(98b) Micro-Structured Fuel Processors as Hydrogen Source for Fuel Cells In Future Distributed Energy Generation Systems

Future sustainable and distributed energy generation will rely in many cases on fuel cell technology. To address the critical issue of hydrogen supply, fuel processing of fossil and renewable fuels is a viable option to meet the limited space demands of auxiliary power units (APUs) due to the high energy density of liquid fuels [1].  Especially for stationary applications of the smaller scale, mobile and portable power generation systems require a compact hydrogen supply when fuel cell technology is applied. Microstructured reactors provide significant potential for the reduction of system size, system complexity and catalyst costs. Scaled-up micro-channel reactors containing thousands of channels create less scale-up issues compared to conventional (fixed bed) systems. They allow a careful heat management during start-up and normal operation, which increases the service life of the catalyst.

At IMM, the development of complete fuel processors for alcohol and hydrocarbon fuels is ongoing, applying microstructured plate heat-exchanger technology. Complete fuel processors are under development applying steam reforming, partial oxidation and partial de-hydrogenation reactions on a large variety of fuels such as methanol[2], ethanol [3,4], natural gas, LPG [5], gasoline, kerosene and diesel [6]. The systems size varies between 100 W and about 20 kW thermal power of the hydrogen produced. All development steps required for building a fuel processor have been addressed i.e. reactor and system simulation and design, catalyst development, catalyst stability against impurities in the fuel and set-up/testing of complete fuel processors for systems up to 13 kW thermal power output. The choice of fuel converted to hydrogen mainly depends on the application and existing infrastructure. While trucks have diesel fuel readily available, LPG is the right choice for caravans. Having demonstrated the feasibility of compact fuel processing, the aspects of future mass production for such devices for consumer applications have been addressed. Complete fuel processor systems (e.g. a 5 kW diesel fuel processor, a 250W fuel processor/ fuel cell system running on LPG as fuel which will be commercialized end of 2010 and a 100 W methanol fuel processor operated with a high temperature PEM fuel cell) and novel components such as a reactor for the partial de-hydrogenation of kerosene will be presented and discussed.

References

[1]        Kolb, G.; Fuel Processing for Fuel Cells, 1 Ed.;  Wiley-VCH, Weinheim (2008).

[2]        Kolb, G., Schelhaas, K.-P., Wichert, M., Burfeind, J., Hesske, C., Bandlamudi, G.; "Development of a Microstructured Methanol Fuel Processor coupled to a High Temperature PEM Fuel Cell", Chem. Eng. Technol. 32, 11 (2009) pp. 1739-1747.

[3]        Men, Y., Kolb, G., Zapf, R., Hessel, V., Löwe, H.; "Ethanol steam reforming in a microchannel reactor", Process Saf. Environ. Prot. 85, B5 (2007) pp. 413-418.

[4]        Kolb, G., Men, Y., Schelhaas, K. P., Tiemann, D., Zapf, R., Wilhelm, J.; "Development Work on a Microstructured 50 kW Ethanol Fuel Processor for a Small Scale Stationary Hydrogen Supply System ", Ind. Eng. Chem. Res. DOI: 10.1021/ie100602w,  (2010).

[5]        Wichert, M., Men, Y., O’Connell, M., Tiemann, D., Zapf, R., Kadhum, A. A. H., Butschek, S., Frank, R., Schiegl, A.; "Self-sustained operation and durability test of a 300 W-class micro-structured LPG fuel processor", Int. J. Hydrogen Energy submitted for publ.,  (2010).

[6]        O'Connell, M., Kolb, G., Schelhaas, K. P., Schürer, J., Tiemann, D., Ziogas, A., Hessel, V.; "Development and evaluation of a microreactor for the reforming of diesel fuel in the kW range", Int. J. Hydrogen Energy 34,  (2009) pp. 6290-6303.