Internal Combustion Engine Vehicle: Emissions and Performance Using Blends of Natural Gas and Hydrogen

Using blends of natural gas (NG) and hydrogen as an alternative to gasoline in Internal Combustion Engines (ICEs) has the potential of a major reduction in CO₂ and other harmful emissions, besides giving insight into the use of gaseous biofuels, rich in methane and hydrogen, and offering a transition scenario towards a hydrogen economy. To investigate the consequences of using blends, the performance of a 240cc stationary ICE and a Yamaha Majesty YP125FI scooter, converted to run on a large variety of blends of hydrogen and NG, have been investigated at HAN University, Netherlands. The effect of the air-to-fuel ratio and the composition of the blend on the performance and the emissions have been studied. This paper gives insight into those effects. Main conclusions: With only minor modifications a large variety of blends can be used. By adding H₂ to NG: CO₂, CO, and HC emissions are reduced; NO_x emission is increased; high λ is possible, which can eliminate high NO_x; power and efficiency drop approximately 10%.