Microchannel reactors for fuel processing applications. I. Water gas shift reactor

The water gas shift reactor is one of the critical components of a multi-reactor fuel processing system that supports distributed energy production through the use of a fuel cell. The water gas shift reaction converts carbon monoxide (produced in the primary conversion stage of the fuel processor) and water to carbon dioxide and hydrogen. The water gas shift reaction has slow observed kinetics, with multiple-second contact times, which are cited in fixed-bed reactors. The intrinsic reaction kinetics, however, are measured to be fast, with millisecond contact times, which enables miniaturized deployment in a microchannel reactor. Microchannel reactors reduce heat and mass transport limitations far reactions, and thus facilitate exploiting fast intrinsic reaction kinetics, ie. high effectiveness factors. The implications of this work suggest that a water gas shift reactor for a fuel processor (and other applications) will approach sizes one-to-two orders of magnitude smaller than conventional processing hardware. (C) 1999 Elsevier Science Ltd. All rights reserved.