxidized using molecular oxygen, the corresponding unsaturated aldehyde and unsaturated carboxylic acid can be produced in high yield.

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Claims (3)

(57) [Claims] 1. When synthesizing an unsaturated aldehyde and an unsaturated carboxylic acid corresponding to propylene, isobutylene, tertiary butyl alcohol or methyl tertiary butyl ether by gas phase catalytic oxidation using molecular oxygen. In producing a catalyst containing at least molybdenum, bismuth and iron used, after heat treating an aqueous slurry containing a catalyst component, the particles of the aqueous slurry have an average particle size of 0.
A method for producing a catalyst for synthesizing unsaturated aldehydes and unsaturated carboxylic acids, which comprises atomizing to 5 to 10 μm, and then using a spray dryer to make spherical particles having an average particle diameter of 10 to 250 μm, followed by firing and molding. 2. The method according to claim 1, wherein before the heat treatment of the aqueous slurry containing the catalyst component, the particles of the aqueous slurry are previously atomized to have an average particle size of 0.5 to 10 μm. For producing a catalyst for synthesizing unsaturated aldehydes and unsaturated carboxylic acids. 3. Propylene, isobutylene, tertiary butyl alcohol or methyl tertiary butyl ether is subjected to gas phase catalytic oxidation using molecular oxygen to synthesize the corresponding unsaturated aldehyde and unsaturated carboxylic acid. In the production of the catalyst containing at least molybdenum, bismuth and iron used, the particles of the aqueous slurry containing the catalyst component are heat treated while being atomized to an average particle size of 0.5 to 10 μm, and then an average particle size using a spray dryer. 10
A method for producing a catalyst for synthesizing unsaturated aldehydes and unsaturated carboxylic acids, which comprises forming spherical particles of ˜250 μm, followed by firing and molding.