FUEL CELL

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 FUEL CELL

They are electrochemical cells. It is an energy conversion device or electricity generator.

ADVANTAGES

  1. Fuel cells are efficient and convert about 75%-83% of available chemical energy to electrical energy.
  2. The electrode materials are supplied in the gaseous form. Examples H2 , CO, hydrocarbons, coal gas, producer gas etc.
  3. It is light, compact, simple and easy to maintain   
  4. Whatever may be the electrode material, CO2 and H2O should be the end products.
  5. The concentration of the electrolyte remains invariant.
  6. Less green house and noise pollution.
  7. They can be stacked and connected in series to generate higher voltage without making any noise.
  8. Reduces the thermal pollution from power generation.

HYDROGEN-OXYGEN FUEL CELL

It is based on the reaction, combustion of H2 in O2 to form water.
2H2 +O2   ------->          2H2O      
The cell consist of two electrodes made of porous graphite, impregnated with platinum catalyst. The electrodes are places in aqueous KOH or NaOH solution. Oxygen and hydrogen gases are continuously fed in at high pressure of 50atms. The reaction taking place is given below, EMF of the cell is found to be 1V.
Anode          2H2 +4OH             ----->       4H2O+4e
Cathode                   O2 + 4e + 2H2O    ------>         4OH
Cell reaction            2H2 +O2                ----->           2H2O      
They can provide energy for systems as large as a utility power station and as small as laptop computer. 
They produce much small quantities of greenhouse gases and none of the air pollutants that create smog and cause health problems.



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