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Direct methanol fuel cells (DMFC’s) are the technology of choice for
many
Portable Power Applications. DMFC is also very important for
Micro Power Applications which includes fuel cell systems for portable
electronic equipment such as laptop computers, 2-way radios, cell phones,
PDA’s etc. The advantage of DMFC’s is that
Methanol is a liquid fuel and is therefore easier to store and transport
than Hydrogen. DMFCs use the same type of electrolyte as PEM Fuel Cells,
but require thicker membranes and greater loading (density) of catalysts.
How it Works
Using a liquid rather than gaseous fuel confers considerable advantages
to DMFC developers. As a liquid, Methanol can integrate effectively with
transmission and distribution systems that are already in existence. One
drawback is that direct reforming of the Methanol within the Fuel Cell Stack
means that the electrodes presently require large quantities of Platinum.
DMFC technology is still in the early stages of development, however DMFC
technology has been demonstrated in automotive and portable applications.
DMFC's operate at between 50°C and 120°C with an efficiency of up to 40%
Chemical Equations:
Anode Reaction: CH3OH + H2O »» CO2
+ 6H+ + 6e-
Cathode Reaction: 3/2O2
+ 6H+ + 6e- »» 3H2O
Cell Reaction:
CH3OH + 3/2O2 »» CO2 + 2H2O
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