Hydrodynamic cavitation-enabled process intensification for sustainable renewable energy production: Advances and perspectives

The global energy transition requires revolutionary process intensification (PI) to overcome both kinetic and mass transfer bottlenecks in traditional renewable energy production. Hydrodynamic cavitation (HC) is an efficient and scalable PI tool; however, it remains a challenge to comprehensively analyze its performance across multiple energy generation regimes and techno-economic scenarios. This article reviews HC-enabled production of biofuels, green hydrogen, and energy storage materials. Specific consideration is given to the connection between cavitation and reactor regimes, such as static constrictions and new rotor-stator reactors, as well as the role of the dimensionless cavitation number ( C v ) in energy density and efficiency. By establishing a unified framework to normalize heterogeneous metrics, this review explicitly distinguishes genuine PI from operational artifacts. Recent studies have shown that optimized micro-reactors enable HC to accelerate biodiesel synthesis rates by more than 90-fold, and simultaneously achieve a 10-fold increase in pretreatment energy efficiency for biogas at the laboratory scale. Beyond technical performance, the proposed approach critically synthesizes existing TEA and LCA studies, showing that reported CAPEX savings depend on application-specific assumptions and erosion-related OPEX, whereas environmental benefits remain highly sensitive to regional electricity carbon intensity. Finally, through a quantitatively upgraded SWOT analysis, we identify “scale-up uncertainty” (constrained by geometric similarity and Reynolds number limitations) and “material erosion” as the fundamental barriers. We propose a roadmap that combines multi-stage parallelization, CFD-based optimization, and AI-driven real-time monitoring to bridge the gap between laboratory success and industrial biorefinery implementation.