Syngas as SI engine fuel: Combustion perspective

Abstract

Depletion of conventional energy resources and the adverse impact of fossil fuel combustion on environment threaten the sustainable development potential in the energy sector. Biomass can be an alternative, renewable fuel to overcome these negativities. Secondary fuels, derived from biomass, can be used to run the transportation engines. Syngas, which is obtained from biomass gasification, is a potential fuel for the spark ignition engines. However, certain combustion characteristics of the fuel are needed to be studied for the efficient and smooth operation of the engines with the alternative fuel. Laminar burning velocity and ignition delay are two such important characteristics, which influence flame propagation and abnormal combustion, like detonation and surface ignition, inside the engine cylinder. Determination of these combustion characteristics shows considerable deviation between conventional gasoline fuel and syngas (50% H2 and 50% CO). However, blending a small amount of conventional hydrocarbons bring the characteristic parameters with syngas fuel close to those of gasoline. Both physical properties and chemical characteristics are attributed as the reasons behind such variations in the combustion behaviour. Use of syngas is found to decrease the emission levels compared to gasoline in many respect.