Performance of an Onboard Fuel Processor for PEM Fuel Cell Vehicles 2005-01-0008

To reduce greenhouse gas emissions, automakers are actively pursuing alternative propulsion systems. European automakers have voluntarily committed to reduce CO2 emissions 25% from 1995 levels by 2008 with the possibility of even lower levels in 2012¹. To achieve these large reductions, improvements to current engine technology are being pursued along with new power plant technologies. Fuel Cell Vehicles offer an exciting option by producing electric power through a reaction that combines hydrogen and oxygen to make water. However, hydrogen storage onboard vehicles and the construction of an expensive hydrogen fueling infrastructure remain as challenges today. In addition, greenhouse gas emissions from the production of hydrogen must be considered since most hydrogen is currently produced from non-renewable sources. While these issues are being worked on, Renault has chosen to pursue a fuel cell vehicle with a fuel processor that converts gasoline to hydrogen onboard the vehicle.

As presented at the 2004 SAE World Congress, Renault and Nuvera Fuel Cells developed a fuel processor that achieved automotive size and power in a project from 2002 to 2004. This work is continuing in a new four-year project that seeks to further advance the technology to achieve the technical requirements for a commercial vehicle system. A main focus of this project is the controls of the fuel processor system, which influence the response of the overall power plant. This controls effort includes development of automotive components for controlling the fluid flows to improve the system response, turndown, and the packaging size. This paper presents an overview of the gasoline fuel cell power plant along with advances in the fuel processing technology and current testing results of the fuel processor system with the custom control system. To date, the fuel processor has shown a startup of under 6 minutes from room temperature to less than 100 ppm CO. Primary advances include heat transfer optimization and automotive-type controls components. In addition, durability tests have revealed areas for improvement.