TRANSESTERIFICATION OF PALM OIL: EFFECT OF REACTION PARAMETERS

摘要

The most practical and suitable method for industrial production of methyl esters of palm oils with negligible free fatty acids (e.g. neutralized palm oil and refined, bleached and deodorized palm oil) is methanolysis of the glycerides catalyzed by sodium hydroxide. Several parts including the type of catalyst, oil/alcohol ratio, temperature, stirring speed and free fatty acids content, have been found to influence the transesterification of palm oil. Optimum reaction conditions were obtained with a molar ratio of methanol-to-oil at 10:1 and a reaction time of 7 min at ca. 65℃. The rate of reaction was optimized at a stirring speed of 150 rpm. The minimum amount of methanol required to achieve total conversion was 233% (excess methanol) (a methanol-to-oil molar ratio of 10:1). The catalyst used should not exceed 0.5 mole kg~(-1) oil as otherwise it would cause solidification of the reaction mixture due to soap formation. For a large number of glyceride oils containing < 5% free fatty acids, transesterification to methyl esters can be readily effected using additional sodium hydroxide to neutralize the free fatty acids. Glycerol from the transesterification process was purified from 80%-85% to more than 96% with a yield of not less than 75%.