Patent GB-587524-A (GB)
Title: Improvements in or relating to the alcoholysis of fatty glycerides
IPC: C11C3/04
Filed: 1943-10-18
Abstract: <PICT:0587524/III/1> A process for the preparation of glycerine and alkyl esters of fatty acids by alcoholysis of fatty glycerides comprises reacting a fatty glyceride with a monohydric aliphatic alcohol having one to six carbon atoms in the molecule in the presence of an alkaline alcoholysis catalyst in excess of that required to neutralise any free fatty acid present, volatilising the unreacted alcohol from the reaction products under conditions precluding any prolonged contact of the reaction products with the catalyst at temperatures conducive to a reverse reaction, and thereafter separating the alkyl esters and glycerine.  The glyceride may be coconut, palm, olive, cottonseed, corn, tung, whale, fish or soyabean oil or tallow, and may be refined to remove moisture and free fatty acids before alcoholysis.  If desired, the glyceride may be refined by an alcohol extraction process with treatment of the alcohol extract as described in Specification 587,751.  The alkaline alcoholysis catalyst may be sodium hydroxide, sodium methylate, sodium carbonate or lime.  After the alcohol has been distilled off, any soap formed by the reaction between fatty glyceride and alkaline catalyst may be removed by salting out with brine or decomposed with acid such as acetic, sulphuric, hydrochloric phosphoric or benzenesulphonic acid or sulphur dioxide, for example as described in Specification 587,532.  Details of other after treatments of the alcoholysis reaction mixture are also given.  Any incompletely reacted glycerides present in the reaction mixture may be recycled as stated in Specification 587,523.  The alcoholysis and the separation of glycerine may be carried out stepwise if desired.  Fig. 2 shows apparatus for carrying out the alcoholysis process.  In this apparatus, fatty glyceride oil from tank 1 and alcohol containing dissolved alcoholysis catalyst from tank 2 mix in coil 3 and the mixture passes into alcoholysis tank 6.  The tank is divided into two parts by partition 9 and from this tank alcohol is flashed off via outlet 10, glycerine is run off through outlet 17 and alkyl esters through outlet 16.  In the examples, coconut oil, corn oil, a mixture of tallow and coconut oil, and a tallow containing free fatty acid, are the fatty glycerides employed and they are reacted with methyl or ethyl alcohol in presence of sodium hydroxide. After removal of the unreacted alcohol by volatilisation and perhaps the acidification of the residue with sulphur dioxide or sulphuric acid, separation into a lower glycerine layer and an upper ester layer occurs.  The ester layer is distilled to separate any partially reacted glycerides and these are returned to the alcoholysis reaction.  The glycerine layer may be purified by salting out any soap present.  Soap manufacture. The alkyl esters may be converted to soaps by saponifying them with sodium or potassium hydroxides, carbonates or silicates, methyl morpholine, piperidine, alkyl amines, alkanolamines, and other inorganic and organic bases and alkaline materials and mixtures of these.  Mixtures of the alkyl esters with monoesters of polyhydric alcohols, of which many are specified, may be saponified and the mixtures may also contain di-, tri- or polyesters.  The saponifying agent may be introduced as a solution in water alcohol or other solvent or may be solvent-free.  Soaps may also be made by hydrolysing the alkyl esters and saponifying the fatty acids thus formed.  Specification 587,533 also is referred to.  The Specification as open to inspection under Sect. 91 refers to the alcoholysis of fatty glycerides and woolfat with alcohols including aryl substituted alcohols such as benzyl alcohol and the use of acid alcoholysis catalysts such as boron trifluoride, aluminium chloride, glycerine sulphate, sulphuric acid, organic sulphonic acids and organic sulphonates is mentioned.  The addition of soap builders, inert materials and antioxidants to either or both of the alkyl ester and the saponifying agent before saponification is described and a long list of adjuvant materials for incorporating in the soaps is given.  This subject-matter does not appear in the Specification as accepted.ALSO:<PICT:0587524/IV/1> A process for the preparation of glycerine and alkyl esters of fatty acids by alcoholysis of fatty glycerides comprises reacting a fatty glyceride with a monohydric aliphatic alcohol having one to six carbon atoms in the molecule in the presence of an alkaline alcoholysis catalyst in excess of that required to neutralize any free fatty acid present, volatilizing the unreacted alcohol from the reaction products under conditions precluding any prolonged contact of the reaction products with the catalyst at temperatures conducive to a reverse reaction, and thereafter separating the alkyl esters and glycerine.  The glyceride may be coconut, palm, olive, cottonseed, corn, tung, whale, fish or soyabean oil or tallow, and may be refined to remove moisture and free fatty acids before alcoholysis.  If desired, the glyceride may be refined by an alcohol extraction process with treatment of the alcohol extract as described in Specification 578,751.  The alkaline alcoholysis catalyst may be sodium hydroxide, sodium methylate, sodium carbonate or lime.  After the alcohol has been distilled off, any soap formed by the reaction between fatty glyceride and alkaline catalyst may be removed by salting out with brine or decomposed with acid such as acetic, sulphuric, hydrochloric, phosphoric or benzenesulphonic acid or sulphur dioxide, for example as described in Specification 587,532. Details of other after-treatments of the alcoholysis reaction mixture are also given.  Any incompletely reacted glycerides present in the reaction mixture may be recycled as stated in Specification 587,523.  The alcoholysis and the separation of glycerine may be carried out stepwise if desired.  Fig. 2 shows apparatus for carrying out the alcoholysis process.  In this apparatus, fatty glyceride oil from tank 1 and alcohol containing dissolved alcoholysis catalyst from tank 2 mix in coil 3 and the mixture passes into alcoholysis tank 6.  The tank is divided into two parts by partition 9 and from this tank alcohol is flashed off via outlet 10, glycerine is run off through outlet 17 and alkyl esters through outlet 16.  In the examples, coconut oil, corn oil, a mixture of tallow and coconut oil, and a tallow containing free fatty acid, are the fatty glycerides employed and they are reacted with methyl or ethyl alcohol in presence of sodium hydroxide. After removal of the unreacted alcohol by volatilization and perhaps the acidification of the residue with sulphur dioxide or sulphuric acid, separation into a lower glycerine layer and an upper ester layer occurs.  The ester layer is distilled to separate any partially reacted glycerides and these are returned to the alcoholysis reaction.  Specification 587,533 also is referred to.  The Specification as open to inspection under Sect. 91 refers to the alcoholysis of fatty glycerides and woolfat with alcohols including aryl substituted alcohols such as benzyl alcohol and the use of acid alcoholysis catalysts such as boron trifluoride, aluminium chloride, glycerine sulphate, sulphuric acid, organic sulphonic acids and organic sulphonates is mentioned. This subject-matter does not appear in the Specification as accepted.