In this work we extend the crossover (CR) modification of the statistical-a
ssociating-fluid-theory (SAFT) equation of state (EOS), recently developed
and applied for non-associating systems [Ind. Eng. Chem. Res. 38 (1999) 499
3] to associating fluids. Unlike the previous crossover EOS that was based
on the parametric linear model for the universal crossover function Y, the
new CR SAFT EOS is based on Fisher's recent parametric sine model. This mod
el can be extended into the metastable region and gives analytically connec
ted van der Waals, loops in the two-phase region. We show that for associat
ing fluids the new CR SAFT EOS not only yields a better description of the
PVT and VLE properties of fluids in the critical region, but also improves
the representation of the entire thermodynamic surface. A comparison is mad
e with experimental data for pure normal methanol, ethanol, propanol, butan
ol, pentanol, and hexanol in the one- and two-phase regions. The CR SAFT EO
S reproduces the saturated pressure and liquid density data with an average
absolute deviation (AAD) of about 1%. In the one-phase region, the CR SAFT
equation represents the experimental values of pressure with an AAD less t
han 1% in the critical and supercritical region and the liquid densities wi
th an AAD of about 2%. (C) 2001 Elsevier Science B.V. All rights reserved.