正常沸点下液体蒸发焓的基团贡献计算法

GROUP CONTRIBUTION METHOD TO ESTIMATE ENTHALPIES OF VAPORIZATION AT NORMAL BOILING POINT

用分子热力学方法建立了纯物质汽液平衡的推广vanderWaals模型 ,并据此得到了一个计算正常沸点下液体蒸发焓的方程 .它只含有一个与分子大小有关的参数 .这个参数的值与正常沸点下液体的摩尔体积成正比 ,且具有基团加和性 .为此 ,用 484个有机物回归得到了 45个基团增量 .对这些有机物的蒸发焓计算结果表明 ,与实验值的平均绝对偏差 (AAD)为 1.39% 。

An augmented van der Waals model of VLE of the pure compounds has been established by the molecular thermodynamic method, and an equation of calculating the enthalpy of vaporization at the normal boiling point is obtained from this model, which contains only a molecular size-dependent parameter.It is found that the parameter is directly proportional to the molar volume of liquid at the normal boiling point, and its values have the additivity of groups.The 45 group increments are regressed by 484 organic compounds.The calculation results of the enthalpy of vaporization for these compounds show that the average absolute deviation with the experimental values is 1.39% and is better than other methods published in the literatures.This method can be also used to calculate the enthalpies of vaporization at other temperatures.