Na/SiO_2新型固体碱催化制备生物柴油的研究

Research on novel Na/SiO_2 soild basic catalyst for synthesis of biodiesel

以NaOH、正硅酸乙酯和乙醇为原料,经溶胶-凝胶法制备新型固体碱催化剂(Na/SiO2),用于催化大豆油与甲醇的酯交换反应制备生物柴油,研究催化剂焙烧温度、n(NaOH)∶n(SiO2)、n(甲醇)∶n(大豆油)、催化剂用量和反应时间对产率的影响以及催化剂的稳定性。结果表明,固体碱催化剂Na/SiO2在大豆油与甲醇的酯交换反应中具有较高的催化活性,在催化剂焙烧温度600℃、n(NaOH)∶n(SiO2)=2∶1、n(甲醇)∶n(大豆油)=15∶1、催化剂用量为大豆油质量的7%和反应时间3 h的条件下,脂肪酸甲酯产率可达97.42%,催化剂在稳定性试验中呈现出优良的稳定性。

Using NaOH, TEOS, and ethanol as the raw materials, Na/SiO2 solid basic catalyst for the transesterification of soybean oil with methanol to biodiesel fatty acid methyl ester were prepared by sol-gel method. The effects of catalyst calcination temperature, NaOH/SiO2 molar ratio, methanol/soybean oil molar ratio, catalyst dosage, reaction time on the yield of fatty acid methyl ester and the stability of the catalyst were investigated. The experimental results showed that Na/SiO2 solid basic catalyst exhibited high catalytic activity for the transesterification, and soybean oil conversion of 97.42% was attained under the optimal condition as follows ： catalyst calcination temperature 600 ℃, n （ NaOH ） ： n （ SiO2 ） = 2 ： 1, n（methanol）： n（ soybean oil） = 15： 1, catalyst dosage 7% of soybean oil mass and reaction time 3 h. Na/SiO2 solid basic catalyst possessed good stability.