A Power Series Approach for Heat of Vaporization Predicted By the SRK & PR Equations of State

The Soave-Redlich-Kwong (SRK) and Peng-Robinson (PR) equations of state can be used to describe thermodynamic properties such as heat of vaporization. In this project, the adjusted heat of vaporization, a similarity variable defined as reduced heat of vaporization divided by reduced temperature , was studied. The adjusted heat of vaporization was expressed as +, where was the acentric factor function and and were two infinite series of the common adjusted temperature η. The first 29 coefficients of and were found for the SRK equation, while the first 25 were generated for PR. Results from exact SRK and PR algorithms were compared to the power series truncated to various numbers of terms. For the maximum number of terms used in the series, the relative truncation error was as low as 10^-9. Plots were produced to express the relationship between η, ω, and the number of terms used. Work is ongoing to find alternative methods to express the truncation error.