Heat-transfer distribution optimization for the heat-integrated air separation column

•The heat-transfer distribution optimization of HIASC is carried out to minimize the investment of heat exchangers.•Heat exchangers tend to concentrate on both ends of the columns for maximum heat-transfer efficiency.•The location of heat exchangers is affected by the feed thermal condition and withdrawal stage.•The total heat exchanger cost is reduced compared with the uniform full-column or partially coupled scheme of HIASC while maintaining the low energy level. The heat-integrated air separation column (HIASC) is an advanced energy-saving technology for the cryogenic air separation process, although a large capital investment is required for installed heat exchangers. These heat exchangers have a location-dependent effect upon the separation which leaves room for optimization. This paper, therefore, aims to optimize the heat-transfer distribution of HIASC regarding minimum heat exchanger costs while maintaining the low energy consumption level. Results indicate that the heat-transfer tends to concentrate at both ends of the column. The influence of operational parameters is further studied by the idea based on the liquid-vapor ratio. Finally, an optimal HIASC with respect to the minimal heat exchanger investment is obtained, and the heat exchanger costs are reduced by 44.4% compared with the uniform distribution with a similar energy-saving level.