Investigating ternary biogas-hydrogen-diethyl ether blends for emission reduction and performance enhancement in CI engines: A Taguchi approach

Abstract

This study evaluates the emissions and performance characteristics of a compression ignition (CI) engine operating in dual fuel mode with ternary blends of biogas, hydrogen, and diethyl ether (DEE). The experiments, designed using the Taguchi L9 orthogonal array, systematically varied biogas flow rate (0–16 lpm), hydrogen flow rate (0–10 lpm), and DEE addition to diesel (0–10 % vol). Results showed that hydrogen addition at 10 lpm significantly reduced CO emissions to 0.01 %, while the inclusion of 10 % DEE minimized NOx emissions to 80 ppm. The optimal brake thermal efficiency (26.46 %) was achieved with 0 lpm biogas, 10 lpm hydrogen, and 10 % DEE addition. ANOVA revealed that biogas flow rate was the dominant factor influencing emissions, contributing 83.87 % to HC, 98 % to NOx, and 80.26 % to smoke emissions. Computational Fluid Dynamics (CFD) simulations validated the experimental results, showing that higher biogas and hydrogen flow rates diluted the intake air, reducing oxygen concentration and leading to lower volumetric efficiency. Sensitivity analysis confirmed the robustness of the model with ±3 % mass conservation error. Grid independence studies ensured accurate CFD outcomes, with 3.5 million cells being sufficient for stable results. These findings highlight the potential of biogas-hydrogen-DEE blends to improve CI engine efficiency and reduce harmful emissions, offering a practical solution for sustainable energy applications in transportation.

Keywords

• Compression ignition engines
• Fuel blending
• Taguchi
• Performance
• Emissions