Improving Breakthrough Curve Calculations in Dynamic PSA Processes Through a Rigorous Cubic State Equation

This study evaluates the improvement of numerical accuracy in the PSA model for ethanol dehydration using molecular sieves. By incorporating cubic state equations for vapor density determination, significant errors were identified when applying the ideal gas assumption to the ethanol–water mixture, particularly under moderate pressure conditions. The integration of the Peng–Robinson equation demonstrated a 5–10% improvement in calculation accuracy compared to the ideal gas law. This enhancement is crucial for achieving reliable predictions under non-ideal conditions, enabling more accurate estimations of real process dynamics across varying scenarios. Notably, improved accuracy in the PSA model is essential for designing more efficient and reliable industrial applications, especially at moderate pressures. The results indicate that the Peng–Robinson equation provides a more accurate representation of the density of the ethanol–water vapor mixture, contributing significantly to more accurate simulation results of the PSA process.