B酸离子液体催化棉籽油酯交换制备生物柴油

制备了5种对水稳定性好、带—SO3H官能团的磺酸类B酸离子液体,并以它们作催化剂进行了棉籽油酯交换反应制备生物柴油的研究。实验结果表明,这些磺酸类B酸离子液体的催化活性高,它们的催化活性与含氮官能团的种类和碳链长度有关,其中,吡啶丁烷磺酸硫酸氢盐离子液体的催化活性最高。考察了吡啶丁烷磺酸硫酸氢盐离子液体的用量、醇与油摩尔比、反应温度对酯交换反应的影响及离子液体的稳定性,实验结果表明,在反应温度170℃、n(甲醇)∶n(棉籽油)∶n(离子液体)=12∶1∶0.057、反应时间5h的条件下,产物中脂肪酸甲酯的质量分数可达92.0%,且离子液体的稳定性好,可循环使用。

Preparation of Biodiesel Oil from Cottonseed Oil Catalyzed by'''' Ionic Liquids

Preparation of biodiesel oil from cottonseed oil catalyzed by B-acidic ionic liquids was studied.Several water-stable B-acidic ionic liquids with an alkane sulfonic acid group were synthesized and showed good catalytic activity in transesterification of cottonseed oil to biodiesel oil.Catalytic activity of each ionic liquid depended upon the type of nitrogen containing group and length of carbon chain.The ionic liquid 1-(4-sulfonic acid)butyl-pyridinium hydrosulfate showed the best catalytic activity to transesterification.Effects of ionic liquids dosage,mole ratio of methanol to cottonseed oil and reaction temperature on transesterification and stability of ionic liquids were investigated.Under optimal transesterification conditions:n(methanol) ∶n(cottonseed oil) ∶n(ionic liquids)=12 ∶1 ∶0.057 ,temperature 170℃ and time 5h,mass fraction of fatty acid methyl ester could reach 92.0%.The ionic liquids were stable and could be reused.