How do thermodynamic model inaccuracies affect multicomponent distillation design?

Thermodynamic model errors propagate significantly in distillation design. K-value errors affect: relative volatility (alpha) directly impacting required stages, minimum reflux calculation, and feed tray location. A 5% error in K-values can lead to 10-20% error in stage requirements. Azeotrope prediction errors can result in completely wrong separation schemes. Temperature profile errors affect heat duties and condenser/reboiler sizing. Mitigation strategies: validate model against experimental VLE data for key binaries, check azeotrope composition predictions, perform sensitivity analysis on K-values, and add design margin (10-15% extra stages). Regressing activity coefficient parameters to available data is essential for non-ideal systems.