Academic Awards 2024 booklet

85 One-step CO 2 hydrogenation to dimethyl ether via packed bed membrane reactors The chemical and energy industries are under increasing pressure to minimize their environmental impact, seeking alternative feedstock, energy sources and sustainable processes. Capturing carbon (CO 2 ) from waste gas streams for reuse in fuel or chemical production presents a dual solution to these challenges. In my PhD research, I focus on converting CO 2 into dimethyl ether (DME), a cleaner fuel compared to diesel for heavy vehicles. However, a major hurdle of this reaction is the excess water by-product that limits the CO 2 conversion and accelerates the catalyst deactivation. My study demonstrates that significant improvement can be achieved with the use of the membrane reactor technology. Integrating carbon molecular sieve membranes into the catalytic bed can selectively remove the water from the reaction environment, shifting the reaction equilibrium to higher CO 2 conversion. Through experimental work, I optimized membrane properties and process conditions, validating crucial modeling tools for scale-up and optimization. Reactor and process simulations reveal that membrane reactor technology substantially reduces DME production costs and carbon emissions, due to its higher performance. Overall, this study allowed moving a significant step forward into the future scale-up of this process, which would certainly contribute to the decarbonization of the chemical and energy sectors. Figure 1: Sketch of a packed bed membrane reactor together with the concentration profiles across the reactor gas phase, membrane and catalyst particles as derived with the modelling tools developed in this research. Figure 2: Cross section of the carbon molecular sieve membrane acquired with a scanned electron microscope. The darker (top) layer corresponds to the carbon (thickness is reported in the image), which is deposited on a porous alumina support. Figure 3: CO 2 conversion and product yield of a conventional packed bed reactor (PBR) and a packed bed membrane reactor (PBMR) derived experimentally. The PBMR leads to a 35% and 20% increase in the CO 2 conversion and DME yield, respectively.