JPS5939413B2 - Method for producing methacrolein and methacrylic acid - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing methacrolein and methacrylic acid from tertiary butyl alcohol or isobutene by a gas phase catalytic oxidation method.

Regarding the method for producing methacrolein and methacrylic acid from tertiary butyl alcohol, the present inventors previously reported that PW
A method using a MoTesb-based catalyst was proposed (Japanese Patent Application No. 96948/1983).

Although the reaction performance of the catalyst shown therein was very good, and the single-stream yield of methacrolein and methacrylic acid reached as much as 80 mol%, it had the drawback that the reaction temperature was relatively high. High reaction temperatures not only shorten the life of the catalyst, but also
Since it is also unfavorable in terms of reaction operation, it is advantageous to keep it as low as possible. As a result of intensive studies on increasing the activity of the above catalyst, the present inventors discovered that by adding magnesium, manganese and/or talc to the above catalyst,
A new fact was discovered that the reaction temperature can be lowered and the yields of methacrolein and methacrylic acid can also be improved.

Furthermore, this catalyst is also effective in the oxidation reaction of isobutene.
The present invention was achieved by discovering that methacrolein and methacrylic acid can be produced in high yield. That is, the method of the present invention uses a mixed gas containing tertiary butyl alcohol or isobutene and oxygen with the general formula PawbMOOTedSbOSnf.
AgBhCiDjOk [However, in the formula, P, . W,. MO,
．． Te,. Sb,. Sn and O represent phosphorus, tungsten, tellurium, antimony tin, and oxygen, respectively. seeds or (d) three combinations of nickel, iron and bismuth, B is potassium, rubidium and (
or) cesium, C hails magnesium and/or manganese, and D hails talc.

In addition, A. b. c. d. e. f. g, H. i and k
indicates the number of atoms of each element, and when b+c=1, Asd and e are numbers less than or equal to 1 not including o, and f is O
-1 range, g is 0.01-2 for each element in total, 0.02-1 for each metal, h is 0-0.6, b
The ratio between and c is 0.01 to 100. k is a value naturally determined from the standard valence of existing metal oxides, and i is O~
6 and when j=0, i is 0.01 or more. j represents the weight percentage in the total weight of the catalyst, O ~ 50% by weight
When i=0, j is 1% by weight or less. ]
This is a method for producing methacrolein and methacrylic acid, which is characterized by contacting the catalyst in a high temperature gas phase. Magnesium or manganese in the catalyst used in the present invention has the effect of improving the yield of the target product and lowering the reaction temperature, and can further extend the life of the catalyst.

Furthermore, unlike carriers such as silica gel and silica alumina, talc has an effect similar to that of magnesium or manganese. There are no particular restrictions on the state of the catalyst used in the present invention; for example, it may be a mixture of phosphorus and each metal element, or it may be an oxide of these elements combined in some way. .

The catalyst used in the present invention can also be used with well known supports such as silica gel, silica alumina, corundum, silicon carbide and the like.

In preparing the catalyst, conventionally known catalyst preparation methods can be used relatively freely, and no special means are required. One example of the preparation method is a method in which an aqueous solution or suspension of the catalyst raw material is evaporated to dryness and then calcined in air.

The catalyst raw material is preferably a metal, its oxide, chloride, or a compound that becomes an oxide when ignited, such as an acid, an ammonium salt, or a nitrate.

It is also possible to use raw materials in which phosphorus and metal elements are chemically combined, such as ammonium phosphomolybdate and tin molybdate. Calcination of catalyst is 250-700℃,
Preferably it is carried out at 350 to 600°C. The reaction can be carried out in any suitable manner, such as a fixed bed method or a fluidized bed method.

The concentrations of tertiary butyl alcohol or isobutene and oxygen in the feed gas can each be varied over a wide range of about 1 to 20% by volume.

For diluting tertiary butyl alcohol, isobutene, and oxygen, nitrogen carbon dioxide, water vapor, or a mixture thereof can be used as a diluent, for example.

The reaction temperature is preferably 200 to 500°C, particularly 250 to 400°C, and the contact time is preferably 0.5 to 10 seconds.

EXAMPLES The content of the present invention will be specifically explained below with reference to Examples and Comparative Examples.

Note that parts are parts by weight, and the single flow yield (%) of methacrolein and methacrylic acid is defined as follows.

Example 1 2.25 parts of ammonium paratungstate was dissolved in 50 parts of water, and 35 parts of ammonium paramolybdate was dissolved in the solution.
．． A solution of 3 parts dissolved in 200 parts of water was added, 100 parts of silicon carbide and 4.9 parts of antimony oxide were added, and further 20.2 parts of ferric nitrate and 4 parts of nickel nitrate were added.
A mixed solution of 3.7 parts of magnesium nitrate and 5.1 parts of magnesium nitrate dissolved in 500 parts of water and a solution of 0.257 parts of potassium nitrate and 0.5 parts of cesium nitrate dissolved in 10 parts of water were added, and then nitric acid A solution of 16.2 parts of bismuth dissolved in 50 parts of 10% nitric acid and 3.8 parts of stannous chloride in 50 parts of water
85% phosphoric acid (0.95%)
part was added.

This mixture was evaporated to dryness by ε heating while stirring, and then calcined at 500° C. for 5 hours under air circulation. 5.35 parts of tellurium dioxide was added to the calcined product, and after stirring well, it was molded into a catalyst. The composition ratio of this catalyst was in atomic ratio.

A mixed gas with a composition of 5% tertiary butyl alcohol, 12% oxygen, 30% water vapor, and 53% nitrogen by volume was heated at 350°C.
was introduced into a catalyst layer maintained at a temperature of 3.5 seconds, and the reaction was carried out for a contact time of 3.6 seconds.

As a result of analyzing the produced gas using gas chromatography, the total single flow yield of methacrolein and methacrylic acid was 85.
．． It was 6%. Comparative Example 1 A catalyst was prepared that differed from Example 1 in that no magnesium nitrate was added, and the reaction was carried out in the same manner as in Example 1, except that the reaction temperature was 370°C.

The total single stream yield of methacrolein and methacrylic acid was 84.
It was 2%. Example 2 27.0 parts of ammonium paratungstate and 600 parts of water
A solution of 35.3 parts of ammonium paramolybdate dissolved in 200 parts of water and 13.5 parts of ferric nitrate and 4.9 parts of nickel nitrate were added. Then, a mixed solution of 3.9 parts of magnesium nitrate dissolved in 100 parts of water was added, and then a solution of 32.3 parts of bismuth nitrate dissolved in 150 parts of 10% nitric acid and 1.54 parts of potassium nitrate were added to 20 parts of water. The dissolved solution and 3.8 parts of 85% phosphoric acid were added.

This mixture was heated and evaporated to dryness while stirring, and then calcined at 500° C. for 5 hours under air circulation. 5.6 parts of tellurium dioxide was added to this calcined product, mixed well, and then molded.
The composition of this molded article was in atomic ratio.

Using this as a catalyst, the temperature of the catalyst layer was set to 335°C,
Other conditions were the same as in Example 1. As a result, the total single flow yield of methacrolein and methacrylic acid was 79.3.
It was %. Comparative Example 2 A different catalyst was prepared in Example 2 except that magnesium nitrate was not added, and the reaction was carried out in the same manner as in Example 1 except that the reaction temperature was 350°C.

Total single stream yield of methacrolein and methacrylic acid is 76%
It was hot. Example 3 4.5 parts of ammonium paratungstate was dissolved in 100 parts of water, 100 parts of silicon carbide and 4.9 parts of antimony oxide were added thereto, and further 35.3 parts of ammonium paramolybdate was dissolved in 200 parts of water. A mixed solution of 4.8 parts of cobalt nitrate, 19.4 parts of nickel nitrate, and 6.2 parts of manganese nitrate dissolved in 100 parts of water, 0.6 parts of rubidium chloride, and 1.0 parts of cesium nitrate. A solution of 8.1 parts of bismuth nitrate dissolved in 60 parts of 10% nitric acid was added, followed by a solution of 8.1 parts of bismuth nitrate dissolved in 60 parts of 10% nitric acid.
% phosphoric acid was added, 2.5 parts of stannic oxide and 0.8 parts of tellurium dioxide were added, and the mixture was heated and evaporated to dryness with stirring, dried at 130°C for 16 hours, and then molded. The mixture was calcined at 500°C for 5 hours under air circulation to obtain a catalyst.

The composition of this catalyst was in atomic ratios.

The temperature of the catalyst layer was set at 345° C. and the reaction was carried out under the same conditions as in Example 1. As a result, the total single-stream yield of methacrolein and methacrylic acid was 84.0%.

Comparative Example 3 A catalyst was prepared that differed from Example 3 in that no manganese nitrate was added, and the reaction was carried out in the same manner as in Example 1, except that the reaction temperature was 370°C.

The total single stream yield of methacrolein and methacrylic acid was 82.
It was 5%. Example 4 38.5 parts of ammonium paratungstate and 600 parts of water
7. parts of antimony oxide and dissolved in boiling water.
A solution of 35.3 parts of ammonium paramolybdate dissolved in 200 parts of water, 33.7 parts of ferric nitrate, and 8.0 parts of nickel nitrate were added.
A mixture of 3 parts of magnesium nitrate, 4.4 parts of magnesium nitrate, and 9.9 parts of manganese nitrate dissolved in 200 parts of water, and 0.257 parts of potassium nitrate, 0.3 parts of rubidium nitrate, and 0.5 parts of cesium nitrate were dissolved in water. Add a solution dissolved in 10 parts,
Next, 6.6 parts of 85% phosphoric acid are added, and finally a solution of 7.5 parts of stannous chloride dissolved in 100 parts of water is added, and the mixture is heated and evaporated to dryness while stirring.

Then, it was fired at 500°C for 5 hours under air circulation, and 6.8 parts of tellurium dioxide was added to this fired product and mixed well.
It was molded and used as a catalyst. The composition of this catalyst was in atomic ratios.

The temperature of the catalyst layer was 330°C, and the other conditions were as in Example 1.
As a result of the reaction in the same manner as above, a total single-stream yield of methacrolein and methacrylic acid of 84.5% was obtained. Comparative Example 4 A catalyst was prepared that differed from Example 4 in that magnesium nitrate and manganese nitrate were not added, and the catalyst was reacted in the same manner as in Example 1 except that the reaction temperature was 360°C.

The total single stream yield of methacrolein and methacrylic acid was 83.
It was 0%. Example 5 Add 38.5 parts of ammonium paratungstate to 600 parts of water, boil and dissolve, add 100 parts of silicon carbide and 0.69 parts of antimony oxide, and further add 5 parts of ammonium paramolybdate. A mixed solution of 27 parts of cobalt nitrate and 2.8 parts of nickel nitrate dissolved in 100 parts of water, and a solution of 0.23 parts of cesium nitrate dissolved in 10 parts of water were added. , then 85% phosphoric acid 5.0
A solution of 1.58 parts of stannous chloride dissolved in 50 parts of water was added, and finally 12.0 parts of talc was dissolved in 50 parts of water.
The suspension was added to the suspension and heated and evaporated to dryness while stirring.

Then, it was calcined at 500° C. for 5 hours under air circulation, and 4.1 parts of tellurium dioxide was added to the calcined product, mixed well, and then molded and used as a catalyst. The composition of this catalyst was in atomic ratios.

The temperature of the catalyst layer was 330°C, and the other conditions were as in Example 1.
As a result of the reaction in the same manner as above, a total single-stream yield of methacrolein and methacrylic acid of 82.2% was obtained.

Comparative Example 5 A catalyst different from Example 5 except that talc was not added was prepared, and the reaction was carried out in the same manner as in Example 1 except that the reaction temperature was 350°C.

The total single stream yield of methacrolein and methacrylic acid was 80.
It was 6%. Example 6 In Example 5, nickel nitrate was followed by manganese nitrate8.
Talc 6.0 after addition of 6 parts and addition of stannous chloride
A catalyst was prepared with the only difference that 1 part suspended in 25 parts of water was added, the reaction temperature was 325°C, and the other conditions were the same as in Example 1. As a result, the reaction was carried out in the same manner as in Example 1. The total single stream yield was 82.9%.

Example 7 5% isobutene, 12% oxygen, 30% water vapor and 53% nitrogen by volume using the catalyst prepared in Example 1.
A raw material mixed gas having the composition was introduced into the catalyst layer maintained at 350°C, and reacted for a contact time of 3.6 seconds.

As a result of analyzing the produced gas by gas chromatography and chemical analysis, the total single flow yield of methacrolein and methacrylic acid was 81.7%. Example 8 Using the catalyst prepared in Example 2, the reaction was carried out under the same conditions as in Example 7 except that the reaction temperature was 335°C. As a result, a total single flow yield of methacrolein and methacrylic acid of 75.0% was obtained. Ta.

Example 9 The reaction was carried out under the same conditions as in Example 7, except that the catalyst prepared in Example 6 was used and the reaction temperature was 325°C. As a result, a total single flow yield of methacrolein and methacrylic acid of 78.7% was obtained. Ta.

Example 10 A catalyst was prepared in Example 5 except that silicon carbide was not added, and the reaction temperature was 320°C.
The reaction was carried out under the same conditions as in Example 1 except for the following conditions.

The total single stream yield of methacrolein and methacrylic acid was 82.
It was 6%. This result shows that silicon carbide, unlike talc, has almost no effect on the reaction performance itself. Example 11 A catalyst was prepared in Example 5 except that 50 parts of alumina powder was added instead of silicon carbide, the reaction temperature was 335°C, and the other conditions were the same as in Example 1. .

The total single stream yield of methacrolein and methacrylic acid was 82.
It was 3%. Comparative Example 6 A catalyst was prepared in Example 5 except that 50 parts of alumina powder was added instead of talc and silicon carbide, the reaction temperature was 355°C, and the other conditions were the same as in Example 1. Made it react.

The total single stream yield of methacrolein and methacrylic acid was 80.
It was 1%.

Claims (1)

[Scope of Claims] 1. A method for producing methacrolein and methacrylic acid, which comprises bringing a mixed gas containing tertiary butyl alcohol or isobutene and oxygen into contact with a catalyst having the following composition in a high-temperature gas phase. P_aW_bMo_cTe_dSb_eSn_fA_g
B_hC_iD_jO_k However, in the formula, P, W, Mo, Te
, Sb, Sn and O are phosphorus, tungsten,
Represents molybdenum, tellurium, antimony, tin and oxygen, A is (a) two types of nickel and cobalt, (b)
Two types: nickel and iron, (c) three types: nickel, cobalt, and bismuth, or (d) three types: nickel, iron, and bismuth.
Represents a combination of species, B represents potassium, rubidium and/or cesium, C represents magnesium and/or manganese, and D represents talc. Also, in the formula a, b, c, d, e, f, g, h, i and k
indicates the number of atoms of each element, and when b+c=1, a, d, and e are numbers less than or equal to 1, not including 0, and f is 0 to
1 range, g is 0.08 to 2 in total for each element, 0.02 to 1 range for each metal, h is 0 to 0.6, b and c
The ratio is 0.01 to 100, k is a value naturally determined from the standard valence of existing metal oxides, and i is in the range of 0 to 6, and when j = 0, i is 0.01 or more. . j represents the weight percentage based on the total weight of the catalyst, and is in the range of 0 to 50% by weight, and when i=0, j is 1% by weight or more.