基于均匀设计的生物柴油最优制备工艺参数研究

Determination of the optimum technological parameters for the preparation of bio-diesel based on uniform experiment design

以均匀设计法安排试验,对大豆油在酯交换反应下制备生物柴油的工艺进行了研究.为获得最优制备工艺参数,考查了n(醇)∶n(油)(3∶1～8∶1)、催化剂质量分数(0.4%～1.4%)、反应温度为(45～70℃)、反应时间(40～140min)及其交互作用对生物柴油产率和原料转化率的影响.结果表明:n(醇)∶n(油)、催化剂用量可显著地影响生物柴油的产率和原料转化率.同时甲醇与反应温度、催化剂与反应时间之间存在对抗效应,而甲醇与反应时间、催化剂与反应温度、反应温度与反应时间之间则存在协同作用.利用回归分析和BP神经网络,确定最优工艺参数为:n(醇)∶n(油)=6∶1;催化剂质量分数1.0%;反应温度45℃;反应时间30min.经液相色谱仪测定,生物柴油产率高达97.6%.

The preparation technology of biodiesel from soybean oil by transesterification reaction is studied by using uniform experimental design.The effects of the molar ratio of methanol to oil (3:1~8:1),the mass ratio of catalyst to oil (0.4%~1.4%),the reaction temperature (45~70 ℃),the reaction time (40~140 min) and their interactions on the yield of biodiesel or the conversion percentage of soybean oil are studied to obtain the optimum reaction parameters.The results show that the molar ratio of methanol to oil and the mass ratio of catalyst to oil have significant effect on the yield or the conversion percentage.Moreover,the results show that there is antagonistic effect between methanol and reaction temperature,catalyst and reaction time; however there is synergistic effect between methanol and reaction time,catalyst and reaction temperature,reaction temperature and reaction time.By means of regression analysis and BP neural network,the optimum technology parameters for the preparation of bio-diesel are determined:the molar ratio of methanol to oil of 6:1,the mass ratio of sodium hydroxide (catalyst) to oil of 1%,the reaction temperature of 45 ℃ and the reaction time of 30 min.The yield of biodiesel can reach to 97.6% under the optimum technological parameters,which is measured by liquid chromatography analysis.