Innovative syngas-biodiesel blends: a step towards cleaner and greener engine technology

• Dual-fuel CI engine: biodiesel pilot with hydrogen-rich, glycerol syngas. • RSM (CCD) models BTE and NOx versus engine load and syngas flow. • Load dominates BTE; syngas yields small, additive efficiency gains. • NOx grows with load and flow; slight positive A × B interaction. • Optimum: 56.76% load, 5 L·min −1 syngas (BTE 27.1%, NOx 579 ppm). The increasing demand for sustainable and cleaner alternatives to fossil fuels has intensified research on Biodiesel and gaseous fuels for internal combustion engines. However, most existing studies focus on individual biodiesel feedstocks or diesel–syngas combinations, leaving limited understanding of the synergistic effects of blended biodiesels enriched with Syngas. This study aims to evaluate the performance, combustion, and emission characteristics of Juliflora and Pine Oil Methyl Ester Biodiesel blends integrated with hydrogen-rich Syngas in a dual-fuel compression ignition engine. Experiments were conducted on a Kirloskar SV1 engine at varying loads and syngas flow rates, and performance metrics were analyzed using Response Surface Methodology (RSM) and ANOVA. Results revealed that the J60 + P40 blend with 20 L/min syngas achieved a brake thermal efficiency of 31.2%, a 12% improvement over neat Biodiesel, while reducing brake-specific fuel consumption by 8% and smoke opacity by 25%. CO and HC emissions decreased by 18% and 22%, respectively, though NO x increased marginally by 5% due to elevated combustion temperatures. These findings demonstrate that syngas enrichment enhances combustion efficiency and supports the utilization of cleaner energy. Future research should focus on integrating exhaust gas recirculation (EGR) or catalytic after-treatment to mitigate NO x emissions and further optimize Biodiesel–syngas blending ratios.