Hybrid Nanofluids for Low-Carbon Chemical Processes

Hybrid nanofluids have emerged as advanced heat-transfer media with the potential to significantly enhance the energy efficiency of thermal systems used in low-carbon chemical processes. By combining two or more distinct nanoparticles within a base fluid, these engineered suspensions demonstrate synergistic improvements in thermal conductivity, viscosity control, and stability compared to conventional nanofluids. This review synthesizes recent progress in hybrid nanofluid formulation strategies, stabilization techniques, and the underlying thermophysical mechanisms governing heat transfer. Their growing relevance is highlighted across applications such as compact heat exchangers, CO₂ capture and conversion, green chemical synthesis, and renewableenergy-based thermal systems. Although hybrid nanofluids offer substantial opportunities for process intensification and emission reduction, industrial integration remains limited by issues related to cost, long-term stability, pumping requirements, and material compatibility. The paper identifies critical research gaps and outlines future directions necessary for enabling the large-scale deployment of hybrid nanofluids in sustainable chemical engineering.