纳米固体碱CaO-ZrO_2催化红麻籽油制备生物柴油

Preparing Biodiesel from Flaxseed Oil Using CaO-ZrO_2 Solid Base Catalyst

采用溶胶-凝胶法制备了CaO摩尔分数为10%～50%的CaO-ZrO2系列纳米催化剂,将其用于催化红麻籽油制备生物柴油,通过CO2-TPD、XRD和TEM等测试技术对催化剂的碱性、结构和表面形貌进行表征。结果表明,CaO摩尔分数低于30%时,CaO与ZrO2形成连续固溶体,催化剂具有良好的热稳定性能,粒径为10～20 nm。催化实验表明,当CaO摩尔分数为30%时,CaO-ZrO2催化剂具有最好的催化活性,甲醇与红麻籽油的摩尔比为12∶1、催化剂为油料质量比的2.5%、反应时间3 h时,最高转化率可达到93.2%。

CaO-ZrO2 nanoparticles with CaO molar fraction ranging from 10% to 50% were prepared by the sol-gel method and their catalytic performances were evaluated in biodiesel production from flaxseed oil; XRD, CO2-TPD, and TEM were employed for the catalyst characterization. The results indicate that when CaO molar fraction was lower than 30%, the samples form CaO-ZrO2 homogeneous solid solution, which possesses good thermal stability and the grain diameter is 10 -20 nm. The experimental results show that the highest catalytic activity can be achieved when CaO molar fraction was 30%. The yield of conversion could reach 93.2% when the reaction conditions were optimized for the transesterification of flaxseed oil. The dosage （ mass ratio） of catalyst to oil was 2. 5%, the reaction temperature and time were 65℃ and 2 h respectively, and the molar ratio of methanol to oil is 12： 1.