Hydrogen is the simplest of natural elements, containing only one proton and one electron. It is also one of the most common elements in the universe.
Hydrogen cannot be found in its gaseous form on earth, because it is always combined with other elements, like with oxygen to form water (H2O), with carbon it forms methane (CH4) and found in biomass.
Hydrogen also has the highest energy content by weight, and the lowest energy content by volume. It is light, and stays in its gaseous form at normal temperature and pressure.
Hydrogen and helium gasses make up the sun’s energy. Through a process of fusion, where four hydrogen atoms combine to form 1 helium atom radiant energy is emitted.
This radiant energy is what helps life on earth, and is stored in fossil fuel, out of which man extracts hydrogen.
It is non-toxic and produces no greenhouse gases upon combustion. It is also extremely efficient, and has a high-energy content. For all these reasons, hydrogen is favoured over much other renewable and non-renewable energy.
Hydrogen is produced industrially from steam reforming which use fossil fuels. The energy of the extracted hydrogen is less than the energy content of the fossil fuel it was extracted from.
A smaller proportion of hydrogen is produced by electrolysis, which uses water and electricity. Hydrogen is also produced as a by-product of refining fossil fuels as it is an active component of coal, gas and oil.
In the 1980s a Norwegian company devised a method of hydrogen production form hydrocarbons like methane, natural gas and biogas. This is called the Kværner-process or the Kvaerner carbon black & hydrogen process (CB&H).
The biological production of hydrogen uses a method similar to anaerobic conversion. The Fermentative hydrogen production method uses multi enzyme systems. This system does not require light energy so they can constantly produce hydrogen from organic compounds throughout the day and night.
One of the cleanest methods of hydrogen production is using electricity generated by photovoltaic systems. Through this method, water is broken down into its hydrogen and oxygen molecules by a process called artificial photosynthesis.
Concentrating solar power, a method of heating water at extremely high temperatures (needed to split the hydrogen and oxygen molecules) is another way of producing hydrogen.
Other less known ways of producing hydrogen are the photoelectrocatlytic production (using special nanoparticles) and thermochemical production both of which are still under much research for energy efficiency.
Pure hydrogen gas needs to be pressurized or liquefied for storage. Vehicles powered by hydrogen have a container tank with compressed hydrogen. However, hydrogen can also be stored as a hydrogen-containing compound (aside from its pure form). When combined like this, storage and transportation are much easier.
Another way of storing hydrogen is by allowing it to absorb into a solid storage material. This way is considered the most efficient and safe out of the three.
It has been used since the late 1970s to power space shuttles and other rockets into orbit. When combined with oxygen, hydrogen fuel cells produce electricity, heat and water.
In theory, a hydrogen economy has many potential economic advantages. The success of hydrogen economy depends on climate change, sustainable energy generation, energy sourcing and using fossil fuels.
However, converting the current infrastructure of the world, which is largely dependent on other fossil fuels to a hydrogen economy, would require a massive shift.
The process of steam reforming is much like a powered car; it emits carbon monoxide fumes into the atmosphere. It is also an extremely flammable compound when mixed with other gases. Therefore, in enclosed spaces, hydrogen is potentially lethal.
Another potential concern is that using renewable energy sources to extract hydrogen (by electrolysis) expends a great amount of energy compared to the direct use of renewable energy.
Apart from carbon monoxide, hydrogen also releases nitrous oxide, nitric acid, hydrogen cyanide and other toxic compounds.
It has also been hypothesised that there is a small amount of molecular hydrogen leakage from containment vessels. This hydrogen gas due to ultraviolet radiation is assumed to form free radicals in the stratosphere. These free radicals are assumed to play a role in the destruction of the ozone.
Robert Boyle made the production of hydrogen gas from a reaction between iron fillings and diluted acids in 1671. It was named as a discrete substance of flammable gas in 1766 by Henry Cavendish, and was found to produce water when it was burned in about 1781.
Therefore, although Boyle made the discovery, Cavendish is credited with its discovery.
In 1783, Antoine Lavoisier named the compound as hydrogen, following a replication of Cavendish’s experiment. He derived the name from the Greek word hydro (water) genes (creator).
James Dewar was the first to liquefy hydrogen in 1898, following his invention of the vacuum flask. Jacques Charles invented the first hydrogen filled air balloon in 1783, and Ferdinand von Zeppelins invented the first hydro lifted airship in 1852.