摘要
以正辛酸和甲醇为原料,以离子液体负载磷钨酸为催化剂,考察反应时间、醇酸物质的量比、催化剂用量及反应温度等因素对正辛酸甲酯酯化率的影响,并采用响应面分析法对这些参数进行优化。研究表明优化的最佳反应条件为:催化剂用量为正辛酸用量的4%,醇酸物质的量比8∶1,反应时间3.0 h,温度363 K,在该条件下,正辛酸甲酯的收率达92.5%,结果与模型预测相符。优化条件下,3.0 h内正辛酸甲酯合成反应的活化能为32.09 k J/mol,动力学方程为:r=-dC_A/dt=1.22×10~3exp(-32.09/RT)C_A^(1.73)。
Methyl caprylate is synthesized from caprylic acid and methanol using phosphotungstic acid-based ionic liquids as catalysts. The effects of reaction time, alcohol/acid molar ratio, the amount of catalyst and reaction temperature are also investigated. Meanwhile, the optimum operation conditions are obtained by response surface methodology （RSM）. The study shows that the optimum operating parameters are amount of catalyst 4% weight of caprylic acid, methanol to caprylic acid molar ratio of 8：1, reaction time of 3.0 h and temperature of 363 K, leading to a ester yield of 92.5%, which in close agreement with values predicted by the mathematical model. Under the optimal conditions, the active energy is 32.09 kJ/mol, the kinetic equation in 3.0 h can be expressed as r=-dCA/dt=1.22×10^3exp（-32.09/RT）CA1.73.
出处
《中国食品学报》
EI
CAS
CSCD
北大核心
2017年第9期125-133,共9页
Journal of Chinese Institute Of Food Science and Technology
关键词
离子液体
杂多酸
响应面法
辛酸甲酯
动力学
ionic liquid
heteropoly acid
response surface methodology
methyl caprylate
kinetic study
