Exergy analysis of an ideal heat-integrated distillation column is conducted in this paper. It is found that the process is most favourable to the separation of binary close-boiling mixtures. Pressure elevation from stripping section to rectifying section appears to be a critical design variable that can affect the thermodynamic efficiency of the process. Feed composition presents almost no effect upon internal heat integration between the rectifying section and the stripping section. Although an implicit limitation has been imposed on the process throughput, it can be obviated through a careful trade-off between capital investment and operating cost during process development. Comparison against a conventional distillation column is also conducted, which shows the great potential of internal heat integration between the rectifying section and the stripping section.