Distillation, the most common separation process in chemical process industries, requires significant energy inputs. Dividing-Wall Column (DWC), which works on the basis of Fully Thermally Coupled Distillation System (FTCDS), is chosen for this study due to its lower energy consumption compared to the conventional column system. The main objective of this study is to investigate the potential of retrofitting conventional 2-column (C2C) systems in operation for separating ternary mixtures into three products, to DWCs. For this, six applications of industrial importance are selected and conventional 2-column systems are designed, which are assumed to be currently in operation in the plants. Then, retrofitting these systems to DWC is studied. Results show that retrofitting the existing 2-column systems to DWCs is very attractive both economically and for its reduced energy requirements. (C) 2008 The institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.