Jan 26 2006
Fuel Cells Working Concept
Fuel cells are electro-chemical device that convert chemical energy on hydrogen into DC electrical energy. Its mainly different with battery, battery consume DC electric energy with long times when charging and generate DC electric energy when discharging. Battery just device to storing electric energy with limitation capability. Fuel cells just need hydrogen gas which flow to electrode to generate DC electric energy. Its similar with internal combustion engine that need fossil fuel to generate mechanical energy then moving the generator to produce the electric energy. The different with internal combustion engine is fuel cells not release carbon-dioxide emission, just water vapour. Fuel cells with hydrogen fuel very environmental-friendly.
|
|
Components that build one fuel cell (PEM - Polymer Electrolyte Membrane case) consist of :
- Anode - negative electrode where hydrogen gas enter the cell
- Cathode - postive electride where oxygen gas or air enter the cell and water vapour exit from cell
- Chatalyst - breaking molecule of hydrogen gas into positive ion (H+) and electron (e-)
- Electrolyte Membrane - where is only H+ can pass though this material
- Interconnect - connect between cells become a stack (usually consist about 100 to 200 cells)
This a simple explanation how fuel cells can generate DC electric energy :
Hydrogen gas flow though anode plate, then catalyst on anode side perform the hydrogen-oxidation reaction so hydrogen gas separated into H+ and electrons. Then H+ ions pass though the electrolyte membrane going to cathode side and the electrons flow though external-circuit. Electrons flowing on the external circuit are we know as DC electric energy and can be used directly for DC electric motor, DC lamp, etc. On the cathode side, electrons from external-circuit and oxygen gas perform the reduction reaction to making oxygen ions. Then the end occur reaction between hydrogen and oxygen ions become water vapour as the product. You can see bellow the reduction-oxidation reaction on the fuel cells :
There are many type of fuel cells base electrolyte type that used, that are :
- PEMFC (Polimer Electrolyte Membrane Fuel Cell)
- AFC (Alkaline Fuel Cell)
- PAFC (Phosphoric Acid Fuel Cell)
- MCFC (Molten Carbonate Fuel Cell)
- ITSOFC (Intermediate Temperature Solid Oxide Fuel Cell)
- SOFC (Solid Oxide Fuel Cell)
- DMFC (Direct Methanol Fuel Cell)
Each type of fuel cell have advantage and disavantage, depend where it will used for some applications. When you are using fuel cell for portable device (like laptop or mobilephone) or your motorcycle, you preferred use PEMFC. But when you are on remote area where there no electric availability, you should use SOFC or DMFC to generate electricity for your house.
For all of fuel cell type, we still have mainly problem that should be solve, which are : highly cost of catalyst and primary components, we still need optimize the efficiency of hydrogen production and make ecomonical analysis to perform this technology enter world marketplace. We should start now quickly!
Read More the Related Posts: