Equation of state for carbon dioxide

An equation of state (EOS) for carbon dioxide has been presented by Span and Wagner (1996). This equation of state is accurate but contains many terms. Some of the terms are complex exponential which become difficult for computation. Therefore a new simple equation of state with 30 terms is proposed. Bank of terms are suggested and an optimum set of terms is selected by a random search method. This new equation of state with less terms and simple exponential is simpler to use. The two equations of state are compared with the available experimental data. The results show that the new EOS is less accurate than Span and Wagner in gas and liquid regions but more accurate in the critical region.

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