Abstract

This work presents two developments in Antoine vapor pressure correlation: (1) Generalization of the correlation using the principle of corresponding state; (2) Prediction of the Antoine coefficients form molecular weight. The coefficients of the generalized correlation are correlated to molecular weight (r²=0.99) for the group of normal alkanes (C₁ to C₂₀). The method is validated using experimental data obtained from reliable literature covering 169 vapor pressure data points covering 11 fluids. The method reproduced the experimental data with a grand absolute average percent deviation (AAPD) of 2.93 while the original Antoine correlation reproduced the same data with 1.90. The method provides a simple procedure for the prediction of Antoine coefficients. On the other hand, the developments, significantly reduces the number of coefficients of C₁ to C₂₀ from (3×20=) 60 to (3×3=) 9. This saves the labor work needed for storage and processing of the large number of coefficients values.

Key words: Antoine coefficients, normal alkanes, vapor pressure.