A method for systematic generation of all possible configurations of distillation columns for multicomponent separation is described. Classic configurations with sharp splits and all the possible (partially and fully) thermally coupled systems are generated by listing all the splits between components and applying various interconnecting streams and column stacking. Separation systems with multiple streams producing the same product (with the same or different purity) are also being generated. Additionally, a method for systematic evaluation of minimum vapor flows in all the configurations has been developed. The method can be used in evaluating various possibilities to select the optimum configuration for a new design or to improve an existing plant. Energy requirements of various column configurations for separation of four components have been evaluated and compared. (c) 2006 American Institute of Chemical Engineers.