(626e) Modeling and Simulation of a Packed Bed Reactor Made of Multiple Catalysts for the Synthesis of DME from Syngas: A Systematic Analysis from Lab-to-Pilot Scale

In recent years, there has been a growing interest in developing eco-friendly synthetic fuels, to address the pressing challenges posed by global warming, decarbonization, and increasing energy demand. Among them, Dimethyl ether (DME) has found a special attention, as it poses superior properties like high cetane number, high oxygen content, as well as improved combustion characteristics compared with traditional fuels [1]. Moreover, DME can be used as an intermediate to further produce high-value gasoline products with little aromatics, termed as High-Octane Gasoline (HOG) [2, 3]. For DME synthesis, the syngas (mixture of CO and H₂) and CO₂ are hydrogenated on a metallic catalyst Cu/ZnO/Al₂O₃ (CZA) along with a water-gas shift reaction to yield methanol (MeOH), followed by the dehydration of MeOH with an acidic catalyst γ-Al₂O₃ resulting in DME (R4).These highly exothermic heterogenous catalytic reactions are usually conducted in tubular reactors, which typically consist of tube bundles filled with catalyst pellets and are wrapped by cooling media to radially transfer the heat of reactions from the catalyst bed. In fact, the transport characteristics in such packed beds are rather complex due to the interplay between different transport mechanisms, and the interconnected nature of chemical reactions with different levels of exothermicity, kinetics, and thermodynamic equilibrium affects the final composition and DME yield. A thorough understanding on transport behavior is imperative to optimize the reactor performance, and thereby ensuring better conversion, selectivity, and yield, as well as economic viability while operating in a commercial setup. Model predicted optimization studies can inform the reactor design to maximize the DME yield and facilitate a successful technology transfer at pilot+ scale. This work presents a unique Computational Fluid Dynamics (CFD) model to analyze the transport and mass transfer effects and to optimize the DME yield in a lab-scale and pilot scale packed-bed reactor.