Thermodynamic Intrinsic\nInsights and Process Design\nfor High-Efficiency Separation of Quaternary System with Three Azeotropes\nand Three Homologues

Pyridine compounds play a vital role in the field of\nbiology and\nmedicine as organic solvents, reagents, and precursors. The existing\nresearch focuses on separating binary systems consisting of water\nand single pyridine homologue. However, industrial pyridine wastewater\ncombines with multiple azeotropes and homologues. As such, a novel\napproach for the simultaneous recovery of various pyridine homologues\nis developed based on heterogeneous azeotropic distillation (HAD).\nBy investigating the coexistence of the complex azeotropic-homologue\nsystem, a suitable separation configuration is proposed. Through a\nsystematic analysis of the intrinsic thermodynamic principles, it\nbecomes feasible to achieve extremely high product purity directly\nafter phase separation, thereby reducing the requirement of a distillation\ncolumn. Additionally, an indirect shared condenser and decenter for\nthe two-column method is proposed to further minimize energy consumption.\nThe findings indicate that the triple-column heterogeneous azeotropic\ndistillation sharing a decanter and condenser (TCHAD-SDC) process\ndemonstrates superior separation capabilities after global optimization.\nFurthermore, this approach offers innovative concepts and solutions\nfor the effective separation of complex industrial systems involving\nmultiple azeotropes and homologues.