| abstract |
Starting from natural fats and oils containing free fatty acids, fatty acid methyl esters can be obtained by a) the free fatty acids present in the starting material in the presence of acidic esterification catalysts at 50 to 120 ° C. and pressures from normal pressure to 5 bar with methanol, compared to the free ones Fatty acids are present in excess, esterified and the alcohol phase containing the catalyst and part of the water of reaction is separated off, b) the remaining oil phase is extracted with a glycerol-methanol mixture to remove the remaining water of reaction and c) the treated oil phase of the alkali-catalyzed unpressurized transesterification with methanol submits. |