GB587530A - Improvements in or relating to the alcoholysis of fatty glycerides - Google Patents

Abstract

In a process for the preparation of alkyl esters of fatty acids, fatty glycerides are subjected to alcoholysis with a saturated straight chain aliphatic alcohol having 1 to 6 carbon atoms per molecule in the presence of an alkaline alcoholysis catalyst and, before separating the alkyl esters and the glycerine of the reaction products, unreacted alcohol is distilled from the reaction products at a temperature above 130 DEG C. at which no substantial reversal of the reaction occurs in the absence of free alcohol. Glycerides mentioned are coconut, palm, olive, cottonseed, corn, soyabean, tung, whale and fish oils and tallow while catalysts mentioned are sodium hydroxide, carbonate or methylate, barium oxide and lime. If desired, the reaction products, after removal of the alcohol, may be acidified with an acid stronger than the fatty acids of the glycerides, preferably with a dilute mineral acid. In examples, (1) coconut oil is subjected to methanolysis in a continuous process in the presence of sodium hydroxide, unreacted methanol being distilled off at 160 DEG C. (2) corn oil is subjected to ethanolysis in a continuous process in the presence of sodium hydroxide, unreacted ethanol being distilled off at 150 DEG C. and (3) a mixture of coconut oil and tallow is subjected to ethanolysis under pressure in a continuous process in the presence of sodium hydroxide, unreacted ethanol being distilled off at 150 DEG C. under reduced pressure. In each of the examples any partially reacted glycerides present among the reaction products are returned for further reaction. Specification 587,533 is referred to. The Specification as open to inspection under Sect. 91 describes the use of aryl-substituted aliphatic alcohols in the alcoholysis process and also refers to the alcoholysis of woolfat. This subject-matter does not appear in the Specification as accepted.ALSO:In a process for the preparation of alkyl esters of fatty acids, fatty glycerides are subjected to alcoholysis with a saturated straight chain aliphatic alcohol having 1 to 6 carbon atoms per molecule in the presence of an alkaline alcoholysis catalyst and, before separating the alkyl esters and glycerine of the reaction products, unreacted alcohol is distilled from the reaction products at a temperature above 130 DEG C. at which no substantial reversal of the reaction occurs in the absence of free alcohol. Glycerides mentioned are coconut, palm, olive, cottonseed, corn, soyabean, tung, whale and fish oils and tallow while catalysts mentioned are sodium hydroxide, carbonate or methylate, barium oxide and lime. If desired, the reaction products, after removal of the alcohol may be acidified with an acid stronger than the fatty acids of the glycerides, preferably with a dilute mineral acid. In examples: (1) coconut oil is subjected to methanolysis in a continuous process in the presence of sodium hydroxide, unreacted methanol being distilled off at 160 DEG C.; (2) corn oil is subjected to ethanolysis in a continuous process in the presence of sodium hydroxide, unreacted ethanol being distilled off at 150 DEG C. and (3) a mixture of coconut oil and tallow is subjected to ethanolysis under pressure in a continuous process in the presence of sodium hydroxide, unreacted ethanol being distilled off at 150 DEG C. under reduced pressure. In each of the examples any partially reacted glycerides present among the reaction products are returned for further reaction. Specification 587,533 is referred to. The Specification as open to inspection under Sect. 91 describes the use of aryl-substituted aliphatic alcohols in the alcoholysis process and also refers to the alcoholysis of woolfat. This subject-matter does not appear in the Specification as accepted.