Automotive Fuel Processor Development and Demonstration with Fuel Cell Systems

摘要

The potential for fuel cell systems to improve energy efficiency and reduce emissions over conventional power systems has generated significant interest in fuel cell technologies. While fuel cells are being investigated for use in many applications such as stationary power generation and small portable devices, transportation applications present some unique challenges for fuel cell technology. Due to their lower operating temperature and non-brittle materials, most transportation work is focusing on fuel cells using proton exchange membrane (PEM) technology. Since PEM fuel cells are fueled by hydrogen, major obstacles to their widespread use are the lack of an available hydrogen fueling infrastructure and hydrogen's relatively low energy storage density, which leads to a much lower driving range than conventional vehicles. One potential solution to the hydrogen infrastructure and storage density issues is to convert a conventional fuel such as gasoline into hydrogen onboard the vehicle using a fuel processor. Figure 2 shows that gasoline stores roughly 7 times more energy per volume than pressurized hydrogen gas at 700 bar and 4 times more than liquid hydrogen. If integrated properly, the fuel processor/fuel cell system would also be more efficient than traditional engines and would give a fuel economy benefit while hydrogen storage and distribution issues are being investigated. Widespread implementation of fuel processor/fuel cell systems requires improvements in several aspects of the technology, including size, startup time, transient response time, and cost. In addition, the ability to operate on a number of hydrocarbon fuels that are available through the existing infrastructure is a key enabler for commercializing these systems. In this program, Nuvera Fuel Cells collaborated with the Department of Energy (DOE) to develop efficient, low-emission, multi-fuel processors for transportation applications. Nuvera's focus was on (1) developing fuel processor subsystems (fuel reformer, CO cleanup, and exhaust cleanup) that were small enough to integrate on a vehicle and (2) evaluating the fuel processor system performance for hydrogen production, efficiency, thermal integration, startup, durability and ability to integrate with fuel cells. Nuvera carried out a three-part development program that created multi-fuel (gasoline, ethanol, natural gas) fuel processing systems and investigated integration of fuel cell / fuel processor systems. The targets for the various stages of development were initially based on the goals of the DOE's Partnership for New Generation Vehicles (PNGV) initiative and later on the Freedom Car goals. The three parts are summarized below with the names based on the topic numbers from the original Solicitation for Financial Assistance Award (SFAA).