Abstract: Tert-butanol was adopted as a reaction medium for lipase-catalyzed methanolysis of oils for biodiesel production, in which both the negative effects caused by excessive methanol and by-product glycerol could be eliminated. The optimum conditions of methanolysis of rapeseed oil were as follow: tert-butanol/oil (volumetric ratio) 1:1, methanol/oil (molar ratio) 4:1, 3% Lipozyme TLIM and 1% Novozym 435 based on oil weight, 35℃, 130 r/min and 12 h. The highest biodiesel yield was 95% and the lipases could be reused 200 cycles without obvious loss of their activity. The technology was further tested in a pilot plant and the product was up to the biodiesel standards of US (ASTM PS121-99) and Germany (DINE51606). Furthermore, soybean oil, tung oil, cottonseed oil, sapium fat and acidified waste oil were also explored for biodiesel production, and lipases also showed good stability in tert-butanol reaction medium.

Key words: biodiesel, tert-butanol, immobilized lipase, stability

摘要： 用叔丁醇作为反应介质，利用固定化脂肪酶催化油脂原料甲醇醇解反应制备生物柴油，消除了甲醇和甘油对酶的负面影响，酶的使用寿命显著延长. 用菜籽油作原料，叔丁醇和油脂的体积比为1:1，甲醇与油脂的摩尔比为4:1，3%的Lipozyme TLIM和1%的Novozym 435结合使用，35℃下130 r/min反应12 h，生物柴油得率可达95%. 该工艺在200 kg/d的规模下制得的生物柴油产品完全满足美国和德国生物柴油标准，脂肪酶重复使用200批次，酶活性基本没有下降. 且在叔丁醇介质体系中大豆油、桐籽油、棉籽油、乌桕油、泔水油、地沟油和酸化油都能被有效转化成生物柴油且脂肪酶保持很好的稳定性.

关键词: 生物柴油, 叔丁醇, 脂肪酶, 稳定性