Fuel processing for fuel cell systems in transportation and portable power applications

Abstract

Small fuel cell systems in the 1–100 kW power range have become the focus of intense R&D activities. Applications envisioned for such systems include primary propulsion power for passenger cars and light-duty vehicles, auxiliary power for trucks and heavy-duty vehicles (for operator quality-of-life and housekeeping needs) and portable power generation for residential and recreational use. The operating mode of these small fuel cell systems differs dramatically from that of larger fuel cell systems (100–1000 kW) designed for utility power generation. These small systems will operate over a wide load range, with only brief periods at full power, considerable time at 30–50% of the rated power, and relatively frequent shutoffs and restarts. The lack of an infrastructure for producing and distributing H 2 has led to a research effort to develop on-board fuel processing technology for reforming hydrocarbon fuels to generate H 2. Existing reforming technology used in large-scale manufacturing operations, such as ammonia synthesis, is cost prohibitive when scaled down to the size of these small systems. Furthermore, these large reforming systems are designed to operate at a constant production rate and with infrequent shutoffs and restarts. In this paper, we provide an overview of the reforming options for generating H 2 from hydrocarbon fuels, the development of new reforming catalysts, and the design of fuel processors for these small fuel cell systems.