Influence of Injection of Hydrogen and Synthesis Gas on Performance Parameters of a Spark Ignition Engine Fueled with Natural Gas

The current research evaluated the influence of hydrogen and synthesis gas in a spark ignition engine fuelled mainly with natural gas. Three blends (NG100%, NG80% + SG20%, and NG80% + SG20% + H(4lpm)) and five load conditions (20%, 40%, 60%, 80%, and 100%) were analyzed and used to investigate changes in performance parameters, thermodynamic balances, exergoeconomic analysis and environmental and social impact of pollutant emissions (CO, HC and NOx). The results show a negative effect when partially replacing natural gas with syngas, with an 18.26% increase in BSFC and a 15.43% reduction in BTE with the blend NG80% + SG20%. However, adding hydrogen significantly improved performance, reducing BSFC by 12.79% and increasing BTE by 14.71%. Thermodynamic balances showed an improvement in efficiency with the addition of hydrogen, reaching a maximum energy and exergy efficiency of 28.74% and 27.84%. In addition, a reduction of 7.32% and 2.70% in the environmental and social impact associated with CO and HC emissions was observed. However, hydrogen concentration increased NOx emissions. In general, hydrogen improves engine performance and efficiency, compensating for the low calorific value of synthesis gas and reducing the environmental impact of pollutant emissions.