An Expression for Ratio of Critical Temperature to Critical Pressure with the Heat Capacity for Low to Medium Molecular Weight Compounds

In this paper, a new correlation for prediction of the ratio of critical temperature to critical pressure has been developed in terms of heat capacity at 298.15 K, which is readily available for many compounds. The correlation has been applied for more than 100 low to medium size compounds. The results of these estimations validate the generalization of this correlation. The comparison between predicted and available experimental data shows an absolute relative error of 4.69 %. The results show that the accuracy of the proposed correlation is similar to the methods of Constantinou and Gani,7 Ambrose,2,3 and Joback5 for various types of compounds.

Critical Temperature, Critical Pressure, Heat Capacity, Molecular Weight Compounds