植物油制备生物柴油的研究

Study on the Preparation of Bio-Diesel by Vegetable Oil

分别以菜籽油、大豆油以及芸香籽油为原料,采用碱催化酯交换法制备了脂肪酸甲酯即生物柴油。结果表明,用碱催化酯交换法制备脂肪酸甲酯,原料的酸价低于1.5mgKOH/g时能够保证较高的脂肪酸甲酯收率,采用酸催化预酯化法对高酸价的油脂原料进行脱酸效果比较显著。浓硫酸不仅是油脂预酯化脱酸反应的催化剂,也是油脂与甲醇进行酯交换反应的催化剂,但与甲醇钠等碱性催化剂相比,相同条件下的酯交换反应转化率低。采用减压蒸馏的方法提纯生物柴油,在0.098MPa的真空度下应控制其馏出温度不超过240℃。

Series of fatty acid methyl esters (bio-diesel ) are prepared by transesterification reaction with vegetable oils such as colza oil, soybean oil etc. as raw materials and using alkaline catalyst. The experimental result indicates that, when acid value of raw materials is lower than 1.5 mg KOH/g, higher yield of fatty acid methyl esters can be obtained. As for vegetable oil of high acid value, preesterification using acid catalyst can lead satisfactory deacidification effect. Concentrated sulfuric acid is not only used as catalyst in deacidficaton reaction in preesterification of vegetable oils, but also is used as catalyst in preesterification reaction between vegetable oils and methanol. But in comparison with alkaline catalyst such as sodium methonate, the conversion rate of transesterification under the same condition is lower . The refining of fatty acid methyl ester takes place by vaccum distillation at vaccum pressure 0.098 MPa and vaccum temperature range lower than 240 ℃.