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| Introduction to Fuel Cells |
Fuel cells are electro-chemical devices that operate at a high level of efficiency with little noise or air pollution. There are many potential applications for fuel cells, including electricity generation in stationary applications and provision of motor force for a new generation of transportation vehicles. All fuel cells operate on the same principle-they convert chemical energy directly into electricity and heat, rather than oxidize (burn) a fuel. In most, but not all fuel cells, the source of the fuel's chemical energy is hydrogen. In some cases, the fuel may need to be processed, or "reformed," before it can be used in the fuel cell. An input
fuel is catalytically reacted (electrons removed from the fuel elements)
in the fuel cell to create an electric current. Fuel cells consist of
an electrolyte material that is sandwiched in between two thin electrodes
(porous anode and cathode). The input fuel passes over the anode and oxygen
passes over the cathode where it catalytically splits into ions and electrons.
The electrons go through an external circuit to serve an electric load
while the ions move through the electrolyte toward the oppositely charged
electrode. At the electrode, ions combine to create by-products, primarily
water and CO2. Depending on the input fuel and electrolyte, different
chemical reactions will occur. |
| Fonte: http://www.repp.org/ |