Due to their intensive use as raw material, propylene is among the most important chemical industry compounds [1-3]. Global propylene market to reach 158.4 million metric tons by 2027. To supply the growing demand, a non-oxidative propane dehydrogenation reaction (PDH) appears as a promise to get propylene (C₃H₈ ⇔ C₃H₆ + H₂) more efficiently and to minimize energy-demands of the process.

PDH is limited by thermodynamic equilibrium, so it requires high temperatures (>600ºC) due to its endothermic character (ΔH>0). These temperatures lead to side reactions, especially coke formation, which deactivates the catalyst [4]. Protonic ceramic membranes (>400°C) offer an alternative to the use of high temperatures. By extracting H₂ from the catalytic chamber, the equilibrium of the reaction is shifted, resulting in higher conversions at a lower temperature (500-600 ºC), and enhancing the selectivity of the reaction. At the same time, this technology affords compressed high-purity H₂, thus intensifying the process. The proton-conducting cell technology has already been successfully applied in other reactive systems such as methane reforming [5 - 6], ammonia cracking [6], water electrolysis [7], or direct conversion of methane to aromatics [8].
In this work, an innovative multifunctional membrane reactor is presented. It combines a novel Pt/Sn/M3 catalyst highly kinetically active and resistant to coke deactivation with a tailor-made flow field geometry and a BaZr_1-x-zCe_xY_zO₃ (BZCY) membrane to separate hydrogen and shift the equilibrium. It leads to a remarkable improvement in conversion and selectivity. This study couples experimental tests with Computational Fluid Dynamics simulations (CFD). CFD studies aims to design, analyse and optimise the reactive system. The flow field geometry was optimized by CFD simulations to avoid any diffusional limitation and maximize the H₂ extraction. In addition, the evaluation of the reactive system is carried out to understand the effect of the new catalyst composition and operating conditions (temperature, space velocity, H₂ extraction) on the PDH conversion and selectivity. In parallel, 25 cm² BZCY membranes are developed and evaluated by EIS analysis, H₂ extraction rate measurements and Faradaic efficiency.

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