【作者】 朱虎刚；

【导师】 田宜灵；

【作者基本信息】 天津大学 ， 化学工艺， 2007， 博士

【摘要】 在自行设计制造的可变体积高压釜中,首先测定子反式十氢化萘的恒温下不同压力下的摩尔体积,温度范围从293K到446K,压力范围从10MPa到200MPa。用改进的Tait状态方程拟合摩尔体积恒温线,分别得到恒温压缩系数和热膨胀率它们分别是通过拟合的恒温线和恒压线的斜率而得到的。状态方程V_m =C₁+C₂T+C₃T₂-C4p-C₅pT中的系数也被求出,平均误差只有0.029%,最大误差不超过2.62%。利用上述高压釜,测定了SC CO₂+CH₃OH,SC CO₂+C₂H₅OH,SC CO₂+丙酸乙酯的高压相平衡数据,得到了不同温度、平衡压力、液相和气相组成、液相和气相密度。实验结果表明SC CO2在三种溶剂中溶解度随压力增加而明显增大,但三种溶剂在气相中含量增加却并不明显,除非接近临界点时。同时发现SC CO2在酯中溶解度明显大于醇中溶解度。根据实验数据,估算了上述三个二元系统的的临界曲线,给出它们的Tc-xc,pc- xc,Tc- pc图。利用一个由微扰理论导出的状态方程,根据热力学数据,计算了（CO₂+CH₃OH、CO₂+C₂H₅OH、CO₂+丙酸乙酯、N₂（1）+CH₃OH（2）、CH4（1）+ CH₃OH（2）、水与正烷烃（C1-C6））系统的临界曲线,这些系统中二组分在分子大小、极性等方面差别有明显不同。该状态方程由一个引力项和一个斥力项组成,特别适用于高压下相平衡和临界曲线的计算,计算结果以图的形式给出,方程中可调参数以表的形式给出。本论文所测的反式十氢化萘的高压下pVT性质的数据,对于进一步研究有机化合物的同系物熔点沸点差的理论研究提供了新的热力学数据。含超临界CO2体系的高压相平衡数据的测定和计算对于超临界CO2的应用提供必不可少的热力学数据。更多还原

【Abstract】 A set of variable-volume autoclave with a quartz window has been made. Using this high pressure autoclave the molar volume isotherms of trans-decahydronaphthalene (C10H8) between 293K and 446K and at pressures from 10 MPa to 200MPa have been determined. A modified Tait equation of state is used to fit each experimental molar volume isotherm. The thermal expansivity (cubic expansion coefficient)αand isothermal compressibilityκwere determined by fitting the slopes of the isobaric curves and isotherms, respectively, The coefficients in equations have been fitted with average deviation of 0.029% and does not exceed 2.62%.The vapor-liquid equilibrium data (including compositions, densities and molar volumes of vapor phases and liquid phases) have been measured at different temperatures and pressures of the three binary systems (SC CO2 + methanol, SC CO2 + ethanol and SC CO2 + ethyl propanate). The experimental data show the solubilities of SC CO2 in three solvents increase drastically with increasing pressures at the given temperature, but the contents of three solvents in gas phases increase faintly the solubilities of SC CO2 in esters is higher than that in alcohols. The critical values pc, Tc, xc and Vc of the three binary systems were estimated.The critical curves are also calculated with an equation of state for binary fluid systems of partners, which differ significantly in molecular size and polarity. The equation consists of a hard body repulsion term and an additive perturbation term, which takes care of the attractive molecular interation. For the repulsion, a Carnahan-Starling-One-Fluid (CSOF) expression or suitable extensions are used. The attractive term used square well potentials. The calculated results are given in figures. The necessary three parameters for(CO2+CH3OH, CO2+C2H5OH, CH4+CH3OH , N2+ CH3OH, CO2+ EP, H2O+n-alkane (C1~C6))systems are listed.更多还原