Reformed methanol fuel cell
From Wikipedia, the free encyclopedia
 |
This article does not cite any references or sources. (October 2007) Please help improve this article by adding citations to reliable sources. Unverifiable material may be challenged and removed. |
Reformed Methanol Fuel Cell systems or RMFCs are a subcategory of proton-exchange fuel cells where, the fuel, methanol (CH3OH), is reformed, before being fed into the fuel cell. RMFC systems offer advantages over DMFC systems including higher efficiency, smaller cell stacks, no water management, better operation at low temperatures, and storage at sub-zero[vague] temperatures. The tradeoff is that RMFC systems operate at hotter temperatures and therefore need more advanced heat management and insulation.
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 other hydrocarbon fuels. Additionally, methanol is naturally occurring, biodegradable, and energy dense.
RMFC systems consist of a methanol reformer (or fuel processor), a fuel cell, a fuel cartridge, and the BOP (the balance of plant).
The fuel cartridge stores the methanol fuel, which is often diluted with up to 40% (by volume) water. The methanol reformer converts methanol to H2 and CO2, a reaction that occurs at temperatures of 250 °C to 300 °C. The 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. The balance of plant consists of any fuel pumps, 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.
[edit] State of development
RMFC systems have reached an advanced stage of development. For instance, a small 25 watt RMFC system developed for the military has met environmental tolerance, safety, and performance goals set by the U.S.Army CERDEC, and is commercially available.
[edit] See also
[edit] External links
|
||||||||
