CO2-H2O-HAc三组分系统高压相平衡

超临界状态下的CO2在含有有机溶剂的水溶液中可作为萃取剂。这种情况可用于水和有机酸的分离，也可以用于从水溶液中萃取产品。要设计这样的过程，CO2-H2O-有机酸系统相平衡的数据是必不可少的。为此，在实验室建立了一套高压相平衡装置。为了验证这套装置的可靠性，测定了CO2-H2O-HAc体系在313K以及压力在15、20、25和30MPa下的相平衡数据，用Peng-Robinson方程^[1,2]进行了计算，并与文献值进行了比较。

Phase Equilibrium in Ternary System with Carbondioxide, Water, and Acetic Acid at High Pressure

Carbon dioxide under supercritical conditions can be used in aqueous solutions as extracting agent. It has been proposed to use this effect for the separation of water and organic acid, it might also be promising to use it for extracting products from aqueous solutions. For the design of such processes, data on the phase behavior of the CO2-H2O-organic acid system are needed. In order to get such data, an analytical equilibrium apparatus was developed. The temperature is measured by calibrated platinum resistance thermometers connected to a resistance bridge. The total error in the temperature measurement is less than 0.05K. The pressure is measured with pressure gauges, which are calibrated with a pressure balance. The error of the pressure measurement is lower than 0.005MPa for pressure less than 10MPa and lower than 0.01MPa for higher pressures. To test this apparatus, the phase equilibrium data of the CO2-H2O-HAc system at temperature 313K and pressures of 15,20,25, 30MPa were measured, and compared with those from literatures. The data calculated by using Peng-Robinson equation were also compaired with those measured and from literatures, and they agree with each other satisfactory.