JPH1071333A - Manufacture of catalyst for synthesizing unsaturated aldehyde and unsaturated carboxylic acid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a catalyst having sufficient strength and excellent reactivity and selectivity by drying a mixed soln. or aq. slurry of constitutent elements of the catalyst containing molybdenum, bismuth and iron and baking the dried matter to a specific temp. in an air atmosphere before subjecting the same to wet shaping. SOLUTION: As constituent elements of a catalyst, there is no special limit if at least molybdenium, bismuth and iron are contained. A mixed soln. or aq. slurry containing these constitutent elements of the catalyst is dried, for example, by a slurry dryer or a spray dryer. Drying temp. is pref. about 100-30 deg.C. Subsequently, the obtained dried powder is baked in an air atmosphere in order to activate the catalyst. Baking temp. may be within a range of 400-700 deg. and is pref. about 430-650 deg.C, especially pref., about 450-600 deg.C. A binder is added to the obtained baked powder and, if necessary, a shape reinforcing agent is appropriately added thereto and all of them are molded by a wet shaping method before again dried at about 80 1 120 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an aldehyde, an unsaturated aldehyde and an unsaturated aldehyde obtained by subjecting propylene, isobutylene, tertiary butanol (hereinafter abbreviated as TBA) or methyl tertiary butyl ether (hereinafter abbreviated as MTBE) to gas-phase catalytic oxidation. The present invention relates to a method for producing a catalyst used for synthesizing a carboxylic acid.

[0002]

2. Description of the Related Art Conventionally, 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. Numerous methods have been proposed for the composition of the catalyst used in the method and the method for producing the same.

[0003] As a method for producing a catalyst, a method of adding various organic compounds such as aniline, methylamine, and pentaerythritol at the time of catalyst preparation for the purpose of controlling the pores of the catalyst and improving the catalyst performance (particularly 58-981
No. 43, JP-A-3-109946), a method of adding starch (JP-A-63-315147, JP-A-4-4048) and the like have been proposed. In these methods, pores are developed in the catalyst by removing the organic compound by heat treatment, and the size of the pore diameter can be controlled by changing the size of the organic compound used.

[0004]

However, in these methods, the catalyst molded body from which the organic substances have been removed by the heat treatment has a significantly lower mechanical strength than before the heat treatment. Such a molded catalyst is damaged when it is dropped and filled in a reactor, so that it is difficult to use it industrially.
Therefore, it is desired to develop a method for producing a catalyst having sufficient strength when the catalyst is dropped and filled into a reactor.

The present invention relates to propylene, isobutylene, T
In producing gas-phase catalytic oxidation of BA or MTBE using molecular oxygen to produce unsaturated aldehydes and unsaturated carboxylic acids, the catalyst has sufficient strength when dropping and filling a catalyst into a reactor, and has an excellent property. It is an object of the present invention to provide a method for producing a catalyst having a high conversion and selectivity.

[0006]

According to the present invention, there is provided a method for producing a catalyst containing at least molybdenum, bismuth and iron as constituent elements of a catalyst. To 400
Propylene, isobutylene, TBA or MTBE, characterized by being subjected to wet shaping after firing at ~ 700 ° C.
Is a method for producing a catalyst for synthesizing an unsaturated aldehyde and an unsaturated carboxylic acid by subjecting the compound to gas-phase catalytic oxidation using molecular oxygen.

[0007]

DETAILED DESCRIPTION OF THE INVENTION The catalysts prepared by the method of the present invention, at least comprising the elements molybdenum catalyst is not particularly limited as long as it contains bismuth and iron, for example, 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 each represents molybdenum, bismuth, iron, silicon and oxygen, a is selected from the group consisting of cobalt and nickel X represents at least one element, X represents at least one element selected from the group consisting of chromium, lead, manganese, calcium, magnesium, niobium, silver, barium, tin, tantalum, and zinc; Z represents at least one element selected from the group consisting of boron, sulfur, selenium, tellurium, cerium, tungsten, antimony, and titanium; 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 a = 1
In the case of 2, b = 0.01-3, c = 0.01-5, d = 1
-12, e = 0-8, f = 0-5, g = 0.001
2, h = 0 to 20, and i is the number of oxygen atoms required to satisfy the valence of each component. And the like.

As the raw materials for the constituent elements of the catalyst, oxides, sulfates, nitrates, carbonates, hydroxides, ammonium salts, halides and the like of the respective elements can be used in combination. Examples of the molybdenum raw material include ammonium paramolybdate, molybdic acid, molybdenum trioxide, and the like.

A mixed solution or an aqueous slurry containing the constituent elements of the catalyst is prepared by mixing a catalyst raw material and water. The mixed solution or aqueous slurry is dried after removing most of the water. For drying, it is preferable to use an apparatus capable of obtaining a dry powder having a relatively narrow particle size distribution, and examples thereof include a slurry dryer, a spray dryer, and a drum dryer. The resulting dried powder preferably has fluidity, and therefore the drying temperature is preferably 100 to 300 ° C.

[0010] To activate the catalyst, the dry powder is heat treated in an air atmosphere. This heat treatment step is called firing. The firing temperature may be in the range of 400 to 700 ° C,
Preferably 430-650 ° C., particularly preferably 450-650 ° C.
600 ° C. The firing method is not particularly limited, and examples thereof include a batch heat treatment method such as a muffle furnace and a continuous heat treatment method using a rotary kiln. The firing time may be in the range of 0.1 to 10 hours, preferably 0.15 to 8 hours, particularly preferably 0.3 to 7 hours.

[0011] A binder is added to the obtained calcined powder. At this time, a shaping reinforcing agent may be appropriately added. The mixture of the calcined powder and the binder is formed by a wet molding method and then dried again at 80 to 120 ° C.

The binder used at this time is not particularly limited, but an organic substance which can be removed by heat treatment at 100 to 350 ° C. is preferable. As such a binder,
For example, gelatin, cellulose, methyl cellulose, ethyl cellulose, hydroxypropyl cellulose and the like can be mentioned. Examples of the shaping reinforcing agent include diatomaceous earth, silica sol, silica gel, bentonite, kaolin, glass fiber, asbestos, ceramic fiber, carbon fiber, and the like.

As the wet shaping method, a generally known extrusion molding method, rounding method, rolling granulation method, supporting method and the like are preferable. Among them, the extrusion molding method is particularly preferable because it can be formed into various shapes such as a ring shape, a column shape, and a star shape.

The shaped catalyst thus obtained is dropped and filled in a fixed bed reactor. Prior to the reaction, the shaped catalyst filled in the reactor may be subjected to a heat treatment in order to remove organic substances such as gelatin, cellulose, methylcellulose, ethylcellulose and hydroxypropylcellulose added as a binder. At this time, the heat treatment is 150 ~
It is preferable to carry out at 350 ° C. Further, the heat treatment is preferably carried out while flowing an appropriate gas, and the use of air or nitrogen is advantageous industrially. Since the strength of the catalyst after removing the binder is reduced, the heat treatment of the shaped catalyst is
It is important to do this after filling the shaped catalyst into the fixed bed reactor.

Using the catalyst prepared by the process of the present invention, propylene, isobutylene, TBA or MTBE
Is subjected to gas phase catalytic oxidation with molecular oxygen to produce unsaturated aldehydes and unsaturated carboxylic acids, the molar ratio of propylene, isobutylene, TBA or MTBE to oxygen in the raw material gas supplied to the catalyst layer is 1: 0. 0.5 to 3 are preferred. The source of oxygen may be pure oxygen gas, but the use of air is industrially advantageous. The raw material gas is propylene,
Water vapor or an inert gas may be contained in addition to isobutylene, TBA or MTBE and oxygen. The inert gas is not particularly limited as long as it does not participate in the reaction, but the use of nitrogen is industrially advantageous. The reaction pressure is preferably in the range of normal pressure to several atmospheres, and the reaction temperature is preferably in the range of 250 to 400 ° C.

The unsaturated aldehyde and unsaturated carboxylic acid produced by this reaction include acrolein and acrylic acid when the raw material is propylene, and methacrolein and methacrylic when the raw material is isobutylene, TBA or MTBE. Refers to acids.

[0017]

Embodiments of the present invention will be described below. "Parts" in the following Examples and Comparative Examples means parts by weight. In the composition formula, Mo, Bi, Fe, Co, Ni, Mg, Zn, W,
Sb, K, Cs and Si represent molybdenum, bismuth, iron, cobalt, nickel, magnesium, zinc, tungsten, antimony, potassium, cesium and silicon, respectively.

The filling and pulverization rate was calculated according to the following definition by dropping and filling the shaped catalyst from the upper part of the reactor installed vertically to the horizontal direction, and then collecting the catalyst from the lower part of the reactor.

Filling powder ratio (%) = (ab) / a × 100 The meanings of a and b in the formula are as follows.

A: Weight of the shaped catalyst dropped and filled b: Weight of the recovered catalyst that did not pass through a 14-mesh sieve The reaction was analyzed by gas chromatography. The conversion of the raw materials, the selectivity of the unsaturated aldehyde to be produced and the selectivity of the unsaturated carboxylic acid were calculated according to the following definitions.

Reaction rate of raw material (%) = B / A × 100 Selectivity of unsaturated aldehyde (%) = C / B × 100 Selectivity of unsaturated carboxylic acid (%) = D / B × 100 The meanings of A, B, C and D are as follows.

A: Number of moles of supplied raw material B: Number of moles of reacted raw material C: Number of moles of unsaturated aldehyde generated D: Number of moles of unsaturated carboxylic acid generated [Example 1] 11. 500 parts of ammonium molybdate, ammonium paratungstate
3 parts and 1.4 parts of potassium nitrate were added and heated and stirred (Solution A). Separately, 41.9 parts of 60% by weight nitric acid was added to 600 parts of water to make the mixture uniform, and 103.0 parts of bismuth nitrate was added and dissolved. To this, 95.3 parts of ferric nitrate, 309.0 parts of cobalt nitrate and 7.0 parts of zinc nitrate were sequentially added, and 400 parts of water was further added to dissolve (solution B). Solution B was added to Solution A to form an aqueous slurry, and then antimony trioxide 24.1 was used.
The resulting mixture was heated and stirred, and spherical particles having an average particle size of 50.5 μm were obtained using a spray dryer. The spherical particles were calcined at 500 ° C. for 6 hours in an air atmosphere using a rotary kiln to obtain a catalyst powder. The composition of elements other than oxygen in the obtained catalyst powder is Mo ₁₂ Bi _0.9 Fe _1.0 Co _4.5 Zn _0.1 W _0.2 Sb _0.7 K
_0.06 .

To 500 parts of the catalyst powder, 15 parts of methylcellulose and 150 parts of water were added, mixed and kneaded, and the outer diameter was 6 mm using an auger extruder.
It was molded into a shape having an inner diameter of 3 mm and a length of 5 mm. This extruded catalyst was dried at 105 ° C. for 2 hours using a hot air dryer.
When the packing and powdering ratio of this catalyst was measured, the packing and powdering ratio was 0.15%.

The molded catalyst was filled in a stainless fixed-bed reaction tube, and heat-treated at 300 ° C. for 1 hour in an air flow. After that, 5% of propylene, 12% of oxygen, 10% of water vapor and 73% of nitrogen (by volume) were added. The raw material gas 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 99.2.
%, Acrolein selectivity was 89.9%, and acrylic acid selectivity was 6.9%.

Example 2 Molding and reaction were carried out in the same manner as in Example 1 except that calcination was performed at 450 ° C. for 6 hours in an air atmosphere using a rotary kiln.

As a result, the powdered powder ratio of this catalyst was 0.1
6%. Also, the reaction rate of propylene is 99.5%,
The selectivity for acrolein was 89.8% and the selectivity for acrylic acid was 6.5%.

Example 3 Molding and molding were performed in the same manner as in Example 1 except that the mixture was calcined in an air atmosphere at 520 ° C. for 3 hours using a rotary kiln and the reaction temperature was set to 330 ° C. The reaction was performed.

As a result, the powdered powder ratio of this catalyst was 0.1
3%. The conversion of propylene is 98.8%,
The selectivity for acrolein was 89.7% and the selectivity for acrylic acid was 6.2%.

[Comparative Example 1] In Example 1, the spherical particles produced by using the spray dryer were fired at 300 ° C for 1 hour in an air atmosphere using a rotary kiln, and wet molding was performed in the same manner as in Example 1. The dried product was filled in a reaction tube, and heat-treated at 500 ° C. for 6 hours under a flow of air, and then reacted under the same conditions as in Example 1.

As a result, the powdered packing ratio of this catalyst was 6.2.
It was 4%, and many of the catalysts recovered for the measurement of the powdering ratio were damaged or powdered. The conversion of propylene was 99.1% and the selectivity of acrolein was 8%.
The selectivity to acrylic acid was 9.0%, and the selectivity to acrylic acid was 6.3%.

[Comparative Example 2] Molding and reaction were performed in the same manner as in Example 1 except that firing was performed at 750 ° C for 6 hours in an air atmosphere using a rotary kiln.

As a result, the powdered powder ratio of this catalyst was 0.1
2%. Also, the reaction rate of propylene is 92.0%,
The selectivity for acrolein was 84.5% and the selectivity for acrylic acid was 4.9%. Compared with Example 1, the conversion of propylene, the selectivity of acrolein, and the selectivity of acrylic acid were significantly reduced.

[Comparative Example 3] Molding and reaction were performed in the same manner as in Example 1 except that calcination was performed at 350 ° C for 6 hours in an air atmosphere using a rotary kiln.

As a result, the powdered packing ratio of this catalyst was 0.1
1%. Also, the reaction rate of propylene is 99.1%,
The selectivity of acrolein was 86.5% and the selectivity of acrylic acid was 5.3%. Compared with Example 1, the selectivity of acrolein and the selectivity of acrylic acid were lower.

Example 4 42 parts of 60% by weight nitric acid was added to 400 parts of water to form a uniform solution, and bismuth nitrate was 68.7.
Was added and dissolved. To this, 274.5 parts of nickel nitrate and 24.1 parts of antimony trioxide were sequentially added and dissolved and dispersed. 165 parts of 28% by weight aqueous ammonia was added to this mixture to obtain a white precipitate and a blue solution. This was heated and stirred to evaporate most of the water. The obtained slurry substance was dried at 120 ° C. for 16 hours, and then dried at 750 ° C. for 2 hours.
The mixture was heat-treated for a long time and pulverized to obtain a fine powder of a bismuth-nickel-antimony compound.

11. 500 parts of ammonium paramolybdate and 1000 parts of ammonium paratungstate in 1000 parts of water.
3 parts and 20.7 parts of cesium nitrate were added, and heated and stirred (Solution A).

Separately, ferric nitrate (190.7) was added to 700 parts of water.
, 150.6 parts of cobalt nitrate and 121.0 parts of magnesium nitrate were sequentially added and dissolved (Solution B).

After adding the liquid B to the liquid A to form a slurry,
354.5 parts of 20% by weight silica sol and the above-mentioned bismuth-nickel-antimony compound fine powder were added and heated and stirred, and dried by a spray dryer to obtain hollow spherical particles having an average particle diameter of 51.3 μm. . The spherical particles were calcined at 500 ° C. for 4 hours in an air atmosphere using a rotary kiln to obtain a catalyst powder. The composition of elements other than oxygen in the obtained catalyst powder is Mo ₁₂ Bi _0.6 Fe _2.0 Co _2.2 Ni
_4.0 Mg _2.0 W _0.2 Sb _0.7 Cs _0.45 Si _5.0 .

To 500 parts of the catalyst powder, 15 parts of methylcellulose and 150 parts of water were added, mixed and kneaded, and the outer diameter was 6 mm using an auger type extruder.
It was molded into a shape having an inner diameter of 3 mm and a length of 5 mm. This extruded catalyst was dried at 105 ° C. for 2 hours using a hot air dryer.
When the packing and powdering ratio of this catalyst was measured, the packing and powdering ratio was 0.14%.

The molded catalyst was filled in a stainless steel fixed bed reaction tube, and heat-treated at 300 ° C. for 1 hour in an air flow. Then, isobutylene 5%, oxygen 12%, steam 10% and nitrogen 73% (vol%) were used. The raw material gas was passed through the catalyst layer for a contact time of 3.6 seconds and reacted at 350 ° C.

As a result, the conversion of isobutylene was 97.8.
%, Methacrolein selectivity was 89.9%, and methacrylic acid selectivity was 3.8%.

Example 5 Molding and reaction were carried out in the same manner as in Example 4 except that calcination was performed in an air atmosphere at 450 ° C. for 4 hours using a rotary kiln.

As a result, the powdered packing ratio of this catalyst was 0.1
6%. The reaction rate of isobutylene is 97.7.
%, Methacrolein selectivity was 89.8%, and methacrylic acid selectivity was 3.7%.

Example 6 Molding and reaction were carried out in the same manner as in Example 4 except that calcination was performed at 520 ° C. for 3 hours in an air atmosphere using a rotary kiln.

As a result, the powdered packing ratio of this catalyst was 0.1
4%. Further, the selectivity of isobutylene is 97.5.
%, Methacrolein selectivity was 89.7%, and methacrylic acid selectivity was 3.5%.

[Comparative Example 4] In Example 4, the spherical particles produced by using a spray dryer were calcined at 300 ° C for 1 hour in an air atmosphere using a rotary kiln, and wet molding was performed in the same manner as in Example 4. Then, the dried product was filled in a reaction tube, and heat-treated at 500 ° C. for 4 hours under a flow of air, and then reacted under the same conditions as in Example 4.

As a result, the powdered packing ratio of this catalyst was 7.5.
%, And many of the catalysts that were broken or powdered were found in the catalyst recovered for the measurement of the filling powdering ratio. The reaction rate of isobutylene was 97.1%, and the selectivity of methacrolein was 8%.
The selectivity to methacrylic acid was 3.1% and the methacrylic acid was 3.1%.

Comparative Example 5 Molding and reaction were carried out in the same manner as in Example 4 except that calcination was performed at 750 ° C. for 6 hours in an air atmosphere using a rotary kiln.

As a result, the powdered packing ratio of this catalyst was 0.1
4%. The reaction rate of isobutylene was 91.6.
%, The selectivity of methacrolein was 84.1%, and the selectivity of methacrylic acid was 2.0%. Compared with Example 4, the conversion of isobutylene and the selectivity of methacrolein were significantly reduced.

[Comparative Example 6] Molding and reaction were performed in the same manner as in Example 4 except that calcination was performed in an air atmosphere at 350 ° C for 6 hours using a rotary kiln.

As a result, the powdered packing ratio of this catalyst was 0.1
5%. The reaction rate of isobutylene was 97.1.
%, The selectivity of methacrolein was 85.1%, and the selectivity of methacrylic acid was 2.2%. The selectivity of methacrolein was lower than that of Example 4.

Example 7 Using the catalyst of Example 4, the reaction was carried out in the same manner as in Example 4 except that the raw material was changed to TBA.

As a result, the conversion of TBA was 100%, the selectivity of methacrolein was 87.5%, and the selectivity of methacrylic acid was 2.8%.

Comparative Example 7 Using the catalyst of Comparative Example 5, the reaction was carried out in the same manner as in Example 4 except that the raw material was changed to TBA.

As a result, the conversion of TBA was 100%, the selectivity of methacrolein was 75.5%, and the selectivity of methacrylic acid was 2.3%.

[0057]

According to the present invention, in the case where propylene, isobutylene, TBA or MTBE is subjected to gas-phase catalytic oxidation using molecular oxygen to produce unsaturated aldehydes and unsaturated carboxylic acids, a sufficient amount of catalyst is required for dropping and filling the reactor. A catalyst having excellent strength and excellent conversion and selectivity was obtained.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical indication location C07C 27/14 9155-4H C07C 27/14 Z 57/05 2115-4H 57/05 // C07C 47 / 22 8114-4H 47/22 A 8114-4H J

Claims (1)

[Claims] 1. A method for producing a catalyst containing at least molybdenum, bismuth and iron as constituent elements of the catalyst,
After drying the mixed solution or the aqueous slurry containing the constituent elements of the catalyst and calcining at 400 to 700 ° C. in an air atmosphere,
Characterized by wet shaping, propylene, isobutylene, tertiary butanol or methyl tertiary butyl ether is subjected to gas phase catalytic oxidation using molecular oxygen to synthesize unsaturated aldehydes and unsaturated carboxylic acids. Method for producing catalyst.