Comparative study of different batch distillation models for simulating the fractionation of essential oils

• Accuracy of distillation models for essential oil fractionation is compared • Accuracy improves with constant volume hold-up over constant molar hold-up • Tray efficiency, pressure drop, and enthalpy accumulation show negligible effect • Thermodynamic properties of key essential oil components comprehensively listed The simulation of essential oil fractionation becomes increasingly complex as the number of components and theoretical stages increases. Nonlinear rigorous models are therefore required to accurately represent the dynamic behavior of batch distillation processes and capture real-world phenomena. Despite their improved predictive capability, the influence of individual modeling assumptions on simulation accuracy and computational reliability has not been systematically evaluated for essential oil systems. In this study, a comparative sensitivity analysis of four nonlinear rigorous batch distillation models is performed, each differing in assumptions related to liquid holdup, Murphree tray efficiency, pressure profile, and enthalpy accumulation. Statistical analysis reveals that the assumption of constant liquid holdup has the most significant impact on model performance (R² = 0.952, MSE = 0.0028), whereas assumptions concerning Murphree tray efficiency, linear pressure drop, and enthalpy accumulation exhibit negligible effects. In addition, the proposed pathway for predicting thermodynamic properties is applied and validated through a simulation study. Based on the most reliable rigorous model type, the operational feasibility of batch distillation for cinnamon leaf oil is investigated. The results indicate that eugenol enrichment is primarily governed by its initial concentration in the feed and the targeted product purity. To achieve a product purity of 95% with acceptable process reliability, a reflux ratio of 2 and 4–5 theoretical stages are recommended. However, attaining 99% eugenol purity with a reasonable yield is not feasible using batch distillation, even at higher reflux ratios and stage numbers.