The proposed of the present work is to develop a method for rigorous prediction of separation performance of the HIDiC. A process simulator (gPROMS) for prediction of performance of the HIDiC with random packing is developed by rate-based model using Maxwell-Stefan equations. The vapor and liquid flow rates of HIDiC increased from the bottom to the top in the stripping section. In the rectifying section, however, the flow rates decreased from the bottom to the top. Evaporation of liquid in the stripping section and the condensation of vapor in the rectifying section take place. Comparison was made observed data from a bench-scale separation (benzene-toluene system) HIDiC plant, about 16 m in height and 254 mm in diameter (concentric R&A sections) and simulation results. The energy-saving ratio shows a good agreement with observed data. The bench HIDiC showed about 40% reduction of energy consumption compared with the conventional distillation column. The effect of nonequilibrium of temperature in the HIDiC is also discussed.