Different concepts for refuelling infrastructure exist that are suitable for different levels of hydrogen demand, from refuelling a single car to large refilling stations able to refuel multiple cars and buses on a daily basis. All hydrogen refuelling stations include the following basic components:
Hydrogen supply: there are two options for hydrogen supply – it can be delivered to the site or it can be generated on-site.
Hydrogen storage: if hydrogen is delivered as a liquid, a cryogenic storage vessel will be required on the site to maintain the temperature in the liquid range (hydrogen has to be cooled down to -253°C). Hydrogen will be decanted from a tanker truck into the storage vessel.
The vast majority of hydrogen produced worldwide is generated by a process of breaking up hydrocarbon molecules into H2 and CO – this process is called reformation. Reformation is performed on an industrial scale, typically using natural gas (methane, CH4) as a feedstock.
Several electrochemical processes in industry, such as the production of chlorine, produce hydrogen as a “waste” or by- product . This by-product is a very clean A-Grade product that is very well suited for fuel cell vehicles and applications.
Liquefaction of hydrogen requires cooling to a temperature of -253 °C and subsequent storage in cryogenic containers. Liquefaction is an energy intensive process and can consume up to 35% of the energy in the stored hydrogen.