Production of hydrogen
Properties and production of hydrogen
Hydrogen is the most common element in the universe. Bound hydrogen is present in almost all organic compounds. Owing to its abundance, it can, in principle, be produced anywhere on earth.
Hydrogen (H2) has the lowest atomic mass of all the elements. It is a colourless, odourless gas that does not self-ignite and burns with a colourless flame leaving no residue. In nature, hydrogen exists exclusively in chemical compounds, in water (H2O) for example, or in methane (CH4), one of the main constituents of natural gas. Not least, hydrogen is present in many minerals and in the Earth's atmosphere in the form of water vapour.
Hydrogen production methods
Hydrogen is not in itself an energy source, but an energy carrier with the help of which energy can be stored and transported. To obtain hydrogen, primary energy must first be used. When obtained using renewable energy sources, energy generation from hydrogen is an environmentally friendly solution.
Currently, most of the hydrogen produced comes from fossil energy sources. In many cases, it is a by-product of chemical industry processes. And it is generally re-used in the same industry. On an industrial scale, H2 is predominantly obtained through catalytic steam cracking of methane, so-called natural gas reforming. Other procedures include partial oxidation of heavy oil and coal gasification. What all the procedures have in common is CO2 as a by-product.
"Green” hydrogen through electrolysis
During electrolysis, water (H20) is mixed with a liquid that renders it electrically conductive. With the help of an electric current, H2O is decomposed into hydrogen (H2) and oxygen (O2). The electric energy is transformed into chemical energy and stored in the hydrogen.
If this process is carried out using energy from renewable sources, no climate-damaging CO2 is produced - so-called "green” hydrogen. The principle can be reversed with the aid of a fuel cell. The chemical energy in the hydrogen is converted back into electricity.
Other procedures for obtaining hydrogen do exist - the fermentation of biomass, for example, or the Kvaerner process. These, however, are still in the test phase.