Since the issue of climate change has been brought to the table, it has been tried not only to reduce greenhouse gas emissions, but also to Capture what has already accumulated and will remain for hundreds of years affecting atmospheric functioning. Replanting felled forests, improving the ocean’s carbon sequestration performance, and even creating technologies that could remove it artificially were considered. Now scientists have gone a step further and believe that: Also, volcanoes can help reverse the damage caused.
This is revealed by a new study published in the journal ‘Geology’ that concludes: An extinct volcano off the coast of Portugal can store between 1.2 and 8.6 gigatons of carbon dioxide in basalt rock. A figure equivalent to that of Spain, every 6 and 37 years, respectively.
For the authors of the article, this finding is very promising. “We know that most countries are making efforts to decarbonize their economies, and this could be one more tool to solve the problem,” says Ricardo Pereira, geologist at the NOVA School of Science and Technology and co-author of the paper.
Considering that 42.6 megatons (0.0426 gigatons) of atmospheric CO2 were removed from the atmosphere in 2022, according to CCS Global Institute data; a single volcano would have the capacity to withdraw at least 2000% more than has been achieved so far.
CO2 stored in rocks
Can capture carbon dioxide thanks to extinct volcanoes a process called “mineral carbonation” on site”. In this process, CO2 reacts with the elements contained in certain types of rock, such as calcium, magnesium or iron, to produce new minerals (calcite, dolomite and magnesite) that can permanently store carbon dioxide.
Therefore, volcanic basalts are ideal candidates for carrying out these reactions because they contain large quantities of these rocks that are rich in strategic minerals. After discovering this process, the researchers decided to further study the Fontanelas volcano off the coast of Portugal. They chose it for several reasons. On the one hand, The structure of the volcano can provide an ideal architecture for carbon injection and storage.. On the other hand, the rocks it contains are the right ones to give the desired reaction. Finally, its location was ideal: neither too far nor too close to neighboring towns.
The volcano is located 100 kilometers off the coast of Lisbon and at its summit, about 1,500 meters below sea level. The most recent submarine eruption in Spain was the Tagoro (El Hierro) eruption, which managed to rise 88 meters below sea level.
Until now, most carbon sequestration projects have relied on the injection of carbon dioxide into porous sedimentary basins. are sealed to prevent gas escape from the reservoirs. In these cases, the carbon is expected to start forming minerals at some point, but never after several decades or centuries.
The benefit of doing it in basalt rock is that the process is much faster.. A 2016 study in Iceland showed that up to 95% of the carbon dioxide injected into the island’s underground basalts mineralized in just two years.
“What makes mineral carbonation really interesting is the timing. The faster you enter a mineral, the safer it becomes, and once the mineral is, it’s permanent.“, underlines Davide Gamboa, a geologist at the University of Aveiro and co-author of the paper. And a much shorter mineralization time makes the process safer and more effective. Not surprisingly, when carbon is stored in minerals, problems such as potential leaks are no longer a cause for concern.
To estimate the potential volume of carbon dioxide that could be stored in this region, the authors used 2D and 3D seismic surveys of the submarine volcano conducted during offshore oil exploration in 2008 and samples collected from the area. There is up to 40% pore space, i.e. spaces within the rocks where carbon dioxide can be injected and mineralized.
Although this study showed a large potential carbon storage capacity at Fontanelas volcano, The authors note that many other places in the world may have similar marine volcanoes. this could be a candidate for carbon capture and storage.
Reference work at this link.
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