The Benedict-Webb-Rubin BWR Equation of State

One of the oldest, but still used, non-cubic equations of state is that proposed by Benedict, Webb and Rubin (1940 1942 1951). It contains eight parameters that are determined from experimental data. Parameter values for several compounds are given by Reid et al. 

The BWR EoS provides excellent description of the volumetric behavior of pure fluids, but has two main drawbacks  

extensive PVT data are needed for the evaluation of the eight parameters. Such data, as we have mentioned, are available for a few compounds only. A generalized form, developed by Lee and Kesler is available, however. (This form, by the way, has been used for the development of the Lee-Kesler tables used in combination with Pitzer s corresponding states approach.) 

Second, solution of the equation for volume is cumbersome and computer-time consuming. 

12 Recommendations for the Estimation of the Volumetric Behavior of Pure Fluids 

---

The Benedict-Webb-Rubin (BWR) equation of state is given by... 

---