Pd/碳纳米管催化转移氢化大豆油工艺优化及动力学分析

Process Optimization and Kinetic Analysis of Pd/Carbon Nanotubes Catalyzed Transfer Hydrogenation of Soybean Oil

为降低油脂氢化过程中反式脂肪酸的含量,本实验以自制的Pd/碳纳米管(Pd/carbon nanotubes,Pd/CNTs)为催化剂,在催化转移氢化体系中氢化大豆油,通过响应面试验以大豆油碘值为响应值摸索最优工艺条件,同时对催化转移氢化大豆油进行动力学分析。结果表明:最佳工艺条件为氢化温度84℃、催化剂添加量0.20%(以体系质量计)、甲酸铵供体浓度0.33 mol/50 mL、氢化时间90 min,产品的三烯酸、二烯酸和单烯酸反应速率常数分别为4.9×10^(-2)、8.7×10^(-3)和8.31×10(-4),氢化亚麻酸和亚油酸的选择性高达5.63和10.47,氢化后大豆油碘值为95.3 g/100 g,反式脂肪酸相对含量仅为10.2%。采用催化转移氢化的方式进行油脂氢化,对制备低反式氢化油脂具有一定的研究意义和应用前景,也可为油脂氢化工业的发展提供一定的理论依据。

In order to reduce the production of trans-fatty acids during oil hydrogenation,Pd/carbon nanotubes(Pd/CNTs)were used as a catalyst for the transfer hydrogenation of soybean oil.Response surface methodology was used to optimize the reaction conditions based on the iodine value of soybean oil,and the kinetics of the hydrogenation reaction was analyzed.The results showed that the optimum reaction conditions were as follows:hydrogenation temperature 84℃,catalyst dosage 0.2%,ammonium formate donor concentration 0.33 mol/50 mL,and hydrogenation time 90 min.The reaction rate constants for trienoic acid,dienoic acid and monoenoic acid were 4.9×10^(-2),8.7×10^(-3) and 8.31×10^(-4),respectively.The selectivity for hydriding linoleic acid and linoleic acid was as high as 5.63 and 10.47.The iodine value of hydrogenated soybean oil,containing only 10.2%trans-fatty acids,was 95.3 g/100 g.Catalytic transfer hydrogenation has great prospects for application in the preparation of low-trans-fatty-acid hydrogenated oils and can provide a theoretical basis for the development of the oil hydrogenated oil industry.