Benedict-Webb-Rubin于1940年提出了能适应气液两相的BWR状态方程，对于预测轻烃及其混合物的热力学性质具有很高的精度。但对H2S、CO2等非烃类气体较多的混合物以及重烃、低温等情况的适应性较差。In 1940, Benedict-Webb-Rubin proposed BWR equation of state, which can be adapted to gas-liquid two phases, and has high accuracy in predicting the thermodynamic properties of light hydrocarbons and their mixtures. However, it is less adaptable to mixtures with more non-hydrocarbon gases, such as H2S and CO2, heavy hydrocarbon and low temperature.