Effects of blending dissociated methanol gas with the fuel in gasoline engine

Abstract

To improve the thermal efficiency and reduce the emissions of an internal combustion engine, this research proposed a new gasoline-syngas engine that used gasoline and dissociated methanol gas as the fuel. The system used exhaust heat to dissociate methanol into syngas, which was then added in an engine cylinder and blended with gasoline for combustion. The experimental data of the gasoline-syngas engine were compared with those of the original gasoline engine before the transformation. For a methanol substitution ratio of 20%, the equivalent fuel consumption rate, CO emission, and HC emission decreased by 4.3%, 37.8%, and 32.4%, respectively, and the NOx emission increased by 10.8% at a speed of 2000 r/min, torque of 60 N·m, and excess air ratio of 1. The NOx emission could be reduced by 72.2% by increasing the excess air ratio from 1 to 1.3. Blending the dissociated methanol gas with the fuel of the gasoline engine recycled the exhaust heat and changed the combustion characteristics of the fuel. It has broad application prospects for the efficient use of energy and reduction of emissions.