Internal Combustion Engine Vehicle: Emissions and Performance Using Blends of Natural Gas and Hydrogen 2007-32-0072

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%.