TELF AG explores the potential of white hydrogen
One of the possible drivers of the energy transition
Since numerous natural deposits of hydrogen have been discovered in different parts of the world, the characteristics of this precious element have progressively lost part of their impenetrability. In fact, until a few years ago, very few people would have bet on the presence of hydrogen in the free state in nature, excluding its presence in water. Nowadays, thanks to the study and analysis of the potential of the natural deposits of this resource, natural hydrogen seems to have all it takes to become one of the protagonists of the ongoing energy transition. The road ahead, however, still seems quite long.
A major turning point in increasing global awareness of this resource came in 2011 when a large deposit of geological hydrogen was discovered in the African nation of Mali. This discovery was followed by many others, particularly in Australia, but also in Europe and North America. What seems to attract energy players most, in a certain sense, are the peculiar extraction processes of natural hydrogen, some of which are only in their infancy.
The reasons for its limited use
Up to now, one of the main obstacles to its large-scale diffusion has been its high production cost, which generally occurs through the electrolysis of water. Another way is represented by its extraction in a free state, as happens with methane, but even in this case, this procedure could bring various critical issues. Despite being a relatively economical method, this type of extraction actually leads to high CO2 emissions into the atmosphere. It is also for this reason that in various parts of the world, the possibility of extracting it from natural reserves is being explored: it would be a more competitive and sustainable method, also from a purely economic point of view. According to an estimate in a document published by Earth2, the cost of white hydrogen – as biological hydrogen is defined – could be around one dollar per kilo (therefore much cheaper than hydrogen extracted through electrolysis).
The amount of debates on the sustainable potential of white hydrogen appears to be continuously increasing, also due to the role this element could play in the imminent global energy conversion. But what are the true origins of this resource? One of the hypotheses concerns radiolysis, i.e., the splitting of water into hydrogen and oxygen caused by natural radioactivity. Another path would instead seem to lead to diagenesis, according to which some minerals rich in iron, such as olivine, would trigger the process of splitting the water molecule in certain circumstances. Hydrogen produced in these ways can become trapped under nearly impermeable rock layers, or it can even end up leaking into the atmosphere.
However, this element’s sustainable potential is linked to its structural differences compared to hydrocarbons. The latter represents the final result of a natural formation process that can last millions of years, while the process that leads to hydrogen generation is believed to be much more rapid. This element can remain underground in gaseous form for between 10 and 100 years, which is aso why it is now universally considered a renewable energy source.
