JPH1157476A - Preparation of catalyst for synthesizing unsaturated aldehyde and unsaturated carboxylic acid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve catalytic performance obtd. by a method wherein an aqueous slurry contg. catalytic ingredients is dried and then, it is calcined and a wet-shaped body obtd. by wet shaping of the calcined product obtd. is dried by using both microwave and hot air. SOLUTION: An aqueous slurry contg. catalytic ingredients is prepd. by a method such as precipitation method and oxide mixing method. As the raw material of the catalytic ingredient, oxides, sulfates, nitrates, etc., of each catalytic element can be used by combining them. The aqueous slurry contg. the catalytic ingredients is dried by using a spray dryer, etc. The mean particle diameter of spherical particles obtd. is pref. 35-90 μm. The dried powder obtd. is calcined. Calcining is performed in a temp. range of 200-600 deg.C and calcining hr is appropriately selected in accordance with the aimed catalyst. Successively, the calcined product obtd. is incorporated with water and the mixture is shaped into an arbitrary shape such as spherical and ring-like shapes by using an extrusion molding machine, etc. The wet-shaped product obtd. is dried by using both microwave and hot air. Temp. of the hot air is pref. 60-150 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to propylene, isobutylene, tertiary butyl alcohol (hereinafter abbreviated as TBA) or methyl tertiary butyl ether (hereinafter MTBE).
Abbreviated as) in the gas phase using molecular oxygen to produce an unsaturated aldehyde and an unsaturated carboxylic acid, the production method involving wet shaping of the catalyst, the catalyst obtained by the production method, And a method for producing an unsaturated aldehyde and an unsaturated carboxylic acid using the catalyst.

[0002]

2. Description of the Related Art A catalyst used for producing acrolein and acrylic acid by gas-phase catalytic oxidation of propylene and a catalyst used for producing methacrolein and methacrylic acid by gas-phase catalytic oxidation of isobutylene, TBA or MTBE. In producing the resulting catalyst, a method for wet-shaping the catalyst precursor is known.

[0003] In such a conventional method, the wet shaped body is dried by hot air. However, the performance of the obtained catalyst is not sufficient, and a method of producing a higher performance catalyst has been desired.

[0004]

Accordingly, an object of the present invention is to provide propylene, isobutylene, TBA or MTBE.
Is to provide a process for producing a catalyst which can advantageously synthesize unsaturated aldehydes and unsaturated carboxylic acids by gas-phase catalytic oxidation using molecular oxygen.

[0005]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that a high-performance catalyst can be obtained by drying a wet-formed body obtained by wet-shaping a fired product by using both microwaves and hot air. The inventors have found that the present invention can be obtained, and have completed the present invention.

That is, the present invention provides a method for synthesizing unsaturated aldehydes and unsaturated carboxylic acids by subjecting propylene, isobutylene, tertiary butyl alcohol and methyl tertiary butyl ether to gas-phase catalytic oxidation using molecular oxygen. In the method for producing a catalyst according to the present invention, in the production of a catalyst containing at least molybdenum, bismuth and iron, an aqueous slurry containing a catalyst component is dried and then calcined. This is a method for producing a catalyst, characterized by drying using both waves and hot air.

[0007]

Catalyst prepared in the method of the embodiment of the present invention contains at least molybdenum is not particularly limited as long as it contains bismuth and iron, the general formula _{Mo a Bi b Fe c M d} X e Y f Z _g Si _h O _i (wherein, Mo, Bi, Fe, Si and O represent molybdenum, bismuth, iron, silicon and oxygen, respectively;
Represents at least one element selected from the group consisting of cobalt and nickel, and X represents chromium, lead, manganese,
Y represents at least one element selected from the group consisting of calcium, magnesium, niobium, silver, barium, tin, tantalum and zinc, and Y represents 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, and e =
0-8, f = 0-5, g = 0.1-2, h = 0-20
And i is the atomic ratio of oxygen necessary to satisfy the valence of each component described above.)

In the method for producing a catalyst of the present invention, the method for producing an aqueous slurry containing a catalyst component does not need to be limited to a special method, and is well known insofar as the component is not significantly unevenly distributed. Various methods such as a precipitation method and an oxide mixing method can be used. As the raw material of the catalyst component, oxides, sulfates, nitrates, carbonates, hydroxides, ammonium salts, halides, and the like of the respective catalyst elements can be used in combination. For example, as a raw material of molybdenum, ammonium paramolybdate, molybdenum trioxide and the like can be used.

The method of drying the aqueous slurry containing the catalyst component is not particularly limited, but it is preferable to dry the slurry using a spray drier in order to obtain a higher performance catalyst.
Dry powder obtained by spray drying is spherical particles,
By performing wet shaping using this, voids surrounded by spherical particles are formed, and a more effective pore structure for the catalytic reaction can be expressed. The average particle diameter of the spherical particles obtained by spray drying is preferably from 30 to 100 μm, particularly preferably from 35 to 90 μm. When the aqueous slurry is dried by the evaporation to dryness method or the like, a lump-shaped dried product may be obtained. In this case, it is preferable to appropriately pulverize the aqueous slurry to obtain a powder.

Next, the thus obtained dried powder is fired. The firing conditions are not particularly limited, and known firing conditions can be applied. Usually firing is 200 ~
The calcination is performed in a temperature range of 600 ° C., and the calcination time is appropriately selected depending on the target catalyst.

Subsequently, water is added to the obtained fired product to perform wet shaping. The method and shape of the wet shaping are not particularly limited, and a general wet molding machine such as an extruder, a rolling granulator, and the like, may be used, such as a sphere, a ring, a column, and a star. It can be shaped into any shape. The amount of water added at the time of shaping is 15 parts per 100 parts by weight of the baked catalyst.
A range of ４０40 parts by weight is preferred. At this time, conventionally known additives, for example, polyvinyl alcohol, carboxymethyl cellulose, and the like can be added as necessary. Further, inorganic compounds such as graphite and diatomaceous earth, and inorganic fibers such as glass fiber, ceramic fiber and carbon fiber may be added.

Next, the obtained wet shaped body is dried. It is important to use microwaves and hot air in combination for drying. Generally, microwaves used for heating in industrial applications are 2,450 MHz and 915 MHz.
The use of a dryer capable of generating microwaves is preferred, but is not necessarily limited to this.

[0013] The temperature of the hot air is preferably from 50 to 200 ° C, particularly preferably from 60 to 150 ° C. Hot air temperature is 50
If the temperature is lower than 0 ° C., water vapor generated during microwave drying is condensed in the drying chamber, and the microwave is absorbed by the condensed water. Further, when the temperature of the hot air exceeds 200 ° C., since the drying speed of the outer surface is relatively increased by the hot air as compared with the inner drying speed, there is a possibility that pores on the outer surface of the wet-type shaped body may be blocked. Not preferred.

The drying time using microwaves and hot air together is usually about 10 seconds to 30 minutes, though it depends on the water content, drying speed, etc. of the desired dried shaped body. It is not necessary to always use the microwave and the hot air together, for example, the drying is started by using the microwave and the hot air together, and only the hot air is used when the moisture content of the wet shaped body reaches less than 15% by weight. It is also possible to switch to drying.

In the conventional drying method using only hot air, since the wet shaped body is heated from the surface, first, the water near the outer surface evaporates rapidly, and is in a relatively movable state. It is presumed that the fine particles inside the wet excipient moved to the vicinity of the outer surface and dried, so that pores near the outer surface were closed.

In the present invention, by irradiating the microwave, the internal drying speed of the wet type shaped body is made closer to the external drying speed, whereby the movement of the internal fine particles is suppressed, and the pores on the external surface are reduced. It is estimated that the blockage was suppressed. However, when drying is performed using only microwaves, unevenness in drying tends to occur in the wet-shaped shaped body depending on the irradiation position of the microwaves, and it is difficult to dry uniformly. Therefore, it is necessary to use hot air in combination for drying.

The dried shaped body obtained by drying the wet shaped body as described above may be used as it is as a catalyst in the reaction, or may be fired again. The firing temperature for firing again is usually 200 to 600 ° C.

The catalyst produced by the method of the present invention is a catalyst used for synthesizing unsaturated aldehydes and unsaturated carboxylic acids by subjecting propylene, isobutylene, TBA or MTBE to gas phase catalytic oxidation. In particular,
It is a catalyst used to synthesize acrolein and acrylic acid from propylene and to synthesize methacrolein and methacrylic acid from isobutylene, TBA or MTBE.

The reaction for synthesizing unsaturated aldehydes and unsaturated carboxylic acids using this catalyst is usually carried out in a fixed-bed reactor. As the reaction conditions at this time, conventionally known ordinary conditions can be applied, but the preferred molar ratio of propylene, isobutylene, TBA or MTBE to oxygen is 1: 0.5 to 3. It is economical to use air as the molecular oxygen source, but if necessary, air enriched with pure oxygen can also be used. The raw material gas is preferably used after being diluted with an inert gas such as nitrogen, and may contain steam, carbon dioxide gas, or the like.

The reaction pressure is preferably from normal pressure to several atmospheres. The reaction temperature can be selected in the range of 200 to 450 ° C, but is particularly preferably in the range of 250 to 400 ° C. In the fixed bed reactor, the catalyst may be diluted with an inert carrier such as silica, alumina, silica-alumina, silicon carbide, ceramic balls, and stainless steel.

[0021]

EXAMPLES Hereinafter, production examples of the catalyst according to the present invention and reaction examples using the obtained catalyst will be specifically described.
In the examples and comparative examples, “parts” means parts by weight. The reaction product was analyzed by gas chromatography. The reaction rate of the starting olefin, TBA or MTBE (hereinafter referred to as the reaction rate of the starting material) and the selectivity of the unsaturated aldehyde and unsaturated carboxylic acid to be formed are defined as follows. Reaction rate (%) of raw material = B / A × 100 Selectivity of unsaturated aldehyde (%) = C / B × 100 Selectivity of unsaturated carboxylic acid (%) = D / B × 100 Here, A was supplied. Raw olefin, TBA or MT
The number of moles of BE, B is the number of moles of the reacted starting olefin, TBA or MTBE, C is the number of moles of the unsaturated aldehyde generated, and D is the number of moles of the unsaturated carboxylic acid generated.

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 66.0 parts of bismuth trioxide in 1000 parts of pure water Was added and stirred with heating (Solution A). Separately, 114.4 parts of ferric nitrate, 288.4 parts of cobalt nitrate and 35.1 parts of zinc nitrate were sequentially added and dissolved in 1000 parts of pure water (solution B). After the solution B is added to the solution A to form an aqueous slurry, the aqueous slurry is dried using a spray dryer to form dried spherical particles (average particle diameter of 72.
2 μm), the obtained dried spherical particles were calcined at 300 ° C. for 1 hour to obtain a calcined catalyst product. 500 parts of the catalyst fired product thus obtained was mixed with 160 parts of pure water, kneaded in a kneader, and extruded to form a ring-shaped wet application having an outer diameter of 5 mm, an inner diameter of 2 mm, and an average length of 5 mm. Obtained the form. A microwave (2,450 MHz) of 1 KW and hot air of 100 ° C. are used in combination with 500 g of the wet shaped body to obtain 7 g.
After drying for a minute, a dried excipient was obtained. 5
Recalcination was performed at 10 ° C. for 3 hours to obtain a catalyst having the following composition (excluding oxygen, the same applies hereinafter). Mo ₁₂ W _0.1 Bi _1.2 Fe _1.2 Sb _0.8 Co _4.2 Zn _0.5 K
_0.06

This catalyst is filled in a stainless steel reaction tube,
A raw material gas of propylene 5%, oxygen 12%, steam 10% and nitrogen 73% (vol%) was passed through the catalyst layer for a contact time of 3.6 seconds, and reacted at 310 ° C. As a result, the conversion of propylene was 99.1% and the selectivity of acrolein was 9
1.1% and selectivity of acrylic acid was 6.5%.

[Comparative Example 1] In Example 1, the wet-type shaped body was irradiated with only 1 kW microwave (2,450 MHz).
After drying for a minute, a catalyst was produced in the same manner as in Example 1 except that hot air was not used in combination. Example 1 using this catalyst
As a result of carrying out the reaction under the same conditions as in
9.0%, acrolein selectivity was 90.7%, and acrylic acid selectivity was 6.3%.

[Comparative Example 2] In Example 1, the wet shaped body was dried for 7 minutes using only 100 ° C. hot air without using microwaves.
A catalyst was produced in the same manner as in Example 1 except that drying was performed for another 15 minutes using only hot air at 00 ° C. Using this catalyst, the reaction was carried out under the same conditions as in Example 1. As a result, the conversion of propylene was 98.9% and the selectivity of acrolein was 9
The selectivity for acrylic acid was 0.6% and the acrylic acid selectivity was 6.2%.

Example 2 500 parts of ammonium paramolybdate, 6.2 parts of ammonium paratungstate, 1.4 parts of potassium nitrate, 27.5 parts of antimony trioxide and 66.0 parts of bismuth trioxide in 1000 parts of pure water Was added and stirred with heating (Solution A). Separately, 95.3 parts of ferric nitrate, 267.8 parts of cobalt nitrate and 35.1 parts of zinc nitrate were sequentially added and dissolved in 1000 parts of pure water (solution B). A to B
After adding the liquid to form an aqueous slurry, the aqueous slurry was dried with a drum dryer (average particle diameter of 40.1 μm).
After obtaining m), the obtained dried particles were fired at 300 ° C. for 1 hour to obtain a fired catalyst product. To 500 parts of the fired catalyst product thus obtained, 160 parts of pure water was mixed, kneaded with a kneader, and extruded to form an outer diameter of 5 mm and an inner diameter of 2 m.
m, a ring-shaped wet shaped body having an average length of 5 mm was obtained. Drying was performed for 6 minutes using a microwave (2,450 MHz) of 1 kW and hot air of 130 ° C. in combination with 500 g of the wet shaped body to obtain a dried shaped body. This dried excipient is placed in 51
The mixture was calcined again at 0 ° C. for 3 hours to obtain a catalyst having the following composition. Mo ₁₂ W _0.1 Bi _1.2 Fe _1.0 Sb _0.8 Co _3.9 Zn _0.5 K
_0.06

This catalyst is filled in a stainless steel reaction tube,
A raw material gas of propylene 5%, oxygen 12%, steam 10% and nitrogen 73% (vol%) was passed through the catalyst layer for a contact time of 3.6 seconds, and reacted at 310 ° C. As a result, the conversion of propylene was 98.7% and the selectivity of acrolein was 9
0.7% and selectivity for acrylic acid were 6.3%.

[Comparative Example 3] In Example 2, the wet extruded body was subjected to a 7 kW microwave (2,450 MHz) alone.
After drying for 2 minutes, a catalyst was produced in the same manner as in Example 2 except that hot air was not used in combination. Example 2 using this catalyst
As a result of carrying out the reaction under the same conditions as in
8.6%, acrolein selectivity was 90.1%, and acrylic acid selectivity was 6.1%.

[Comparative Example 4] In Example 2, the wet shaped body was dried for 6 minutes using only 130 ° C. hot air without using microwaves.
A catalyst was produced in the same manner as in Example 2, except that drying was performed for another 15 minutes using only hot air at 30 ° C. As a result of performing a reaction using this catalyst, the conversion of propylene was 98.
4%, acrolein selectivity was 90.1%, and acrylic acid selectivity was 6.0%.

Example 3 500 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 The mixture was heated and stirred (Solution A). Separately, 190.7 parts of ferric nitrate, 68.6 parts of nickel nitrate, 446.4 parts of cobalt nitrate, 39.1 parts of lead nitrate and 2.7 parts of 85% phosphoric acid were sequentially added to 1000 parts of pure water and dissolved. B liquid). Liquid B was added to Liquid A to form an aqueous slurry, and the aqueous slurry was dried using a spray drier to obtain dried spherical particles (average particle diameter of 65.3).
μm), the obtained dried particles were fired at 300 ° C. for 1 hour to obtain a fired catalyst product. After mixing 160 parts of pure water with 500 parts of the catalyst fired product thus obtained, the mixture is kneaded with a kneader, and extruded to form an outer diameter of 5 mm and an inner diameter of 2 m.
m, a ring-shaped wet shaped body having an average length of 5 mm was obtained. Drying was performed for 7 minutes using a microwave (2,450 MHz) of 1 kW and hot air of 100 ° C. in combination with 500 g of the wet shaped body to obtain a dried shaped body. This dried excipient is placed in 51
The mixture was calcined again at 0 ° C. for 3 hours to obtain a catalyst having the following composition. Mo ₁₂ W _0.1 Bi _0.6 Fe ₂ Sb _0.8 Ni ₁ Co _6.5 Pb
_0.5 P _0.1 Cs _0.5

The catalyst is filled in a stainless steel reaction tube,
A raw material gas containing 5% of isobutylene, 12% of oxygen, 10% of water vapor and 73% of nitrogen (volume%) was passed through the catalyst layer for a contact time of 3.6 seconds, and reacted at 340 ° C. as a result,
The conversion of isobutylene was 97.9%, the selectivity of methacrolein was 89.9%, and the selectivity of methacrylic acid was 4.0%.

[Comparative Example 5] In Example 3, the wet shaped body was subjected to 7 MW only with a 1 kW microwave (2,450 MHz).
A catalyst was produced in the same manner as in Example 3 except that the catalyst was dried for a minute and hot air was not used in combination. Example 3 using this catalyst
As a result, the reaction was 97.7% for isobutylene, 89.5% for methacrolein, and 3.8% for methacrylic acid.

[Comparative Example 6] In Example 3, the wet shaped body was dried for 7 minutes using only hot air at 100 ° C without using microwaves.
A catalyst was produced in the same manner as in Example 3, except that drying was performed for another 15 minutes using only hot air at 0 ° C. The reaction was carried out under the same conditions as in Example 3 using this catalyst. As a result, the conversion of isobutylene was 97.5%, the selectivity of methacrolein was 89.4%, and the selectivity of methacrylic acid was 3.7%.

Example 4 500 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 The mixture was heated and stirred (Solution A). Separately, 209.8 parts of ferric nitrate, 54.9 parts of nickel nitrate, 446.4 parts of cobalt nitrate and 2.7 parts of 85% phosphoric acid were sequentially added and dissolved in 1000 parts of pure water (solution B). After the aqueous slurry was added to the liquid A to obtain the aqueous slurry, the aqueous slurry was dried using a spray drier to obtain dried spherical particles (average particle diameter: 48.3 μm), and the obtained dried particles were calcined at 300 ° C. for 1 hour. This was performed to obtain a fired catalyst product. After mixing 160 parts of pure water with 500 parts of the catalyst calcined product thus obtained, mixing the mixture with a kneader until the mixture becomes clay-like, and then extruding the mixture to form an outer diameter of 5 mm and an inner diameter of 2 m.
m, a ring-shaped wet shaped body having an average length of 5 mm was obtained. Drying was performed for 9 minutes using a microwave (2,450 MHz) of 1 kW and hot air of 75 ° C. in combination with 500 g of the wet shaped body to obtain a dried shaped body. This dried excipient is added to 510
The mixture was calcined again at 3 ° C. for 3 hours to obtain a catalyst having the following composition. Mo ₁₂ W _0.1 Bi _0.6 Fe _2.2 Sb _0.8 Ni _0.8 Co _6.5 P
_0.1 Cs _0.5

This catalyst is filled in a stainless steel reaction tube,
A raw material gas containing 5% of isobutylene, 12% of oxygen, 10% of water vapor and 73% of nitrogen (volume%) was passed through the catalyst layer for a contact time of 3.6 seconds, and reacted at 340 ° C. as a result,
The conversion of isobutylene was 97.9%, the selectivity of methacrolein was 89.9%, and the selectivity of methacrylic acid was 4.1%.

[Comparative Example 7] In Example 4, the wet shaped body was subjected to 9 microwaves only with 1 kW microwave (2,450 MHz).
A catalyst was produced in the same manner as in Example 4 except that the catalyst was dried for a minute and hot air was not used in combination. Example 4 using this catalyst
The reaction was carried out under the same conditions as described above. As a result, the conversion of isobutylene was 97.6% and the selectivity of methacrolein was 89.6.
%, And the selectivity of methacrylic acid was 3.8%.

[Comparative Example 8] In Example 4, the wet shaped body was dried for 9 minutes using only hot air at 75 ° C without using microwaves.
A catalyst was produced in the same manner as in Example 4, except that drying was performed for another 15 minutes using only hot air at ° C. The reaction was carried out under the same conditions as in Example 4 using this catalyst. As a result, the conversion of isobutylene was 97.5% and the selectivity of methacrolein was 8
The selectivity of 9.5% and methacrylic acid was 3.7%.

Example 5 Using the catalyst prepared in Example 3, the reaction was carried out under the same conditions as in Example 3 except that the raw material isobutylene was changed to TBA. The selectivity for rain was 88.8% and the selectivity for methacrylic acid was 3.1%.

Comparative Example 9 Using the catalyst prepared in Comparative Example 5, the reaction was carried out under the same conditions as in Comparative Example 5 except that the raw material isobutylene was changed to TBA. The selectivity for rain was 88.3% and the selectivity for methacrylic acid was 2.9%.

Comparative Example 10 Using the catalyst prepared in Comparative Example 6, the reaction was carried out under the same conditions as in Comparative Example 6 except that the raw material isobutylene was changed to TBA. Rain selectivity 88.0%,
The selectivity of methacrylic acid was 2.8%.

[0041]

According to the process of the present invention, a catalyst can be obtained which is capable of advantageously synthesizing unsaturated aldehydes and unsaturated carboxylic acids by subjecting propylene, isobutylene, TBA or MTBE to gas-phase catalytic oxidation using molecular oxygen. .

Continued on the front page (51) Int.Cl. ⁶ Identification code FI C07C 45/39 C07C 45/39 47/21 47/21 57/05 57/05 // C07B 61/00 300 C07B 61/00 300 (72) Inventor Masahide Kondo 20-1, Miyuki-cho, Otake-shi, Hiroshima Prefecture, Central Research Laboratory of Mitsubishi Rayon Co., Ltd. (72) Inventor Toru Kuroda 20-1, Miyuki-cho, Otake City, Hiroshima Prefecture, Central Research Laboratory of Mitsubishi Rayon Co., Ltd.

Claims (3)

[Claims] 1. A catalyst used for synthesizing unsaturated aldehydes and unsaturated carboxylic acids by subjecting propylene, isobutylene, tertiary butyl alcohol and methyl tertiary butyl ether to gas phase catalytic oxidation using molecular oxygen. In the production method, in the production of a catalyst containing at least molybdenum, bismuth and iron, an aqueous slurry containing a catalyst component is dried and then calcined, and the obtained calcined material is subjected to wet shaping by microwave and hot air. And drying the catalyst. 2. A catalyst produced by the method of claim 1. 3. An unsaturated aldehyde obtained by subjecting propylene, isobutylene, tertiary butyl alcohol and methyl tertiary butyl ether to gas-phase catalytic oxidation using molecular oxygen, using the catalyst according to claim 2. And a method for producing an unsaturated carboxylic acid.