微藻油脂制备生物柴油和富集多不饱和脂肪酸甘油酯工艺的研究

发布时间：2018-01-20 16:06

  本文关键词： 微藻油脂 生物柴油 PUFAs甘油酯 Novozym 435脂肪酶 分子蒸馏法 单因素优化 响应面法 二十二碳五烯酸(DPA) 二十二碳六烯酸(DHA) 回收率　出处：《华中科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：微藻油脂不仅是生物柴油制备的理想原料,还可作为多不饱和脂肪酸的重要来源。对于多不饱和脂肪酸含量相对较高的微藻油脂,可将生物柴油生产和多不饱和脂肪酸(PUFAs)富集工艺过程整合起来,从而在获得高价值的PUFAs甘油酯产品的同时解决藻油制备生物柴油成本较高的问题。本文首先研究并优化了微藻油脂乙酯化工艺,然后探索了分子蒸馏法富集PUFAs乙酯的条件,在此基础上,研究了PUFAs乙酯转化为PUFAs甘油酯的酶法工艺,获得如下主要结果。(1)通过单因素实验优化,获得碱法催化藻油乙酯化最优条件为:NaOH用量1.0%,温度75.0°C,醇油摩尔比10.0:1,反应时间2.0 h,乙酯得率达96.03%。同时,通过单因素及响应面优化,获得的酶法乙酯化最优条件为:Novozym 435脂肪酶用量6.0%,醇油摩尔比4.0:1,温度44.7°C,反应时间17.6 h,乙酯得率可达94.86%。通过比较发现,酶法催化乙酯化反应条件温和,得到的产品品质好,且不需要后期处理,是更适合的工艺方法。(2)研究了分子蒸馏法富集多不饱和脂肪酸乙酯工艺,优化获得的最优条件为温度90°C,转速150 rpm,最优条件下重相得率为43.79%,主要脂肪酸成分为C18:1(4.36%),C18:2(2.02%),C20:5(1.54%),C22:5(22.39%)和C22:6(58.96%),重相中二十二碳五烯酸(DPA)和二十二碳六烯酸(DHA)乙酯含量为81.35%,DPA和DHA乙酯回收率为87.20%。轻相得率为56.21%,主要脂肪酸成分为C14:0(15.56%),C16:0(35.80%),C16:1(2.76%),C18:1(17.30%),C18:2(9.33%),C18:3(2.16%),C22:5(2.80%),C22:6(6.50%),可作为生物柴油。(3)通过单因素及响应面法优化了PUFAs乙酯转化为PUFAs甘油酯的酶法工艺,获得的PUFAs甘油酯合成的最优条件为:Novozym 435脂肪酶用量3.1%,乙酯甘油摩尔比3.1:1,温度61.3°C,PUFAs甘油酯得率为96.96%。通过分子蒸馏除去反应中残留乙酯后,产物成分为甘油三酯(TAG,71.74%),1,3-甘二酯(1,3-DAG,23.26%),1,2-甘二酯(1,2-DAG,4.75%),单甘酯(MAG,0.10%)。(4)在整个生物柴油制备和PUFAs甘油酯富集工艺中,生物柴油得率为56.07%,主要脂肪酸成分为C14:0(15.56%),C16:0(35.80%),C16:1(2.76%),C18:1(17.30%),C18:2(9.33%),C18:3(2.16%),C22:5(2.80%),C22:6(6.50%)。PUFAs甘油酯得率为43.04%,甘油酯成分为TAG(71.74%),1,3-DAG(23.26%),1,2-DAG(4.75%),MAG(0.10%),甘油酯中DPA和DHA总含量为83.93%,是原油中的2.2倍,DPA和DHA回收率为85.80%。
[Abstract]:Microalgal oil is not only the ideal raw material for biodiesel preparation, also can be used as an important source of polyunsaturated fatty acids. The unsaturated fatty acid content was relatively high in microalgal oil, the biodiesel production and polyunsaturated fatty acids (PUFAs) enrichment process integration, so as to solve the algae oil preparation the high cost of biodiesel in PUFAs glycerol ester products of high value at the same time. This paper research and optimization of the microalgae oil ethyl esterification, and then explore the molecular distillation process of ethyl PUFAs enrichment conditions, on this basis, the research of PUFAs ethyl into enzymatic process PUFAs glycerol ester, the main results are as follows. (1) optimized by single factor experiment, obtained by alkali catalyzed esterification of algal oil optimal conditions were: NaOH dosage 1%, temperature 75 C, molar ratio of methanol to oil 10.0:1, the reaction time is 2 h, the yield of ethyl 96.03%. When optimized by single factor and response surface, the optimal conditions of enzymatic ester obtained for: Novozym 435 lipase dosage 6%, molar ratio of methanol to oil 4.0:1, temperature 44.7 C, reaction time is 17.6 h, the yield of ethyl 94.86%. by comparison, enzymatic esterification reaction conditions are mild, the quality of products well, and do not need treatment, process is more suitable. (2) to study the molecular distillation enrichment of polyunsaturated fatty acid ethyl ester process, the optimal conditions obtained for the temperature of 90 degrees C, speed of 150 rpm, the optimum conditions of heavy phase was 43.79%, main fatty acid compositions were C18:1 (4.36%), C18:2 (2.02%), C20:5 (1.54%), C22:5 (22.39%) and C22:6 (58.96%), phase twenty-two heavy carbon five acid (DPA) and twenty-two (DHA) six carbon acid ethyl ester content is 81.35%, DPA recovery rate of 87.20%. and DHA ethyl light phase was 56.21%, the main fatty acid composition C14:0 (15.56%),C16:0(35.80%),C16:1(2.76%),C18:1(17.30%),C18:2(9.33%),C18:3(2.16%),C22:5(2.80%),C22:6(6.50%),鍙�浣滀负鐢熺墿鏌存玻�

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