DE1142167B - Process for the continuous production of carboxylic acids from olefins, alcohols, alkyl halides or mercaptans, carbon monoxide and water - Google Patents

Description

It is known that carboxylic acids are obtained when olefins and carbon monoxide are present in the presence allows acidic compounds to act on each other under pressure and then the reaction product hydrolyzed. The catalysts used are sulfuric acid, phosphoric acid, boron trifluoride, boron trifluoride hydrates, Hydrogen fluoride or mixtures of these compounds are used. It is already described that alcohols, mercaptans or alkyl halides can be used in place of olefins, it may be assumed that olefins are formed as intermediates under the reaction conditions. Processes of this type are advantageously applied to olefins which have the C = C double bonds have a branching of the carbon skeleton. They are described in the German patents 942 987, 972 291 and 972 315, in the German Auslegeschrift 1 080 537, in the Belgian patents 567 112, 566 845, 584 496 and 586 117, also in fuel chemistry, vol. 36, 1955, p. 321 to 328.

There are considerable difficulties involved in carrying out this reaction in a continuous manner. This is because the reaction mixture usually consists of two liquid phases, and one obtains only good yields if the reactants are intensively mixed. In all known continuous embodiments, there is therefore intensive mixing a nearly homogeneous mixture considered necessary. This mixing is for example carried out in several reaction vessels connected in series. When carrying out the procedure Satisfactory solutions can be obtained on a small scale using magnetic stirrers find, even if the technical effort is great. If, on the other hand, you want a production on a larger scale Record a scale, so the use of agitators, their drive shafts from the outside are introduced into the pressure vessel, do not avoid; then kick because of the strongly acidic medium and because of the high pressure, corrosion and sealing problems to a great extent.

It has been found that in the carboxylic acid synthesis by reaction of olefins, alcohols, Mercaptans or alkyl halides with carbon monoxide in the presence of strongly acidic compounds as catalysts and under increased pressure when carried out continuously, those mentioned Difficulties avoided when you use the catalyst and the olefin, the alcohol, the mercaptan or the alkyl halide under carbon monoxide pressure

Process for continuous

Manufacture of carboxylic acids from

Olefins, alcohols, alkyl halides or mercaptans, carbon monoxide and water

Applicant:

ίο Badische Anilin- & Soda-Fabrik

Aktiengesellschaft, Ludwigshafen / Rhein

Dr. Walter Himmele, Walldorf near Heidelberg, and Dr. Nikolaus von Kutepow, Karlsruhe-Rüppurr,
have been named as inventors

lets trickle a stretch of packing and then the liquid reaction product in the usual way Hydrolyzed water.

As the procedure is generally carried out in a Tower carried out, which is filled with the packing. Different shaped fillers can be used, for example cylindrical, ring, conical or saddle-shaped. They must be made of a material which is inert under the reaction conditions; fillers made of aluminum oxide are suitable, Activated carbon, glass, stainless steel.

The fill level determines the length of the trickle path and thus the residence time of the reactants.

The new process achieves very uniform residence times for all reactants (ie the residence time spectrum is narrow), as a result of which the uniformity of the reaction products is considerably improved. In general, the reaction is carried out with residence times of 1 to 10 minutes. However, shorter and longer residence times can also be set by varying the trickle path.
The other reaction conditions for the continuous process for reacting the olefins, alcohols, mercaptans or alkyl halides with carbon monoxide under pressure in the presence of strongly acidic compounds are the same as in the known processes.

Aliphatic or cycloaliphatic olefins can be used. The method is particularly suitable for olefins connected to the double bond

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are branches. Examples of olefins that can be used are propylene, butylene, isobutylene, pentenes, hexenes, Nonenes, hexadecenes and mixtures of such compounds, also cyclohexene, cyclooetene, cyclododecene.

Instead of the olefins, alcohols, mercaptans or alkyl halides can be used, for example tertiary butanol, 2-ethylhexanol, cyclohexanol, methylcyclohexanol, decahydronaphthol.

In the examples below, parts are parts by weight, unless otherwise stated. Weight and parts by volume are in relation to grams to milliliters.

example 1

where a reaction mixture consisting of two liquid phases is formed, e.g. B. when using of olefins with 4 or more carbon atoms.

In a vertical high pressure pipe (ratio of diameter to length as 1: 600, volume 3000 parts by volume), which with a corrosion

Particularly advantageously, the novel process for i _0-resistant lining made of a Ni-Mo-Crder use of such reactants in type alloy Hastelloy C is provided with

Trickle bodies made of aluminum oxide are filled with 200 atmospheres of carbon monoxide after flushing with nitrogen pressed in and separated every hour 900 parts of sulfur

You can the starting materials in an inert i ₅ acid and 150 parts of a mixture of the same solvent, for. B. in saturated unbranched parts of cyclohexene and cyclohexane at its upper hydrocarbons, such as n-octane, cyclopentane, pumped in at the end.

Cyclohexane, cyclooctane, dissolve and in dilute The reaction components flow over the

Apply state. Aluminum oxide trickle bodies and react in the process.

You can use both pure carbon monoxide and ao The aluminum oxide trickle bodies are small cylindrical carbon monoxide containing gases, e.g. B. water gas drical strands, about 4 to 5 mm long and with a or generator gas. Diameter from 0.6 to 1.0 mm. For temperature

Catalysts can be checked, for example, located in the middle of the reaction turn: sulfuric acid, phosphoric acid, boron fluoride tube a thermal sleeve in which several resistance and Hydrates of boron trifluoride and mixtures of these 25 elements are housed at different heights. Links. The pressure of 200 at carbon monoxide is during

The quantitative proportions of the reactants of the whole experiment by repressing and the catalysts are within the usual limits of maintaining fresh carbon monoxide. At the per mole of olefin, 2 to 10 moles of catalyst are produced at the top of the reaction tube used. However, outside of this temperature range from 30 to 32 ° C can also be used. The one at the bottom Limits are worked. At the end of the high-pressure pipe

The reaction temperature is between about -25 product flows into a small pressure separator and about + 40 ° C, the pressure over 40 at, in particular and is from there every hour into a collecting vessel those between 100 and 500 at, but you can also drain. That which is released during relaxation use lower or even higher pressures. The 35 carbon monoxide is passed over the roof. That Pressure data relate to carbon liquid reaction product is at intervals of monoxide, d. H. with pure carbon monoxide hydrolyzed with ice for the 12 hours; thereby separates Total pressure, in the case of gas mixtures on the partial an upper organic layer, consisting of cyclic pressure. hexane and the carboxylic acid mixture, which one

The hydrolysis of the primary reaction 40 is separated off in the separating funnel. After distilling off the products is made with water or ice. Cyclohexanes from this layer remain 1058 parts

The process can be returned to a carboxylic acid mixture, for example, as follows. The carbon performing: Olefin or olefin-forming acid mixture becomes in a water jet pump vacuum bond and catalyst, e.g. B. sulfuric acid with distilled at 20 torr and provides 830 parts of a a content of more than 90% (so-called mono-45 fraction, which passes between 124 and 144 ° C, hydrate) or a mixture of phosphoric acid and The fraction contains 1-methylcyclopentane boron trifluoride, are separated into a reaction carboxylic acid (l) 68% cyclohexanecarboxylic acid. the tower, which is under a carbon monoxide pressure, yield of both carboxylic acids corresponds to 60% pumped. The reaction tower is packed with the theory. 220 parts of higher carboxylic acids, filled. The liquid reactants trickle down through isomerization and subsequent reaction Via the packing, at the lower end the carbon monoxide will arise, remain as a Destilla reaction mixture deducted. It has fallen back as a functional deficit. Do you work under otherwise moderately proven, the catalyst higher than the olefins same conditions, but without using one give up, because then first the catalyst route of trickling particles, with the starting solution saturates with carbon monoxide and in the case of additives and the catalyst in the usual way If the reaction is brought together immediately with the olefin, then essentially one obtains. In this way, undesired borrowed isomerization products, in addition to only minor ones Avoid isomerizations as far as possible. Amounts of carbonylation products. You wanted to

Then in the majority of cases this will increase the yield of carbonylation products, two-phase mixture either as a whole or after 60 so one would have to use a lot of equipment Separation of the predominantly catalyst-containing intensive magnetic stirrer build in what the Layer hydrolyzed with water or ice.

The new procedure is characterized by its simplicity. The success of the procedure could not be foreseen, because in reactions between liquid multiphase systems and a gas phase one does without intensive mixing could not expect a complete course of the reaction.

Severely affect the economics of the process
would.

Example 2

The procedure is as in Example 1 and the reaction is carried out
but with a carbon monoxide pressure of 500 at
by. Obtained after distilling off the cyclohexane

1384 parts of crude carboxylic acid mixture and from it, by distillation in a water jet ^{pump vacuum at 20 torr, 1098 parts of a carboxylic acid mixture which passes between 120 and 148 0} C and which consists of 86% cyclohexanecarboxylic acid and 1-methylcyclopentanecarboxylic acid-i 1). The yields of these two carboxylic acids are based on applied cyclohexene is 76% of theory. In addition, 296 parts of distillation residue are obtained, which consists of higher-boiling carboxylic acids. The acid number of the residue is 136.

Example 3

strong Raschig rings at a carbon monoxide pressure of 500 at and the temperature that is set trickled. The reaction product collected over a 12 hour reaction time is added by additions hydrolyzed by ice and provides 1461 parts of an upper layer. By fractionating this layer under reduced pressure (20 torr) a total of 1088 parts of a Cg-carboxylic acid are obtained pass at a temperature of 143 to 147 ° C, ίο The Cg carboxylic acid is practically pure a-methyl-ethyl-n-caproic acid. The yield is 89.4% of theory.

If the procedure is as in Example 2, but used instead of the cyclohexene-cyclohexane mixture 150 parts per hour of a mixture of equal parts of tertiary butyl alcohol and cyclohexane, see above 742 parts of trimethyl acetic acid are obtained by distillation under otherwise identical conditions, correspondingly a yield of 69.2% of theory, based on tertiary butyl alcohol, and a distillation residue, consisting of higher boiling isomeric acids.

Example 4

In the reaction tower described above, 83 parts of 2-ethylhexanol and 900 parts per hour concentrated sulfuric acid over a 5 mm glass

Claims (1)

PATENT CLAIM: Process for the continuous production of carboxylic acids by reacting olefins, alcohols, alkyl halides or mercaptans with carbon monoxide in the presence of inorganic, strongly acidic catalysts under increased pressure in a temperature range from -25 to +40 ⁰ C and subsequent decomposition of the reaction product with ice or water, characterized in that, for the conversion, the catalyst and the organic component to be converted are allowed to flow under carbon monoxide pressure over a section of trickle bodies. © 209 757/171 1.63