JP2001096162A - Method for production of catalyst for synthesis of unsaturated aldehyde and unsaturated carboxylic acid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method for a catalyst for synthesizing unsaturated aldehydes and unsaturated carboxylic acids at a high yield in a gas-phase catalytic oxidation reaction. SOLUTION: A raw material salt solution containing at least molybdenum, bismuth, iron, nickel and/or cobalt as catalyst ingredients is subjected to a heating treatment to obtain a catalyst precursor powder having an ignition loss of 1-5%. Subsequently the catalyst precursor powder is molded and burned to form a catalyst for synthesis of unsaturated aldehydes and unsaturated carboxylic acids.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a catalyst for synthesizing unsaturated aldehydes and unsaturated carboxylic acids.
More specifically, the present invention relates to a method for producing a catalyst for synthesizing unsaturated aldehydes and unsaturated carboxylic acids used for vapor phase catalytic oxidation of propylene, isobutylene, tertiary butanol, or the like.

[0002]

2. Description of the Related Art Conventionally, as a method for producing a catalyst for synthesizing unsaturated aldehyde and unsaturated carboxylic acid, molybdenum
A method is known in which a raw salt aqueous solution containing vanadium is heat-treated, and then molded and fired (for example, JP-A-8-10621).

However, the obtained unsaturated aldehyde and unsaturated carboxylic acid synthesizing catalysts do not have a sufficient yield in the gas phase catalytic oxidation reaction of propylene, isobutylene, tert-butanol or the like.

[0004]

An object of the present invention is to provide a method for producing a catalyst for synthesizing unsaturated aldehydes and unsaturated carboxylic acids which has a high yield in a gas phase catalytic oxidation reaction.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to solve the above problems, and as a result, completed the present invention. That is, according to the present invention, at least molybdenum, bismuth, iron, nickel and/or
Alternatively, a raw material salt aqueous solution containing cobalt is heat-treated to obtain a catalyst precursor powder having an ignition loss of 1% to 5%, and then the catalyst precursor powder is molded and fired to form an unsaturated aldehyde and an unsaturated carboxylic acid. A method for producing a catalyst for acid synthesis is provided.

[0006]

[X indicates the weight (g) after drying the catalyst precursor powder at 150° C. for 3 hours to remove the attached water, and Y indicates the catalyst precursor powder from which the attached water has been removed for a further 3 hours at 495° C. Represents the weight after baking. ]

The raw material salt aqueous solution used in the present invention is an aqueous solution, water slurry or cake containing at least molybdenum, bismuth, iron, nickel and/or cobalt as a catalyst component. Examples of the catalyst component include ammonium paramolybdate, molybdenum trioxide, molybdenum chloride and other molybdenum compounds, bismuth nitrate and bismuth chloride and other bismuth compounds, iron sulfate, ferric nitrate and other iron compounds, nickel sulfate and nickel nitrate. Examples thereof include nickel compounds such as nickel carbonate, cobalt compounds such as cobalt sulfate, cobalt nitrate, and cobalt carbonate.

The method for preparing the raw material salt aqueous solution may be any conventionally known method, for example, a solution obtained by mixing an acidic salt selected from the catalyst component and a basic salt selected from the catalyst component. And a method of mixing with a solution obtained by mixing, and as a specific example, an aqueous solution of a molybdenum compound,
Examples include a method of adding a mixture of a bismuth compound, an iron compound, a nickel compound and/or a cobalt compound. Further, an acid or a base may be present in the raw salt aqueous solution. The raw salt solution usually has a water content of 40% to 70%.
%, preferably 44% to 53%, and the viscosity is 50 centipoises to 8000 centipoises, preferably 500 centipoises to 2000 centipoises.

The heat treatment of the present invention generally removes nitrate radicals, sulfate radicals, carbonate radicals, ammonium radicals and the like derived from raw material salts, and the resulting catalyst precursor powder has a loss on ignition of 1% to 5%.
The heat treatment conditions may be appropriately selected using a known apparatus so that the heat treatment is preferably performed in the range of 1.5% to 3%.

When the ignition loss of the catalyst precursor powder is in the above range, the unsaturated aldehyde and unsaturated carboxylic acid synthesis catalyst (hereinafter referred to as "catalyst") having a high yield in the gas phase catalytic oxidation reaction is obtained. can get. The reason for this is not clear, but when the catalyst precursor powder is molded and fired to obtain the catalyst, the catalyst primary particles sinter due to the liquid phase generated by melting of the salt and various roots remaining in the catalyst precursor powder. It is presumed that this may be suppressed, or the BET specific surface area of the catalyst precursor powder may be suppressed from being significantly reduced, the BET specific surface area of the obtained catalyst may be increased, and the yield may be improved.

In the heat treatment, for example, the raw material salt aqueous solution is introduced into a dryer by a screw feeder, a slurry pump or the like, the inlet temperature is 420° C. to 600° C., the dryer outlet temperature is 350° C. to 530° C., and the residence time is 0. 01
The catalyst precursor powder may be obtained by heat treatment under the condition of seconds to 7 seconds, preferably 0.05 seconds to 0.7 seconds, and the obtained catalyst precursor powder may be collected by a cyclone, a bag filter or the like. When the inlet temperature is lower than the above range, the ignition loss of the catalyst precursor powder may exceed 5%. When the inlet temperature is higher than the above range, the ignition loss of the catalyst precursor powder is 1
It may be lower than %.

As the dryer, the heat treatment is performed while dispersing the raw salt aqueous solution and the intermediate product of the heat treatment process in a high-speed air stream so that a desired ignition loss can be achieved without locally producing a liquid phase. A dryer capable of obtaining a certain catalyst precursor powder is preferable, and examples thereof include a spray pyrolyzer, a stirred fluidized bed dryer, and an airflow dryer, and more preferably an airflow dryer. A specific example of the airflow dryer is a continuous instantaneous airflow dryer (eg, trade name: flash jet dryer, manufactured by Seishin Enterprise Co., Ltd.).
Is mentioned. Usually, the airflow dryer is composed of a dryer main body, a blower, a heater, a feeder, a cyclone, a bag filter and the like.

The catalyst precursor powder obtained by the present invention is
Usually, the BET specific surface area is about 10 m ² /g to about 50 m ² /
g, preferably from about 20 m ² / g to about 40 m ² / g.

In the present invention, the obtained catalyst precursor powder is then shaped to obtain a shaped body. In the molding, for example, a tablet molding method, a Marumerizer method, an extrusion molding method, a liquid granulation method, a press molding method, etc., such as a columnar shape, a ring shape, a granular shape, a clover shape, a star shape, a honeycomb shape, etc. It may be formed into any shape. Further, water, alcohols, methylcellulose, starch, polyvinyl alcohol, polyethylene glycol, stearic acid, waxes, water-absorbent resin and the like may be added for the purpose of improving moldability. Further, for the purpose of increasing the strength of the catalyst, alumina sol, silica sol, alumina fiber, silica fiber, glass fiber, silicon carbide whisker, etc. may be added and molded.

In the present invention, the obtained molded body is then calcined to obtain a catalyst. The calcination may be carried out by a conventional method, for example, a method of calcination in a static calcination furnace in an air atmosphere at about 400°C to about 600°C.

The catalyst obtained by the production method of the present invention is
Usually the composition is Mo_aBi_bFe_cA_dB _eC_fD_gO_x(In the formula,
Mo, Bi, Fe and O are molybdenum and bisma, respectively.
Represents iron, iron and oxygen, A is nickel and/or coba
Means B, manganese, zinc, calcium, magne
At least selected from the group consisting of sium, tin and lead
Represents one element, C is phosphorus, boron, arsenic, tellurium,
Selected from the group consisting of tungsten, antimony and silicon
Represents at least one element that is exposed, D is potassium, ru
Selected from the group consisting of bidium, cesium and thallium
Represents at least one element. a to x are atoms of each element
It represents a ratio, and when a=12, 0<b≦10, 0<
c≦10, 1≦g≦10, 0≦e≦10, 0≦f≦1
0, 0≦g≦2, and x is determined by the oxidation state of each element.
It is a whole value. ).

[0017]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Loss on ignition Z (%): Catalyst precursor powder 20
The weight X (g) after drying g at 150° C. for 3 hours and the weight Y (g) after further calcination of the catalyst precursor powder at 495° C. for 3 hours were measured and calculated by the following formula (1). I asked. Z=(X−Y)÷X×100 (1)

Viscosity (centipoise): Using a B-type viscometer (manufactured by Tokyo Keiki), the rotor No. 3, rotation speed 12r
It was measured under the conditions of pm and temperature of 20°C.

BET specific surface area (m ² /g): Using a specific surface area measuring device Monosorb manufactured by Kantachrome Co., 0.5 to 1 g of a sample was put in a sample cell, and N ₂ /He (30
/70) Degassed under carrier gas flow (350°C, 15
After that, the carrier gas is adsorbed at the liquid nitrogen temperature.
After that, the temperature was raised to room temperature, the desorption amount was measured with a thermal conductivity type detector, and the BET specific surface area was determined. (BET 1-point method)

Reaction rate, selectivity and yield: In a glass reaction tube having an inner diameter of 18 mm and filled with 7 g of catalyst and 13 g of silicon carbide (-14 mesh product), mixed gas [propylene (supplied olefin): oxygen: nitrogen: Steam =
(Molar ratio 1:2.2:6.2:2) at reaction temperature 369
The concentration of propylene at the outlet of the reaction tube (unreacted olefin), the concentration of acrolein and the concentration of acrylic acid (product) are measured by circulating the reaction solution under the conditions of ℃ and space velocity SV=750/H.
The reaction rate, selectivity, yield, and reaction were calculated from the following formulas. Reaction rate (%) = [(mol number of supplied olefin)-(mol number of unreacted olefin)] / (mol number of supplied olefin) x 100 Selectivity (%) = (mol number of product) / [ (Mole number of supplied olefin)-(Mole number of unreacted olefin)] x 100 Yield (%) = (Mole number of product) / (Mole number of supplied olefin) x 100

Example 1 Ammonium paramolybdate [(NH_Four)₆Mo₇O_{twenty four}
・4H₂O] 423.7 parts by weight dissolved in 800 parts by weight of warm water
20% silica sol [SiO₂] 60.1 weight
Parts are added and this is designated as solution A. Cobalt nitrate [Co(N
O₃)₂・6H₂O] 436.6 parts by weight and ferric nitrate
[Fe (NO₃)₃・9H₂O] 161.6 parts by weight of warm water
It is dissolved in 400 parts by weight, and this is designated as solution B. Warm water 40
Cesium nitrate [CsNO] in parts by weight₃] 2.93 parts by weight
Dissolve and use this as liquid C. 60% nitric acid in 60 parts by weight of water
26.4 parts by weight of bismuth nitrate [Bi(NO₃)₃
・5H ₂O] 97.0 parts by weight are dissolved, and this is referred to as liquid D
It Next, while stirring, the liquid A, liquid B, liquid C and liquid D
Add the mixture and concentrate to a viscosity of 1695 centipoise.
A raw material salt aqueous solution having a water content of 44.5% was obtained.

[0023] Then, the raw salt solution is dried with a flash dryer (flask).
Shujet Dryer FJD-4, Seishi Co., Ltd.
Air flow rate of 8.5 Nm³/Min, dry
Air inlet temperature 450°C, dryer outlet temperature 371°C,
Slurry supply speed 30kg/hr, slurry nozzle 4m
Heat treatment under the conditions of mφ, knocker interval 3 seconds/time
Thus, a catalyst precursor powder was obtained. Of the obtained catalyst precursor powder
BET specific surface area is 23.5m²/G, loss on ignition is 1.8
%Met.

Next, the catalyst precursor powder is press-molded and sized within a range of 10 to 24 mesh, and then 530
The catalyst was obtained by calcination for 6 hours in an air atmosphere. The resulting catalyst had a propylene conversion rate of 98.7%, acrolein and acrylic acid selectivity of 93.4%, and a yield of 92.2.
%Met.

[0025] Example 2 Example nitrate in 1 ferric _{[Fe (NO 3) 3 · 9H} 2
A raw material salt aqueous solution was obtained in the same manner except that the charged amount of [O] was changed to 181.8 parts by weight. The raw material salt aqueous solution had a viscosity of 60 centipoise and a water content of 67.2%.

Next, this raw salt solution was dried using a flash dryer (flash jet dryer FJD-2, manufactured by Seishin Enterprise Co., Ltd.) with an air volume of 2.8 Nm ³ /min.
Dryer inlet temperature 490°C, dryer outlet temperature 38
A catalyst precursor powder was obtained by heat treatment at 5° C., a slurry supply rate of 3.5 kg/hr, a slurry nozzle of 3 mmφ, and a knocker interval of 3 seconds/time. The obtained catalyst precursor powder had a BET specific surface area of 32.1 m ² /g and an ignition loss of 3.3%. The propylene reaction rate of the obtained catalyst was 98.0%, the acrolein and acrylic acid selectivity was 93.3%, and the yield was 91.4%.

Comparative Example 1 In Example 1, the airflow of the airflow dryer was 5 Nm ³ /mi.
n, the dryer inlet temperature was 390° C., the dryer outlet temperature was 280° C., and the slurry feed rate was changed to 28 kg/hr. The obtained catalyst precursor powder had a BET specific surface area of 14.3 m ² /g and an ignition loss of 8.7%. The propylene conversion of the obtained catalyst was 92.7%, the acrolein and acrylic acid selectivity was 94.8%, and the yield was 87.8%.

[0028]

According to the present invention described in detail above, there is provided a method for producing a catalyst for synthesizing an unsaturated aldehyde and an unsaturated carboxylic acid, which has a high yield in a gas phase catalytic oxidation reaction. The utility value of is great.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C07C 57/055 C07C 57/055 A (72) Inventor Kozaburo Nomura 5-1 Sokai-cho, Niihama-shi, Ehime Sumitomo Chemical Co., Ltd. F-term (reference) 4G069 AA08 AA15 BA03B BA37 BB12B BC06B BC25A BC25B BC59A BC59B BC66A BC66B BC67A BC67B BC68A CB07 EA01Y FB30 FB57 4C06 BA13 CA62 BA30 BA81 BA30 BA81 BA20 BA81 BA20 BA81 BA20 BA21 BA20 BA20 BA21 BA20 BA21 BA20 BA21 BA20 BA20 BA21 BA20

Claims (3)

[Claims] 1. At least molybdenum as a catalyst component,
A raw material salt aqueous solution containing bismuth, iron, nickel and/or cobalt is heat-treated to obtain a catalyst precursor powder having an ignition loss of 1% to 5%, and then the catalyst precursor powder is molded,
A method for producing a catalyst for synthesizing an unsaturated aldehyde and an unsaturated carboxylic acid obtained by firing. 2. The method for producing a catalyst for synthesizing an unsaturated aldehyde and an unsaturated carboxylic acid according to claim 1, wherein the heat treatment is carried out by using a gas stream dryer. 3. The method for producing a catalyst for synthesizing unsaturated aldehydes and unsaturated carboxylic acids according to claim 1 or 2, wherein the raw material salt aqueous solution has a viscosity of 50 to 8,000 centipoise.