The demand for dimethyl ether (DME) will continue increasing, since DME is categorized as one of the green energy sources, which has higher heat value than natural gas and less toxic to human beings than methanol. There are two methods; direct and indirect method for DME. The CO transformation rate of direct method is higher than indirect method due to Le Chatelier's principle. However, we can achieve the same CO high transformation rate in indirect method, if we get rid of the product methanol from the reaction field simultaneously.

Many DME production processes have reactant recycle system with product separation. Distillation processes have often been used for this product separation from reactant recycle stream. However, the distillation processes are well known as energy consuming processes since the large latent heat (vaporization and condensation heat) has to be provided to reach at the gas-liquid equilibrium in the column.

Recently, authors have developed a self-heat recuperation technology based on exergy destruction minimization to reduce the energy consumption of chemical processes. Applying the self-heat recuperation technology to chemical processes, not only the latent heat but also the sensible heat of the process stream can be circulated into the processes without any heat addition. As a result, the energy consumption and exergy destruction of a process can be greatly reduced in the steady state. In fact, this technology has been applied to several chemical processes as case studies and shows large energy saving potentials in these processes. From these previous studies, it found that thermal and separation processes are suitable processes for self-heat recuperation technology.

In this research, we investigated the feasibility of applying self-heat recuperation technology to DME production process using indirect method from synthesis gas and developed an innovative process for DME production process using indirect method from the energy saving point of view. By installing the self-heat recuperation technology to the DME production process, the energy consumption of the thermal and separation processes can be greatly reduced. Thus, it can be said that installation of self-heat recuperation technology is the other option of process design and method selection.