The fuel cell is a powerful technology and will gain importance in the future. But the principle of the fuel cell is already about 180 years old.
Principle
The fuel cell uses an electrode-chemical reaction, called “cold combustion”. In this reaction hydrogen atoms react with oxygen atoms to water molecules. Full reaction:
hydrogen + oxygen –> water molecules
2 H2 + O2 –> H2O
A lot of energy is set free during the “cold combustion ” so it is an exothermic reaction. Now you can see how it works:
The fuel cell consists of two electrodes separated by a membrane. The hydrogen reaches the first electrode and is separated into hydrogen ions and free electrons.
hydrogen –>; hydrogen ions + electrons
2 H2 –> 4 H+ + 4 e–
The electrons travel through the conductor to the second electrode. Now we have got electricity which we can use in many ways. When the electrons arrive at the second electrode there are already some oxygen atoms waiting for them. So every oxygen atom reacts with two electrons to one oxygen ion.
oxygen + electrons –>; oxygen ions
O2 + 4 e– –>; 2 O2-
While the electrons cross the conductor the hydrogen ions travel through the membrane in the middle of the fuel cell. When they arrive on the other side they react with the oxygen ions there to water molecules. That’s it.
hydrogen ions + oxygen ions –> water molecules
4 H+ + 2 O2- –> 2 H2O
Energies
During the “cold combustion” chemical reaction-energy, which is set free when oxygen and hydrogen reacts to water, is transformed into electrical energy and thermal energy.
chemical energy –>electrical energy + thermal energy
Ech –> Eel + Eth
Advantages and Disadvantages
Advantages | Disadvantages |
|
|
History and potential
The first fuel cell was developed by William Grove in 1839. But the technology wasn’t powerful enough compared with developments like the electro-dynamo.
During the “Cold War” fuel cells were used by the space and the marine forces. For a couple of years automobile concerns like Toyota and Honda have been selling cars with fuel cells and in September this year the first trains with fuel cells will travel through Germany.
by Florin Wohlfahrt
Web sources
co2online.de
heizung.de
wikipedia.de
Picture sources
Brennstoffzelle Funktionsweise
Brennstoffzelle Toyota
Brennstoffzelle Züge
Brennstoffzelle Heizung
Be First to Comment