Modeling study of combustion and pollutant formation in HCCI engine operating on hydrogen rich fuel blends

•2D CFD simulation of combustion and emission characteristics of HCCI engine is conducted.•CH4, syngas, CH4/H2 and CH4/syngas blends were considered as a fuel.•Replacement of CH4 by CH4/H2 blend increases output energy and decreases substantially CO emission.•The usage of CH4/syngas blend improves HCCI performance and reduces the pollutant emissions.•Addition of a certain amount of H2 or syngas to CH4 can decrease NO emission.

Comprehensive analysis of combustion and emission characteristics of HCCI engine operating on alternative fuels, including methane, syngas, methane/hydrogen and methane/syngas blends is conducted on the basis of CFD simulation with the use of detailed reaction mechanism. It is shown that the replacement of methane to methane/hydrogen blend with 50% H2 volume content makes it possible to increase the output energy during HCCI combustion and simultaneously to reduce the NO and CO emissions. The use of methane/syngas blend as a fuel also leads to an improvement of HCCI performance and to reducing the pollutant emissions, including the emission of CO2.