Welcoming Remarks

Methane dehydroaromatization (DHA) over Mo/HZSM-5 offers a potential route to a value-added liquid product, however, DHA conversion is severely limited by thermodynamics at most industrially relevant temperatures. We developed an integrated process coupling methane DHA, chemical looping for selective hydrogen oxidation, and subsequent water removal to achieve higher yields of aromatic products and in this talk I will present an overview of our investigations on the effectiveness and limits of this system. We validate this process via the construction and operation of a one-of-a-kind multibed recirculating reactor, and achieve a combined aromatics yield of 42%. We further determined that in this system, the hydrogen oxidation using Fe₃O₄ particles is limited by thermodynamic equilibrium to about 60% and to overcome this limitation we developed novel oxygen carrier (silica-encapsulated Fe₂O₃ with Fe/Si mole ratio of 1.2) yields high overall methane conversion (49%) and aromatics yield (up to 36%) during 4 hours of recirculation. A silica layer encapsulating Fe₂O₃ favors hydrogen transport and oxidation, preventing aromatics diffusing to the Fe₂O₃ surface. Lastly, we model this intensified DHA process and postulate dynamic and steady-state surrogate models to analyze and optimize the production of the aromatic. The model-based optimization maximized the production of the aromatic and shows that a recycle ratio of R_recycle = 0.47, and a temperature of 725°C achieve an optimal economic operation.