It is not common knowledge that pure hydrogen is produced in huge amounts in industrial technological processes.

The most known and widespread process of this type is steam reforming of methane or other "light" hydrocarbons, such as propane-butane or light gasoline. The reforming process takes place at high temperatures, in the range of 650-900⁰C, in the presence of a nickel catalyst. Reactions occur in catalyst furnace pipes. Water vapor is added to the methane. The hydrogen production process is illustrated by the following reactions:

CH4 + H2O <---> CO + 3H2 reforming

CO + H2O <---> CO2 + H2  CO conversion

CH4 + 2H2O <---> CO2 + 4H2 reforming

Steam reforming is currently the most widespread hydrogen production process. Other production methods are gasification of hydrocarbons or biomass. In this process we obtain a mixture of carbon monoxide and hydrogen. Gas mixture containing carbon monoxide and hydrogen, also called synthesis gas, is used for Fischer-Tropsch synthesis in the production of so-called synthetic hydrocarbons. As with steam reforming, you can go towards increasing the proportion of hydrogen through a carbon monoxide conversion reaction.

The last stage is the purification of hydrogen in the PSA (Pressure Swing Adsorption) process, i.e. pressure swing adsorption. It is a process of purifying hydrogen from impurities, i.e. methane, carbon monoxide and dioxide after the process part of the installation. Gaseous hydrogen impurities are adsorbed on the surface of a suitable adsorbent. As a result, we obtain hydrogen with a purity of over 99.5% by mass.

Both the steam reforming process and gasification are intended for the production of hydrogen on an industrial scale. For smaller scale of hydrogen production an electrolysis of water is used. Electrolysis of water is  decomposition of water into oxygen and hydrogen gas due to the passage of an electric current. This technique can be used to make hydrogen gas, a main component of hydrogen fuel, and breathable oxygen gas, or can mix the two into oxyhydrogen, which is also usable as fuel. It is also called water splitting. It ideally requires a potential difference of 1.23 volts to split water.

Under the influence of the potential difference, the water decomposes into hydrogen and oxygen. However, due to the high price of electricity, the production of hydrogen with this method is significantly more expensive than e.g. obtaining it  from methane.