- Reformed methanol fuel cell
Reformed Methanol Fuel Cell (RMFC) or Indirect Methanol Fuel Cell (IMFC) systems are a subcategory of proton-exchange fuel cells where, the fuel,
methanol (CH3OH), is reformed, before being fed into thefuel cell . RMFC systems offer advantages overdirect methanol fuel cell (DMFC) systems including higher efficiency, smaller cell stacks, no water management, better operation at low temperatures, and storage at sub-zero temperatures because methanol is a liquid from -97.0 °C to 64.7 °C (-142.6 °F to 148.5 °F). The tradeoff is that RMFC systems operate at hotter temperatures and therefore need more advanced heat management and insulation. The waste products with these types of fuel cells arecarbon dioxide and water.Methanol is used as a fuel because it is naturally hydrogen dense (a hydrogen carrier) and can be steam reformed into hydrogen at low temperatures compared to otherhydrocarbon fuels. Additionally, methanol is naturally occurring,biodegradable , and energy dense.RMFC systems consist of a
fuel processing system (FPS) [ [http://www.istanbul.edu.tr/eng/ee/jeee/main/pages/issues/is51/51005.pdf fuel processing system] ] , afuel cell , a fuel cartridge, and theBOP (thebalance of plant ) [ [http://www.fuelcellseminar.com/pdf/2005/Thursday-Nov17/Fisher_Allison_275.PDF Balance of plant] ] .torage
The fuel cartridge stores the
methanol fuel, which is often diluted with up to 40% (by volume) water.Fuel processing system (FPS) in
Methanol →Partial oxidation (POX)/Autothermal reforming (ATR)→Water gas shift reaction (WGS)→preferential oxidation (PROX)The reformer converts methanol to H2 and CO2, a reaction that occurs at temperatures of 250 °C to 300 °C.Fuel cell
→The
membrane electrode assembly (MEA) fuel cell stack produces electricity in a reaction that combines H2 (reformed from methanol in the fuel processor) and O2 and produces water (H2O) as a byproduct.Fuel processing system (FPS) out
→Tail gas combustor (TGC)
catalytic combustion afterburner or (catalytic combustion ) with aplatinum -alumina (Pt–Al2O3) [ [http://www.azom.com/SearchResults.asp?MaterialKeyWord=Pt-Al2O3 Pt-Al2O3] ]catalyst [ [http://journals.tubitak.gov.tr/chem/issues/kim-07-31-5/kim-31-5-14-0706-22.pdf Catalytic Processes for Clean Hydrogen Production from Hydrocarbons] ] [] →condenserBalance of plant
The balance of plant (
BOP ) consists of anyfuel pump s, air compressors, and fans required to circulate the gas and liquid in the system. A control system is also often needed to operate and monitor the RMFC.State of development
RMFC systems have reached an advanced stage of development. For instance, a small [http://www.ultracellpower.com 25 watt RMFC system] developed for the military has met [http://mae.pennnet.com/articles/article_display.cfm?Section=ARTCL&C=News&ARTICLE_ID=298419&KEYWORDS=%22ultracell%22&p=32 environmental tolerance] , [http://rfdesign.com/military_defense_electronics/CERDEC-methanol-fuel-cell-system-0607/index.html safety] , and performance goals set by the [http://www.rdecom.army.mil/rdemagazine/200606-07/itf_CERDEC.html U.S.Army CERDEC] , and is commercially available.
ee also
*
Methane reformer
*Methanol (data page)
*Methanol economy
*Micropump
*Fuel cell
*Glossary of fuel cell terms
*Hydrogen technologies
*Portable fuel cell applications References
External links
* [http://www.portabledesign.com/article?article_id=20 Fuel Cells for Portable Computing and Communications: Extended Power Away from the Grid]
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