GB587533A - Improvements in or relating to alcoholysis of fatty glycerides - Google Patents

Abstract

Glycerine and alkyl esters of fatty acids are prepared by heating a fatty glyceride with an aliphatic monohydric alcohol having one to six carbon atoms per molecule in the presence of an alcoholysis catalyst at a temperature above the normal boiling point of the monohydric alcohol and at a pressure sufficient to maintain a liquid monohydric alcohol phase. Suitable fatty glycerides are coconut, palm, olive, cottonseed, corn, tung, whale or fish oils and tallow, while suitable monohydric alcohols are methyl, ethyl, propyl, isopropyl, butyl, isobutyl, secondary butyl, tertiary butyl and the amyl alcohols. Alcoholysis catalysts which may be employed are sodium hydroxide, sodium methylate, sodium carbonate, barium oxide, lime, tetramethyl ammonium hydroxide, boron trifluoride, aluminium chloride, hydrochloric acid, trichloracetic acid, phosphoric acid, glycerine mono-acid sulphate, sulphuric acid, organic sulphonic acids and alkyl sulphuric acids. The glyceride employed may be refined but the presence of water or free fatty acid may be tolerated. The alcoholysis process, which may be a batch or a continuous process, may be brought to the degree of completion desired in a single contacting of the reaction materials or, alternatively, the multi-stage process of Specification 587,523 may be employed. If desired, the pressure employed during the alcoholysis may be low enough to permit the volatilization of a portion of the monohydric p alcohol. Following the alcoholysis, any soap formed through the presence of an alkaline alcoholysis catalyst may be decomposed with acid and any unreacted monohydric alcohol may be distilled off. Glycerine and alkyl esters may be recovered by distillation or by allowing the mixture to settle, the glycerine separating as a lower layer. In examples, (a) coconut oil is reacted with ethyl alcohol in presence of caustic soda or sulphuric acid, (b) coconut oil or tallow is reacted with methyl alcohol in presence of sulphuric acid and (c) cottonseed oil or a mixture of coconut oil and tallow is reacted with methyl alcohol in presence of caustic soda. The Specification as open to inspection under Sect. 91 describes the alcoholysis of fatty acid esters of higher alcohols, such as woolfat, and states that aryl-substituted aliphatic alcohols such as benzyl alcohol may be employed. This subject-matter does not appear in the Specification as accepted.ALSO:Glycerine and alkyl esters of fatty acids are prepared by heating a fatty glyceride with an aliphatic monohydric alcohol having 1 to 6 carbon atoms per molecule in the presence of an alcoholysis catalyst at a temperature above the normal boiling point of the monohydric alcohol and at a pressure sufficient to maintain a liquid monohydric alcohol phase. Suitable fatty glycerides are coconut, palm, olive, cottonseed, corn, tung, whale or fish oils and tallow, while suitable monohydric alcohols are methyl, ethyl, propyl, isopropyl, the butyl and the amyl alcohols. Alcoholysis catalysts which may be employed are sodium hydroxide, carbonate or methylate, barium oxide, lime, tetramethyl ammonium hydroxide, boron trifluoride, aluminium chloride, hydrochloric acid, trichloroacetic acid, phosphoric acid, glycerine mono-acid sulphate, sulphuric acid, organic sulphonic acids and alkyl sulphuric acids. The glyceride employed may be refined but the presence of water or free fatty acid may be tolerated. The alcoholysis process, which may be a batch or a continuous process, may be brought to the degree of completion desired in a single contacting of the reaction materials or, alternatively, the multi-stage process of Specification 587,523 may be employed. If desired, the pressure employed during the alcoholysis may be low enough to permit the volatilisation of a portion of the monohydric alcohol. Following the alcoholysis, any soap formed through the presence of an alkaline alcoholysis catalyst may be decomposed with acid and any unreacted monohydric alcohol may be distilled off. Glycerine and alkyl esters may be recovered by distillation or by allowing the mixture to settle, the glycerine separating as a lower layer. In examples: (a) coconut oil is reacted with ethyl alcohol in presence of caustic soda or sulphuric acid; (b) coconut oil or tallow is reacted with methyl alcohol in presence of sulphuric acid and (c) cottonseed oil or a mixture of coconut oil and tallow is reacted with methyl alcohol in presence of caustic soda. The Specification as open to inspection under Sect. 91 describes the alcoholysis of fatty acid esters of higher alcohols, such as wool fat and states that aryl-substituted aliphatic alcohols such as benzyl alcohol may be employed. This subject-matter does not appear in the Specification as accepted.