Quantitative analysis of atomic contribution to interaction and phase equilibrium experiment dominated the process design for ternary multi-azeotropic system

Sufficient and accurate physical property data is the basis for thermodynamic analysis and process simulation analysis. Reliable thermodynamic model data is essential for the study of extractive distillation separation of azeotropic mixtures. The vapor-liquid equilibrium data of 2-butanol alcohol-ethylene glycol and cyclohexane-butyl butyrate were measured by using a reliable experimental device, namely a modified Rose vapor-recirculating-type equilibrium still. The effects of 12 solvents on the relative volatility of the azeotrope of cyclohexane, 2-butanol alcohol and water were calculated, and ethylene glycol was selected as the best solvent. On this basis, the contribution of different atom pairs and atoms to the interaction between ethylene glycol and cyclohexane/2-butyl alcohol/water was compared and studied, and the reason why ethylene glycol can separate cyclohexane-2-butyl alcohol-water was analyzed. The thermodynamic model parameters obtained from the vapor-liquid equilibrium experiment were used to simulate the extractive distillation process, and total annual cost optimization was performed to improve the process accuracy. Overall, this study improves the application potential of phase equilibrium data in azeotropic separation technology, and establishes a reliable data and model foundation for the sustainable development of 2-butyl alcohol and cyclohexane.