- Hydrogen is the lightest and the most plentiful of all gases. Hydrogen is not freely available but it is found in compound forms such as in water (H2O)., fossil fuels including methane(CH4), propane, coal and petroleum and in biomass.

Hydrogen is a powerful energy carrier which has been used variously in the past for industrial activities and as fuel for automobiles. It is a clean-burning fuel and is therefore considered environmentally friendly.

Hydrogen can be considered only "partially renewable energy resource". Since Hydrogen is not freely available, its "extraction" from certain compounds (e.g. methane and/or water) requires the use of energy from fossil fuel sources which release greenhouse gases to the atmosphere. However, during usage, hydrogen, burns very cleanly releasing very little GHGs emission to the atmosphere.

How to Obtain Hydrogen

The two approaches that have been used for obtaining Hydrogen from compounds are: Steam Reforming (ref: Encyclopedia of Earth) to separate hydrogen from fossil fuels and carbon compounds e.g. methane(CH4) and Electrolysis (ref: US DoE Energy, Efficiency and Renewable Energy) to separate hydrogen from water.

In Steam reforming, hydrogen containing compounds (e.g. methane or natural gas) are heated to very high temperature and pressure to separate the hydrogen gas from the carbon chains. This gas then goes through a clean-up process to remove substances such as sulphur. After the clean-up, the two remaining gases (hydrogen and carbon dioxide) are separated, by stripping the carbon from the hydrogen atoms. The hydrogen is burned in a specially modified gas turbine to make electricity or transformed to hydrogen fuel cells. The carbon dioxide is compressed and transported through a pipeline and then injected deep underground into the depleted oil and gas fields or coal beds, where it is stored safely and permanently (sequestration or carbon capture and storage). The carbon dioxide (CO2) resulting from this process can also be injected into the reservoirs to flush out reserves of oil or gas that would otherwise be left behind.

One disadvantage of Steam Forming is that it generates GHGs thereby aiding global warming. Electrolysis is seldom practiced because it is an expensive process.

Uses of Hydrogen

Hydrogen can be combusted in an ordinary car in an internal combustion engine like the fossil fuels - gasoline or diesel. However, it this is not an efficient way to use the hydrogen fuel. Alternatively, fuel cells are manufactured to convert the hydrogen into electricity, and then the electricity is used to power an electric motor, used to run electric cars.

How to Improve the Production of Hydrogen

The major downside of hydrogen as a clean fuel is the production of GHGs when fossil fuels are used for steam reforming and /or electricity. However, steam reforming does not have to use fossil fuels. Other energy sources such as wind energy, solar energy, nuclear energy and other forms of cleaner energy sources can be used to perform the heating during steam reforming. Using cleaner fuels reduces the amount of GHG production and makes hydrogen a viable renewable clean energy source.