Because cooling water is much less expensive than refrigeration in removing heat, many distillation columns are designed so that reflux-drum temperatures are higher than the available cooling water temperature. This is achieved by adjusting the column pressure. However, if the light-key component in the distillate has a high vapor pressure (low-boiling component), the resulting column pressure is high. This usually makes the separation more difficult than that in lower-pressure operation and increases the energy consumption. This paper explores an alternative configuration called "refrigerated purge" in which two stages of condensation are used. The first condenser uses cooling water and condenses a portion of the vapor coming from the top of the column. The condensate is refluxed to the column. The remaining vapor flows to a small refrigerated vent condenser, operating at a lower temperature and resulting in lower pressure. Expensive refrigeration is required in this second condenser, but less energy is used in the column reboiler because the pressure in the column is lower. This paper compares the two alternative flowsheets in terms of both the steady-state design and the dynamic controllability. Results demonstrate that the refrigerated-purge configuration is more economical than the conventional one when the column feed contains small amounts (about 10%) of the light-key component. However, dynamic control of this more complex process is more difficult.