Hydrogen enriched biodiesel with a CuO ‐ WO ₃ ‐g‐ C ₃ N ₄ nanocomposite for enhanced performance and emission reduction in a CI engine using experimental and machine learning approaches

Renewable fuels and advanced nanomaterials are being investigated to address the growing demand for sustainable energy and reduced diesel engine emissions. Biodiesel blends and nanocomposite additives can improve CI engine efficiency and emission characteristics. This research investigates the combined use of hydrogen enrichment and a multifunctional CuO‐WO 3 ‐g‐C 3 N 4 (CWOGCN) ternary nanocomposite to improve the performance and emission characteristics of a CI engine fueled with a 20% honge oil methyl ester blend (H20). The developed CWOGCN nanocomposite was characterized using XRD, SEM–EDX with elemental mapping, FTIR, and XPS analyses. The results confirmed the crystallinity, surface morphology, elemental composition, chemical states, and uniform elemental distribution of the synthesized nanocomposite. Engine experiments were conducted using 50 and 100 ppm CWOGCN nanocomposites with 10 LPM hydrogen enrichment under varying engine load conditions. The highest brake thermal efficiency (BTE) of 30.16% was obtained at 4.78 kW, while the lowest brake specific fuel consumption (BSFC) was 0.446 kg/kWh. Compared with diesel operation, the hydrocarbon emission was reduced to 38 ppm, carbon monoxide emission decreased to 0.12%, NO x emission was limited to 842 ppm, and smoke opacity was reduced to 42%. The RSM models showed high predictive capability ( R 2 = 0.991), while machine learning models, particularly Gradient Boosting, showed superior nonlinear prediction performance. The combined experimental, RSM, and machine learning analysis demonstrated that H20CWOGCN100H provided improved thermal efficiency and reduced exhaust emissions, highlighting the potential of hydrogen‐enriched ternary nanocomposite biodiesel blends for cleaner and more efficient CI engine operation.