Hydrogen economy, hydrogen natural, industrial hydrogen
KN: Isabelle MORETTI (ENGIE, Paris, FR)
IL1: Régis RÉAU (Air Liquide, Jouy-en-Josas, FR)
IL2: Chris BALLENTINE (Geochemistry, Earth Sciences, Univ. Oxford, UK)
IL3: Eric DEVILLE (Geosciences, IFPEN, Rueil-Malmaison, FR)
The place of hydrogen in the energetic transition is a widely discussed issue and has taken an increasing important role, but mostly as an energy vector. Recently, hydrogen has been mentioned as a mean for electricity storage in parallel to the growing demand of sustainable electricity production from hydroelectricity, solar or wind power which need to be stored because of present transient consumption supply and demands. So far, the best storage, in terms of efficiency, is the transformation of electricity into hydrogen by electrolysis and the transformation of hydrogen into electricity with fuel cells. In the world, manufactured hydrogen for chemical applications (ammoniac synthesis and petrochemistry) already represents a 100 billion dollars global budget, and an equivalent of 22% of the produced natural methane gas (in volume). However, production costs remain high. Moreover, when generated from fossil fuel energies, which financially may be considered the least expensive, its environmental impact and cost are non-negligible. When generated from electrolysis, which may be considered as “green” hydrogen, its financial cost is even higher. The recent assessment of natural hydrogen in continental areas, sheds a new perspective to consider it as a supplementary source of energy, in addition to the main vectors of chemical production. Subsurface deep kitchens of hydrogen source are actively being studied. More superficial accumulations are located in specific geological contexts and, in some cases, not so remote from urban development areas, which may facilitate its valorization. Naturally sourced hydrogen in continental context has been found to be associated with noble gas helium, whose concentrations may reach 2-3%, higher than any known gas field where helium is produced today. So far, only minor pilot hydrogen industrial projects exist in Mali (West Africa) and in the United States, but most recently, substantial discoveries of hydrogen seeps have been reported in Russia, Canada and Brazil and may highlight a natural source of hydrogen for future World exploitation.