Process for the preparation of hexamethyl tetracosanes

A process for the preparation of 2,6,10,15,19,23-hexamethyl tetracosane and isomers thereof having a basic hexamethyl tetracosane structure, wherein condensed oleins of vegetable origin comprising a mixture of unrefined free fatty acids and unsaponifiables are subjected to:

• a first step in which there is applied a separation process giving rise to the substantial separation, on the one hand, of the fatty acids and, on the other hand, of a concentrated residue of hexamethyl tetracosahexene containing material, said separation process comprising a conversion of the fatty acids into esters and subsequent fractionated distillation;
• a second step in which the fatty material still in said concentrated residue is saponified, resulting in the separation thereof and the preparation of technically pure hexamethyl tetracosahexenes, together with other unsaturated products, said saponification process being conducted by treating said concentrated residue with a base selected from the group comprising an alkaline or alkali earth hydroxide, ammonia, mono- or polyamines, alkanolamines or mixtures thereof and in the presence of a hydrotrope selected from the group comprising sodium toluene sulphonate, sodium xylene sulphonate, sodium naphthalene sulphonate, alcohols of less than 11 carbon atoms, phosphoric esters thereof or of aromatic hydrocarbons or mixtures of any of them, all of which provides an aqueous fraction containing saponified fatty acids and other impurities and a non-polar fraction comprising the hexamethyl tetracosahexenes, which is separated by decantation and subsequently washed;
• a third step consisting of a hydrogenation process, whereby, on the one hand, 2,6,10,15,19,23-hexamethyl tetracosane and the isomers thereof having a basic hexamethyl tetracosane structure are obtained from said hexamethyl tetracosahexenes and, on the other hand, paraffins and other saturated compounds are obtained from said other compounds;
• and a fourth step of deparaffining the hydrogenated products obtained in the previous step by way of a fractionated crystallisation of the paraffins and saturated compounds, subsequent separation by centrifugation or filtration, and formation of urea complexes which remove the paraffins, and purification by steam stripping under high vacuum and high temperature.