评“正常沸点下液体蒸发焓的基团贡献计算法”兼论Benson法在理论上的缺陷和改进途径

Comment on "Group contribution method to estimate enthalpies of vaporization at normal boiling point" and on the theoretical defect of Benson method and modified way

阐明发表在2001年《化工学报》第6期的“正常沸点下液体蒸发焓的基团贡献计算法”中的“阻碍因子是液体密度的函数”等理论观点是有片面性的;分析了将van der WaalS方程中的a,b两个参数都加以忽略,实际上就已经变为理想气体方程,与该文所谓“用分子热力学方法建立了纯物质的气液平衡的推广van der Waals模型”的提法是矛盾的,该文自报“平均误差为1.39％,优于文献发表的其它方法”经证明并不符合实际。结合已经造成严重局限性的具体事实揭示出国际上著名的Benson基团法在理论上的缺陷,提出应用有机分子半金属结构理论加以改进的若干例证,作为今后基团法发展新方向的先例,也是使基团法经验式发展成为理论式或半理论式的例证。

'Group contribution method to estimate enthalpies of vaporization at normal boiling point' (shorted for GEE)was published in J.Chem. Ind. Eng.(China) in 2001(6). There were several onesided viewpoints in the GEE. For example, block factor is a function of liquid density, etc. Analyze the GEE that the parameters a and b in the equation of van der Waals were analyzed. Actually, this turned the equation of van der Waals into that of the ideal gas law. However, the GEE provided 'An agumented van der Waals model of VIE of the pure compounds has been established by the molecular thermodynamic method' contradicted the fact in the above analysis. The GEE introduced 'the average absolute deviation with the experimental values is 1.39% and is better than other methods published in the literatures' was not consistented with the fact. Combined with the detail fact made the serious limitation presented the theoretic defect of Benson's group contribution and gave the several modified instances based on the semi-metal structural theory of organic molecular. These are made as the previous cases in the new direction of development in group contribution method to come and it also makes Group contribution method develop into a good example for theoretic theory and semi-metal strucuture theory.