The minimum energy requirements of six different heat-integrated multieffect and three nonintegrated distillation arrangements for separating a ternary mixture have been considered. The focus is on a heat-integrated complex distillation configuration, called a multieffect prefractionator arrangement. The comparison of the different arrangements is based on the minimum vapor flow rates at infinite number of stages, which are easily visualized and compared in a V-min diagram. This tool can be used as a basis for screening and the best arrangement(s) can be studied further using more rigorous simulation methods. (c) 2005 American Institute of Chemical Engineers.