Crossover CPA equation of state for associating fluids

Associating fluids are of great interest from an industrial point of view and their thermophysical properties are needed for many practical applications. The Cubic-Plus-Association (CPA) equation of state has been successfully used to describe systems contain associating compounds. However, this equation does not take into account the effect of long scale density fluctuations, which causes it to fail to represent the non-analytical, singular behavior in the critical region. A crossover CPA EOS based on White's renormalization group (RG) theory was derived, which can be used both near and far from the critical point. This equation provides good agreement with experimental data for 1-alkanols (methanol, ethanol, 1-propanol, 1-butanol, 1-octanol) and water, with much better results obtained in the vicinity of the critical point than the original CPA EOS.