Hydrogen is a naturally occurring chemical element that can be found in almost unlimited quantities on Earth. It is one of the building blocks of our universe. It is 14 times lighter than air, can be combusted without producing any CO2 emissions and is not self-igniting, corrosive or radioactive. In order to use its energy content, however, this colourless and odourless gas first has to be separated off from hydrogen-rich compounds such as natural gas, biomass or water.
The separation process to obtain pure hydrogen makes use of chemical, electrical, thermal or solar energy.