Optimal heat distribution in the internally heat-integrated distillation column (HIDiC)

The internally heat-integrated distillation column (HIDiC) is an interesting separation alternative to the conventional column or the vapor recompression distillation (VRC). In an HIDiC, the influence of heat distribution along the column section has a significant impact on the design and optimization in addition to the compressor pressure ratio. In this work, the optimization of heat distribution in the HIDiC is completely investigated through the application of flowsheet modeling and optimization solver in Aspen Plus. A commercial-scale propylene/propane splitter is used as a case study to illustrate the effect of heat distribution on energy or cost performance. A comparison of the optimum HIDiC structures obtained from different objective functions is discussed. Some optimum HIDiC structures could be evolved into Linde double columns with a side rectifier, which is a common application found in air separation process. This structure is potentially another interesting alternative to the conventional VRC.

► The effect of heat distribution on the energy/cost performance of a HIDiC was thoroughly investigated.
► The heat distributing pattern was found to be as important as the compressor pressure ratio in the HIDiC design.
► Some HIDiC structures obtained from the optimization may be evolved into Linde double columns with side rectifier.