Abstract:

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.

Key words: CaO-ZrO2, solid base, flaxseed oil, biodiesel