DE1283219B - Process for the production of mainly straight-chain butyraldehyde and butanol by the oxo process - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

C07c

German class: 12 ο -7/03

Number: File number: Filing date: Display date:

P 12 83 219.8-42 (B 87606)

June 18, 1966

November 21, 1968

It is known from British patent specification 903 589 that one has a higher proportion of straight-chain Compounds are obtained when the oxo reaction is carried out at temperatures from 110 to 130.degree. Disadvantageous is, however, that only relatively low conversions are achieved at the lower temperatures. To Another known method (French patent 1,374,941) is obtained by working at high pressures, e.g. B. 500 to 1200 atm, a higher proportion of straight-chain Oxierungsprodukte. The use of such high pressures, however, requires a disproportionately large technical effort. Furthermore, it is described in US Pat. No. 2,694,735 that the oxo reaction with propylene is in favor the formation of straight-chain products occurs when one works in the presence of ketones. However, this requires an additional stage for the recovery of the work-up Ketones. According to a method described in Belgian patent specification 627 371, it is possible to use the Increase proportion of straight-chain butyraldehyde and butanol when using a mixture of cobalt carbonyl and tertiary phosphines used as a catalyst. The process leads primarily to alcohols and not to aldehydes, since the phosphine-containing catalysts have a high hydrogenation activity.

It is also known (German patent specification 977 269) that the oxo reaction can be carried out in two reaction stages connected in series, lower temperatures in the first and higher temperatures in the second, which are not uniform across the reaction space. This is intended to give the discharge a temperature that is sufficient for the subsequent cob removal. An increase in the nC ₄ content when using propylene is not possible in this way. Finally, it is known (German patent specification 888 094) to oxidize higher olefins in two reaction stages connected in series with increasing temperature. However, due to the lack of equipment for longitudinal mixing, this process is not suitable for the oxygenation of propylene because of its high reaction rate and high exothermicity per kilogram of olefin.

There has now been a process for the production of butyraldehydes and butanols with a predominantly straight carbon chain by the oxo process by reacting propylene with carbon monoxide and hydrogen in the presence of cobalt carbonyl compounds under elevated pressure and at elevated temperature in two reaction stages connected in series, with a process for the second reaction stage Manufacture of mainly
straight chain butyraldehyde and butanol
according to the oxo method

Applicant:

Aniline & Soda Factory in Baden
Aktiengesellschaft, 6700 Ludwigshafen

Named as inventor:

Dr. Hans Nienburg,

Dr. Friedrich Franz Wiese, 6700 Ludwigshafen;

Dr. Karl Eichner, 8000 Munich;

Dipl.-Ing. Ludwig Vogel, 6710 Frankenthal

higher temperature prevails than in the first, which is characterized in that one

ao at least in the first reaction stage one over the maintains a uniform temperature throughout the entire stage.

The new process has the advantage that butyraldehydes and butanols are predominantly straight Carbon chain in very good yield, based on the propylene, without great technical effort and with an improved space-time yield.

Carbon monoxide and hydrogen can be used in a volume ratio of 5: 1 to 1: 5. It is advisable to work with a mixture in which carbon monoxide and hydrogen are about behave like 1: 1.

The propylene is expediently exposed in stoichiometric amounts, based on the mixture Carbon monoxide and hydrogen. But it is also possible to use propylene or the mixture mentioned to be used in excess, for example up to 10 mole percent.

The catalytically active cobalt carbonyl compounds are best produced in the reaction mixture. To this end, aqueous cobalt salt solutions or cobalt soaps in organic solvents are used, which can also be the end product or propylene. But you can also use preformed cobalt carbonyl compounds, such as cobalt carbonyl hydrogen, with the synthesis gas stream or dissolved in organic Bring in solvents.

In general, 0.1 to 5 parts by weight of cobalt in the form of are used for 1000 parts by weight of propylene Carbonyl compounds. Particularly good results are obtained if one uses 1000 parts by weight 0.5 to 3 parts by weight of cobalt used in the form of carbonyl compounds.

809 638/1716

In the first reaction stage, temperatures of 120 ° to 150 ° C. are generally maintained, preferably 130 to 145 ° C, while in the second reaction stage at temperatures of 155 to 200 ° C, preferably from 160 to 180 ° C, works.

The process can be carried out, for example, at pressures between 50 and 500 atmospheres. Works advantageously between 200 and 400 atm.

The reaction is carried out in two successive reaction stages, in the first of which Reaction stage in which a lower temperature prevails, over 70%, advantageously about 75% of the total conversion takes place, while the remainder is reacted in the second reaction stage at a higher temperature will.

In the first reaction stage, stirring or internals, such as circulation pipes, or in some other manner known per se, ensure that the reaction mixture is mixed well enough that a uniform temperature prevails in the entire reaction stage. The temperature difference, which is measured at different points in the reaction mixture, should expediently not be more than 4 ° C, preferably less than 4 ° C. In the second reaction stage, as in the first, homogeneous mixing can be ensured, it being possible to maintain a uniform temperature in the reaction space, just as in the first stage. But it is also possible to simply let the reaction medium flow through the reaction space.

An essential feature of the process is that cobalt salt solutions used in the feed in the reactor can be very finely divided. The distribution should be so fine that the entire cobalt content of the aqueous solution has passed into the organic phase after circulation.

The process according to the invention can be carried out, for example, by placing in a pressure reactor, which is equipped with an inner circulation pipe to achieve a fluid circuit, Via feed lines the above-mentioned catalysts, propylene and the mixture of carbon monoxide and Feeds hydrogen in the specified ratio through one or more nozzles. this happens with such a high linear speed that by the density difference between the interior and the Outside of the circulation pipe, a rapid liquid 'keitsumlauf and thus extensive standardization the temperature is achieved in the first stage. The reactor is with the reaction medium of the specified temperature so far filled that the circulation pipe is flooded, the stand by a Overflow is observed. The heat of reaction can, for example, by indirect cooling or additionally by circulating the gaseous reactants and evaporation of the end product and optionally derived from water. The outflowing reaction mixture then passes into a second pressure reactor, which, like the first, is equipped with internals for mixing the contents or can simply be flowed through by the reaction medium. Then that flows Reaction mixture via a high pressure cooler into a separator, where the liquid components from the Gases are separated. Unconverted reaction gases can be fed back into the first reaction stage will.

Cobalt is then removed from the oxo reaction mixture in a manner known per se. This can be, for example non-oxidizing by treatment with 0.5 to 5 percent strength by weight aqueous solutions Mineral acid nerves such as hydrochloric acid or sulfuric acid, take place. It is particularly advantageous, the oxo reaction mixture by gassing with air or other oxygen-containing gases with the addition of 0.5 to 5 percent by weight aqueous acids, like aqueous acetic acid, to be freed from cobalt at 0 to 50 ° C. The cobalted reaction mixture is then worked up in the usual way by distillation.

The parts given in the following example are parts by weight. They relate to the room dividers like kilograms to liters.

example

Be for the reaction. two vertical pressure pipes connected in series with a volume of 10.6 and 5.3 volume parts are used. In the first pressure pipe there is a circulation pipe which is completely immersed in the liquid phase during operation. The pressure pipes are jacketed for heating and cooling. At the bottom of the first pressure pipe, 7500 normal space parts of carbon monoxide and hydrogen in a ratio of 1: 1, 10.2 parts by volume of liquid propylene and 0.485 parts by volume of aqueous cobalt acetate solution containing 2.4 percent by weight of cobalt are metered in every hour through nozzles. A uniform temperature of 130 ± 1.5 ° C is maintained in the first pressure pipe, while an initial temperature of 167 ° C is established in the second pressure pipe. After the gaseous constituents have been separated off, the reaction mixture discharged is decobed at about 30.degree. C. with 3 percent strength by weight aqueous acetic acid while aerating. 8.8 parts of oxygenation product are obtained per hour, which corresponds to a propylene conversion of 100%. The proportion of n-butyraldehyde and n-butanol in the crude reaction product is 78.6 percent by weight. If the temperature increase in the second pressure tube is dispensed with and this is also kept at 130 ± 1.5 ° C. with the use of a circulation tube, the propylene conversion is only 79.8% with an nC ₄ content of 79.5% under otherwise identical conditions.

Claims (1)

Claim: Process for the production of butyraldehyde and butanol with a predominantly straight carbon chain according to the oxo process by reacting propylene with carbon monoxide and hydrogen in the presence of cobalt carbonyl compounds under increased pressure and at increased Temperature in two reaction stages connected in series, with a higher temperature prevailing in the second reaction stage than in the first, characterized in that at least one in the first reaction stage Maintains a uniform temperature over the entire stage.