Economic Optimization of Internal Thermally Coupled Air Separation Column Configurations

Abstract

An internal thermally coupled air separation column (ITCASC) process is an effective energy‐saving technology in the air separation process. However, a large economic investment is a crucial factor for the widespread use of this technology in practical applications. In this article, an alternative configuration design, namely, top‐integrated (T‐ITCASC), bottom‐integrated (B‐ITCASC), and top‐bottom‐integrated ITCASC (T‐B‐ITCASC) with a focus on energy savings and economic feasibility are studied. A rigorous optimization based on a nonlinear interior‐point algorithm was developed by integrating the dynamic model into the optimization formulation. In the context of ITCASC process design and optimization, numerical simulations demonstrated that T‐ITCASC, B‐ITCASC, and T‐B‐ITCASC configurations improved energy‐saving potential and reduced capital investment, compared to the F‐ITCASC and conventional air separation column (CASC) configurations. Among these optimized configurations, the T‐B‐ITCASC configuration is preferred.