Flexible syngas-biogas-hydrogen fueling spark-ignition engine behaviors with optimized fuel compositions and control parameters

This paper presents the results research on the optimal fuel compositions , the control parameters of the spark ignition engine fueled with syngas-biogas-hydrogen for the pur-pose of setting up a flexible electronic control unit for the engine working in a solar -biomass hybrid renewable energy system. In syngas-biogas-hydrogen mixture, the optimal content of hydrogen and biogas is 20% and 30%, respectively. Exceeding these thresholds, the improvement of engine performance is moderate, but the pollution emission increases strongly. The optimal advanced ignition angle is 38 degrees CA, 24 degrees CA, and 18 degrees CA for syngas, biogas, and hydrogen, respectively. With the same content of hydrogen or biogas in the mixture with syngas, the advanced ignition angle of the hydrogen-syngas blend is less than that of the syngas-biogas blend by about 4 degrees CA at the engine speed of 3000 rpm. The derating power of the engine is 30% and 23% as switching from the hydrogen and biogas fueling mode to the syngas fueling mode, respectively. However, NOx emission of the engine increase from 200 ppm (for syngas) to 2800 ppm (for biogas) and to over 6000 ppm (for hydrogen). The optimal advanced ignition angle, the optimal equivalence ratio of the syngas-biogas-hydrogen fuel mixture vary within the limits of the respective values for syngas and hydrogen. To improve the engine efficiency and reduce pollutant emissions, the loading control system of the engine should prioritize the adjustment of the fuel flow (c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.