Process intensification for sustainable pyridine/water separation: Thermodynamic insights and energy‐efficient design

Abstract To address the challenge of treating pyridine wastewater generated in the chemical industry, thermodynamic phase diagrams and the COSMO‐RS model identified benzyl alcohol (BA) as an entrainer. Quantum chemical calculation further elucidated its separation mechanism. Based on these findings, an extractive pressure‐swing distillation process (EPSDP) was designed to achieve effective separation. Further process intensification exploration applied heat integration (HI), vapor recompression heat pump (VRHP), and dividing wall column (DWC) technologies, yielding seven integrated processes. A comprehensive evaluation across total annual cost (TAC), energy consumption, acid gas emissions, and thermodynamic efficiency identified the heat integrated vapor recompression heat pump assisted extractive pressure‐swing distillation with dividing wall column (HI‐VRHP‐DWC‐EPSDP) as the optimal solution. Compared to EPSDP, HI‐VRHP‐DWC‐EPSDP reduces TAC by 26.14%, cuts energy consumption and acid gas emissions by 54.68%, and boosts thermodynamic efficiency by 74.47%, demonstrating outstanding application potential.