The applications in which hydrogen is used can be broadly divided into few major groups, hydrogen as a feedstock to industry for its chemical value and hydrogen as an energy carrier either for mobility or for heating.
Hydrogen’s largest use historically, by far, has been as a feedstock or chemical agent in the refining, petrochemical, chemical, fertilizer, steel, and food industries. Hydrogen is vital to the major reactions of hydrodesulfurization, hydrocracking, hydrodealkylation, hydrogenation and reduction reactions that upgrade/clean our fossil fuels, saturate fats and oils, and produce building block chemicals (like ammonia and methanol).
Fuel for transport
Hydrogen’s use is expanding as an energy carrier for transport/mobility through through fuel cells (which generate electricity to power electric motor vehicles).
Hydrogen’s use is expanding as an energy carrier; i.e. as a source of heat through combustion.