KAGAKU KOGAKU RONBUNSHU, Vol.39, No.6, 493-502, 2013
Reversible Distillation Curve and Operating Locus as Criteria for Appropriate of HIDiC
In the Heat Integrated Distillation Column (HIDiC), the driving force of mass transfer and heat transfer is different at each stage due to the difference in irreversibility at each stage. Accordingly, a higher energy saving should be possible by optimal allocation of heat duties to appropriately selected and discrete internal heat exchangers rather than having internal exchanges at all stages. We have previously developed a design methodology for HIDiC that incorporates the reversible distillation curve and the operating locus on H-xy diagram, which is further integrated with the T-xy diagram, but have yet to establish criteria for the applicability of HIDiC. Here, by utilizing the H-xy and T-xy diagrams, we investigated characteristics of systems in which use of HIDiC is advantageous and showed that the feed composition and the product purity are determinative parameters under the identical target of energy saving based on reboiler duty. HIDiC was found to be advantageous in all applications other than where a light key component is rich in the feed and the product specification in both distillate and bottoms is for high purity.