Patent GB-590951-A (GB)
Title: An improved process for converting lower into higher molecular weight glycerides
IPC: C11C3/10
Filed: 1945-04-20
Abstract: <PICT:0590951/III/1> Glyceride oils or fats containing glycerides of relatively low molecular weight fatty acids, such as fish or coconut oil, are improved by subjecting them to the vapours of lower alkyl esters of higher molecular weight fatty acids (e.g. the methyl esters of the fatty acids of linseed, soya bean or dehydrated castor oil) so as to replace the lower molecular weight fatty acids in the glycerides by the higher molecular weight fatty acids of the alkyl esters.  The lower molecular weight fatty acids may be recovered from their alkyl esters formed in the above process and utilised as plasticizers or for soap manufacture, while the methyl alcohol simultaneously recovered may be used for the preparation of further quantities of higher molecular weight fatty acid esters. In the illustrated embodiment the glyceride oil may be continuously treated with the alkyl esters by introducing it into the top of a fractional distillation column 1 through conduit 4, heat interchanger 5 and control valve 6 while the vapours of the esters are led into the bottom of the column through valve 31, conduit 30 and boiler 2, the vapours of the alkyl esters of the low molecular weight fatty acids formed by the reaction being continuously removed from the top of the column through conduit 11, condenser 12 and valve 15.  The reconstituted glyceride oil is continuously discharged from the bottom plate of the column through conduit 25 and liquid trap 26 and any unreacted alkyl esters of high molecular weight fatty acids recovered therefrom by distillation in the still 20 preferably at an absolute pressure of the order of 1-4 mm. of mercury by means of the barometric condensers 35, 40 and 41 and the boosters 36.  The fractionating column 1 is preferably maintained at a reduced pressure of the order of 20-40 mm. absolute at the top and at a temperature range from top to bottom of about 250-300 DEG C.  The process may be carried out in the presence of a catalyst, e.g. 0.5 per cent. sodium methylate.  Fish oil treated as above is given physical and chemical characteristics similar to those of tung oil, and hence rendered more suitable for varnish manufacture.  The C6, C8 and C10 fatty acids in coconut oil may be replaced by higher fatty acids and the oil thereby rendered more suitable for soap manufacture, while the recovered lower fatty acids may be used as plasticizers.  In the treatment of coconut oil the alkyl esters employed may be prepared from coconut oil itself. Specification 249,916, [Class 91], is referred.ALSO:<PICT:0590951/IV/1> Glycerides of relatively low molecular weight fatty acids are converted into glycerides of higher molecular weight fatty acids by subjecting them to the vapours of lower alkyl esters of the higher molecular weight fatty acids, alkyl esters of the lower molecular weight fatty acids being simultaneously formed.  In the illustrated embodiment of a continuous method of carrying out the invention, the glyceride to be converted is introduced into the top of a fractional distillation column 1 through conduit 4, heat interchanger 5 and control valve 6, while the ester vapours enter the bottom of the column through valve 31, conduit 30 and boiler 2, the vapours of the alkyl esters of the low molecular weight fatty acids formed by the reaction being continuously removed from the top of the column through conduit 11, condenser 12 and valve 15.  The converted glyceride is continuously discharged through the bottom plate of the column through conduit 25 and liquid trap 26 and unreacted alkyl esters removed therefrom by distillation in the still 20, preferably at about 1-4 mm. mercury absolute pressure, by means of the barometric condensers 35, 40 and 41 and the boosters 36.  The fractionating column 1 is preferably maintained at a pressure of about 20-40 mm. absolute at the top and at a top to bottom temperature range of about 250-300 DEG  C.  A catalyst such as sodium methylate may be used.  The process may be used for converting the lower molecular weight glycerides present in oils such as fish or coconut into higher molecular weight glycerides.  Fish oils thus modified are said to be rendered more suitable for varnish manufacture, and coconut oils for soap manufacture.  Specification 249,916, [Class 2 (iii)], is referred to.