DE594481C - Process for the production of higher aliphatic alcohols - Google Patents

Description

Process for the production of higher aliphatic alcohols It is known that by the action of hydrogen in the presence of hydrogenation catalysts Can convert esters of carboxylic acids into the corresponding alcohols. This method has the disadvantage that the carboxylic acids are first converted into their alkyl esters must, which is associated with considerable expenditure of material, labor and time and always leads to more or less large losses of starting material.

A method has already become known, palmitic acid at hydrogen pressure and to be heated to a high temperature in the presence of aluminum oxide .. In this case Gasoline-like products are obtained in the process of splitting, which are predominantly between 140 and distill about 50 °, but no alcohols.

It has now been found that higher aliphatic alcohols with more than eight carbon atoms directly from the corresponding aliphatic carboxylic acids produce by catalytic reduction in a simple manner and with a very good yield can, if you rely on a mixture of the corresponding free fatty acids with lower aliphatic alcohols in the presence of hydrogenation catalysts with hydrogen increased temperature and pressure can act. The following examples show such as the preparation of the catalyst and the reduction process carried out advantageously can be.

Preparation of the catalyst Copper acetate is dissolved in water and stir the appropriate amount of kieselguhr into the solution. Then you fail An excess of soda solution, the copper in the form of copper carbonate, washes very much carefully, dry the product and rub it in finely. One reduces to this the copper carbonate by heating in a stream of hydrogen at zgo to 2oo ° .- The proportions 4verden chosen so that the finished catalyst has about 15% metallic copper and contains about $ 5 per cent. diatomaceous earth.

It can also be dried and precipitated on kieselguhr Use finely ground copper carbonate directly without prior reduction as it itself is reduced.

Execution of the reduction 160 g of lauric acid and 26 g of methyl alcohol are mixed with 16 g of the copper catalyst prepared according to the above procedure and placed in an autoclave. Then will Hydrogen in the Pressed in the autoclave, the temperature brought to about 31o to 3a5 ° by heating and kept in this interval during the entire duration of the reaction. The reaction pressure is about 26o Atm. After two hours of exposure, the lauric acid is quantitative converted into lauric alcohol, which, from the methyl alcohol by distillation separated and then put to technical use without further purification, z. B. can be sulfonated by one of the known sulfonation processes. To neutralization with sodium hydroxide solution gives a completely clear solution in water Product, which shows excellent surface-active properties and therefore especially as an aid for the various finishing processes in the textile industry excellently suited.

In an analogous manner, lower and higher homologues of lauric acid be converted into the corresponding alcohols.

Since in the present process the cumbersome and costly Conversion of the carboxylic acids into the alkyl esters is omitted, represents the new way of working represents a significant technical advance and points a way too significant cheaper production of the higher fatty alcohols.

Claims (1)

PATENT CLAIMS: i. Process for the production of higher molecular aliphatic alcohols with at least eight carbon atoms in the chain Treatment of the corresponding free carboxylic acids with hydrogen in the presence of Hydrogenation catalysts at elevated temperature and pressure, characterized in that that the reaction is carried out in the presence of lower aliphatic alcohols will. z. Process according to Claim i, characterized in that a copper catalyst is used used.