Patent GB-399848-A (GB)
Title: Manufacture of higher alcohols from fats or fatty oils
IPC: C07C29/149
Filed: 1932-03-07
Abstract: Higher alcohols are prepared by the treatment of a fat or fatty oil with excess of hydrogen at a temperature of 300-400 DEG  C. and a pressure of 100-205 atmospheres in the presence of a mixed cadmium-copper-zinc chromite catalyst.  If olefinic linkages are present in the products, they may be reduced by further hydrogenation in known manner using a nickel catalyst.  The chromite catalyst may be prepared by adding a solution of ammonium bichromate and ammonium hydroxide to a solution of zinc, copper and cadmium nitrates; after neutralization with further ammonium hydroxide, the mixture is allowed to settle, and the resulting precipitate then washed, dried and ignited; the residue is compressed into tablets and either reduced before or during the reaction.  Examples are given of the hydrogenation of cottonseed oil, palm oil, coco nut oil, and castor oil.  In the case of cottonseed oil and castor oil, further hydrogenation in the presence of nickel is resorted to.  The product obtained from palm oil is mainly cetyl alcohol and from coco nut oil a mixture of octanol, decanol, lauryl alcohol and myristyl alcohol; from the remaining oils, the products comprise semi-solid or solid masses having a reduced saponification value and iodine number. Specifications 356,606, 356,731 and 385,625 are referred to.  The Specification as open to inspection under Sect. 91 also describes the use of mixed hydrogenation catalysts containing substantial quantities of difficulty reducible oxides of hydrogenating metals, in particular those used in the synthesis of methanol and preferably in the form of their chromites.  The metals themselves may also be present, finely-divided copper, cadmium and zinc being specified. Manganese and magnesium oxides, in addition to those above-mentioned, are referred to. The process is stated to be applicable to animal as well as vegetable fats and oils, and to give rise to wax-like materials as well as alcohols.  The amount of wax may be increased by incompletely hydrogenating the oil and then heating it to a temperature above 200 DEG  C., or by heating the partially-hydrogenated oil with more oil or fat or free fatty acids or anhydrides; ester interchange may then take place to form esters of the higher alcohols with the fatty acids.  Reference is also made to the use of a minimum pressure of 13,5 atmospheres and a minimum temperature of 200 DEG  C.  Examples are also included of the partial reduction of linseed oil and china wood oil in the presence of a zinc chromite catalyst, and of the hydrogenation of triacetin and tributyrin to ethyl alcohol and n-butyl alcohol respectively.  This subject-matter does not appear in the Specification as accepted.ALSO:Mixed cadmium-copper-zinc chromite catalysts, used for the conversion of fats or fatty oils with hydrogen into the corresponding higher alcohols, are prepared by adding a solution of ammonium bichromate and ammonium hydroxide to a solution of zinc, copper, and cadmium nitrates, allowing the mixture to settle after neutralization with further ammonium hydroxide, compressing the washed, dried, and ignited precipitate into tablets and effecting reduction before or during the reaction.  Specifications 356,731 and 385,625 are referred to.