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

Abstract

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.

Introducing the I&ECR Virtual Collection of Industrial and Industrially Relevant Research (2022–2023)

“…Although most studies in Process Systems Engineering come from academic groups, the topic area is very important to industrial researchers, with papers in the collection including an August 2023 cover article on the impact of H 2 /N 2 ratio for NH 3 synthesis, a methodology for multipurpose batch plant scheduling, an image-based control method for an agrochemical crystallization process, and a process for preparing propanol from methane …”