超声波辅助浸出油茶籽油的动力学和热力学
The Kinetics and Thermodynamics of Ultrasonic-Assisted Camellia Oil Extraction
王琳琳 1邬明娟 1陈小鹏 1韦小杰 1封志远1
作者信息
- 1. 广西大学化学化工学院广西石化资源加工及过程强化技术重点实验室,南宁530004
- 折叠
摘要
采用超声波辅助绿色溶剂碳酸二甲酯浸出油茶籽油,考察了温度、料剂比、超声波功率和油茶籽仁粒径对油茶籽油浸出过程的影响.以分离变量法建立了由洗涤和扩散过程组成的Phenomenological动力学模型,拟合获得浸出活化能Ea、焓△H0、熵△S0和自由能△G0.结果表明,油茶籽油浸出得率随温度、料剂比的增加及粒径的减小而提高,随超声波功率的加强先增加后减少;洗涤阶段速率常数k1为0.619～1.112 min-1,扩散阶段速率常数k2为0.022 ～0.065 min-1,2个阶段的活化能分别为4.41和5.85 kJ/mol,试验数据与动力学模型拟合良好;浸出过程的焓△H0和熵△S0分别为18.02 kJ/mol和72.20 J/mol,自由能△G0为-7.10～-4.94 kJ/mol.表明浸出过程是吸热、不可逆且自发进行的.
Abstract
The influence of temperature,solid-to-solvent ratio,ultrasound power and particle size on ultrasonic-assisted camellia oil extraction by green solvent dimethyl carbonate were investigated.The phenomenological kinetic model including washing and diffusion steps was developed based on the separated variable method.The activation energy Ea,enthalpy change AH0,entropy change AS0 and free energy AG0 were calculated.The value of washing step rate constant k1 was 0.619 ～ 1.112 min-1 and the value of diffusion step rate constant k2 was 0.022 ～ 0.065 min-1 Activation energy values of the two steps were 4.41 and 5.85 kJ/mol,respectively.The results indicated that the phenomenological model fitted the experimental data very well.The value of enthalpy change and entropy change were 18.02 kJ/mol and 72.20 J/mol,respectively.The value of free energy obtained from the camellia oil extraction was-7.10 ～-4.94 kJ/mol.The results indicated that the process was endothermic,irreversible and spontaneous.
关键词
油茶籽油/碳酸二甲酯/超声波辅助浸出/动力学/热力学Key words
camellia oil/dimethyl carbonate/ultrasonic-assisted extraction/kinetics/thermodynamics引用本文复制引用
基金项目
广西自然科学基金(2013GXNSFAA019050)
广西自然科学基金重点项目(2014GXNSFDA118010)
出版年
2015
NETL
NSTL
维普
万方数据