Investigation on Combustion Processes of Gasoline Blended with Dissociated Methanol Gas

As a fuel that can be made from renewable energy and carbon dioxide, methanol has a wide range of application prospects as an energy carrier for the vehicle-application. In order to improve engine efficiency and reduce emissions, a concept of the gasoline-syngas engine is proposed which dissociates methanol to hydrogen (H2) and carbon monoxide (CO) by recycling exhaust heat of the engine through a methanol dissociation device and then adding the dissociated methanol gas to the engine to improve combustion. In this study, the effect on gasoline combustion processes with dissociated methanol gas is investigated. Blending dissociated methanol gas into gasoline could improve its flame speed. In addition, the equivalence ratio corresponding to the maximum laminar flame speed increased with the increase of the dissociated methanol ratio. The addition of dissociated methanol gas increased the concentration of the O, H, and OH radicals, enhanced the rate of key elementary reactions, and made the peak appear earlier. H2 could have a significant impact on the elementary reactions of O2 + H = O + OH and H2 + OH = H + H2O, while CO remarkably affected the elementary reaction of CO + OH = CO2 + H.