Combustion and Emission Behavior of Fusel Oil–Gasoline Blends in a Modern Spark-Ignition Engine

Abstract

The global pursuit of sustainable energy solutions has intensified interest in alternative fuel sources, particularly bio-derived alcohol fuels such as fusel oil. This study investigates the combustion characteristics and emissions mitigation potential of fusel oil–gasoline blends (F10, F20, F30) in a turbocharged gasoline direct injection (GDI) engine under steady-state conditions at 2000 rpm and 40% throttle load. Employing detailed combustion analysis and emissions measurement, the study highlights that blending fusel oil, a renewable by-product of ethanol production, can significantly enhance combustion completeness due to its inherent oxygen content. Methodologically, each fuel blend was tested systematically, ensuring high data reproducibility by averaging results over 200 combustion cycles per test condition, repeated three times. Results showed fusel oil blends accelerated combustion initiation, as evidenced by an earlier peak in-cylinder pressure and rate of heat release. Specifically, HC emissions decreased notably from 125 ppm (F0) to 90 ppm (F30), signifying improved combustion efficiency. Conversely, CO emissions increased from 0.22 mg/kg (F0) to 0.45 mg/kg (F30), indicating localized incomplete combustion due to fusel oil's high latent heat of vaporization. This research uniquely explores fusel oil's viability in turbocharged GDI engines without hardware modifications, contributing valuable insights toward optimizing biofuel integration and reducing harmful emissions, thus supporting sustainable automotive advancements.