Design of an internally heat-integrated distillation column via an economic-based column energy profile approach

The internally heat-integrated distillation column (HIDiC) is considered one of several approaches for process intensification in chemical processes. Research on the design of the HIDiC has generated great interest during the past few decades. The design of an HIDiC could be carried out via various design approaches such as rigorous process simulation, mathematical programming, genetic algorithm, or H-xy and T-xy diagrams. In this study, an alternative approach based on an economic-based column energy profile was applied to the design of an HIDiC. The economic criterion for generating column energy profiles is the maximum energy saving per additional investment (MESAI). Each data point on the MESAI profile is generated by optimizing the heat load and by the additional investment required when adding a side exchanger at any stage. Aspen Plus simulation software was used in the profile generation and the HIDiC simulation. The resulting column profiles could help provide insights into the economic viability of the heat-integrated distillation column, aiding decision-making and reducing optimization efforts. The economic analysis conducted in this study reveals that the designs obtained from the MESAI profiles demonstrate lower costs compared to the design based on the H-xy and T-xy diagrams. Among the configurations studied, the best design from the MESAI profiles is the HIDiC with three side exchangers.