DE2159442A1 - PROCESS FOR THE PRODUCTION OF MALEIC ACID ANHYDRIDE AND OR. OR MALE ACID - Google Patents

Description

Badische Anilin- & Soda-Fabrik AG

Our symbols: O-.Z. 27 829 Hee / Fe 6700 Ludwigshafen, November 29th, 1971

Process for the production of maleic anhydride and or

or maleic acid

This invention relates to a new process for the preparation of maleic anhydride and / or maleic acid by oxidation of benzene or straight-chain unsaturated hydrocarbons with 4 carbon atoms with oxygen or ^ - Oxygen-containing gases in the presence of carrier caialyzers.

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German Patent 1,292,649 discloses a process for the preparation of maleic anhydride and / or maleic acid, in which the starting materials mentioned are oxidized in the presence of a catalyst composed of 2 to 20 percent by weight of VpOc, 1 to 20 percent by weight of WO ,, 1 to 25 percent by weight 1 * 2 ^ 5 ^U P ^ ^ ^{0 tis} ^ 5 percent by weight TiO ₂ as a carrier. Here, the TiO _{0 has} an inner surface

from 0.8 to 15 m per gram, when transferring this working method In the large-scale operation there was the disadvantage that with the catalysts, one of which was long Lifetime with consistently high yields is required, the desired high yield is not obtained in continuous operation will.

It has now been found that in the production of maleic anhydride uml or or maleic acid by oxidation of benzene or straight-chain unsaturated aliphatic hydrocarbons having 4 carbon atoms with oxygen or oxygen-containing gases at temperatures of 300 to 500 ⁰ C in the presence of a. Supported catalyst which contains VpO ₁ -, PpO ₁ -, TiOp and optionally WO, and / or MoO, achieves particularly advantageous results if the oxidation is carried out in the presence of a supported catalyst which consists of an inert support and which contains the oxides VpO ₁ - , ^P 2 ° 5 ' ^Ti0 2 and optionally WO, and / or MoO- containing active

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Mass consists in which the JEIOp is made up of a mixture of two Anatas varieties, one of which has an inner upper

area of 8 to 30 ι per g and the other an inner surface

has an area of more than 50 m per g.

The considerable advantage of the new process arises from the fact that the catalyst to be used according to the process maintains a high level of activity even in large-scale continuous operation and delivers high yields.

The starting materials are benzene and olefinically unsaturated straight-chain aliphatic hydrocarbons with 4 carbon atoms suitable, such as butene and eutadiene. Preferably - ^ is a technical butene and / or butadiene-rich

Hydrocarbon mixture of, for example, 10 to 95 wt .- $ Butenes and 1 to 95% by weight of butadiene are used, which is still 1 up to 50% by weight of butane, isobutane and / or isobutene can. The butane and isobutane remain almost unchanged under the reaction conditions; while the isobutene burns. Even considerable amounts of isobutene, for example 10% by weight, do not interfere.

A mixture of oxygen and nitrogen with more than 1 wt .- ^ is expediently used as the oxygen-containing gas Oxygen, preferably air. You can also use pure oxygen work.

The catalyst according to the process of the invention consists of an inert support and the active material. As a carrier material z. B. silicates, pumice stone, alumina, quartz, silica, rutile, silicon carbide, magnesia, zirconium oxide, geroxide, zinc oxide, or manganese oxide into consideration. Porous or non-porous supports can be used. They can be used in the form of balls, rings, pills or strands. The catalytic mass is located on the support, for example in an amount of 5 to 30, preferably 10 to 25 percent by weight, based on the support.

The active material contains the oxides Vo ° 5 '■ ^P 2 ° 5' TiOp and optionally VfO and / or MoO. For example, there is the

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Active mass of 2 Ms 20, preferably 2 to 15 weight percent ^ O ^, 1 Ms 35, preferably 3 to 25 weight percent - ^ ⁰ S '50 Ms 95, preferably 75 Ms 90 weight percent TiO «and 0 to 25, preferably 2 big 25 Weight percent WQ, and / or MoO ,. The TiOp in the active material consists of "90 to 30, in particular SO Ms 20 percent by weight, one

Anatase with an inner surface of 8 to 30 m per g,

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preferably 8 to 25 m per g, and 10 to 70, in particular 20 to 80 percent by weight from an anatase with an internal one

Surface of more than 30 m per g, - preferential prices of more

than 30 to 150 m per g. Sound is of particular advantage to that to choose both types of anatas in such a way that the difference

2 ren surfaces of both types in the mixture 20 to 100 m per g.

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The PpOc content is conveniently set so that z. B. half to twice the amount of PpOc, based on WO, weight, used when benzene is to be oxidized. Pure the Oxidation of the aliphatic compounds is chosen, for. B. a catalyst with the same to ten times the amount of PpOf, based on 'WO, weight. ■

The catalyst is prepared in a customary manner, for example by advantageously adding V-, W-, Mo- and P-containing compounds which convert into VpOp., WO, MoO, and P ₂ ⁰ C on heating, or their oxides mixed as a solution or slurry in water or a solvent, with the two Anatassorten to a suspension, the suspensions ■ board in the zweckmäsig preheated to 250 to 450 ⁰ C: applying carrier and the so coated support at temperatures from 300 to 500 ⁰ G grumbles. As solvents are, for. B. amides of low molecular weight acids such as formamide, molten urea or thiourea or amines such as ethanolamine are suitable. You can also apply the mixture to be applied to the carrier, for. B. add up to 30 percent by weight, based on the mixture, below 600 ⁰ C combustible solid organic substances such as sawdust, ¥ eizengries or starch with a grain size of up to about 2 mm. · '

-Suitable compounds containing vanadium, tungsten and phosphorus

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are for example: ammonium vanadate, vanadium (IY) oxalate, -formiate, -acetate, -tartrate, -salicylate or other organic Complex compounds of "vanadium, tungstic acid, Phosphotungstic acid or especially solutions of tungstic acid in amines, such as ethanolamine, methylamine, diethylamine, Trimethylamine, piperidine, optionally with the addition of water; Phosphoric acid, phosphorous acid, ammonium dihydrogen phosphate or esters of phosphoric acid or phosphorous acid.

The process for the production of maleic anhydride or .. the maleic acid is expediently known per se Way carried out in a tube bundle furnace. The pipes this furnace have a clear width of preferably 25 to 40 mm. With the catalyst filling there are balls with a ■

W ^; Diameters of 4 to 12 mm are well suited. Spherical catalytic converters * whose diameter is about a third of the inside diameter of the pipe are particularly advantageous. The pipes filled with catalyst are surrounded by a molten salt as a coolant. The melt is generally maintained at temperatures of 360-400 ⁰ C. The course of the reaction takes place at temperatures from 400 to 500 ⁰ O, measured at the hot spot. In some cases it is appropriate to low during the oxidation quantities to give as 0.1 to 200 parts per 1 million parts of the gas mixture ¹ of a volatile inorganic or organic phosphorus compound to the reaction mixture. The catalyst used according to the invention can with

a 2,000 to 4,000 liters of air and 40 g of hydrocarbons or more depending on whether air is polluted per hour without its activity in large-scale operations declining. The opposite known Catalysts increased activity can be z. B. can be recognized by the fact that one is using significantly lower salt bath temperatures get by, achieve higher yields and achieve a longer life of the catalyst.

example 1

A mixture of the following components: · · 1. 63 g of an aqueous solution containing 16 wt .- ^ ^ 2% as vanadium oxalate contains; .

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2. a solution of 20 g of ammonium dihydrogen phosphate in 300 ml. Water;

3. a solution of 15 g of tungstic acid in 7 g of ethanolamine and 7 ml of water;

4. "100 g of powdered anatase with an inner surface area of 11.2 m ² / g;

5. 100 g of powdered anatase with an internal surface area of 87.2 m ² / g;

6. 100 ml formamide and 200 ml water. ".

is mixed intimately. The mixture is in a coating drum at 300 ⁰ C heated steatite spheres having a diameter of 5,4 now sprayed. Coating is carried out until the applied catalytic mass is 17.5% by weight of the coated spheres.

The treated beads are then gemuffelt 12 hours at 450 ⁰ C. The mass located on the carrier consists of: 84.7 wt .- $ TiO
5.9 Gevr.-fo WO ,.

84.7 wt. $ TiO ₂ -, 4.2 wt. Φ V ₂ ° 5 ' ⁵ ' ^{2 wt} . "^ ^P 2 ° 5 ^and

600 ml of catalyst are poured into a 1.2 m long tube with a clearance of 25. The pipe is from one Surrounding molten salt which is set to 412 0.

4000 liters of air and ISO g of benzene are passed over the 'catalyst every hour. 18% by weight of the benzene are not converted and are recycled. The remaining benzene content is converted to 96% by weight in maleic anhydride.

Example 2

267 g of a ground anatase with an internal surface area of 11 m ~ / g ^mic * '53 Q anatase with an internal surface area of 85 m / g are mixed and mixed with 92 g of an 85% strength by weight phosphoric acid, 34.8 g of nadyl oxalate (corresponds to 45 % vauadine pentoxide), 100 g formamide, 800 g water and 50 g wheat starch are added. The suspension is stirred vigorously and ram in a Dragier drum 1 200 g of steatite balls having a diameter of 5.4 - which have been previously heated to 300 ⁰ O plotted. The catalyst is 12 hours at 450 0 ge

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grumbles. The supported catalyst contains 19.2 percent by weight of active material. The active mass consists of 87.7 3ev /.-# anatase, 12 G-ew.-U P ₂ ⁰ 5 ^and ^ '^ weight-vS T ₂ Q ₁ -.

A 2 m long tube with a clear text of 25 mm is filled with 750 ecm of catalyst. Jas tube is surrounded by a salt melt which is heated to 380 ⁰ C. Every hour, 2,500 liters of air and 54 g of an Oy mixture containing 67.5% by weight of utilizable fractions, such as 1utene-1, 2-butene and butadiene, are passed over the catalyst.

During the reaction, 200 mg of triisobutyl phosphate are continuously added added to the starting material per hour.

Uach a throughput of 13,000 g of the C. mixture with 8,670 g of usable fractions are formed, 8,100 g of maleic anhydride. That's 92.6

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Claims (1)

Claims . Process for the production of maleic anhydride and / or maleic acid by oxidation of benzene or straight-chain unsaturated aliphatic hydrocarbons with 4 carbon atoms with oxygen or oxygen-containing gases at temperatures from 300 to 500 ⁰ G in the presence of a supported catalyst, the VpO ₁ -, PpO, -j TiOp and optionally WO ™ and / or MoOi 'contains', characterized in that the oxidation is carried out in the presence of a supported catalyst which consists of an inert support and which contains the oxides V ₂ Oc, ^P 2 ° 5 » ^Ti0 2 ^and S ^e g ^etenenia H ^s WO, and / or MoO, containing active material, in which the TiO ₉ consists of a mixture of two types of anatase, 2 of which one has an inside surface of 8 to 30 m ^ e g.'unct di§ other-an inner surface of more than 2 ■ ■ 30 m per g. Q / j.Verfahren according to claim 1, characterized in that a supported catalyst is used, the TiOp content of two types of anatase, or the inner upper areas differ from one another by 20 to 100 m per g Badische Anilin- & Soda-Fabrik AG INSPECTED. 309823/0998 ■ '- / ■'