微生物油脂酯化工艺优化

Optimization Process for Catalytic Esterification of Microbial Lipid

深黄被孢霉M2(M.iabellina)高效利用玉米秸秆水解液中的五碳糖和六碳糖,发酵产微生物油脂(细胞干重21.2g/L,菌体油脂含量56.5%)。研究酸催化脱酸-碱催化酯交换两步法由微生物油脂产微生物柴油的工艺条件。确定了微生物油脂脱酸条件:催化剂H2SO4用量为5%,醇油摩尔比为12∶1,反应温度为65℃,反应时间为2h,在此优化反应条件下,微生物油脂从高酸值24.47mgKOH/g降至1.60mgKOH/g。利用Box-Benhnken中心组合设计实验和响应面分析法(response surface methodology,RSM)优化微生物油脂转酯化工艺参数:催化剂KOH用量为1.25%,醇油摩尔比为10∶1,反应温度为57℃,反应时间为1.47 h,此优化条件下微生物柴油收率达到93.39%。

Microbial lipid fermentation production（cell dry weight of 21.2g/L, microbial lipid content exceed 56.5%） from corn straw hydrolysate of pentose and hexose used efficiently by Mortierella iabellina M2. The process for prepared microbial diesel from microbial lipids by a two-step catalyzed process of acid catalysis deacidification-base catalysis transesterification was focused. The optimal reaction conditions of esterification： the H2SO4 catalyst concentration of 5%, methanol to oil molar ratio 12∶1, reaction temperature is 65℃ and reaction time 2 h, during the optimization of reaction conditions, the acid value from 24.47mgKOH/g drop to 1.6mgKOH/g, then using the Box-Benhnken center unitized design experiment and the response surface methodology（RSM） optimum microbial oil transesterification reaction conditions： the KOH catalyst concentration of 1.25%, methanol to oil molar ratio10∶1, reaction temperature is 57℃, reaction time was 1.47h. The microbial diesel yield higher than 93.39%.