DE1136685B - Process for the oxidation of olefins with 3 or more carbon atoms to aldehydes and ketones - Google Patents

Description

The subject of some patents corresponding to Belgian patent specification 569 038 are processes according to which ethylene or other olefins such as propylene, butylene, isobutylene and pentene with oxygen or Oxygen-containing gases in acidic to neutral medium in the presence of water and redox systems and noble metals or noble metal compounds which form complexes with olefins to the corresponding Aldehydes, ketones and acids are oxidized.

If the method of operation of the above-mentioned patents is applied to olefins containing 3 or more carbon atoms, so z. B. propylene, butene and pentene, one obtains almost exclusively ketones (see also Angewandte Chemie, 1959, Vol. 71, p. 179). So you get z. B. in the oxidation of propylene to 200 parts acetone formed only a part of propionaldehyde, and in the oxidation of butene-1 is also formed only about 0.5% butyraldehyde, based on the methyl ethyl ketone formed. With a freshly inserted In the first 2 to 3 hours of contact, the amount of aldehyde formed is greater and decreases but then to the values given above as an example.

It has now been found that the amount of aldehyde formed in comparison to the ketone is substantial can increase if you work with catalysts that are more than 0.25, especially more than about 0.5 mol of noble metal salts, preferably palladium chloride, in addition to salts, preferably halides, contain metals that can form several stable valence levels per liter of contact. This is all the more surprising as when changing the amount of precious metal salts, e.g. B. on palladium chloride, otherwise within wide ranges, e.g. B. between 0.1 and 20 g per liter of contact, practical no shift in the ketone / aldehyde ratio was observed.

The amounts of noble metal salts to be used according to the invention should be over 0.25 mol, that is, for. B. 45 g of PdCl ₈ , per liter of catalyst and preferably above 0.5MoI, which corresponds to about 90 g of PdCl ₂ , per liter of contact. In the case of liquid contacts, the upper limit is given by the solubility of the noble metal compound at the working temperature used. When using very large amounts of noble metal salts, however, the ratio of aldehyde to ketone can occasionally worsen again slightly compared to the optimal values. The catalysts must still contain redox compounds, such as copper or iron salts, as protected in the patents mentioned at the beginning. The process for the oxidation of olefins
with 3 and. more carbon atoms
to aldehydes and ketones

Applicant:

Farbwerke Hoechst Aktiengesellschaft

formerly Master Lucius & Brüning,

Frankfurt / M., Brüningstr. 45

Dr. Wilhelm Riemenschneider,

Frankfurt / M.-Unteriliederbach,

Dr. Walter Schmidt, Frankfurt / M.-Höchst,

and Dr. Lothar Hörnig,

Frankfurt / M.-Unterliederbach,

have been named as inventors

Aldehyde formation in relation to ketone formation increases with the amount of noble metal compound used and likewise with the increase in temperature. However, only then have higher temperatures an intensifying influence on the aldehyde formation when the claimed minimum amount of the noble metal compound is available. When working with liquid contacts at a higher temperature than the boiling point corresponds to the solution, an increase in pressure must also run in parallel, but can the use of increased pressure may also be advantageous at lower temperatures.

In the reaction of propylene with oxygen in the liquid contact mentioned in Example 2, for. B. the ratio of propionaldehyde to acetone at 20 ⁰ C = 1: 7.2, at 85 ° C = 1: 4.3, at 00 ° C = 1: 3.5, at 1 atm and 12O ⁰ C = 1: 2 , 0.

1 already at 100 ⁰ C reach: Under similar conditions, a methyl ethyl ketone-butyraldehyde ratio can be of butene-1 of 4.8. By further increasing the temperature and optionally the pressure, the aldehyde-ketone ratio can be shifted even further in favor of the aldehyde.

Both solid and liquid catalysts can be used. When in use halogen losses occur in the contacts of halogen compounds, then for the replacement of the lost

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quantities gone, ζ. B. by adding hydrochloric acid.

The method can be z. B. in the Belgian patents 569 036 and 585166 indication of foreign Execute property rights as described and under the conditions specified there, both in the liquid and in the solid phase, with continuous operation during the reaction Anion-yielding compounds, such as hydrogen chloride, are supplied. You can z. B. at temperatures from 20 to 200 ° C or at even higher temperatures, preferably between 50 and 170 ° C.

example 1

100 ml of an aqueous contact containing 100 g of PdCl ₂ and 400 g of CuCl ₂ · 2 H ₂ O in 11 of liquid are poured into a vertical reaction tube. 41 per hour of propylene and 1 liter of oxygen are passed through a frit into this catalyst solution and the acetone and propionaldehyde formed are recovered by washing the gases with water. At a temperature of 85 ° C propionaldehyde and acetone, in the ratio 1: 4.2, at 100 ⁰ C in the ratio 1: 3.6 and at 12O ⁰ C and 1 atm pressure in a ratio of 1: 2.9. The conversion of propylene to aldehyde and ketone in the last experiment is 23%, based on the propylene used. The unconverted gases can be recycled and used again.

Example 2

In the same apparatus as in Example 1, 100 ml of contact liquid containing 160 g of PdCl ₂ and 320 g of CuCl ₂ · 2 H ₂ O per liter are used and the procedure is otherwise the same as in Example 1. A propionaldehyde-acetone ratio is obtained at 20 ° C from 1: 7.2, at 85 ° C from 1: 4.3, at 100 ° C from 1: 3.5 and at 120 ° C from 1: 2.0. In the latter case, the conversion of propylene to acetone + propionaldehyde is 31.6% in a single pass.

Example 3

_{If an aqueous catalyst solution containing 220 g of PdCl 2} and 440 g of CuCl ₂ * 2 H ₂ O is used in the same apparatus and under the same conditions as in Example 1, the propionaldehyde-acetone ratio at 85 ° C is 1: 4.0.

Example 4

_{100 ml of a contact which contains 160 g of PdCl 2} and 320 g of CuCl ₂ · 2 H ₂ O in 11 are used in an apparatus as described in Example 1. The liquid is gassed with a mixture of 41 butene-1 and 11 oxygen per hour. Butyraldehyde and methyl ethyl ketone are obtained at 2O ⁰ C in a ratio of 1: 11, at 85 ° C in a ratio of 1: 6.7 and at 100 ° C in a ratio of 1: 4.8.

Example 5

A long tube of 30 mm diameter provided with a heating jacket is charged with 200 ml of activated carbon, which is impregnated _{with a solution of 40 g of CuCl 2} · 2 H ₂ O and increasing amounts of PdCl _2. Water at a constant temperature of 85 ° C runs through the heating jacket by means of a thermostat. Every hour, a mixture of 201 propylene and 40 l of air is passed through an evaporator installed in front of the reaction tube and then from top to bottom through the catalyst. In the evaporator heated by an oil bath, 10 ml of 0.1N hydrochloric acid are uniformly dropped in per hour, evaporated and fed to the catalyst with the gas stream. The resulting carbonyl compounds, propionaldehyde and acetone are taken up by washing with water and finally a residue by hydroxylamine from the reaction mixture leaving the reaction tube, freed of water by a cooler and continuously analyzed by gas chromatography.

As the concentration of PdCl ₂ in the catalyst increases, the percentage of propionaldehyde in the reaction product increases, from 1.6% at a concentration of 2 g PdCl ₂ per 200 ml of catalyst to 12.4% at a concentration of 20 g PdCl ₂ per 200 ml of catalyst. The following table clearly shows the shift in the reaction product from the ketone to the aldehyde side, which is dependent on _{the PdCl 2 content of the contact.}

Load of 200 ml activated charcoal Gram MoIPdCl ₂ temperature
in the Reak Propionic Gram PdCl ₂ per liter tion product dJucnyu ² 5 CuCl ₂ -2H ₂ O 2 0.056 ° C 1.6 40 4th 0.113 85 2.0 40 10 0.28 85 4.6 40 20th 0.56 85 12.4 3o 40 85

Example 6

A mixture of 121 propylene and 51 oxygen is passed every hour as in Example 5 together with 10 ml of evaporated 0.1 η-hydrochloric acid at 95 ° C. over 200 ml of silica gel, which was previously treated with a solution of 40 g of CuCl ₂ -2 H ₂ O and 20 g of PdCl _{2 was} impregnated.

The reaction mixture, the composition of which after the separation of water 700 working hours long monitored by gas chromatographic analysis contains an average of 7.9% acetone and 0.8% propionaldehyde, i.e. over 10% aldehyde, based on acetone. Most of the carbonyl compounds is condensed in a freezer trap kept at -40 to -50 ° C. The exhaust gas can after being refreshed, they can be reused in the cycle if necessary.

Example 7

A mixture of 7.5 liters of propylene and 301 of air is passed every hour at 85 ° C. into a _{contact solution of 50 g of Pd Cl 2} and 200 g of Cu Cl ₂ .2 H ₂ O in 500 ml of water to which 10 ml of concentrated hydrochloric acid have been added. The reaction mixture examined in a manner similar to that in the preceding examples contains 14% propionaldehyde, based on acetone, in the first 24 hours of operation. The aldehyde content then gradually drops to about half and maintains this value in a long-term test of 600 hours.

In an experiment with only 5 g of PdCl ₂ under otherwise identical conditions, only 1.2% of propionaldehyde, based on acetone, were found in the reaction product.

Example 8

A heatable tube with an internal diameter of 10 mm is charged with 30 cm ^{3 of} silica gel, which is filled with 10 cm ³

a solution of 250 g per liter of CuCl ₂ · 2 H ₂ O and varying amounts of PdCl ₂ per liter was impregnated. The reaction temperature is about 9O ⁰ C. Every hour 2 Nl propylene and 1 Nl of oxygen introduced. The oxygen-containing compounds formed, in particular acetone and propionaldehyde, are obtained from the gas mixture leaving the reaction zone by washing with water.

Tempera-
Ήιτ * Volume ratio of Pd Cl ₂ concentration door Acetone to propionalde per liter ⁰ C hyd in the reaction catalyst 90 mix after 5 hours G 90 running time 30th 90 5: 1 90 3.7: 1 180 2: 1

Example 9

A. The apparatus described in Example 1 is filled with a catalyst solution which contains 0.2 g of IrCl ₄ and 10 g of CuCl ₂ -2 H ₂ O in 100 g of water. 41 propylene and 11 oxygen per hour are allowed to flow through this solution at a temperature of 100.degree. The resulting reaction products, acetone and propionaldehyde, are washed out with water. This gives 20 times as much acetone as propionaldehyde.

B. If one adds enough iridium chloride and copper chloride to the above catalyst solution that g of water contains 16.7 g of IrCl ₄ (corresponding to 0.48 mol per liter) and 33.4 g of CuCl ₂ · 2 H ₂ O, and works under otherwise identical conditions, propionaldehyde to acetone is obtained in a ratio of 3: 7. The amount of water evaporated is replaced by occasional topping up with 0.05 η-hydrochloric acid during the reaction. The unconverted gases are circulated after the reaction products have been washed out and used again.

Claims (2)

PATENT CLAIMS: 1. A process for the preparation of aldehydes and ketones by reacting olefins having 3 or more carbon atoms with oxygen or oxygen-containing gases in the presence of water and redox systems and in the presence of noble metal salts, preferably palladium salts, characterized in that the reaction is carried out in the presence of Carries out catalysts which, in addition to salts, especially halides of those metals which can form several stable valence levels, contain more than 0.25, especially more than 0.5 mol of noble metal salts per liter of catalyst. 2. The method according to claim 1, characterized in that the reaction at elevated temperature and / or increased pressure is carried out. © 209 657/271 9.