Computational fluid dynamics (CFD) modelling as a power multiplier tool for the design improvement of gaseous and liquid fuels: current status, challenges and perspectives

Climate change and global warming are urgent concerns, prompting the scientific community to focus on achieving net-zero greenhouse gas (GHG) emissions primarily through renewable energy sources. Carbon capture and utilisation (CCU) technology offers a practical solution by converting carbon dioxide (CO2) into usable chemicals and fuels, while hydrogen (H2) presents a highly efficient, zero-emission fuel alternative, despite challenges in its production and storage. The processes for generating these fuels differ, necessitating specific system conditions for each. Computational tools, especially computational fluid dynamics (CFD), have become vital for optimizing these processes. Central to CFD models are kinetic equations that describe the conversion of feedstock and the generation of products. This review discusses the reaction pathways for gaseous and liquid fuel production, along with the proposed kinetic rate equations from existing literature. Additionally, it emphasises the significance of accounting for various factors in CFD models, including catalyst deactivation and competitive reactions, to maintain selectivity for desired products. Accurate physical representations are also crucial for modelling fluid flow, mixing, and heat transport, improving reactor design, optimisation, and scaling processes effectively compared to traditional experiments. The presentation of governing equations varies based on reactor types and flow systems. Ultimately, CFD not only validates experimental results but also aids in discovering optimal reactor designs and parameters for enhanced efficiency and product yields. Its ongoing advancement in predictive modelling and optimization marks it as an essential tool in contemporary research and industrial sectors focused on sustainable fuel production.