(215e) A Novel Concept for Heat Integrated Distillation Column as An Outcome of De-Tuning of Reversible Distillation System

Distillation still plays an important role on separation unit operation in chemical process industry. However, as well recognized, it is energy consuming process. Clearly, energy saving in distillation can contribute largely to reducing the overall operating cost. Furthermore, recent demand for green house gases abatement is another big driving force for energy saving in this operation. In view of energy saving distillation system, reversible distillation system provides ultimate target figure although it is a hypothetical system due to the assumption of infinite theoretical stage accompanied by side-cooler and side-reboiler having infinitesimal heat duty at each stage. Heat Integrated Distillation Column is an effort to realize this concept by making the theoretical stages finite and introducing the vapor re-compression heat pump concept. Several types of the apparatus have been developed in attempt for the commercial application, e.g. double pipe equipped with structured packing or trays, plate-fin heat exchanger, etc. What these apparatuses have in common is that the heat duty at side exchanger is largely dependent on the temperature profile of the distillation column. This is because heat transfer area is just a consequence of column sizing, which is usually determined from the production capacity and product specification. Thus, even if the total heat transfer area of internal heat exchange is the same, the heat transfer profile of both sections in current HIDiC is different from the optimal profile. In this research, the optimum heat transfer profile is first derived through process simulation. Then, a novel concept for HIDiC to realize such optimum heat transfer profile is proposed.