Non-equilibrium stage based modeling of heat integrated air separation columns

• A non-equilibrium model of heat integrated air separation column (HIASC) is proposed.
• The characteristic analyses show that the proposed model is more accurate.
• The configuration parameters are tuned in this study.
• The murphree efficiencies of the HIASC are first investigated.
• The energy consumption of HIASC decreases by 12.4% compared with CASC.

The heat integrated air separation column (HIASC) is a frontier of energy saving distillation column due to its large energy saving potential. However, up to now, most of the related research works are based on an equilibrium stage model, which is of limited value for design and practical application purposes. A novel non-equilibrium stage based model of HIASC, which includes both the mass and energy transfer, is first proposed. The tuning of configuration parameters including the total stage number, the feed position and the sidestream position is then carried out. The characteristic analyses show that the non-equilibrium stage model is more accurate and valuable and thus provides an efficient tool for further design, optimization and control studies. At last, the operation optimization is further carried out, and the optimization results show that the energy consumption of HIASC decreases by about 12.4% compared with the conventional air separation columns (CASC).