DE1154798B - Process for the preparation of aldehydes, ketones and / or acids corresponding to the aldehydes - Google Patents

Description

A number of patent applications and publications have made known processes in which aldehydes, ketones and acids corresponding to the aldehydes can be obtained in a simple and continuous manner if olefins are brought into contact with catalysts in a neutral to acidic medium in the presence of water, the noble metal salts which form addition compounds or complexes with the olefins, and regenerate the catalyst with oxygen or a gas containing free oxygen. As noble metal salts that form addition compounds or complexes with the olefins, z. B. salts of palladium, platinum, rhodium, iridium and ruthenium in question. These compounds are dissolved in aqueous solutions of other metal salts which can function as redox systems. As such, salts of metals are used, which can occur in several oxidation stages under the reaction conditions, e.g. B. salts of Cu, Hg, Fe, V, Sb, Pb, Mn, Cr, Ti, Os, mainly the halides.

Leaving olefins under mild conditions, e.g. B. act on the catalyst at temperatures around 100 ^° C. and at any pressure, the desired carbonyl compounds are formed in excellent yields and with a high conversion of the olefin.

As a rule, the oxidation products can be removed by appropriate measures, e.g. B. by distillation, easily separated from the catalyst liquid. Of the aldehydes formed, one can Part, under special conditions also the whole amount, right on up to the associated acids are oxidized.

In the special case of using ethylene as an olefin for this process, the product is obtained acetaldehyde (and acetic acid) only. The higher olefins produce ketones and aldehydes side by side, the ratio of the two carbonyl compounds to each other through Choice of process conditions, e.g. B. by the catalyst composition, by temperature and Pressure, can be varied within certain limits. As a rule, however, the ketones are the preferred ones Products. The associated acids can be formed from the aldehydes by further oxidation.

It is known that olefins can be used in these processes without damage, which as Contains paraffinic hydrocarbons. The paraffins, such as ethane, propane, butane, pass through the catalyst liquid without changing the process for the production of aldehydes, Ketones and / or the aldehydes

corresponding acids

Applicant:

Farbwerke Hoechst Aktiengesellschaft ίο formerly Master Lucius & Brüning, Frankfurt / M.

Dr. Lothar Hornig, Frankfurt / M.-Unterliederbach, Dr. Gerhard Theilig, Lorsbach (Taunus),

and Dr. Erhard Weber, Frankfurt / M.-Höchst,

have been named as inventors

to become. It is a question of economy in any particular case, whether pure olefins or with Paraffins mixed olefins are used for the oxidation.

On the other hand, impurities in the olefins by dienes, especially those with accumulated double bonds, such as B. Propadiene, or with conjugated double bonds, such as. B. the butadiene (l, 3), not easily acceptable for these procedures. Such dienes can be used as components of technical olefins can be undesirable or even disruptive in the process described.

It is known that propadiene (allene) rearranges very easily to methylacetylene (propyne), which with heavy metal salts precipitation of metals, a depletion of the catalyst and thus a Causes a decrease in reaction speed.

In addition, the dienes as such can react with the catalyst; the resulting products then make it difficult to obtain and purify the main reaction products. For example in the oxidation of a propylene, which contains propyne and propadiene, in addition to acetone and Propionaldehyde also formed acrolein. The complete separation of the acrolein, which is necessary for a Obtaining specification-compliant acetone makes processing and cleaning more difficult and makes it more expensive Procedure.

When processing diene-containing olefins under the reaction conditions, a

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further serious complication thereby to be removed without later difficulties in the that the catalyst liquid has to be feared to a great extent for the oxidation reaction. Foaming tends to. The reaction space fills up when the hydrogenation catalyst becomes less effective Time with foam, which loosens when more is added, can be saved by careful regeneration Gas quantities finally overflow and are reactivated with the waste 5 oxygen-containing gases, gases and vapors are entrained, so that a. . , .. orderly work becomes impossible. üeispie

The procedural difficulties described do not occur, a) (comparative experiment) In the reactor of a two, as mentioned, as long as olefins or stage experimental apparatus consisting of an olefin-paraffin mixture are used for the reaction, 10 m long titanium tube arranged in a meandering manner and free from Are impurities from diene. In a reactor with a clearance of 10 mm as a reactor and one of the technology, however, there are often primarily only olefin tubes as regenerators, mixtures were available every hour that consist of thermal or 150 l of a mixture of 90% pure propylene catalytic cleavage and dehydrogenation processes (99, 9 ¹⁰ ZoIg) and 10% nitrogen fed in. The reactants and the always certain concentrations ran without difficulty for 48 hours and contained dienes. Acetone and some propionaldehyde yielded a substantial or complete amount. Removal of these impurities from the olefins b) (comparative experiment) A technical raw proist is possible, but increases the price of the olefins pylene showed, determined by gas chromatography, consequently considerably. analysis:

It has now been found that one aldehydes, 20 component

Ketones or acids corresponding to the aldehydes Hydrogen 0%

by conversion of olefins with oxidizing air 0.01%

Agents in neutral to acidic medium in ethane 0.31%

Presence of water, precious metal compounds and propane 5.65%

Redox systems can be produced by using 25 propylene 92.77%

technical crude olefins contaminated by dienes η-butane 0.01%

used and this before their oxidation one of n-butene-1,. 0.01%

known selective hydrogenation using an i-butene trace

Excess of hydrogen on a fixed bed - n-butene-2 0.01%

Hydrogenation catalyst, preferably among the 30 (cis and trans-j

same pressure and temperature conditions as butadiene 0.10%

they prevail in the subsequent oxidation, propadiene 0.41%

subject. Propyne 0.72%

The selective hydrogenation of the "~ HTf> ö /

The diene contained is expediently made at precious metal 35 ^e °

containing fixed bed catalysts, e.g. B. those that 140 Nl / h of this crude propylene were in the

Palladium or platinum in finely divided form on the reactor of the oxidation apparatus described under a)

a carrier with a large pore volume, such as. B. ratur fed. Made after 15 minutes of running time

Silica gel included. In the same way, strong foaming of the catalyst is noticeable.

also nickel catalysts. The hydrogenation can be 4 ° bar, after a further 20 minutes to turn off

directly before the gas mixture entered the Oxyda- the apparatus.

perform tion reaction and under the same c) (inventive method) The under b)

or similar pressure and temperature conditions defined crude propylene was at 15 at pressure and

work as in the subsequent oxidation to 120 ⁰ C in an amount of 60 kg / h over 81 one

another cooling and reheating or 45 Pd-containing fixed bed contact. Before entering

Avoid decompressing and compressing the gas. enters the hydrogenation tube, the gas was 2.3%

For example, it is advisable to add hydrogen during processing. After hydrogenation had

of propylene in both stages a pressure of about the gas following composition (gas chromatography

10 atm and a temperature of 100 to 120 ° C. graphic analysis).

The catalyst necessary for the hydrogenation 50

volume fluctuates depending on the concentration and it at e

Amount of compounds to be hydrogenated and is hydrogen 0.14%

also from the activity of the catalyst from air 0.01%

pending. But since the diene to be hydrogenated in the ethane 0.31%

Usually only small percentages in the raw 55 propane 6.02%

olefin are present, e.g. B. 1 to 2%, if you get propylene 93.41%

with small amounts of catalyst. So has z. B. η-butane 0.05%

in the hydrogenation of 60 kg / h of a crude propylene n-butene-1 0.05%

a trace of i-butene with 0.6% propadiene and 0.8% methyl acetylene

Catalyst volume- of 81 proved to be sufficient. 60 n-butene-2 0.01%

A content of unused hydrogen, such as (cis and trans)

it may still be present after hydrogenation, butadiene j ^^

does not interfere with the subsequent oxidation. One can Propadien > detectable

hence the hydrogen for hydrogenation in a propyne J.

Dose an excess of, for example, 50 to 100 mol percent, 65 total 100% based on the dienes to be hydrogenated,

to ensure that the impurities were fully 140 Nl / h of this hydrogenated gas in the

constantly or at least except for harmless residues ent- reactor of the apparatus described in Example 1

Claims (1)

5 6 fed in. The oxidation reaction of propylene (CuCl ₂ · 2 H ₂ O per liter) brought into contact. the ran without difficulties, in particular without foam apparatus consisted of a 3 m long glass tube education, over 30 hours. 3 cm in diameter, into the one at the bottom . · ₁₉ ^eme gas distribution frit was melted down. By Example 2 _{5 a} water jacket with steam heating was used A C _{4 cut} with the analysis: catalyst kept hot. The one introduced below Inert gases 0.50% gas mixture passed after exiting the Propane 0.33% reaction space a water cooler and a cooling Propylene 0.01% fall where the resulting methyl ethyl ketone together with Propine trace ^ao water and very little butyraldehyde frozen out n-butane was 0.30%. The apparatus was in operation for 120 hours i-butane kept 0.05%. The conversion of the butylenes corresponded to 15%. n-butene-1 0 07% diacetyl or methyl vinyl ketone could be used in the i-butene 0, '02% product cannot be detected. The catalyst cis-butene-2 52'50% ¹ S showed no precipitations. trans-butene-2 38.27% Butadiene-1,3 3.30% PATENT CLAIM: Butadiene-1,2 0.05% Butadiene 0.60% process for the production of aldehydes, Vinylacetylene 0.50% ²⁰ ketones and / or the aldehydes Ethylacetylene 1.10% of the acids by reacting olefins with C-- and higher oxidizing agents in neutral to acidic "Hydrocarbons 2.40% medium in the presence of water, precious metal c _{inno /} compounds and redox systems, characterized gefcumme .... lUU / o ₂₅ indicates that technical, processed by diene in an amount of 50Nl / h are used together with impure crude oil and Nl / h hydrogen is sent through a hydrogenation tube before it Oxidation of a hydrogenation known per se and then selective in a laboratory apparatus by means of an excess for olefin oxidation. The hydrogenation tube was charged with hydrogen on a fixed bed hydrogenation with 100 ecm of a fixed bed catalyst which contained 30 catalyst, preferably among the same finely divided palladium on silica gel. The pressure and temperature conditions as at catalyst was maintained at 130 ⁰ C. The reaction of the subsequent oxidation prevailed under about 0.5 atm overpressure. After being thrown
the hydrogenation were no butadiene and none Acetylenes are more detectable in the gas. 35 Publications considered: The hydrogenated gas was described in an oxidizing Luxembourg patent No. 36,201; apparatus with the same amount of air and Industrial and Engineering Chemistry, 52, 1960, the 80 ° C hot catalyst (2 g PdCl ₂ , 170 g S. 901 to 904. © 309 689/284 9.63