JP3321300B2 - Process for producing oxide catalyst containing molybdenum, bismuth and iron - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a gas phase catalytic oxidation of propylene, isobutylene, tertiary butyl alcohol or methyl tertiary butyl ether using molecular oxygen, and to the corresponding unsaturated aldehyde and unsaturated carboxylic acid, respectively. The present invention relates to a method for producing an oxide catalyst containing at least molybdenum, bismuth and iron, which is used when synthesizing an acid.

[0002]

2. Description of the Related Art Molybdenum, bismuth and iron-containing oxide catalysts are already effective for producing aldehydes and acids by oxidizing organic compounds and producing unsaturated aldehydes and unsaturated acids by oxidative dehydrogenation. It is known. For example,
A catalyst effective for the production of acrolein and acrylic acid by gas phase catalytic oxidation of propylene and oxygen, or a mixture of isobutylene, tertiary butyl alcohol (hereinafter abbreviated as TBA) or methyl tertiary butyl ether (hereinafter abbreviated as MTBE) and oxygen As a catalyst effective for producing methacrolein and methacrylic acid by gas phase catalytic oxidation, a catalyst containing at least molybdenum, bismuth and iron is disclosed in JP-A-60-28.
No. 824, JP-A-62-234549 and JP-A-63-234.
No. 5,494,541 and JP-A-63-54942. These conventional proposals recommend a water-soluble bismuth compound, that is, bismuth nitrate or bismuth hydroxide, as the bismuth raw material.

There is also a report that it is advantageous to use bismuth subcarbonate or a carbonate of another metal element with bismuth.

[0004] However, in these proposals, it is difficult to improve the catalyst performance including the catalytic activity and to make the catalyst excellent in reproducibility, so that the catalyst performance is improved and the production of the catalyst excellent in reproducibility is performed. At present, the development of a law is desired.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a molybdenum, bismuth and iron-containing oxide catalyst for synthesizing unsaturated aldehydes and unsaturated carboxylic acids, which improves the catalytic performance including catalytic activity. .

[0006]

According to the present invention, a molybdenum-containing aqueous solution (Solution A) and an iron-containing aqueous solution (Solution B) are mixed to form propylene, isobutylene, tertiary butyl alcohol or methyl tertiary butyl ether. The method for producing an oxide catalyst containing at least molybdenum, bismuth and iron, which is used for synthesizing the corresponding unsaturated aldehyde and unsaturated carboxylic acid by gas-phase catalytic oxidation using oxygen in the form, Production of molybdenum, bismuth and iron-containing oxide catalysts for synthesizing unsaturated aldehydes and unsaturated carboxylic acids, wherein bismuth trioxide is added to solution A, followed by ultrasonic treatment, and then mixed with solution B. Is the law.

[0007] preparation of molybdenum, bismuth and iron-containing oxide catalysts of the present invention have 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, M represents at least one element selected from the group consisting of cobalt and nickel, and X represents chromium, lead, manganese, calcium, magnesium, niobium. , Represents at least one element selected from the group consisting of silver, barium, tin, tantalum and zinc, and Y is selected from the group consisting of phosphorus, boron, sulfur, selenium, tellurium, cerium, tungsten, antimony and titanium. At least one element, Z
Is at least one selected from the group consisting of lithium, sodium, potassium, rubidium, cesium and thallium
Indicates the species element. a, b, c, d, e, f, g, h and i represent the atomic ratio of each element, and when a = 12, b = 0.01
-3, c = 0.01-5, d = 1-12, e = 0-8,
f = 0 to 5, g = 0.001 to 2, h = 0 to 20, and i is the number of oxygen atoms necessary to satisfy the valence of each component. This is preferable for the preparation of a catalyst having the composition represented by the formula (1).

As the molybdenum-containing aqueous solution A used in the present invention, it is preferable to use ammonium paramolybdate as a molybdenum raw material, but various raw materials such as molybdenum trioxide and molybdenum chloride can also be used. Further, the above-mentioned M component, X
It is also possible to add a component, a Y component, a Z component and / or silicon.

As the solution B, which is an iron-containing aqueous solution used in the present invention, it is preferable to use ferric nitrate as a raw material of iron, but it is preferable to use various raw materials such as iron hydroxide and iron trioxide. Can also. Further, the above-mentioned M component, X component, Y component, Z component and / or silicon can be added to the B solution.

In practicing the present invention, it is possible to further add the above-mentioned M component, X component, Y component, Z component and / or silicon to a mixture of the liquid A and the liquid B. Various raw materials such as oxides, carbonates, chlorides, ammonium salts, nitrates, acetates, and sulfates can be used as the M component, the X component, the Y component, the Z component, and the silicon source. Furthermore, in the present invention, not only water-soluble compounds that are commonly used, but also metals and hardly-soluble compounds can be used.

In the present invention, it is important to add bismuth trioxide to the solution A in advance and perform ultrasonic treatment. As a method of the ultrasonic treatment, a bismuth trioxide previously added to A
There is a method of inserting an ultrasonic vibrator inside or below a reaction vessel containing a liquid, and performing ultrasonic treatment with an ultrasonic generator.

The ultrasonic treatment conditions are not particularly limited, and the wavelength of the sound wave used is usually 20,000 to 40.
It is in the range of about 000 Hz, preferably 21.0 Hz.
The range is from 00 to 350,000 Hz, and more preferably from 22,000 to 300,000 Hz. If the frequency is too low, the reactivity of bismuth trioxide is poor, and it is difficult to sufficiently obtain the effects intended by the present invention. On the other hand, if the frequency is too high, the design and maintenance of the ultrasonic generator and the like become complicated and impractical.

The ultrasonic treatment temperature is not particularly limited, but is usually in the range of 0 to 100 ° C., preferably 1 to 100 ° C.
0-90 ° C, more preferably 15-85 ° C
Range. If the treatment temperature is too low, the reactivity of bismuth trioxide is extremely poor, and the desired effects of the present invention cannot be sufficiently obtained. On the other hand, if the processing temperature is too high, the durability of the ultrasonic vibrator is extremely poor, which is not practical.

The ultrasonic treatment time is not particularly limited, but is usually in the range of 1 minute to 10 hours, preferably in the range of 10 minutes to 7 hours, and more preferably in the range of 1 minute to 7 hours.
The range is from 5 minutes to 5 hours. If the treatment time is too short, the reaction of bismuth trioxide is insufficient, and the desired effects of the present invention cannot be sufficiently obtained. On the other hand, if the treatment time is too long, the productivity of the catalyst tends to be extremely poor, which is not preferable.

In general, the reactivity between solution A and bismuth trioxide is extremely poor. However, according to the present invention, the reactivity is significantly improved by adding bismuth trioxide to solution A in advance and performing ultrasonic treatment. As a result, it has become possible to remarkably improve catalytic performance including catalytic activity. It is not clear why the catalyst performance including catalytic activity is significantly improved by adding bismuth trioxide to liquid A in advance and performing ultrasonic treatment, but it is probably because the structure of the catalyst surface is different from that of the prior art. Can be

In the practice of the present invention, bismuth trioxide is added to solution A in advance, ultrasonic treatment is performed, and then solution B is added. After that, it is preferable to further perform atomization treatment. By performing the atomization treatment, the catalyst precursor becomes uniform particles and particle diameters, and the effect of the present invention is further improved.

In the present invention, as described above, bismuth trioxide is added to solution A in advance, followed by ultrasonic treatment, and then solution B is added. 200 ° C. temperature range, preferably 110-1
It is preferable to maintain the temperature in a temperature range of 80 ° C, more preferably in a temperature range of 115 to 175 ° C. By maintaining the mixture after the ultrasonic treatment in this temperature range, the catalytic performance can be further improved.

When the temperature to be held is lower than 100 ° C., the catalyst performance is less improved than when the temperature is held in the temperature range of 100 to 200 ° C. Also, if the holding temperature is 200
When the temperature exceeds ℃, it is difficult to design and control as a catalyst manufacturing apparatus, which is not practical.

The holding time in the temperature range of 100 to 200 ° C. is not particularly limited, but is suitably in the range of 1 second to 30 hours, preferably in the range of 1 minute to 20 hours.
Particularly preferably, it is in the range of 3 minutes to 15 hours. If the holding time is too short, the desired effect of the present invention is not sufficient.
On the other hand, if the holding time is too long, the productivity of the catalyst is extremely poor, which is not preferable.

Although it is not clear why the catalyst performance is further improved by maintaining the temperature in the above-mentioned temperature range of 100 to 200 ° C., the catalyst performance is improved by improving the reactivity of the catalyst precursor. thinking.

When the oxide catalyst of the present invention is used as a catalyst thereafter, it is dried and calcined as required. Various drying methods such as evaporative drying and spray drying can be used as the drying method. The firing conditions are not particularly limited, and known firing conditions can be applied. Firing is usually performed in a temperature range of 200 to 400 ° C.

In practicing the present invention, the resulting catalyst can then be shaped. Incidentally, the method of molding the catalyst is not particularly limited, tablet molding machine, extrusion molding machine, using a general powder molding machine such as a rolling granulator, spherical, ring-shaped, columnar, It can be molded into any shape such as a star shape. Further, it can be used by being supported on a carrier.

At the time of molding the catalyst, conventionally known additives, for example, organic compounds such as polyvinyl alcohol and carboxymethyl cellulose may be further added. Further, inorganic compounds such as graphite and diatomaceous earth, and inorganic fibers such as glass fiber, ceramic fiber and carbon fiber may be added. In addition, as a carrier used when carrying, silica, alumina, silica-alumina, magnesia, titania and the like can be mentioned.

The catalyst obtained as described above is then subjected to a heat treatment. The heat treatment conditions are not particularly limited, and known heat treatment conditions can be applied. The heat treatment is usually performed in a temperature range of 300 to 600C.

The catalyst according to the production method of the present invention can be used after being diluted with an inert carrier such as silica, alumina, silica-alumina, magnesia, titania, silicon carbide and the like.

The catalyst according to the production method of the present invention comprises a gas phase catalytic oxidation of propylene and oxygen and isobutylene, TBA or MBA.
Used when performing a gas phase catalytic oxidation reaction between TBE and oxygen. Gas-phase catalytic oxidation is performed in the presence of the above-mentioned catalyst by adding molecular oxygen to propylene, isobutylene, TBA or MTBE as a raw material. In performing the gas phase catalytic oxidation reaction, the molar ratio of propylene, isobutylene, TBA or MTBE to oxygen is preferably in the range of 1: 0.5 to 3. The source gas is preferably diluted with an inert gas for use. It is economical to use air as the oxygen source, but if necessary, air enriched with pure oxygen can be used. 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. Particularly, the range of 250 to 400 ° C. is preferable.

[0027]

EXAMPLES Hereinafter, production examples of the catalyst according to the present invention and reaction examples using the same will be described together with comparative examples. In the description, “parts” means parts by weight. Analysis was by gas chromatography. The activity tests of the catalysts in the examples and comparative examples were carried out by taking as an example gas-phase catalytic oxidation of propylene and oxygen and gas-phase catalytic oxidation of isobutylene, TBA or MTBE and oxygen. The conversion of the starting olefin, TBA or MTBE, and the selectivity of the unsaturated aldehyde and unsaturated carboxylic acid to be formed are defined as follows, respectively.

Reaction rate (%) of starting olefin, TBA or MTBE = (reacted starting olefin, TBA or MBE
Number of moles of TBE / number of moles of feed olefin, TBA or MTBE supplied) × 100 Selectivity (%) of unsaturated aldehyde = (number of moles of unsaturated aldehyde formed / number of moles of reacted olefin, TBA or MTBE reacted) ) × 100 Selectivity (%) of unsaturated carboxylic acid = (moles of unsaturated carboxylic acid generated / moles of reacted starting olefin, TBA or MTBE) × 100

Example 1 500 parts of ammonium paramolybdate was added to 1,000 parts of water.
Parts, 6.2 parts of ammonium paratungstate and 1.4 parts of potassium nitrate were dissolved and mixed at 60 ° C. (A-1)
Liquid. Thereafter, 49.5 parts of bismuth trioxide was added, and while maintaining the temperature at 60 ° C., the ultrasonic cleaner 82 manufactured by Branson (Branson) was used as the ultrasonic treatment condition.
Ultrasonic treatment was performed for 1 hour using 00J4 to obtain a white precipitate. Separately, ferric nitrate 1 in 1,000 parts of pure water
33.5 parts, zinc nitrate 14.0 parts and cobalt nitrate 29
5.3 parts were sequentially added to obtain a solution (B-1). Next, the solution (B-1) was added to the solution (A-1) subjected to the ultrasonic treatment to form a slurry. Then, 6.9 of antimony trioxide was added thereto.
Then, after aging at 80 ° C. for 1 hour, most of the water was evaporated.

After the obtained cake-like substance was dried at 120 ° C., it was baked at 300 ° C. for 1 hour in an air atmosphere and pulverized. Then, it was press-molded and fired again at 500 ° C. for 6 hours in an air atmosphere, and used as a catalyst.

The composition of elements other than oxygen in the catalyst thus obtained (the same applies hereinafter) is Mo ₁₂ W _0.1 Bi _0.9 Fe _1.4 Sb _0.2
Co _4.3 Zn _0.2 K _0.06 .

This catalyst is filled in a stainless steel reaction tube,
Propylene 5%, oxygen 12%, steam 10% and nitrogen 7
A 3% (vol%) raw material mixed gas was passed through the catalyst layer at a contact time of 3.6 seconds, and reacted at 310 ° C. As a result, the conversion of propylene was 99.5% and the selectivity of acrolein was 9
The selectivity for acrylic acid was 6.6%.

Example 2 A catalyst was prepared, heat-treated and reacted in the same manner as in Example 1 except that the time of addition of antimony trioxide was changed to the same as that of bismuth trioxide. as a result,
The conversion of propylene was 99.6%, the selectivity of acrolein was 92.3%, and the selectivity of acrylic acid was 6.5%.

Example 3 A catalyst was prepared, heat-treated and reacted in the same manner as in Example 1 except that the ultrasonic treatment was carried out and then the temperature was maintained at 150 ° C. for 1 hour. As a result, the conversion of propylene was 99.6% and the selectivity of acrolein was 92.5%.
% And selectivity of acrylic acid was 6.6%.

Comparative Example 1 A catalyst was prepared, heat-treated, and reacted in the same manner as in Example 1 except that no ultrasonic treatment was performed. As a result, the conversion of propylene was 98.1% and the selectivity of acrolein was 89.1.
% And selectivity of acrylic acid was 6.2%.

Comparative Example 2 500 parts of ammonium paramolybdate were added to 1,000 parts of water.
Parts, 6.2 parts of ammonium paratungstate and 1.4 parts of potassium nitrate were dissolved and mixed at 60 ° C. (A-2)
Liquid. Separately, 41.9 parts of 60% nitric acid was added to 1,000 parts of pure water, and the mixture was made uniform.
3.0 parts were added and dissolved. 133.5 ferric nitrate
, 14.0 parts of zinc nitrate and 295.3 parts of cobalt nitrate were sequentially added and dissolved to obtain a solution (B-2). Next, the liquid (B-2) was added to the liquid (A-2) to form a slurry.
Thereafter, 6.9 parts of antimony trioxide was added thereto, and the mixture was added at 80 ° C.
After aging for 1 hour, most of the water was evaporated.

After the obtained cake-like substance was dried at 120 ° C., it was baked at 300 ° C. for 1 hour in an air atmosphere and pulverized. Then, it was press-molded and fired again at 500 ° C. for 6 hours in an air atmosphere, and used as a catalyst.

The composition of the element of the catalyst thus obtained is Mo
₁₂ W _0.1 Bi _0.9 Fe _1.4 Sb _0.2 Co _4.3 Zn _0.2 K _0.06 .

This catalyst was reacted under the same conditions as in Example 1. As a result, the conversion of propylene was 99.5%, the selectivity of acrolein was 91.0%, and the selectivity of acrylic acid was 6.6%.

Comparative Example 3 A catalyst was prepared, heat-treated and reacted in the same manner as in Example 1 except that bismuth trioxide was replaced with 103 parts of bismuth nitrate instead of 45.9 parts. As a result, the conversion of propylene was 98.6%, the selectivity of acrolein was 89.6%, and the selectivity of acrylic acid was 6.2%.

Example 4 500 parts of ammonium paramolybdate were added to 1,000 parts of water.
Parts, 6.2 parts of ammonium paratungstate and 27.6 parts of cesium nitrate were dissolved and mixed at 60 ° C. (A-
3) The solution was used. Thereafter, 38.5 parts of bismuth trioxide was added, and the mixture was stirred at a temperature of 60 ° C. and an ultrasonic cleaner 8 manufactured by Branson (Branson) was used as an ultrasonic treatment condition.
Ultrasonic treatment was performed for 1 hour using 200J4 to obtain a white precipitate. Separately, 200.2 parts of ferric nitrate, 85.8 parts of nickel nitrate and 1 part of zinc nitrate were added to 1,000 parts of pure water.
4.0 parts and 336.5 parts of cobalt nitrate were sequentially added and dissolved to obtain a solution (B-3). Next, the solution (B-3) was added to the solution (A-3) subjected to the ultrasonic treatment to form a slurry.
Thereafter, 24.1 parts of antimony trioxide was added thereto, and
After aging at C for 1 hour, most of the water was evaporated.

After the obtained cake-like substance was dried at 120 ° C., it was calcined at 300 ° C. for 1 hour in an air atmosphere and pulverized. Then, it was press-molded and fired again at 500 ° C. for 6 hours in an air atmosphere, and used as a catalyst.

The composition of the elements of the catalyst thus obtained is Mo
₁₂ W _0.1 Bi _0.7 Fe _2.1 Sb _0.7 Ni _2.5 Co _4.9 Zn _0.2
Cs was _0.6 .

This catalyst was filled in a stainless steel reaction tube,
A raw material mixed gas of 5% isobutylene, 12% oxygen, 10% steam and 73% 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 98.5%, the selectivity of methacrolein was 91.1%, and the selectivity of methacrylic acid was 3.2%.

Example 5 A catalyst was prepared, heat-treated and reacted in the same manner as in Example 4, except that antimony trioxide was added at the same time as bismuth trioxide. as a result,
The conversion of isobutylene was 98.4%, the selectivity of methacrolein was 91.1%, and the selectivity of methacrylic acid was 3.3%.

Example 6 A catalyst was prepared, heat-treated and reacted in the same manner as in Example 4 except that the ultrasonic treatment was carried out and the temperature was maintained at 160 ° C. for 2 hours. As a result, the conversion of isobutylene was 98.6%, and the selectivity of acrolein was 91.4.
% And selectivity of acrylic acid was 3.4%.

Comparative Example 4 A catalyst was prepared, heat treated and reacted in the same manner as in Example 4 except that no ultrasonic treatment was performed. As a result, the conversion of isobutylene was 98.1% and the selectivity of methacrolein was 8
The selectivity of 9.1% and methacrylic acid was 3.4%.

Comparative Example 5 500 parts of ammonium paramolybdate were added to 1,000 parts of water.
Parts, 6.2 parts of ammonium paratungstate and 27.6 parts of cesium nitrate were dissolved and mixed at 60 ° C. (A-
4) The solution was used. Separately, 60% for 1,000 parts of pure water
After adding 41.9 parts of nitric acid and homogenizing, bismuth nitrate 8
0.1 part was added and dissolved. Ferric nitrate 200.2
Parts, 85.8 parts of nickel nitrate, 14.0 parts of zinc nitrate and 295.3 parts of cobalt nitrate were sequentially added and dissolved (B-
4) The solution was used. Next, the liquid (B-4) was added to the liquid (A-4) to form a slurry. Thereafter, 38.5 parts of antimony trioxide was added thereto, and then the same treatment as in Example 4 was performed.

The composition of the elements of the catalyst thus obtained was Mo
₁₂ W _0.1 Bi _0.7 Fe _2.1 Sb _0.7 Ni _2.5 Co _4.9 Zn _0.2
Cs was _0.6 .

This catalyst was reacted under the same conditions as in Example 4. As a result, the reaction rate of isobutylene was 97.7%,
The selectivity for methacrolein was 89.1%, and the selectivity for methacrylic acid was 3.0%.

Comparative Example 6 A catalyst was prepared, heat-treated and reacted in the same manner as in Example 4, except that bismuth trioxide was changed to 80.1 parts instead of 38.5 parts of bismuth trioxide. As a result, the conversion of isobutylene was 97.9%, the selectivity of methacrolein was 89.3%, and the selectivity of methacrylic acid was 3.0%.

Example 7 A reaction was carried out under the same conditions as in Example 4 except that the catalyst used in Example 4 was used and the raw material was changed to TBA. As a result, the conversion of TBA was 100%, the selectivity of methacrolein was 87.9%, and the selectivity of methacrylic acid was 3.1%.

Comparative Example 7 Using the catalyst used in Comparative Example 5, a reaction was carried out under the same conditions as in Comparative Example 5, except that the raw material was changed to TBA. As a result, the conversion of TBA was 100%, the selectivity of methacrolein was 86.2%, and the selectivity of methacrylic acid was 2.8%.

[0054]

According to the present invention, propylene, isobutylene, tertiary butyl alcohol or methyl tertiary butyl ether is subjected to gas-phase catalytic oxidation using molecular oxygen by adopting the above-mentioned constitution, and It has an excellent effect that a catalyst for producing unsaturated aldehydes and unsaturated carboxylic acids having improved catalytic performance including catalytic activity can be produced.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI // C07B 61/00 300 C07B 61/00 300 (56) References JP-A-6-114272 (JP, A) JP-A-60 -166039 (JP, A) JP-A-57-136540 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B01J 21/00-38/74 C07C 45/37 C07C 47/22 C07C 57/05

Claims (2)

(57) [Claims] 1. An aqueous solution containing molybdenum (solution A) and an aqueous solution containing iron (solution B) are mixed, and propylene, isobutylene, tertiary butyl alcohol or methyl tertiary butyl ether is subjected to gas phase contact using molecular oxygen. In the method for producing an oxide catalyst containing at least molybdenum, bismuth and iron, which is used for oxidizing and synthesizing the corresponding unsaturated aldehyde and unsaturated carboxylic acid, bismuth trioxide is added to the solution A in advance. A method for producing a molybdenum, bismuth and iron-containing oxide catalyst for synthesizing unsaturated aldehydes and unsaturated carboxylic acids, which is followed by ultrasonic treatment and then mixing with the solution B. 2. A liquid A which has been subjected to ultrasonic treatment after adding bismuth trioxide is mixed with a liquid B, and the resulting mixed liquid is mixed with 100 to 2 parts.
The method for producing a molybdenum, bismuth and iron-containing oxide catalyst for synthesizing unsaturated aldehydes and unsaturated carboxylic acids according to claim 1, wherein the catalyst is kept at 00 ° C.