US2340687A - Process of forming alcohols - Google Patents

Description

Patented Feb. 1, 1944 2.340.687 PROCESS OF FORMING ALOOHOLS Wyoming, and Samoa E.

assigno Albert s. Richardson, Taylor, (miclnnati, Procter and Gamble No Drawing;

Ohio,

rstoThe Company, Ivorydale, Ohio, a corporation of Ohio Application April 13, 1942, crial No. 438,852

. 8 Claims. (CL 260-638) Our invention relates to a process for forming v alcohols by reacting hydrogen with certain metallic salts of carboxylic acids.

The present application is a continuation inpart of our applications Ser. Nos. 380,072 and 380,073, both filed February 21, 1941. The first of these disclosed a general process for forming alcohols and esters by hydrogenating the corremeans of forming higher alcohols, which may contain unsaturated carbon-carbon linkages ii the starting materials are unsaturated. Such a process, which is not dependent upon added metallic or metal oxide catalysts, has grcatadvantages over previously described methods of maksponding carboxylates of certain metals at high temperature and pressure; and the second disclosed a similar process directed specifically to I forming unsaturated alcohols and esters from corresponding unsaturated carboxylates or certain metals.

Among the carboxylates which respond to the process of the above mentioned applications are those of cadmium. When subjected to reaction with hydrogen under the conditions of our general process cadmium soaps, for example, are converted to alcohols and esters corresponding to the fatty acid radical of these soaps, with liberation of metallic cadmium and water:

If the B group of the carboxylate contains one or more double carbon bonds,

application are based upon our discovery that when the cadmium of the soaps, in this process, is replaced inpart by any one or more of the metals, chromium, nickel, or copper, the proportionate yield of alcohol is greatly increased and the yield of esters is decreased. Stated differently, mixtures of metallic soaps comprising cadmium soaps and soaps of any of these three metals give higher yields of alcohol than do cadmium soaps alone. Furthermore, we have found that if the fatty acid radicals of the soaps are unsaturated, the process yields principally unsaturated alcohols. The hydrogenation of nickel carboxylates is not claimed herein, being claimed specifically in our continuing application Ser. No. 488,736, filed May 2'7, 1943.

Thus our present process provides an improved build up the pressure in ferred to as oleic acid,"

hours. The bomb was ing higher fatty alcohols. The reaction is rapid, the yields of the desired product are high, and the metals are readily recoverable for reuse in making fresh lots of carboxylates for hydrogenation.

The following examples will illustrate typical small scale applications of our process. In each of these examples the hydrogenation was carried out in a reaction vessel consisting of a stainless steel bomb of 300 cubic centimeters capacity. The mixed'fatty acids present in commercial oleic acid, or red oil," are for convenience reand the alcohols resulting from the process are referred to as "oleyl alcohol.

The extent of the reduction of the carboxyl group is calculated from the saponiflcation value of the original oleic acid and the saponificatlon value of the acid-washed, water washed, and dried reaction product. The per cent total alcohol in the acid washed (and water washed and dried) product is determined either by calculation irom the hydroxyl value determined on the unsaponiflable matter in the acid washed prodnot, or by calculation from the acid value, 39,-.

not is saponifled.

Example L-cadmium oleate and chromium oleate were separately prepared-by treating solutions of "red oil" sodium soaps with solutions of cadmium nitrate and chromium sulfate, respectively, and washing and drying the precipitated metallic soaps. this cadmium oleate and 50 grams of this chromium cleate was placed in the reaction bomb at room temperature. air vessel by admitting hydrogen and venting the bomb, and then hydrogen was introduced to the bomb to about 1800 pounds per square inch. The bomb was sealed and heated to about 340 C. The contents were agitated by rocking the bomb, while maintaining a pressure of 3500 pounds per square inch by adding more hydrogen when necessary, for three then allowed to cool to A mixture of 50 grams of was displaced from this a a temperature convenient for handling, excess gas pressure was released. and the non-gaseous organic contents were removed, boiled with a aqueous solution of hydrochloric or other suitable mineral acid, water washed until free from mineral acid, and dried.

This acid washed product was found to contain slightly over 90% of free and combined oleyl alcohol having an iodine value slightly under 90.

Free alcohol was obtained from the acid washed material by reacting fatty acids and esters in this material with caustic alkali, extracting with ether, and distilling off this solvent. The step of separating the free alcohol from the alkali soap may alternatively be accomplished by distillation or by any other convenient method.

Example 2.-A mixture of 90 grams of cadmium oleate and 10 grams of nickel oleate was subjected of hydrogenation under conditions similar to those of Example 1, except that the hydrogen pressure was maintained at 4000 pounds per square inch and the time .of agitation at elevated reaction temperature and pressure was only one hour.

The resulting acid washe to contain 85% free and an iodine value of 75.

Example 3.-A mixture of 97.5 grams of cadmium oleate and 2.5 grams of copper oleate was hydrogenated under conditions similar to those of Example 2. The acid washed product was found to contain about 88% of free and combined alcohol having an iodine value of 82. 7

The following table contains further data concerning some or the above examples, together with corresponding data for other mixtures of oleates or these metals and for oleates of each of the four metals when hydrogenated alone.

- d product was found combined alcohol havin a,aso,ee7 v I not claim that it is generally, although we do equally eilicient as applied such salts to alcohols. It is that carboxylic acids and their in thermal stability and the of our process as applied to production of the higher alcohols is due in large part to the resistance of the salts or. the fatty acids to decomposition by side reactions under the conditions emplayed in our process.

It will be appreciated that the advantages of t o conversion of all w known, orcourse. derivatives diller outstanding merit the instant invention may be achieved in increas-' ing degree by the use of greater amounts of carboxylates of the preferred metals set forth herein and correspondingly lesser amounts of carboxylates of other metals suitable for use in the process as more generally claimed in the parent applications. It is, of course. essential in order to achieve a beneficial result to use substantial proportions of the carboxylates of the preferred metals Preferred conditions for our process include the maintenance of temperatures between about tact between the hydrogen and the reacting salts, the maintenance of a constant supply of hydrogen. and time under these reaction conditions sufiicient for the attainment of substantial completion of the reaction.

Having thus described our invention, what we claim and desire to secure by Letters Patent is:

1. In a process for forming alcohols, the step which consists essentially of subjecting to reaction with hydrogen a. mixture of salts of carboxylic acids corresponding to said alcohols, said mixture of salts comprising essentially carboxylates of cadmium and of at least one metal se- Process conditions Results Pressure Time Percent alcohol I as e e as; sees as p... MI- WN was? Lbs.

as a 8 car sass ado" 1 Percent reduction oi oarboxyl grou Percent total alcohol, free and com Iodine value of acid alcohol) obtained thereir 4 Values not determined.

Our process as exemplified by the above specific applications is equally applicable to treatment of soaps or all fatty acids occurring in natural vegetable, animal, and marine fats and oils. Thus carboxylates of our preferred metals and of fatty acids derived from coconut oil, tallow, vegetable oils, fish oils, hydrogenated oils, etc., may be treated to produce the corresponding fatty alcohols. Similarly, our process is applicable to hydrogenation of metallic salts or carboxylic acids ined. in acid washed product we shed product or o! unsaponiflable matter iincluding total lected from the and copper, the reaction temperature and hydrogen pressure being sufliciently above atmospheric to efiect substantial reduction CH20- of said alcohols.

2. In a process for forming fatty alcohols, the step which consists essentially of subjecting to reaction with hydrog fatty acids corresponding to said alcohols, said group consisting of chromium" en a mixture of soaps of assaoar mixture 0! soaps comprising essentially soaps oi cadmium and of at least one metal selected from the group consisting of chromium and copper, the reaction temperature and hydrogen pressure being suillciently above atmospheric to effect sub-' stantial reduction of the carboxylic group -CO0 of said soaps to the group -CH2-O- of said alcohols.

3. The process of forming fatty alcohols, which comprises subjecting to reaction with hydrogen, at a temperature between about 240 and 400 C. and at a hydrogen pressure above 2000 pounds per square inch, a mixture oi! soaps of fatty acids corresponding to said alcohols, said mixture of soaps comprising essentially soaps of cadmium and of at least one metal selected from the group consisting of chromium and copper. 4. The process of claim 3, in which the soaps are soaps of unsaturated fatty acids, whereby the alcohols formed are for the most part unsaturated alcohols.

5. The process of claim 3, comprise soaps of oleic acid.

6. The process oi claim comprise soaps oi coconut oil mixed fatty acids.

in which the soaps s, in which the scars '7. The process of forming iatty alcohols which comprises subjecting to reaction with hydrogen. at a temperature between about 240 and 400 C. and at a hydrogen pressure above 2000 pounds per square inch, a mixture'oi soaps of fatty acids corresponding to said alcohols, said mixture consisting of soaps of cadmium and copper.

8. The process of forming higher alcohols which comprises: subjecting to reaction with hydrogen, at a temperature between about 240 and 400 C. and at a hydrogen pressure above 2000 pounds per square inch, a mixture of soaps of fatty acids corresponding to said alcohols, said mixture of soaps ,comprising essentially soaps of cadmium and of at least one metal selected from the group consisting of chromium and copper, freeing the organic reaction products of said hydrogenating step of tree and combined metal by treatment with mineral acid; reacting fatty acids and esters in the resulting acid washed material with caustic alkali: and separating free alcohols from the resulting mixture.

ALBERT S. RICHARDSON. JAMES E. TAYLOR.