Heat Integrated Distillation Column (Hidic): Experimental Study on a New Concentric Column Technology

Abstract

Distillation is the most applied separation technology. Its major drawback is the low thermodynamic efficiency (typically around 15 %). In response to the environmental issues that concerns energy consumption of distillation column, HIDiC (heat integrated distillation column) which combines advantages of vapor recompression and diabatic operation, is expected to have a large impact on energy saving. In this study, a concentric column which contains an innovative column packing designed in LGC research lab of Toulouse is carried out. First of all, this novel technology is characterized from a heat transfer point of view in a dedicated pilot plant. Compared to the Raschig super-ring results, the heat transfer in this innovative column packing is much more efficient, with a heat transfer increase of 102 %. A second HIDiC pilot has been implemented to test the operability and the overall performances of this HIDIC technology. Different tests have been made to reach a time of steady state of 90min. Several experiments were carried out with different operating parameters (boiler heat and pressure ratio). The Cyclohexane/n-Heptane binary mixture is used for these experiments. The simulation results of a classical distillation column are compared to HIDiC column steady state operation. This comparison demonstrates an energy saving about 40 %.