Simulation of direct dimethyl ether (DME) synthesis using existing methanol production infrastructure in Arzew, Algeria

This study investigates the direct synthesis of dimethyl ether (DME) from syngas using the existing methanol production infrastructure at the Methanol and Synthetic Resins complex in Arzew, Algeria. The primary objective is to assess the feasibility of repurposing the adiabatic multiphase fixed-bed methanol production reactor for DME production while maintaining the original reactor dimensions, flow conditions, syngas composition, as well as temperature and pressure parameters used in methanol production. The research introduced a significant modification by replacing the initial copper oxide-based catalyst with a hybrid catalyst composed of γ-alumina and CuO/ZnO/Al2O3. This catalyst enables the direct production of DME from syngas, which is a mixture of carbon dioxide, carbon monoxide, and hydrogen. The study employed simulation models using Aspen-HYSYS V11 to predict DME productivity, manage the high temperatures resulting from exothermic reactions in each catalyst bed, and determine the required quench gas injection for temperature reduction. The simulation results indicated an overall DME yield of 2.81%, which is comparable to the methanol production rate of 3%. Further simulations with recycling stages increased the crude DME mass to 4.11%. These findings highlight the potential of using the current infrastructure to improve profitability and time efficiency in producing this alternative fuel.