Abstract: High energy and cost consumption of wastewater treatment has always been a huge problem in chemical industries, especially in coal chemical industry since it generates a large amount of high-concentration organic wastewater. Fixed-bed Lurgi gasifier wastewater was employed as an example to perform the research of wastewater treatment to evaluate added chemicals for cost reduction. The process design of coupling the coal gasification wastewater treatment and the solid oxide cells (SOCs) system with renewable energy was proposed to synthesize dimethyl ether (DME) by comparison of one-step and two-step scenarios. Afterwards, process simulation, integration, tech-economic and carbon emission were all performed to analyze the coupling system. The economy analysis and carbon dioxide emission showed that although the carbon emission of unit productivity for one-step scenario was better than that of two-step, the carbon sequestration rate of the latter was much higher than the former, and the two-step scenario was superior in unit production cost with only 2.32% more CO₂ emission. Besides, two-step method for DME production under wind power was better in economy and carbon emission. Investment breakdown revealed that the cost of renewable energy was the main contributor of the annual production cost, therefore looking for cheap alternative energy is an effective way to reduce the production cost and improve economic performance. In summary, it is economically and environmentally feasible to deepen and efficiently use wastewater as resources by coupling the energy efficient SOCs system and producing value added chemicals.