Title :
A microfabricated suspended-tube chemical reactor for thermally efficient fuel processing
Author :
Arana, Leonel R. ; Schaevitz, Samuel B. ; Franz, Aleksander J. ; Schmidt, Martin A. ; Jensen, Klavs F.
Author_Institution :
Dept. of Chem. Eng., Massachusetts Inst. of Technol., Cambridge, MA, USA
Abstract :
We present a suspended-tube chemical reactor/heat exchanger for high-temperature fuel processing in micro energy conversion systems, primarily for hydrogen production in portable fuel cell systems. This reactor, designed to thermally isolate a high-temperature reaction zone, consists of four free-standing silicon nitride tubes comprising two independent U-shaped fluidic channels. Portions of the tubes are encased in silicon to enable heat exchange between the fluids in these channels. A thin-film platinum resistor is embedded for localized heating and temperature sensing. This paper describes the design and fabrication process for the MEMS fuel processor. Fluidic testing, thermal characterization up to 825°C, and preparation of catalyst washcoats in the reactor microchannels are discussed. In addition, results from catalytic autothermal butane combustion and ammonia cracking in the reactor are presented.
Keywords :
catalysis; chemical technology; fuel; fuel cells; heat exchangers; hydrogen economy; microfluidics; 825 degC; H2; MEMS device; NH3; Pt; Si; SiN; ammonia cracking; butane combustion; catalyst washcoat; fluidic channel; heat exchanger; high-temperature fuel processing; hydrogen production; localized heating; micro energy conversion system; portable fuel cell system; silicon microfabrication; silicon nitride tube; suspended-tube chemical reactor; temperature sensing; thermal management; thin-film platinum resistor; Chemical reactors; Energy conversion; Fuel cells; Hydrogen; Inductors; Platinum; Production systems; Resistors; Silicon; Transistors;
Journal_Title :
Microelectromechanical Systems, Journal of
DOI :
10.1109/JMEMS.2003.817897
