Patent ID: 6538146
Filing Date: 2003-03-25
Classification: C07C,C10L,C11B,C11C,Y02E

Abstract:
Method for producing fatty acid esters of monovalent alkyl alcohols by base-catalyzed transesterification of triglycerides from natural or synthetic oils and/or fats, which contain free fatty acids as interfering accompanying substances, wherein initially the oils and/or fats are processed with an immiscible basic glycerin phase so as to neutralize the free fatty acids and cause them to pass over into the glycerin phase, and subsequently, following separation of the glycerin phase by means of monovalent alcohols, the triglycerides are subjected to transesterification in an agitator vessel, using a base as a catalyst, to form said fatty acid esters, characterized in that following separation of the fatty acid esters, the basic glycerin phase, produced during transesterification of the triglycerides is used for processing the oils and/or fats for removal of the free fatty acids, with the minimum quantity of catalyst used being calculated, relative to 1,000 g of the oil to be processed, as a function of the acid number of the oil and the mean molar mass of the oil, according to the equations (I) to (III):with an acid number satisfying the inequation (I) SZM(KOH)*Yâ€ƒâ€ƒ(I) according to equation (II)minimum quantity of cat/1,000 g of oil=0.088 mol/100 g oil*Yâ€ƒâ€ƒ(II) or else according to equation (III)minimum quantity of cat/1,000 g oil=(SZ/M/KOH)*(0.088/0.084)â€ƒâ€ƒ(III) withY=(880 g/mol)/(mean molar mass of the used oil) and SZ=acid number of the oil used [(g KOH)/(1,000 g of oil)].