Simulation Analysis for Design of H₂/N₂ Ratio of Feed Gas to Ammonia Synthesis Process Using Ru/CeLaTiOx Catalyst

In this study, we investigated the catalytic performance and kinetic model of novel lanthanoid oxide-supported Ru catalysts for NH3 synthesis in mild conditions (P ≤ 8 MPa, T ≤ 425 °C), Ru/Ce0.5La0.4Ti0.1Ox (termed as Ru/CeLaTiOx). It was found that Ru/CeLaTiOx significantly outperformed conventional Ru/MgO and Ru/CeO2 catalysts across the evaluated operating conditions. High NH3 synthesis rates up to ∼30 mmol gcat–1 h–1 were attainable under conditions of 400 °C, 5 MPa, and H2/N2 ratios between 1.0 and 1.5. Optimization of the Langmuir–Hinshelwood (LH) kinetic model incorporating nitrogen hydride (NHx) adsorption was performed, which revealed their strong influence compared to adsorbed N and H adatoms as intermediate species. Further, the model kinetics showed favorable dependence toward N2 and H2 concentrations, which highlights operational advantage of the introduced catalysts for renewable-derived NH3 synthesis over the currently commercial Fe and Ru catalysts. Process simulation analysis incorporating the above-mentioned catalysts and heat recovery system was performed, which attained predicted process efficiency and specific energy consumption of 62.8% and 8.32 GJ/ton NH3 for the synthesis loop, respectively.