A Correlation for the Prediction of the Adiabatic Joule-Thomson Coefficient of Pure Gases and Gas Mixtures

Document Type : Research Article


1 Department of Chemical Engineering, Faculty of Engineering, Tehran University, Tehran, I.R. IRAN

2 Department of Chemistry, Sharif University of Technology, Tehran, I.R. IRAN



A correlation based on the general form of cubic equations of state has been derived. This equation provides a convenient mathematical form of the Joule-Thomson coefficient in terms of the state variable V and T. The Joule-Thomson coefficient calculated by this correlation has been compared with experimental data. It has been shown that the Redilich-Kwang equation of state is a suitable equation for prediction of Jule-Thomson coefficient of non-hydrocarbon compounds. The joule-Thomson coefficient of light hydrocarbons can be obtained with greater accuracy through the use of the Soave-Redich-Kwang equation of state. As hydrocarbon compounds become heavier the Joule-Thomson coefficient correlation based on the Peng-Robinson equation of state gives more accurate results. In the superheat region and for simple and quantum compounds the Redlich-Kwang equation of state is superior. Because of the complexity of the Joule-Thomson coefficient the correlation obtained by the Lee-Kessler equation of state and based on the high average percent error resulting from this correlation, the Lee-Kessler equation of state is not recommended for prediction of the Joule-Thomson coefficient.


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