JP2657693B2 - Preparation of catalysts for the production of methacrolein and methacrylic acid - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a method for preparing a catalyst used for producing methacrolein and methacrylic acid by subjecting isobutylene or tertiary butanol to gas phase catalytic oxidation.

[Conventional technology]

Numerous proposals have been made for catalysts used in the production of methacrolein and methacrylic acid by gas-phase catalytic oxidation of isobutylene or tertiary butanol. Also,
Many catalyst preparation methods have been proposed. For example, as a method for preparing a multi-component catalyst containing molybdenum-bismuth, GB-1289057, GB-1
No. 330474, GB-1333030, JP-A-60-28824 and the like have reported unique preparation methods. However, the catalyst used in this reaction is generally required to be improved from an industrial standpoint in terms of catalytic activity, selectivity of methacrolein and methacrylic acid, and catalytic performance such as catalyst life.

[Problems to be solved by the invention]

It is an object of the present invention to provide a novel method for preparing a catalyst for advantageously producing methacrolein and methacrylic acid from isobutylene or tertiary butanol.

[Means for solving the problem]

The present invention is a multi-component containing at least molybdenum, bismuth, iron and antimony in a catalyst composition used in producing gasoline catalytic oxidation of isobutylene or tertiary butanol using molecular oxygen to produce methacrolein and methacrylic acid. The present invention relates to a method for preparing a catalyst, which is characterized by introducing a compound obtained by preliminarily heat-treating a part of its constituent elements in the form as it is when preparing a system catalyst.

The present invention has the general formula _{Mo a W b Bi c Fe d} Sb e A f X g Y h Z i O j ( wherein Mo, W, Bi, Fe, Sb and O represent molybdenum, tungsten, bismuth, iron, Antimony and oxygen, A is at least one element selected from the group consisting of nickel and cobalt, X is at least one element selected from the group consisting of potassium, rubidium, cesium and thallium, Y is magnesium, zinc, At least one element selected from the group consisting of manganese, cadmium, lead, barium and chromium; Z is phosphorus, boron, sulfur, chlorine,
At least one element selected from the group consisting of silica, selenium, cerium, tin and titanium, a, b, c, d,
e, f, g, h, i and j indicate the atomic ratio of each element,
When a = 12, b = 0.01-2, c = 0.01-3, d = 0.5-
5, e = 0.01-3, f = 1-12, g = 0.01-2, h = 0.
01 to 10, i = 0 to 20, and j is the number of oxygen atoms required to satisfy the valence of each component.) In preparing a catalyst having a composition represented by the following components: Bi component, Sb component And D component (here, D component means at least one element selected from the group consisting of the W component, A component and Y component) in advance at a temperature of 700 to 850 ° C. A method for preparing a catalyst for producing methacrolein and methacrylic acid by subjecting isobutylene or tertiary butanol to gas-phase catalytic oxidation using molecular oxygen, characterized by using the obtained compound.

As a raw material of an element for preparing the catalyst, an oxide or a chloride, a sulfate, a nitrate, an ammonium salt, a carbonate, or a mixture thereof, which can be converted into an oxide when heated, is preferable.

A feature of the present invention is that a part of the constituent elements of the catalyst is introduced in the form of a compound obtained by heat treatment in advance.
At this time, the atomic ratio by the combination of the Bi component, the Sb component and the D component can be selected at an arbitrary ratio.

The D component represents at least one element selected from the group consisting of the W component, the A component, and the Y component.
Particularly, a combination with the W component and the A component (nickel or cobalt) is preferable.

In the present invention, a favorable result is obtained only for the combination of the Bi component, the Sb component and the D component. In order to examine what caused this in the contact structure, Ni was extracted from the D component to prepare a Bi-Sb-Ni compound. After X-ray diffraction analysis after heat treatment of this compound,
In this compound, it was confirmed that nickel oxide, bismuth oxide, antimony oxide and several types of nickel and bismuth were antimony compounds, but there were several diffraction peaks that could not be analyzed at this stage. Suggests the generation of We speculate that this new compound exhibits a very effective action.

To prepare a mixture of Bi component, Sb component and D component,
The compounds containing the respective components may be mixed as they are, or the compounds may be dissolved or dispersed in water, and then the water may be removed.

The heat treatment temperature of the mixture of the Bi component, the Sb component and the D component is usually 700 to 850 ° C, preferably 730 to 830 ° C. The heat treatment time is usually 2 to 5 hours.

Next, the obtained heat-treated product is mixed with other catalyst components.
It is preferable that each component is dispersed or dissolved in water and mixed. Water is removed from the mixture and heat treatment is carried out by a conventional method to obtain a target catalyst. The heat treatment is preferably performed at a temperature of 450 to 600 ° C. for 2 to 10 hours. In preparing the catalyst, known methods such as an evaporation to dryness method, a precipitation method, and an oxide mixing method can be used. Although the catalyst obtained by the method of the present invention is effective without a carrier, it can be supported on an inert carrier such as silica, alumina, silica-alumina, silicon carbide or diluted with these.

When producing methacrolein and methacrylic acid using the catalyst of the present invention, molecular oxygen is added to raw material isobutylene or tertiary butanol, and gas phase catalytic oxidation is carried out in the presence of the catalyst.

The molar ratio of isobutylene or tertiary butanol to oxygen is 1:
0.5 to 3 is preferred. The source gas is preferably diluted with an inert gas for use. The molecular oxygen used for the oxidation may be pure oxygen gas or air, but air is industrially advantageous. The reaction pressure is preferably from normal pressure to several atmospheres. The reaction temperature is preferably in the range of 250 to 450 ° C., and the reaction can be carried out in a fluidized bed or a fixed bed.

The catalyst obtained by the method of the present invention has advantages such as extremely high catalytic activity and long catalyst life.

Parts in the following Examples and Comparative Examples mean parts by weight, and the analysis was performed by gas chromatography. The reaction rate of isobutylene or tertiary butanol and the selectivity of methacrolein and methacrylic acid to be formed are defined as follows.

Example 1 After adding 42 parts of 60% nitric acid to 400 parts of water to form a uniform solution,
68.7 parts of bismuth nitrate 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. To this mixture was added 165 parts of 28% aqueous ammonia to obtain a white precipitate and a blue solution. This was heated and stirred, and most of the water was evaporated. The obtained slurry was dried at 120 ° C. for 16 hours, heat-treated at 750 ° C. for 2 hours, and pulverized. As a result of X-ray diffraction analysis of this pulverized product,
In addition to nickel oxide, bismuth oxide, antimony oxide and several kinds of metal antimony compounds, several diffraction peaks which are difficult to identify at this stage were recognized.

500 parts of ammonium molybdate, 18.5 parts of ammonium paratungstate and 20.7 parts of cesium nitrate in 1000 parts of water
The mixture was heated and stirred (solution A).

Separately, in water 700 parts, ferric nitrate 190.7 parts, cobalt nitrate 137.
3 parts and 121.0 parts of magnesium nitrate were sequentially added and dissolved (solution B).

After the solution B was added to the solution A to form a slurry, 354.5 parts of a 20% silica sol and the fine powder of the bismuth-nickel-antimony compound were added, and the mixture was heated and stirred to evaporate most of the water. The obtained cake-like substance was dried at 120 ° C. for 16 hours, and then heat-treated at 500 ° C. for 6 hours to be molded. The composition of the catalyst thus obtained is as follows.

Mo ₁₂ W _0.3 Bi _0.6 Fe ₂ Sb _0.7 Ni ₄ Co ₂ Cs _0.45 Mg ₂ Si ₅ O _j The atomic ratio j of oxygen is a value that is naturally determined by the valence of other elements, and will not be described below.

This catalyst was filled in a stainless steel reaction tube, and a raw material mixed gas of 5% isobutylene, 12% oxygen, 10% steam and 73% nitrogen 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 97.0%, the selectivity for methacrolein was 89.0%, and the selectivity for methacrylic acid was 3.1%.

Example 2 After adding 42 parts of 60% nitric acid to 400 parts of water to form a uniform solution,
68.7 parts of bismuth nitrate 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. This was heated and stirred, and most of the water was evaporated. The obtained slurry was dried at 120 ° C. for 16 hours, heat-treated at 800 ° C. for 2 hours, and pulverized.

Otherwise in the same manner as in Example 1, a catalyst having the same composition as in Example 1 was prepared. Using this catalyst, a reaction was performed under the same reaction conditions as in Example 1. As a result, the reaction rate of isobutylene
The selectivity for methacrolein was 98.5%, the selectivity for methacrylic acid was 3.5%.

Example 3 After adding 25 parts of 60% nitric acid to 400 parts of water to make a uniform solution,
34.3 parts of bismuth nitrate was added and dissolved. To this, 137.3 parts of nickel nitrate and 17.2 parts of antimony trioxide were sequentially added to dissolve and disperse. 100 parts of 28% ammonia water was added to this mixed solution, followed by heating and stirring. And then pulverized.

Bismuth, nickel, and antimony, which were insufficient in the catalyst composition of Example 1, were added by the following method, and the final catalyst had the same composition ratio as in Example 1. That is, after adding 100 parts of 60% nitric acid to the solution B of Example 1 to make a uniform solution,
34.3 parts of bismuth nitrate was added and dissolved, and nickel nitrate was added thereto.
137.3 parts were added. Further, 6.9 parts of the remaining antimony trioxide was added after the solution B was added to the solution A. Otherwise in the same manner as in Example 1, a catalyst having the same composition as in Example 1 was prepared.
Using this catalyst, a reaction was carried out under the same reaction conditions as in Example 1. As a result, the isobutylene conversion was 97.0%, methacrolein selectivity was 89.0%, and methacrylic acid selectivity was 3.3%.

Example 4 After adding 50 parts of 60% nitric acid to 400 parts of water to form a uniform solution,
80.1 parts of bismuth nitrate was added and dissolved. Zinc nitrate 7
0.2 part and 26.7 parts of antimony pentoxide were sequentially added and dissolved and dispersed. After 165 parts of 28% ammonia water was added to the mixture, the mixture was heated and stirred to evaporate most of the water. The obtained white slurry was dried at 120 ° C. for 16 hours, heat-treated at 750 ° C. for 6 hours, and pulverized. Otherwise, the following catalyst was prepared according to the method of Example 1.

Mo ₁₂ W _0.5 Bi _0.7 Fe ₂ Sb _0.7 Co ₇ K _0.5 Zn ₁ This catalyst was reacted under the same reaction conditions as in Example 1. As a result, the conversion of isobutylene was 96.0%, the selectivity of methacrolein was 89.0%, and the selectivity of methacrylic acid was 2.7%
It was.

Example 5 After adding 50 parts of 60% nitric acid to 1000 parts of water to make a uniform solution,
80.1% of bismuth nitrate was added and dissolved. 43.1 parts of ammonium paratungstate and 51.6 parts of antimony trioxide
Were added in sequence and heated. 28% ammonia water in this mixture
After adding 165 parts, the mixture was heated and stirred to evaporate most of the water. The obtained white slurry was dried, heat-treated at 800 ° C. for 2 hours, and pulverized. Otherwise, the following catalyst was prepared according to the method of Example 1.

Mo ₁₂ W _0.7 Fe ₂ Sb _1.5 Ni ₇ Rb _0.4 Cr _0.1 Mn _0.4 P _{0.08 Using} this catalyst, a reaction was carried out under the same reaction conditions as in Example 1. As a result, the conversion of isobutylene was 96.0%, the selectivity of methacrolein was 90.0%, and the selectivity of methacrylic acid was 3.6%
It was.

Examples 6 to 12 The following catalysts were prepared according to Example 5.

Example 6: Mo ₁₂ W _0.7 Bi ₁ Fe ₂ Sb _0.8 Ni ₇ Tl _0.4 Cd _0.6 B _0.4 Example 7: Mo ₁₂ W _0.7 Bi ₁ Fe _1.5 Sb _1.5 Ni ₄ Co ₃ Cs _0.3 Tl _0.1 Zn _0.6
Pb _0.4 S _0.2 Example 8: Mo ₁₂ W _0.6 Bi ₂ Fe _1.5 Sb _1.5 Ni ₄ Co ₃ Cs _0.4 Ba _0.4 Cl _0.2 Example 9: Mo ₁₂ W _0.6 Bi ₂ Fe _1.5 Sb _1.5 Co ₇ Cs _0.4 Mg _0.7 Cr _0.1 Se
_0.4 Example 10: Mo ₁₂ W _0.6 Bi ₂ Fe _1.5 Sb _1.5 Co ₇ Tl _0.4 Zn _0.5 Si ₁₀ Ce
_0.5 Example 11: Mo ₁₂ W _0.6 Bi ₂ Fe ₂ Sb _1.5 Co ₇ Rb _0.4 Ba _0.2 Cr _0.1 Si ₁₀
Sn _0.5 Example 12: Mo ₁₂ W _0.6 Bi ₂ Fe ₃ Sb _1.5 Co ₇ Tl _0.4 Mg _0.5 Zn _0.5 Cr
_0.1 Ti _{0.5 Using} these catalysts, a reaction was carried out under the same reaction conditions as in Example 1. Table 1 shows the results.

Examples 13 to 14 The reaction was carried out in the same manner as in Example 1 except for using the catalyst of Example 1 or 4 and changing the starting material to tertiary butanol. Table 2 shows the results.

Comparative Example 1 500 parts of ammonium molybdate, 18.5 parts of ammonium paratungstate and 20.7 parts of cesium nitrate in 1000 parts of water
The mixture was heated and stirred (Solution A).

Separately, after adding 250 parts of 60% nitric acid to 800 parts of water and making it uniform,
68.7 parts of bismuth nitrate was added and dissolved. Ferric nitrate
190.7 parts, nickel nitrate 274.5 parts, cobalt nitrate 137.3 parts and magnesium nitrate 121.0 parts were sequentially added and dissolved (B
liquid).

The solution B was added to the solution A to form a slurry. Then, 354.5 parts of a 20% silica sol and 24.1 parts of antimony trioxide were added, and the mixture was heated and stirred to evaporate most of water. The obtained cake-like substance was dried at 120 ° C., and then heat-treated at 500 ° C. for 6 hours to be molded. The composition of the catalyst thus obtained is represented by the same Mo ₁₂ W _0.3 Bi _0.6 Fe ₂ Sb _0.7 Ni ₄ Co ₂ Cs _0.45 Mg ₂ Si _{5 as} in Example 1.

Using this catalyst, the reaction was carried out under the same reaction conditions as in Example 1 except that the reaction temperature was changed to 360 ° C. As a result, the conversion of isobutylene was 95.0% and the selectivity of methacrolein was 8
8.5% and methacrylic acid selectivity was 3.6%.

Comparative Example 2 The heat treatment temperature of bismuth, nickel and antimony was 65
A catalyst having the same composition as in Example 1 was prepared in the same manner as in Example 1 except that the temperature was 0 ° C. Using this catalyst, raise the reaction temperature
The reaction was carried out under the same reaction conditions as in Example 1 except that the temperature was changed to 360 ° C. As a result, the conversion of isobutylene was 94.0%, the selectivity of methacrolein was 89.0%, and the selectivity of methacrylic acid was 3.
It was 5%.

Comparative Example 3 The heat treatment temperature of bismuth, nickel and antimony was 90
A catalyst having the same composition as in Example 1 was prepared in the same manner as in Example 1 except that the temperature was 0 ° C. Using this catalyst, raise the reaction temperature
The reaction was carried out under the same reaction conditions as in Example 1 except that the temperature was changed to 360 ° C. As a result, the conversion of isobutylene was 92.0%, the selectivity of methacrolein was 89.5%, and the selectivity of methacrylic acid was 3.
It was 5%.

Comparative Example 4 A heat treatment temperature of bismuth and antimony was set to 750 ° C., and nickel was added to the solution B described in Example 1 as nickel nitrate. Using this catalyst, the reaction temperature is 360 ° C
The reaction was carried out under the same reaction conditions as in Example 1 except for the above. As a result, the conversion of isobutylene was 90.0%, the selectivity of methacrolein was 85.0%, and the selectivity of methacrylic acid was 3.9%.

Comparative Example 5 A catalyst having the same composition as in Example 1 was prepared in the same manner as in Example 1 except that the heat treatment temperature of nickel and antimony was set to 750 ° C., and bismuth and nitric acid were added to the solution B described in Example 1. Using this catalyst, the reaction was carried out under the same reaction conditions as in Example 1 except that the reaction temperature was 360 ° C. As a result, the conversion of isobutylene was 92.0% and the selectivity of methacrolein was 8
8.0% and methacrylic acid selectivity was 3.3%.

Comparative Example 6 A heat treatment temperature of bismuth and nickel was set to 750 ° C., and antimony was added after adding B solution to A solution described in Example 1; otherwise, a catalyst having the same composition as in Example 1 was prepared in the same manner as in Example 1. did. Using this catalyst, the reaction was carried out under the same reaction conditions as in Example 1 except that the reaction temperature was 360 ° C. As a result, the conversion of isobutylene was 95.0%, the selectivity of methacrolein was 88.0%, and the selectivity of methacrylic acid was 3.6%.

As shown in Comparative Examples 4 to 6, in the preparation method of the present catalyst system, other components are required in addition to the bismuth component and the antimony component.

Comparative Example 7 A catalyst of Example 5 was prepared according to Comparative Example 1. Using this catalyst, the reaction temperature was changed to 360 ° C.
The reaction was carried out under the same reaction conditions as described above. As a result, the conversion of isobutylene was 96.0%, the selectivity of methacrolein was 88.0%, and the selectivity of methacrylic acid was 3.9%.

Comparative Example 8 In preparing the catalyst of Example 5, a mixture of tungsten, bismuth and antimony was previously heat-treated.
Here, a mixture of only tungsten and bismuth was heat-treated according to the preparation method of Example 5. Therefore, antimony was added after mixing the solution A and the solution B of Example 5, and a catalyst having the same composition as that of Example 5 was prepared. Using this catalyst, the reaction was carried out under the same reaction conditions as in Example 1 except that the reaction temperature was changed to 360 ° C. As a result, the reaction rate of isobutylene was 9
The selectivity was 5.0%, the selectivity for methacrolein was 89.0%, and the selectivity for methacrylic acid was 3.6%.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical indication location C07C 47/22 9049-4H C07C 47/22 A 57/05 2115-4H 57/05 // C07B 61 / 00 300 C07B 61/00 300

Claims (1)

(57) [Claims] 1. A general formula _{Mo a W b Bi c Fe d} Sb e A f X g Y h Z i O j ( wherein Mo, W, Bi, Fe, Sb and O represent molybdenum, tungsten, bismuth, iron , Antimony and oxygen, A is at least one element selected from the group consisting of nickel and cobalt, X is at least one element selected from the group consisting of potassium, rubidium, cesium and thallium, Y is magnesium, zinc , Manganese, cadmium, lead, barium, and at least one element selected from the group consisting of chromium, Z is phosphorus, boron, sulfur, chlorine,
At least one element selected from the group consisting of silica, selenium, cerium, tin and titanium, a, b, c, d,
e, f, g, h, i and j indicate the atomic ratio of each element,
When a = 12, b = 0.01-2, c = 0.01-3, d = 0.5-
5, e = 0.01-3, f = 1-12, g = 0.01-2, h = 0.
01 to 10, i = 0 to 20, and j is the number of oxygen atoms required to satisfy the valence of each component.) In preparing a catalyst having a composition represented by the following components: Bi component, Sb component And D component (here, D component means at least one element selected from the group consisting of the W component, A component and Y component) in advance at a temperature of 700 to 850 ° C. A method for preparing a catalyst for producing methacrolein and methacrylic acid by subjecting isobutylene or tertiary butanol to gas-phase catalytic oxidation using molecular oxygen, comprising using the obtained compound.