Effect of H2:CO ratio in syngas on the performance of a dual fuel diesel engine operation

► Syngas as an alternative fuel in an unmodified conventional diesel engine. ► We examine three different H2:CO composition syngas fuels under dual fuel modes. ► Higher H2 composition syngas mode registered higher diesel replacement levels. ► Increasing H2 fraction increase thermal efficiency and NOx emissions of syngas modes. ► The CO emission levels sensitive to the presence of CO% fraction in syngas.