Process for the preparation of fatty-acid esters of short chain aliphatic alcohols from free fatty-acid-containing fats and/or oils

摘要

For the production of fatty acid esters of short-chain, aliphatic alcohols by the catalytic transesterification of natural fats and/or oils containing free fatty acids (oil phase) with the corresponding monoalcohols, the oil phase is subjected to preliminary esterification with the monoalcohols in the presence of acidic esterification catalysts at temperatures no higher than 120 DEG C. and under pressures no higher than 5 bars and in the presence of a liquid entraining agent substantially immiscible with the oil phase, after which the reaction product is separated into an entraining agent phase containing the acidic catalyst and water of reaction and the treated oil phase, the oil phase is then subjected to transesterification while the acidic catalyst-containing entraining agent phase is returned, after at least partial drying, to the preliminary esterification stage. By this process, fats and/or oils with acid numbers of up to 60 can be processed in the preliminary esterification stage to give an oil phase having a low acid number.