Feasibility of Methanol–Gasoline Blends in a Production Grade Spark-Ignited Carbureted Genset Engine—Part 2: Unregulated Emission Characteristics

Abstract This study aims to evaluate the effect of methanol–gasoline blends on unregulated emissions of carbureted spark-ignited genset engines. The test engine was fueled with M15 (15% methanol + 3% isopropyl alcohol + 82% gasoline, v/v), M20 (20% methanol + 80% gasoline, v/v), and baseline gasoline. The test engine was operated at a constant speed of 3500 rpm at varying loads (no load, 0.4, 0.8, 1.2, 1.6, 2, 2.4, and 2.8 kW), and the results obtained from methanol blends were compared with baseline gasoline. Fourier transform infrared spectrometry exhaust gas analyzer was used to measure unregulated emissions. Methanol–gasoline blends emitted higher nitrogen dioxide, nitrous oxide, formaldehyde, acetaldehyde, and methanol emissions than baseline gasoline. M15 showed slightly higher butadiene, iso-butylene, ethanol, methane, ethylene, benzene, and toluene emissions at lower engine loads than baseline gasoline. M20 showed lower formic acid, acetic acid, methanol, methane, ethane, butadiene, iso-butylene, benzene, and toluene emissions than baseline gasoline. Both blends showed lower ammonia emissions than baseline gasoline.