JPS5923854B2 - Catalyst for the oxidation of benzene to maleic anhydride - Google Patents

Description

[Detailed description of the invention] This invention relates to basic organic synthesis.

More specifically, the present invention relates to a catalyst suitable for the oxidation of benzene to maleic anhydride. Maleic anhydride is one of the most important products derived from organic synthesis, and is used in polymeric substances and coatings, plant protection compositions, paper manufacturing chemicals, food industry chemicals, wood processing chemicals, It is useful in the production of chemical products for oil modification.

Currently, the world market accounts for about 80% of the total production of maleic anhydride.
~90% is obtained by oxidation of benzene.

V, sMo. ．． B. ．． P. A number of catalysts are known in the art for the oxidation of benzene to maleic anhydride, including respective oxides of sNa (see GB 1371652).

This composition includes Co. ．． Nl1 or Fe may be added (US Pat. Nos. 3,759,840 and 3,867,412, British Patent No. 1,371,653, French Patent No. 21,084).
94), similarly Mn1SnW or Bl
may be added (U.S. Pat. No. 3,838,067, No. 3).
(See each specification of No. 947474). Such a mixture of active components is deposited on a non-porous solid support.

Fused alumina, silica and similar materials can be used as supports by pretreating them with an acid such as hydrochloric acid. The oxidation of benzene using these catalysts is 370-3
It is carried out in a temperature range of 90°C. The production rate of such catalysts does not exceed 1009/l of catalyst per hour, the conversion of benzene is 98-99% and the yield of maleic anhydride is less than 75 mol%. However, these catalysts have insufficient selectivity and productivity.

The carrier pretreated with hydrochloric acid was treated with vanadium, molybdenum,
phosphorus, nickel and sodium compounds, and O.
A rare earth element (REE) in an amount of 01 to 0.1 mol%
Catalysts for the gas phase oxidation of benzene to maleic anhydride are known (see USSR Inventor's Certificate No. 333,793), prepared by impregnation with a solution of an active ingredient containing a compound of

The conversion of benzene achieved using this catalyst is 98
At ~99%, the selection range reaches 93% by weight (74% by mole) and the production rate is equal to 55 to 1009 per liter of catalyst per hour.
This catalyst exhibits poor selectivity and productivity.

The present invention provides a method which exhibits higher selectivity and productivity by selecting the appropriate metal compound as the active part.
The purpose is to provide a catalyst for the oxidation of benzene to maleic anhydride. It is therefore an object of the present invention to increase the selection and production of such catalysts. The purpose is to provide a catalyst for the vapor phase oxidation of benzene to maleic anhydride, which contains oxides of vanadium, molybdenum, phosphorus, nickel, sodium and rare earth elements supported on a support, containing rubidium oxide. is achieved by having each of these components present in the catalyst composition in proportions by weight.

The catalyst is 0.1~O. It is preferred to contain boron oxide in an amount of 45% by weight. Incorporation of boron and rubidium additives into the active part of the catalyst can increase the yield of maleic anhydride up to 80 mol % and the productivity of the catalyst up to 120 g/l per hour.

This catalyst is manufactured as follows.

Ammonium molbdate is added to a furnace-type reaction vessel containing concentrated hydrochloric acid.

It melts at a temperature of 60°C. After the completion of its dissolution ammonium metavanadate was gradually added thereto and
Melt at a temperature of °C. After that, sodium phosphate, sodium tetraborate, nickel nitrate, rare earth elements (R
EE) and rubidium are added in succession, and then the hydrochloric acid pretreated support is added to the reactants. The resulting catalyst is activated in its reaction vessel for 50 hours, after which the oxidation of benzene is carried out at a temperature of 370 DEG to 400 DEG C. and a benzene concentration of 37 to 41 g/Nm@3 in the benzene-air mixture.

The selection range for this catalyst is 98-100% by weight (78-80% by mole). Its productivity is 120g per liter of catalyst per hour.
It is. Example 1 A 4409 carrier, corundum (irregularly shaped particles with a diameter of 4-6 mm), is fed to a reaction vessel and treated with concentrated hydrochloric acid.

This treated carrier was taken out from the reaction vessel and 435 ml
of concentrated hydrochloric acid was added to the reaction vessel, and 30.
Add 29 ammonium molybdate. Heat the solution to 60°C. After the ammonium molybdate has completely dissolved, 48.39 ammonium metavanadate is gradually introduced into the reaction vessel with stirring. Next, a sodium phosphate solution (4.359 of this salt dissolved in 10 ml of distilled water) was added to the reaction vessel and stirred.
Sodium tetraborate (25 m of this salt of 3.299
1 of distilled water) is added thereto. After stirring, nickel nitrate solution (2.54 g of this salt dissolved in 10 ml of distilled water) was added to the reaction mixture, stirred, and praseodymium nitrate solution (0.00389 of this salt dissolved in 10 ml of distilled water) was added to the reaction mixture. and a rubidium nitrate solution (0.001 g of this salt dissolved in 5 ml of distilled water) are added. Once these salts are completely dissolved, the 4409 carrier pretreated with hydrochloric acid is placed in the reaction vessel and impregnated at a temperature of 80-90°C. After 3 hours of impregnation, the catalyst body is stirred and then calcined at a temperature of 80-400'C.

The resulting catalyst has the following characteristics: bulk weight 1.6-1.7
ky/dm3: particle size 4-6 mm; specific surface area 1.5-2.
5 m"/g. This catalyst has the following composition in weight percent: Speed 2700
~169/Nm3 to 419/Nm3 at 2900/hr
It becomes active at 360-3800C while gradually increasing to .

Oxidation of benzene to maleic anhydride at 370-390°C
and a benzene concentration in the benzene-air mixture of 37-419/Nm3. Under these conditions, the conversion of benzene is equal to 98-99%, depending on the process selection (
The yield of maleic anhydride calculated on the raw material is 10
0% by weight (80% by mole). Production notes are per hour, catalyst 1
It is 120g per liter. Example 2 A catalyst is prepared according to the method described in Example 1 above.

The following amounts of starting products are used for the preparation of the catalyst: 47
．． 29 ammonium metavanadate; 30.7 fl ammonium molybdate; 5.039 nickel nitrate; 10.739 tri-monosubstituted sodium phosphate; 0. O9
96 g praseodymium nitrate and 0.01009 rubidium nitrate. This catalyst has the following composition in weight percent: ν no'f/ru~noha Benzene oxidation under the conditions of Example 1 using a catalyst of the above composition results in 93% by weight (75,0 mol%). Maleic anhydride is produced in a yield of .

The productivity of the catalyst is 1089 per liter of catalyst per hour.
Example 3 A catalyst is prepared according to the method described in Example 1.

The following amounts of each component are used in the preparation of this catalyst: 42.0
9 ammonium vanadate; 33.19 ammonium molyfdate; 2.69 g nickel nitrate; 7.31
fl 3-monosubstituted sodium phosphate: 0.03319 cerium nitrate; 0.0005 g rubidium nitrate; and 5.
549 sodium tetraborate. This catalyst has the following composition in % by weight: The yield of maleic anhydride with this catalyst is 98% by weight (77.7 mol%), the production rate is 1179 per liter of catalyst per hour.

Example 4 The catalyst is prepared according to the method of Example 1.

The following amounts of feedstock components for the preparation of this catalyst are used: 43.
6g ammonium metavanadate: 29.69 ammonium molybdate; 2.079 nickel nitrate; 1
4.769 3-substituted sodium phosphate; 0.0124
9 praseodymium nitrate; 0.01119 rubidium nitrate; 8.869 sodium tetraborate. The catalyst obtained has the following composition in weight percent: Using this catalyst composition, when benzene is oxidized under the conditions of Example 1, maleic anhydride is converted to 9
Produced with a yield of 9.5% by weight (79% by mole), the production rate of this catalyst is 1159/11 catalyst/hour.

Example 5 The catalyst is prepared according to the method described in Example 1.

The following amounts of starting components are used for the preparation of this catalyst:
36.79 ammonium metavanadate; 32.6g
ammonium molybdate; 14.409 tri-monosubstituted sodium phosphate; 7.739 nickel nitrate; 0.0
1119 rubidium nitrate; 0.00129 praseodymium nitrate and 9.119 sodium tetraborate. The catalyst obtained has the following composition in % by weight: maleic anhydride with a yield of 99% by weight (78.7 mol%) by the oxidation of benzene under the conditions of Example 1 carried out with this catalyst. is manufactured.

The production rate is 118 g per 11 catalysts per hour. Example 6 A catalyst is prepared by the method of Example 1.

The following amounts of feedstock components are used for the preparation of this catalyst: 48
．． 69 ammonium metavanadate; 32.7 g ammonium molybdate; 3.60 f! 3-monosubstituted sodium phosphate: 0.529 nickel nitrate; 4.939
of sodium tetraborate; 0.005619 of rubidium nitrate and 0.3169 of praseodymium nitrate. The resulting catalyst has the following composition in weight percent: the yield of maleic anhydride (this step is carried out under the conditions of Example 1) is 97.8
% by weight (77.0 mol %) and its production rate is 1169 per 11 catalysts per hour.

Example 7 (comparative example) Oxidation of benzene with V2O, :52.

5, MOO3: 37.0, NlO: 5.68, P2O5
: 1.08, Na2O: 3.65, Pr2O3: 0.9
The catalyst described in USSR Inventor's Certificate No. 333793, which has an active part composition of (all percentages by weight) and uses corundum pretreated with hydrochloric acid as a carrier, is used.

The oxidation temperature is 390°C. The conversion rate of benzene on this catalyst is 98-99% and the yield of maleic anhydride is 74%.
and its production capacity is at least 559 per 11 catalysts per hour.
It is. Example 8 (Comparative Example) A catalyst is prepared according to the method described in Example 1.

The following amounts of each starting component are used in the preparation of the catalyst: 26
．． 24g ammonium metavanadate; 23.06g
of ammonium molybdate; 6.74 g of nickel nitrate; 11.39 g of trisubstituted sodium phosphate; 0.10
26 g of braceodymium nitrate; 0.0104 g of rubidium nitrate and 6.21 g of sodium tetraborate. This catalyst has the following composition in weight percent: When the oxidation of benzene is carried out under the conditions of Example 1, this catalyst serves to make maleic anhydride with a yield of 74.3 mole percent.

The productivity is 95.5 g per 11 catalysts per hour. Example 9 (
Comparative Example) A catalyst is prepared according to the method described in Example 1.

The following amounts of each starting component are used in the preparation of the catalyst: 19
．． 09g ammonium metavanadate: 18.82g
ammonium molybdate; 0.327 g nickel nitrate; 1.059 g trisubstituted sodium phosphate 0.00
061 g Braseodymium Nitrate: 0.00031 g Rubidium Nitrate and 1.15 g Sodium Tetraborate.
This catalyst has the following composition in weight percent: When the oxidation of benzene is carried out under the conditions of Example 1 on this catalyst, maleic anhydride is produced in a yield of 75.2 mol %, 105.5 g per 11 catalyst hours. Obtained through sex.

As is clear from the comparison of Examples 1-6 with Examples 8-9 above, the yield of maleic anhydride (selective sex)
However, when the various components of the catalyst are present in amounts outside the specific ranges of the present invention, the yield (selectivity) and productivity of maleic anhydride decrease.

Claims (1)

[Scope of Claims] 1. A catalyst for gas phase oxidation of benzene to maleic anhydride, comprising oxides of vanadium, molybdenum, phosphorus, nickel, sodium and rare earth elements supported on a carrier, comprising: rubidium oxide; Catalyst as defined above, characterized in that each of these components is present in a proportion by weight. 2 Vanadium, molybdenum, phosphorus supported on a carrier,
A catalyst for the gas phase oxidation of benzene to maleic anhydride, containing oxides of each of nickel, sodium and rare earth elements, containing rubidium oxide and boron oxide, each of which components being present in weight percent. The above-mentioned catalyst is characterized in that: