SciencePower in the Future
Water may possibly be the fuel of the future for our planet. The idea of using water as a power source is, in principle, a clean and reliable method of power production. One possibility rather than harnessing the kinetic energy in flowing water by running it through a turbine the water itself can be split into its products and these used as fuel. The second method is to use a process known as nucleur fusion
The Chemistry
Water can be split into two different products, hydrogen and oxygen, this is because hydrogen and oxygen atoms are bonded to form a water molecule. More information about this can be found here. To gain access to these elements the bond between them needs to split, this can be done by passing an electric current through the water. This process is known as electrolysis, oxygen is produced at one of the electrodes that is is placed in the water and hydrogen from the other. The hydrogen can the be collected and used as a fuel due to its flammable properties, and the oxygen can be released into the atmosphere.
A Release
The word equation below shows hydrogen being burnt in oxygen.
Hydrogen + Oxygen --> Water + 572 kJ/mol
As you can see the only physical product of this reaction is water, which was used to create the hydrogen in the first place! Importantly energy is also produced by this reaction.
Disadvantages
Although hydrogen may seem like the perfect fuel it, like most others, has its disadvantages. If used as fuel in a car, the car could be filled with water which is then undergoes electrolysis giving off hydrogen and oxygen to run the car the hydrogen would be burnt and the water could be collected and go back into the fuel tank. The problem here occurs if the car were to crash, or possible malfunction. Although current fuels are flammable they are not explosive like hydrogen. In a crash the hydrogen tank could be ignited meaning a higher chance of fatalities in car crashes due to the explosion following the crash.
The second disadvantage to this process is that the process of electrolysis requires more power to be put in than to be extracted as a fuel. This means the fuel would never be suitable for use in a power station, as another power station would be required to create the electricity to split the water into hydrogen and oxygen. Its use in cars seems to be the main possibility for water used as a fuel in this way.
Nuclear Fusion
So it seems that hydrogen is not the future for the production of electricity but seawater contains an important ingreidant for nucelar fusion. Nuclear fusion is the process of joing two light nuclei together to form a heavier nuclei and releasing energy. The two reactants required for this process are called Deuterium and Tritium, below is the equation for nucleur fusion:
Deuterium + Tritium --> Helium-4 + Neutron
Both deuterium and Tritium are isotope of hydrogen, deutrium is naturally occuring and can be extracted from sea water by the process of electrolysis, as explained above. Tritium also occurs naturally but in very small ammounts so has to be made from deuterium and lithium. So water is very important to this process, it is only limited by the ammount of lithium in supply. The energy from this then heats water to form steam, driving a turbine.
It produces no greenhouse gases and the radioactive waste would be present in much smaller quantities, grams rather than tonnes as well as being of a lower yield. The question is whether we can turn it into a reality that makes economical sense. The international project, ITER hopes to lay the ground for a commercial method by causing just 0.5g of a deuterium tritium mixture to undergo fusion. Every attempt at this process brings it closer to hbeing the power source of the future however, this comes at a massive monetry cost with research costing billions of dollars.
References
Google Definition Isotope
http://www.google.com/search?hl=en&rls=GGGL%2CGGGL%3A2006-32%2CGGGL%3Aen&q=define%3Aisotope&btnG=Search
Wikipedia Article Fusion Power
http://en.wikipedia.org/wiki/Fusion_power
Definition Kinetic Energy
http://www.google.com/search?sourceid=navclient-ff&ie=UTF-8&rls=GGGL,GGGL:2006-32,GGGL:en&q=define%3Akinetic+energy
Wikipedia Article Hydrogen Combustion
http://en.wikipedia.org/wiki/Hydrogen#Combustion
Google Definition Turbine
http://www.google.com/search?sourceid=navclient-ff&ie=UTF-8&rls=GGGL,GGGL:2006-32,GGGL:en&q=define%3Aturbine