【作者】 孙丽霞；

【导师】 童张法；

【作者基本信息】 广西大学 ， 化学工艺， 2013， 博士

【摘要】 由松树树脂经过蒸馏得到的松节油是世界上最丰富的精油资源之一,其主要成分包括α-蒎烯、β-蒎烯、对伞花烃和柠檬烯等。松节油广泛应用于精细化学品的合成,如合成萜烯树脂、萜烯表面活性剂、化妆品以及药物等。松节油组分的汽液平衡和超额焓热力学数据对其深加工及分离过程研究有着重要的意义。通过对不同汽液平衡实验装置的比较,选择适合本体系的改进型Ellis平衡釜测定了β-蒎烯+对伞花烃和β-蒎烯+柠檬烯二元体系以及β-蒎烯+对伞花烃+柠檬烯三元体系在100.7kPa下的汽液平衡数据,二元体系的实验数据通过了Herington法和Van Ness点检验法的热力学一致性检验。以压力为目标函数,采用最小二乘法拟合了Wilson, NRTL, UNIQUAC和Liebermann-Fried的模型能量参数,四个模型具有相近的偏差,但Wilson模型对于易混溶体系的拟合偏差最小。三元体系的汽液平衡数据通过了Wisniak和Tamir改进McDermott-Ellis法的热力学一致性检验。用二元子体系的Wilson模型参数推算出三元体系数据并与实验值比较,三元体系的平均绝对偏差分别为：δT=0.17K, δy1=0.0038, δy2=0.0015, δy3=0.0037,三元体系温度和汽相组成的预测值与实验值吻合良好。采用C80微量量热仪测定了α-蒎烯+声-蒎烯、α-蒎烯+对伞花烃、α-蒎烯+柠檬烯、β-蒎烯+对伞花烃、β-蒎烯+柠檬烯和对伞花烃+柠檬烯六个二元体系在常压及298.15K、303.15K、313.15K下的超额焓数据,用Redicih-Kisetr方程进行关联,实验的绝对误差和相对误差较小,且实验值与文献值分布趋势相吻合。由于四种组分分子结构和双键位置的不同,导致不同组分混合时所需的热量不同,表现出超额焓数值的差异。采用C80微量量热仪测定了α-蒎烯+对伞花烃+柠檬烯、β-蒎烯+对伞花烃+柠檬烯和柠檬烯+α-蒎烯+β-蒎烯三个拟二元体系在常压及298.15K、303.15K、313.15K下的超额焓数据HEm,1+23,并将其与Tsao和Smith推荐的方程计算值进行比较,实验值与计算值偏差较小。结果表明,C80微量量热仪测定的超额焓数据是准确可靠的。结果显示所有的HEm,1+23实验值均为正值,每个体系的最大值均出现x1≈0.5附近,两端呈对称趋势。用HEm,1+23实验值计算出三个三元体系在常压及298.15K、303.15K、313.15K下的超额焓HEm,123,并经过平滑后在Roozeboom图中绘制出等焓线,每个三元体系的一般特性是相似的,而且对于恒定的x1,HEm,123值随着x2/x3摩尔比的增大而增大。采用二元体系β-蒎烯+对伞花烃和β-蒎烯+柠檬烯的超额焓值获得的参数预测两个二元体系的泡点温度和汽相组成,对温度和汽相组成的预测值与实验值进行比较,由Wilson模型预测的泡点温度值与实验测量值吻合良好,平均绝对偏差均小于0.16K,合理地预测了汽相组成,其摩尔分数平均绝对偏差小于0.0032。更多还原

【Abstract】 Turpentine oil, obtained by steam distillation of pine resins, is one of the richest resources of refined oil in the world, its main constituents include a-pinene,β-pinene,p-cymene and (S)-(-)-limonene. Turpentine oil is widely used in the synthesis of fine chemicals, such as synthetic terpenic resins, terpenic surfactants, cosmetic and pharmaceutical.(Vapor+liquid) equilibrium (VLE) and excess enthalpy thermodynamic data had the important significance on the further processing and separation of Turpentine oil components.By comparing different vapor-liquid equilibrium experiment device, the modified Ellis equilibrium still was selected to measure vapor-liquid equilibrium (VLE) data for binary systems of β-pinene+p-cymene and β-pinene+(S)-(-)-limonene and the ternary system of β-pinene+p-cymene+(S)-(-)-limonene at100.7kPa. The experimental data of binary systems were tested for thermodynamic consistency with the method of Herington and point-to-point test of Van Ness. The parameters of four solution models-Wilson, NRTL, UNIQUAC and Liebermann-Fried-were calculated with the aid of the least-squares method to minimize an objective function based on the total pressure. The four models yield similar deviations, but the best fit for the miscible mixtures is obtained with the Wilson model. The thermodynamic consistency of the VLE data of the ternary system was tested with the method of McDermott-Ellis, modified by Wisniak and Tamir. Also, the ternary system data were compared with the predicted values, using the parameters of Wilson model obtained from the binary subsystems. The absolute average deviations for the ternary system was δT=0.17K,δy1=0.0038,δy2=0.0015, and δy3=0.0037, respectively, the predicted bubble-point temperature and the vapor composition for the ternary system were in good agreement with the experimental results.The excess enthalpies data for six binary systems of a-pinene+β-pinene, a-pinene+p-cymene, a-pinene+(S)-(-)-limonene, β-pinene+p-cymene, β-pinene+(S)-(-)-limonene and p-cymene+(S)-(-)-limonene were measured at298.15K,303.15K,313.15K and atmospheric pressure by C80microcalorimeter. The experimental data were correlated by Redlich-Kister equation and the absolute deviation and the relative deviation were quite small. The experimental data of binary systems are in good agreement with that of the reference. The difference of the molecular structure and double bond position for the four components lead to the different of heat needed when mixed and the different of the excess enthalpy numerical. The excess enthalpies Hm,1+23E for three pseudo-binary systems of α-pinene+p-cymene+(S)-(-)-limonene,β-pinene+p-cymene+(S)-(-)-limonene and (S)-(-)-limonene +α-pinene+β-pinene were measured at298.15K,303.15K,313.15K and atmospheric pressure by C80microcalorimeter. The experimental data were compared with the values calculated by the equations of Tsao and Smith recommending and the deviations between the experimental values and the calculated values were quite small. The results show that the excess enthalpy data determined by C80micro calorimeter is accurate and reliable. The results serve to show that all the experimental Hm,1+23E values are positive. Curves show a symmetrical trend and maximum values were observed in the vicinity of x1≈0.5. Using the experimental Hm,1+23E values calculate the excess molar enthalpies Hm,1+23E of the three ternary system at298.15K,303.15K,313.15K and atmospheric pressure. Smooth representations of the tenary system results are presented and used to construct constant excess molar enthalpy contours on Roozeboom diagrams, the general characteristics of each ternary system are similar. Furthermore, at constant x1, the Hm,1+23E values increase monotonically as the mole ratio of x2/x3increases.Using the parameters determined from the HE values for the binary systems of β-pinene+p-cymene and β-pinene+(S)-(-)-limonene, we calculated the bubble-point temperatures and the vapor compositions for the two binary systems. The predicted temperatures and vapor compositions were compared with the experimentally determined values. It can be seen that the bubble-point temperatures predicted by means of the Wilson model agree very well with the experimentally measured values; the average absolute deviation are mostly <0.16K. The predicted vapor compositions are also of reasonable accuracy; the mole fraction average absolute deviations are mostly<0.0032.更多还原