Study and utilization of microscale phenomena for operation of microscale devices and high-temperature microreactors

Microreactors for H₂ production are promising portable power sources. H₂ can be produced by reactions such as the decomposition of NH₃ or the steam reforming of hydrocarbons. Efforts in fabricating macroporous SiC and SiCN catalyst supports with high-temperature stability and tailored pore size, and the integrating of these catalyst supports within an alumina housing are presented. NH₃ is decomposed within these reactors at up to 1000°C to show their use for H₂ production. The extent of reorientation of the interface is related to two dimensionless numbers, Fr, the square root of the ratio of inertial to gravitational forces, and Re/Fr², the ratio of gravitational to viscous forces. The extent of reorientation is independent of the ratio of inertial to gravitational forces, and aids in the design of microdevices using fluids of different densities by establishing conditions under which the reorientation of the interface can be avoided. This is an abstract of a paper presented at the AIChE Annual Meeting and Fall Showcase (Cincinnati, OH 10/30/2005-11/4/2005).