Microreactors and microchannel networks enable compact, thermally efficient multi-stage reforming of hydrocarbon fuels to hydrogen gas, as part of an overall portable-power system. Theoretical and experimental studies of microchannel networks coupling endothermic and exothermic processes indicate that optimal efficiencies are obtained by using low thermal conductivity construction materials (e.g. glass, ceramics).1-3

Our research group is developing a new class of ceramic microchannel reactor, combining the benefits of precision machining and ceramics extrusion. An extruded ceramic microchannel network is combined with a precision-machined distributor to realize complex distribution patterns which allow integration of two or more processes within a monolithic unit. This novel technique presents the following advantages; (i) ease of catalyst introduction, (ii) flexibility in material thermal conductivities, and (iii) space-separation of process flows in a variety of radial distribution patterns.

This talk presents the construction and demonstration of a prototype mini-channel reactor based on this new microchannel reactor design. The device is comprised of machined brass distributors designed to evenly distribute two unique fluids in a checker-board pattern among a 3x3 network of parallel mini-channels cut from a stock cordierite monolith (72 cpsi). The resulting ceramic mini-channel will be investigated in order to: i) perform simple heat transfer studies between non reacting fluids to quantify transport rates and verify 1-D models, ii) introduce a catalyst into individual channels by traditional wash coating methods and iii) carry out high-temperature heat transfer experiments between reacting fluids by using methanol as a fuel for conversion to hydrogen with appropriate catalytic micro channel networks. Experimental results will serve as validation of concept for the device as a new class of thermally integrated micro-reactors and will provide the basis for the creation of a powerful fuel reformer design.

1Moreno, A.; Murphy, K.; Wilhite, B. Parametric Study of Solid-Phase Axial Heat Conduction in Thermally-Integrated Microchannel Networks. Industrial and Engineering Chemistry Research. Article In Press.

2Terazaki, T.; Nomura, M.; Takeyama, K.; Nakamura, O.; Yamamoto, T. Development of Multi-Layered Microreactor with Methanol Reformer for Small PEMFC. Journal of Power Sources 2005, 145, 691.

3Kolios, G.; Glockler, B.; Gritsch, A.; Morillo, A.; Eigenberger, G. Heat-Integrated Reactor Concepts for Hydrogen Production by Methane Steam Reforming. Fuel Cells 2005, 5 (1), 52.