GFZ researchers used cutting-edge simulations of plate structure processes to identify locations where natural hydrogen resources were discovered.
Hydrogen gas (H2) may replace current fossil fuels, while also eliminating the associated release of CO2 and other contaminants.
However, a major obstacle is the need for mass production. Current synthetic hydrogen production is based at best on renewable energy, but it can also be contaminated with the use of fossil energy.
The solutions are in nature as various geological processes can produce hydrogen. Until now, it remains unknown where they were searching for potentially large-scale natural hydrogen accumulation.
A team of researchers led by Dr. Frank Zwaan, scientist in the Geodynamic Modeling section of the GFZ Helmholtz Center for Geosciences, presents the answer to this question.
Natural hydrogen hotspots in deep mantle rocks
Using plate structure modeling, researchers discovered that near the surface there is a mountain range where deep mantle rocks represent potential natural hydrogen hotspots.
These mountain ranges are not only ideal geological environments for large-scale natural H2 production, but also to form large-scale H2 accumulations that can be drilled for hydrogen production.
Natural hydrogen can be produced in several ways, for example, by bacterial transformation of organic matter or by the division of water molecules, driven by the decay of radioactive elements within the Earth’s continental crust.
The general survival rate of natural hydrogen as an energy source has already been demonstrated in Mali, where a limited capacity of H2, derived from iron-rich sedimentary layers, is produced through underground boreholes.
However, the most promising mechanism for large-scale natural hydrogen production is the geological process in which mantle rocks react with water. The minerals in mantle rocks change their composition and form new minerals in the so-called serpentine group and H2 gas.
For these rocks to come into contact with water and to contact serpentine, they must be excavated structurally towards the surface of the earth.
Structural modeling can improve hydrogen production in rocks
Using a state-of-the-art numerical plate structure modeling approach tailored with data from natural examples, the team simulates the evolution of the complete plate structure from initial lifting to continental division, followed by basin closure and mountains. simulated buildings.
These simulations allowed researchers to determine for the first time when, when and how much mantle rocks were excavated in the mountains and when these rocks were in contact with water at preferred temperatures. .
It can be seen that serpentine conditions, and therefore natural H2 production, are significantly better in mountain ranges than in the fissure basin.
Due to the relatively cold environment of the mountain range, a large amount of excavated mantle rock is found at a preferred meandering temperature of 200-350°C. At the same time, many water circulations along large faults within the mountains allow for the possibility of meandering.
As a result, the annual hydrogen production capacity of mountainous regions can be up to 20 times the lift environment.
Enhanced natural hydrogen search
This study provides a powerful impulse to enhance the quest for natural H2 in the mountain range.
Various exploration efforts are already underway in places such as the Pyrenees, the European Alps and the Balkans, where researchers previously discovered signs of ongoing natural hydrogen production.
Dr. Zwaan explained: “Essential to the success of these efforts is the development of new concepts and exploration strategies.
“What is particularly important is how the formation of economically natural H2 accumulation is controlled by the structural history of a particular exploration site.”
He concluded: “We need to determine the timing of the important geological processes involved, because if the H2 reservoir was formed in a mountain building, there must have been some lifting beforehand.
“Overall, the insights gained from plate structure simulations, such as those performed in this study, are extremely valuable.”
Source link
