The vapor phase dimethyl ether (DME) synthesis is simulated by Hysys process simulation software and relevant cost analysis is also conducted. Based on cost estimation results, it is found that capital investment of the classic DME process is greatly influenced by the distillation towers and operating costs. Accordingly, to solve these problems an innovative-DME process based on a top-wall dividing-wall column (DWC) in vapor phase is proposed, in this work. It is shown that the novel proposed DWC process leads to 44.53% reduction in operating costs compared to the conventional one, while both schemes predict almost the same output specifications. (C) 2013 Elsevier B.V. All rights reserved.