Environmental and enviro-economic effect analysis of hydrogen-methanol-gasoline addition into an SI engine

This paper provides a novel approach to the environmental and enviro-economic assessment of an SI engine at various loads (25Nm, 50Nm, 75 Nm, 100 Nm, and full load) using different fuel blends such as methanol-gasoline (20% methanol + 80% gasoline in volumetric), and hydrogen-methanol-gasoline (methanol-gasoline blend + 5% hydrogen). Environmental and enviro-economic analysis methods are applied based on emitted carbon amount in the atmosphere and carbon price. The average brake-specific fuel consumption value was observed to substantially increase the rate by 12.82% with the methanol and a reduction of 4.34% with the hydrogen addition. Moreover, the maximum engine torque increased by 4.15% with hydrogen at full engine load. The average values of the annual CO2 environmental effect were calculated at 29.02 tCO2/y, 29.06 tCO2/y, and 28.51 tCO2/y for gasoline, methanol, and hydrogen fuel blends, respectively. The environmental impact of CO2 values slightly increased by 0.11% with adding methanol to gasoline. However, a reduction was observed at 1.89% with the hydrogen addition. The average value of NO decreased by 2.25% with methanol, whereas it dramatically increased by 5.80% with hydrogen. The average values of the annual CO2 enviro-economic effect were obtained at 1863.98 $/y, 1866.02 $/y, and 1830.67 $/y for gasoline, methanol, and hydrogen fuel blends, respectively. The best engine parameters and the environmental effect values were obtained at 77.80 Nm, 286.93 g/kWh, and 28.99 tCO2/y according to over-fuel consumption and over-pollution amount. For the enviro-economic overpollution cost, the best results have occurred at 83.03 Nm, 278.90 g/kWh, and 1960.20 $/y. The obtained results will present a new perspective for evaluating the use of alternative fuels in internal combustion engines. Thus, further investigations are required to assess alternative fuels' longer-term environmental and enviro-economic impacts.