Enhancing Sustainability of Water-Emulsified Diesel-Hydrogen Carrier Biogas as Fuel in Dual-Fuel Engines through the Parametric Optimization

This study investigates the usage of biodiesel-based emulsified fuel as pilot fuel and waste-derived biogas as prime fuel to run dual-fuel engines at varying compression ratios (17, 17.5, 18), injection timing (23 degrees, 26 degrees, 29 degrees, 32 degrees BTDCs), and engine loads (20%, 40%, 60% 80%, 100%). Mahua biodiesel, surfactants, and water were used to produce two-phase stable emulsification. The findings showed that using biodiesel-based emulsified fuel as pilot fuel combined at the compression ratio of 18 and advanced fuel injection time of 29 degrees BTDC increased performance and lowered emissions. Additionally, response surface methodology with variance analysis was used to create prediction models for all engine outputs with a robust R2 value (0.8927-0.9974). The engine operation was optimized employing the desirability approach to be 85.3% of engine load, compression ratio of 18, and injection timing of 29 degrees BTDC. At optimal settings, the anticipated engine outputs were 17.46% for brake thermal efficiency, 318.5 degrees C for exhaust gas temperature, 76.1% for liquid fuel replacement, 45.3 bar of peak in-cylinder pressure, 3.97 vol.% carbon dioxide, 137.43 ppm carbon monoxide, 132 ppm hydrocarbon, and 42 ppm oxides of nitrogen. The lab-based engine testing found that the results were well within 7.14% of the projected values at these optimal operating parameters.