Exploring Methanol and Naphtha as Alternative Fuels for a Hybrid-ICE Battery-Driven Light-Duty Vehicle

Abstract

In pursuing sustainable automotive technologies, exploring alternative fuels for hybrid vehicles is crucial in reducing environmental impact and aligning with global carbon emission reduction goals. This work compares methanol and naphtha as potential suitable alternative fuels for running in a battery-driven light-duty hybrid vehicle by comparing their performance with the diesel baseline engine. This work employs a 0-D vehicle simulation model within the GT-Power suite to replicate vehicle dynamics under the Worldwide Harmonized Light Vehicles Test Cycle (WLTC). The vehicle choice enables the assessment of a delivery application scenario using distinct cargo capacities: 0%, 50%, and 100%. The model is fed with engine maps derived from previous experimental work conducted in the same engine, in which a full calibration was obtained that ensures the engine's operability in a wide region of rotational speed and loads. The calibration suggested that the engine could operate in a selected region where both the fuel consumption and emissions were optimal to reduce the environmental impact significantly compared to its diesel counterpart. The results show that the operation at higher engine speeds and loads to charge the battery and the engine running with naphtha or methanol significantly reduces the NOx emissions and the overall CO2 impact. Additionally, the study highlights that the challenges associated with using pure methanol in a compression ignition engine at low-load conditions are substantially mitigated in a hybrid setup, which assists in engine start-up and stabilization, facilitating optimal operational efficiency.