超临界CO_2中聚碳酸酯的合成 Ⅱ.超临界CO_2密度的计算

超临界流体的密度对溶质在其中的溶解度具有重要影响。利用Peng-Robinson状态方程计算了超临界CO2在不同操作条件下的密度,与现有文献报道的实验值比较,最小相对偏差为0.13%,最大为9.44%,平均为3.60%,表明计算值与实验值吻合良好。在温度为305.15~398.15K、压力为8.0~35.0MPa的范围内,将计算的CO2密度值绘成了密度图,方便查找和插值。随着压力升高,温度降低,超临界CO2的密度增大,苯酚的溶解度增加。

Synthesis of Polycarbonate in Supercritical CO2 Ⅱ. Calculation of Supercritical CO2 Density

The density of the supercritical fluid seriously affects the solubility of a solute in the fluid. Using Peng-Robinson equation of state, the densities of supercritical CO2 at different operating conditions were calculated. The results of calculation were compared with the existing experimental data reported in the literature. The smallest absolute relative deviation is 0.13%, the largest is 9.44% and the mean is 3.60%. These indicated that the calculated density of supercritical CO2 by PR EOS is in a good agreement with experimental data. Under the pressure ranging from 8.0MPa to 35.0MPa and temperature from 305.15K to 398.15K, CO2 densities were calculated and formed the density map, which will facilitate the searching and interpolation of density. With the increase of pressure and the decrease of temperature, the density of supercritical CO2 increases, as well as the solubility of phenol in supercritical CO2 increases.