Multi-component separation by distillation is known as a conventional method in chemical processes. In this study the effects of feed splitting on three classical arrangements (with and without heat integration) were investigated in order to reduce the total annual cost (TAC). Ternery mixture separation (propane, butane and pentane) by distillation was selected as a case study. An optimization problem was defined based on the effective parameters affecting the total annual cost. Optimum values for decision variables were calculated by applying the genetic algorithm. Calculation results showed that the heat integration procedure in the feed splitting method reduced the TAC significantly. It was also indicated that the prefractionator arrangement with heat integration resulted in the greatest decrease in the total annual cost. (C) 2012 Elsevier B.V. All rights reserved.