Well-to-Wheel Analysis of Ethanol-Gasoline Flex-Fuel Hybrid Vehicle

Abstract

India's reliance on crude oil imports to meet its energy demands, coupled with the escalating pollution issues stemming from contemporary vehicle technologies, underscores the urgency of evaluating prospective future fuel and propulsion systems. This necessitates a comprehensive examination of the entire fuel cycle, spanning from production to utilization in propulsion systems, commonly referred to as a Well-to-Wheels (WTW) analysis. This report comprises three essential segments: the Well-to-Tank (WTT) analysis, the Tank-to-Wheel (TTW) analysis, and the amalgamated WTW analysis. The WTT segment assesses the energy consumption and emissions generated during fuel production, while the TTW stage focuses on the energy usage and CO₂ emissions associated with vehicle operation across a typical Indian driving cycle. Integration of both WTT and TTW results yields final WTW estimates of energy consumption and CO₂ emissions. The WTW energy consumption, efficiency, and CO₂ emissions were scrutinized across three vehicle/fuel configurations for a passenger sedan within the Indian context: ethanol-gasoline blended fuel powering a Hybrid Electric Vehicle (HEV), a gasoline-powered conventional vehicle, and a Battery Electric Vehicle (BEV). These vehicles were simulated using Matlab Simulink-based software – Autonomie over the Modified Indian Drive Cycle (MIDC). The current electricity generation mix with its substantial reliance on coal accounting for nearly 70%, renders the electricity pathway less efficient and emits high levels of CO₂. Consequently, BEVs exhibit efficiency comparable to conventional gasoline vehicles but with higher CO₂ emissions from a WTW perspective. This contradicts the prevailing public perception that EVs are environmentally superior and have significantly reduced impact compared to conventional vehicles. This study underscores that hybridization and biofuel utilization notably enhance WTW efficiency and reduce CO₂ emissions. Specifically, hybrids powered by ethanol and ethanol-gasoline blends demonstrate superior WTW efficiency and reduced CO₂ emissions compared to their conventional counterparts. Significantly, the WTW CO₂ emissions are lowest for the E100-HEV, primarily due to the powertrain's efficiency and the carbon neutrality of sugarcane ethanol. The combination of sugarcane ethanol with hybrid technologies holds considerable promise in enabling India to diminish its reliance on crude oil imports while mitigating environmental impacts.