Calculation of the Virial and Fugacity Coefficients of Heavy Water Using New Generalized Equation of State

Abstract

By replacing hydrogen with deuterium in water molecules, the energy level of molecular bonds changes which cause different physical, chemical, nuclear, and biological properties. Owing to that, the Equation of State (EOS) is an important and appropriate tool for studying the thermophysical behavior of materials and predicting them in different conditions in terms of pressure, temperature, and volume. Due to the importance of heavy water and its role in various researches, especially nuclear research and its application in medicine and industry, the present work aims to calculate the fugacity and virial coefficients of this material using the new generalized state equations and to compare the results obtained with experimental data to have an accurate evaluation of the equations used. The generalized equations in this research include the generalization of the equations based on the Redlich-Kwong equation (RK) and the Dietrici equation (D). The studies showed that generalization improves the results of the second virial coefficient below the critical temperature, which is more effective in the RK equation and leads to appropriate results according to the experimental data. However, in the case of fugacity, generalization improves the results in Equation D and further deviates the results in the RK equation. The results show that below the critical temperature, the van der Waals and Dietrici models do not offer a good prediction of the behavior of the third virial coefficient. Therefore, more other models should be used to predict their behavior quantitatively and qualitatively.

Keywords

• heavy water
• fugacity
• virial coefficients
• redlich-kwong equation
• dietrici equation