Hydrogen

– Fuel Of The Future Essay, Research Paper

HYDROGEN – THE POWER SURCE OF THE FUTURE

Since the beginning of the scientific revolution in the early nineties the mankind looks for an energy source that is clean and renewable; solution of this problem would be probably the most common thing in our life – WATER.

Water consists of two chemical elements, hydrogen and oxygen. Each molecule of water consists of two hydrogen (H2) atoms and one oxygen (O) atom. Chemical binding between these three atoms is very stable and strong. Therefore, the reaction of hydrogen and oxygen is under normal circumstances very intense and generates a lot of energy.

2H2 + O2 . 2H2O + energy

Both, hydrogen and oxygen are gases at normal temperatures and pressures and the product of this reaction is pure water, usually in its gaseous form – steam.

Now it may look like hydrogen is the ideal power source that mankind is ever since looking for. More than 70 % of the Earth surface is covered by water, therefore hydrogen is renewable and unlimited. Reaction of hydrogen with oxygen generates a lot of energy and it does not have any negative output, only water. But, the respectable power hidden in water is known for more than 200 hundred years and as long scientists are trying to find a way to extract this energy, rather how to split the water molecules into hydrogen and oxygen. Hydrogen can be used to power cars, rail engines, airplanes, to produce electricity and heat. But, although the technical breakthrough in 19th and 20th century brought hydrogen into experimental use in many applications, there are still many problems to deal with.

There sure is a lot of misinformation about hydrogen gone to public, so here are the basic facts about hydrogen as a power source according to the Nuts & Volts Magazine (May 1999, WWW).

Hydrogen on earth is not a fuel. It is only an energy carrier. Following the definition of the word fuel, fuel is a substance that is capable of delivering new energy when burning or other chemical reaction occurs. On the other hand energy carrier is a substance that is only able to move previously acquired energy from one place to another. To be accurate, water molecule is energetically very advantageous for both oxygen and hydrogen atoms and needs much energy to disintegrate it again into hydrogen and oxygen atoms, or better H2 and O2 molecules, therefore H2 and O2 are only carrying energy.

There is more hydrogen in gasoline than there is in liquid hydrogen. Configuration of hydrogen atoms in gasoline is much more space saving than in pure liquefied hydrogen, therefore larger storage tanks are needed to store it.

Electrolysis is not usually the best way to generate hydrogen. Most of the today’s hydrogen comes from raw petrol as one of the by-products of petroleum processing. According to United States Alternative Fuels Data Center (2000, WWW) now, hydrogen is made using the following two methods. Electrolysis: Uses electrical energy to split water molecules into hydrogen and oxygen. Applying low DC voltage will result in releasing hydrogen on one electrode and oxygen on the other. The electrical energy can come from electricity production sources including renewable fuels. United States Department Of Energy (DOE) has concluded that electrolysis is unlikely to become the predominant method for large quantities of hydrogen production in the future. (2000, WWW) The best electrolysis is only 62 percent efficient. Synthetic gas (methane) reformation: Predominant method of Hydrogen producing is stream reforming or partial oxidation of natural gas, where other hydrocarbons can be used as feedstocks (for example biomass or coal can be gasified and used in a steam reforming process to create hydrogen). Commercial methane reformation can be around 68 percent efficient. According to Stanford University research of hydrogen (2000, WWW) the main present way of getting hydrogen is steam methane reformation and this will probably remain the most economical way as long as methane (natural gas) is available cheaply and in large quantities. When the price of methane goes up to more than three times it will be cheaper to produce hydrogen by splitting water molecules – H2O into hydrogen – H2 and oxygen – O2.

2H2O + energy . 2H2 + O2

This is accomplished by electrolysis. If fossil fuels e.g. coal, oil or natural gas, are used to generate the electricity, there is no advantage over using fossil fuels directly. Indeed you still get CO and CO2 and there is a considerable loss of energy. Therefore the large-scale use of hydrogen depends on using either nuclear or solar electricity. In both nuclear and solar cases, there are possible technologies that do not use electricity as an intermediate form of energy.

For example it is possible to “resonate” the water molecule and make it to “fall apart”, but the frequencies to do this are in microwave and infrared range. There are no energy advantages to doing so, because emitting these frequencies is very energy demanding.

There is some hope that this process could be somewhat more efficient than electrolysis, but all of these technological procedures are still in development and are mostly only in a position of an experimental project. Besides new energy uses, hydrogen gets widely used to make ammonia, to stabilize fats, for welding, rocket fuel, acid manufacture, ba