R Ravi

A four-parameter equation of state proposed by Serrin is investigated for its ability to predict accurately the saturation pressures of pure substances. The area rule or the generalized Maxwell’s rule is used for the calculation. An algorithm has been proposed by Serrin for implementing the calculations. The algorithm as it appears in print is found to yield results which are vastly different from those presented in Serrin’s article. As a result, a corrected algorithm has been derived and presented in the present article. Although the structure of the algorithm remains intact, the various coefficients and equations in the algorithm are found to differ from what appears in print. Saturation pressure predictions of the corrected algorithm are found to match very closely the predictions of an independent MATLAB-based algorithm developed in this work thereby providing validation of the corrections to Serrin’s algorithm proposed in this article. The corrected algorithm predicts saturation pressures that are close to the experimental values (error within 10%) for water when the parameters of the equation state as predicted by the critical point criteria are used. The sensitivity of the predictions to the specific heat model is also discussed.