A NEW METHOD FOR PREDICTING CRITICAL VOLUMES OF ORGANIC-COMPOUNDS

A new method based on atomic and structural contributions is proposed for estimating the critical volumes of organic liquids. The proposed m ethod gives more accurate values compared with the methods of Lydersen , Joback and Somayajulu, the average absolute deviations being 2.3%, 3 .2%, 3.1.% and 2.7% respectively for these four methods when tested ag ainst the experimental data for 279 organic liquids. The methods of Am brose and Fedors recommended by the API technical data book for hydroc arbons and the AIChE data prediction manual for non-hydrocarbons gave overall average deviations of the same order as those for the Lydersen et al. method. The proposed constants can also be used to calculate t he volume of liquids at the normal boiling point, with accuracies bett er than or comparable to those of the existing methods. (C) 1997 Elsev ier Science B.V.