The study of process design for production of the clean fuel - Dimethyl ether (DME)

It is known that dimethyl ether (DME) has wide application, such as solvent, propellant, chemical intermediate, refrigerant replacement, LPG substitute and transportation fuel. Furthermore, DME has currently attracted considerable attention as an alternative clean fuel for diesel engines because it can emit much less pollutants such as CO, NO_x and particulates. Traditionally, in industrial processes, DME is produced by dehydration of methanol using acidic porous catalyst. Methanol is commercially synthesized from CO/CO₂ hydrogenation over Cu-based catalyst. Thus one can prepare DME from synthesis gas (syngas) in a two-step process of syngas to methanol and further to DME, or in a single-step process of synthesis gas direct to DME. Due to attracting attention of the DME synthesis research, this work first uses commercial process simulators to analyze different DME synthesized methods presented in the literature. The optimal operating conditions for DME direct synthesis are then clearly evaluated. Finally, a feasible process flow diagram for the direct DME process is developed to meet the desired production specifications. These steady-state simulation results are demonstrated to fit with those shown in the literature.