An inherently safer development approach for thermally coupled distillation sequences: Application in hazardous chemical separation

Abstract

Process safety is always a core issue in chemical industry, which is conventionally not taken into consideration during the conceptual design stage of a process flowsheet. Distillation handles more than ninety percent of the separation and purification tasks of hazardous chemicals and accounts for no less than forty percent of the total energy consumption. Therefore, this work presents an inherently safer synthesis framework for thermally coupled distillation sequences with structure constraints, which can efficiently quantify and optimize the inherent safety index of each column configuration in the sequence, based on State-Task Network and Dow’s F&EI. To efficiently quantify the inherent safety index of each column configuration, a series of structure constraints are proposed. Within the superstructure, Hengstebeck-Underwood-Gilliland shortcut method is employed for distillation column design. Finally, two hazardous zeotropic mixture separation examples are performed to demonstrate the feasibility and validity of the proposed synthesis methodology.