摘要
以黄连木籽为原料,采用乙醇/异己烷两相不互溶溶剂对其进行萃取处理。考察了乙醇/异己烷体积比、萃取温度和萃取时间对萃取过程的影响。通过实验确定最佳的萃取条件为,黄连木仁粉50 g,乙醇异己烷总体积300 mL,乙醇/异己烷体积比为50∶50,萃取温度40℃,萃取时间30 min。在此条件下,黄连木籽油出油率达到99.5%,黄连木籽油中游离脂肪酸的质量分数降低到0.37%,水的质量分数降低到0.046%,达到碱催化转酯化制备生物柴油对原料油脂的要求。考察了参加酯交换反应的非极性相中异己烷与黄连木籽毛油的比例对酯交换反应的影响,确定了异己烷与黄连木籽油的最佳质量比为2∶1;考察了酯交换反应的条件,结果表明,以Li2O/MgO为固体碱催化剂,用量为2.0%,反应温度65℃,醇油摩尔比9∶1,反应时间3 h下,产物中脂肪酸甲酯的质量分数可达98.1%,催化剂使用10次甲酯质量分数维持在90%左右,表明催化剂具有较高的催化活性和稳定性。
The preparation of biodiesel from pistacia chinensis bunge （PCB） seed oil produced by twophase solvent extraction （TSE） was studied. The results show that the optimal extraction conditions are 50 g samples, ethanol/iso-hexane volume ratio 50：50 and the total volume of 300 mL at 40 ℃ with duration of 30 min. Under these conditions, the extraction rate of PCB seed oil could achieve 99.5 %, and the free fatty acid （FFA） and water contents of PCB seed oil are reduced to 0.37% and 0. 046%, respectively. This meets the requirement of alkalicatalyzed transesterification. After the TSE process of PCB seed, the investigations were carded out on transesterification of methanol with oil-isohexane solution coming from TSE process in the presence of Li20/ MgO as solid base catalyst. The influences of weight ratio of iso-hexane to PCB seed oil, alkali catalyst amount, reaction temperature, molar ratio of methanol to oil and reaction time on PCB seed oil conversion were investigated separately. The fatty acid methyl ester content could achieve 98. 1% using 2.0% （catalyst/oil weight ratio） solid base catalyst at 65 ℃ and 3 h, 2 ： 1 weight ratio of isohexane/oil and 9 ： 1 mole ratio of methanol/oil. The fatty acid methyl ester content remains 90% after the solid base catalyst was reused ten times. The results indicates that the catalyst of Li20/MgO has a higher activity and stability.
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
2011年第12期907-911,共5页
Journal of Fuel Chemistry and Technology
关键词
生物柴油
脂肪酸甲酯
两相萃取
黄连木籽油
固体碱催化
biodiesel
fatty acid methyl ester
twophase solvent extraction
pistacia chinensis bunge seed oil
solid base catalyst
