Fuel Cell Reformer

Courtesy of U.S. Department of Energy, Argonne National Laboratory 

Department of Energy. Fuel Cell Basics. http //www.eere.energy.gov/hydrogenandfuelcells/fuelcells/baslcs.html 

Argonne National Laboratory. Argonne s Fuel-Flexible Reformer. http //www.cmt.anl.gov/science-technology/fuelreformer.shtml 

Energy Educators of Ontario Energy Fact Sheet. Fuel Cells. http //www.iclei.org/EFACTS/FUELCELL.HTM 

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Borup, R. et al., Fuel composition effects on transportation fuel cell reforming, Catal. Today, 99, 263,2005. 

Farrauto el al.549 report that It is clear that an ideal catalyst for WGS needs to be developed, especially for mobile applications. Indeed, Cu-Zn still dictates the performance standard for fuel cell reformers, even though its pyrophoricity is prohibitive for its use. Higher activity is always desired, as well as the tolerance to flooding and sulfur. In that respect, a precious metal catalyst has obvious advantages but often cannot compete with the price of a base metal system. A three- to four-fold increase in activity would be needed to achieve that advantage. ... 

Because of the modular nature of fuel cells, they are attractive for use in small portable units, ranging in size from 5 W or smaller to 100 W power levels. Examples of uses include the Ballard fuel cell, demonstrating 20 hour operation of a portable power unit (32), and an IFC military backpack. There has also been technology transfer from fuel cell system components. The best example is a joint IFC and Praxair, Inc., venture to develop a unit that converts natural gas to 99.999% pure hydrogen based on using fuel cell reformer technology and pressure swing adsorption process. 

This new technique incorporates a catalyzed short contact time (SCT) substrate into a shock tube. Fig. 13. These SCT reactors are currently used in industry for a variety of applications, including fuel cell reformers and chemical synthesis.The combination of a single pulse shock tube with the short contact time reactor enables the study of complex heterogeneous reactions over a catalyst for very well defined regimes in the absence of transport effects. These conditions initiate reaction in a real environment then abruptly terminate or freeze the reaction sequence. This enables detection of intermediate chemical species that give insight into the reaction mechanism occurring in the presence of the chosen catalyst. There is no limitation in terms of the catalyst formulations the technique can study. 

A more normal shutdown sequence would first flush the fuel cell, reformer, and scrubber with nitrogen or C02 (if it is safe for the cell design). This step is followed by a slow bleed of air and nitrogen to repassivate the fuel cell and reformer under temperature control. If this is not done gradually, the reformer can reach temperatures high enough to violate its containment (meltdown) and become unrecoverable. The reformer performance does decrease after this treatment, but over 90% of its capacity can be retained. Similar problems are present when reforming the fuel cells themselves. 

A.3.5 Contrast with Practical Fuel Cell Reformer Pairs... 

For high-temperature fuel cells (such as solid oxide fuel cells), reforming of methanol and certain other hydrocarbons to hydrogen occurs naturally within the fuel cell itself, in the presence of a catalyst such as Ru, but with an efficiency varying somewhat according to feed (Hibino et ah, 2003). 

Presting, H., Konle, J., Starkov, V., Vyatkin, A., Konig, U. (2004). Porous silicon for micro-sized fuel cell reformer units. Materials Sci. Eng. B108,162-165. 

Lampert, J.J. Selective catalytic oxidation A new catalytic approach to the desulfurization of natural gas and liquid petroleum gas for fuel cell reformer applications. Journal of Power Sources, 2004, 131, 27. 

SIZE VERSUS COST—NEW CATALYSTS FOR ON-SITE Hz GENERATION AND FUEL CELL REFORMERS... 

The size of catalytic reactors is a factor of minor importance compared to catalyst and process cost in the industrial environment. This changes as we look at potential future applications of hydrogen production fuel cell reformers, hydrogen filling stations and on-site hydrogen generation. In some of these applications, size, simplicity, and durability are equally or even more important than minimal cost. 

New applications for WGS catalysis are slowly emerging. These are small-scale hydrogen production and fuel cell reformers. For these new applications, a new generation of catalysts, including precious metal-based monolith catalysts, is being developed, since the traditional catalysts do not fit the application profile (duty cycle, size and safety requirements). 

II.C.ll DFMA Cost Estimates of Fuel-Cell/Reformer Systems at Low/Medium/ High Production Rates... 

James, B., Thomas, C.E., Ho, J., and Lomax, F. DFMA Cost Estimates of Fuel-Cell/Reformer Systems at Low/Medium/High Production Rates in Fuel Cells for Transportation 2001 Annual Progress Report. U.S. Department of Energy, Office of Advanced Automotive Technology. Washington, D.C., 2001. 

The 7-kWnet system will consist of the fuel cell, reformer and ancillary systems. The final packaged system will be optimized for laboratory use and outfitted with an extensive, PC based, data acquisition system. 

IV.C.7 Evaluation of Partial Oxidation Fuel Cell Reformer Emissions... 

Perform extensive emissions testing of a fuel cell/reformer system to include particulate, formaldehyde, and ammonia as well as NO, hydrocarbons, and CO. 

Recently great interest has been shown all over the world in the study of desulfurization of liquid fuels on various adsorbents [7, 8, 13, 145-158], It is driven by the fact that US federal regulations mandate the reduction in sulfur level for gasoline and diesel fuel to 30 and 15 ppm, respectively. The current levels are 300-500 ppmw. The new requirements will be implemented in 2006 [6]. Tire reason for lowering sulfur level, besides detrimental environmental effects is in the fact that sulfur compounds poison both automobile and fuel cell reformer catalysts. 

Key words Fuel Cell/Reforming/Coal/Steam Gasification/Fluidized Bed/Hyhrid Co-Generation Power Plant/Fuel Cell Test Installation... 

Borup RL, Inbody MA, Wood DL, Pacheco SD, Guidry DR, Xie J, Tafoya JI, Blom D (2003) Fuel cell reformer and stack durability gasoline reformate hydrogen - PEM fuel cell durability, Fuel Cell Seminar, Nov 2003, Miami... 

M. Liska. Alternative Catalysts and Synthesis Methods for Fuel Cell Reformers. M.S. thesis. University of Illinois at Chicago, 2003. 

Micro-reactors As for CHEs Drug and fine chemical manufacture. Fuel cell reformers for mobile phones 5... 

Borup, R., Inbody, M., Semelsberger, T., Perry, L. and Parkinson, J. (2002) Testing of fuels in fuel cell reformers. Progress report hydrogen, fuel cells and infrastructure, technologies, US Department of Energy. 

Cooper, R. and Feasey, G. Summary of dbb s fuel cell engine development activities, in Proceedings of the Fuel Cell Reformer Conference, pp. 116-125 (1999) Diamond Bar, CA, USA. 

There are many different ways to approach this problem, some of which may seem rather complex because of the simultaneous reactions (fuel cell, reforming, and water gas shift reactions) and the recycle stream supplying moisture required for the reforming reaction. The solution to this problem can be simplified by focusing on the fuel cell exit condition. 

Lakshmanan, B., W. Huang, and W.J. Weidner. 2002. Electrochemical filtering of CO from fuel-cell reformate. Electrochem. Solid State Lett. 5 A267-A270. 

Start-up of an entire fuel cell reformer system could also be divided into different phases in order to decrease start-up time, by, for example. 

Fig. 21.14 Example of fuel cell reformer system hybrid electric power system...

The reforming process requires heat, which is delivered by a burner that can either be fed with fuel from the tank or with recycled anode waste gas from the fuel cell [19]. Supplying the reformer with heat solely from the combustion of recycled anode waste gas is the basis for an efficient fuel cell reformer process. The anode stoichiometry (Aa,min) required to satisfy the heat demand is determined by the specific enthalpy of the reforming reaction (AH°) for each fuel (see Table 23.2). The efficiency of heat transfer fi-om the burner gas and the reformer is not included in this theoretical value because it depends on the individual hardware design. 

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