Patent GB-762123-A (GB)
Title: A process for the separation of saturated and unsaturated fatty acids or their volatile esters with the simultaneous preparation of condensation products of the unsaturated fatty acids
IPC: C11C1/00
Filed: 1954-02-19
Abstract: Saturated and unsaturated fatty acids having 8 to 24 carbon atoms, or esters thereof, are separated by heating a mixture containing not more than about 10 per cent of unsaturated fatty acids having two or more double bonds and in total not more than about 60 per cent, preferably not more than about 50 per cent of unsaturated fatty acids, with an excess of maleic anhydride, calculated on the unsaturated fatty acids, at a temperature of 120-300 DEG  C. for such a time that the unsaturated fatty acids are completely or substantially completely condensed with the maleic anhydride, the unchanged fatty acids or esters being separated from the condensation products by distillation and/or by treatment with a solvent. Preferably at least 200 mol. per cent of maleic anhydride is used and the condensation is carried out in the presence of iodine or a compound capable of generating iodine as catalyst as described in Specification 762,122.  The preferred temperature range is from 175 DEG  to 250 DEG  C.  The catalyst is advantageously added at a temperature at which the mixture of fatty acids or esters and maleic anhydride is homogeneous, preferably at reaction temperature.  The condensation may be effected in a high-boiling inert solvent such as " Tetralin ", " Decalin " (Registered Trade Marks) or ketones. Suitable solvents for separating the unchanged acids or esters from the condensation products are petrol ether, gasoline, cyclohexane and " Decalin ".  When non-volatile esters, e.g. triglycerides, are the starting materials, the reaction product may be saponified or converted into volatile esters by re-esterification, prior to separation from the condensation products by distillation.  The process may be used for the removal of unsaturated acids from destruction fat and bone fat, coconut and palm oil fatty acids, partly hydrogenated fats and oils, and stearins.  In examples using some of the above starting materials, the substrate is heated with maleic anhydride in the presence of iodine for about 3 hours, and then the unchanged fatty acids are distilled off. Specification 500,348, [Group IV], U.S.A.  Specifications 2,298,501, 2,306,281, 2,444,328 and French Specification 775,700 also are referred to.ALSO:Saturated and unsaturated fatty acids having 8-24 carbon atoms, or esters thereof, are separated by heating a mixture containing not more than about 10 per cent of unsaturated fatty acids having two or more double bonds and in total not more than about 60 per cent, preferably not more than about 50 per cent, of unsaturated fatty acids, with an excess of maleic anhydride, calculated on the unsaturated fatty acids, at a temperature of 120 DEG -300 DEG C. for such a time that the unsaturated fatty acids or esters are completely or substantially completely condensed with the maleic anhydride, the unchanged fatty acids or esters being separated from the condensation products by distillation and/or by treatment with a solvent. Preferably at least 200 mol per cent of maleic anhydride is used and the condensation is carried out in the presence of iodine or a compound capable of generating iodine as catalyst, as described in Specification 762,122 [Group IV(b)].  The preferred temperature range is 175-250 DEG C.  The catalyst is advantageously added at a temperature at which the mixture of fatty acids or esters and maleic anhydride is homogeneous, preferably at reaction temperature.  The condensation may be effected in a high-boiling inert solvent such as "Tetralin" or "Decalin" (Registered Trade Marks).  Suitable solvents for separating the unchanged acids or esters from the condensation products are petrol ether, gasoline, cyclohexane and "Decalin."  When non-volatile esters, e.g. triglycerides, are the starting materials, the reaction product may be saponified or converted into volatile esters by re-esterification, prior to separation from the condensation products by distillation.  The process may be used for the removal of unsaturated constituents from bone fat, coconut and palm oil fatty acids, partly hydrogenated fats and oils, and stearin. In examples using some of the above starting materials the substrate is heated with maleic anhydride in the presence of iodine for about 3 hours, and then the unchanged fatty acids are distilled off. Specification 500,348, U.S.A. Specifications 2,298,501, 2,306,281, 2,444,328 and French Specification 775,700 also are referred to