GB704591A - A method of continuously refining fatty oils - Google Patents

Abstract

<PICT:0704591/III/1> In the continuous refining of fatty oils by admixing therewith alkali hydroxide and alkali sulphate and separation of the soapstock formed by centrifuging, the oil is mixed with excess alkali hydroxide to neutralize the free fatty acids and to effect decolorizing of the oil, and with alkali sulphate in amounts corresponding to 30-80 grs. per 100 grs. alkali hydroxide, the centrifugation of the mixture being carried out at a temperature which has an emulsion-breaking effect on the soap-in-oil type of emulsions. The oil-in-soap type of emulsions which are also formed are unable to exist at this temperature when alkali sulphate is present in the stated proportions. The alkali hydroxide and alkali sulphate may be separately mixed with and atomized in the oil or they may be mixed with one another in the stated relation and together mixed with and atomized in the oil. The alkali hydroxide is perferably mixed with the oil in an amount of 10 to 30 per cent. in excess of that required to neutralize the free fatty acids. The oil may be heated to its emulsion-breaking temperature necessary for the centrifuging, either prior to or after the alkali agents are added. In a suitable plant, the oil in a tank 1 and an aqueous solution of the alkali hydroxide and sulphate in the stated relation in a tank 2 are pumped in measured quantities respectively to a mixer 5. From the latter the mixture is led to a heating unit 6 and thence, after the heating, to a centrifuge 7 for removing the soapstock. In an example, palm oil is refined using sodium hydroxide of 20 DEG B<\>ae. and sodium sulphate.