Hydrogen for Reducing Emissions from Alternative Fuel Vehicles

Hydrogen is presently more expensive than the fossil fuels that it must replace in a renewable energy future. In order for hydrogen to become economically viable in the near future, it must provide benefits that justify its cost. This paper describes recent progress in an ongoing DOE/NREL-sponsored effort to apply the special properties of hydrogen in ways that produce leveraged benefits. Laboratory data and “Cold 505” emissions test results show the benefits of starting a vehicle on hydrogen (ultralean) and flowing extra hydrogen directly into the exhaust stream to heat the catalyst.