A microfabricated suspended-tube chemical reactor for fuel processing

A microfabricated suspended-tube reactor has been developed and demonstrated to operate at temperatures over 900/spl deg/C for efficient thermal processing of chemical fuels. This reactor uses thin-walled SiN tubes to directly address the most significant problem in small-scale fuel processors: thermal management. It efficiently isolates a high-temperature zone while maintaining a temperature gradient of up to 2000/spl deg/C/mm. This design is ideally suited to serve as a combustor/recuperator for thermoelectric (TE) and thermophotovoltaic (TPV) generators, and as a reformer to produce hydrogen for portable fuel cell systems. Using the integrated heaters, catalytic ammonia cracking has been carried out to produce up to 1.6 W (9 sccm) of hydrogen with 97% fuel utilization.