For more than a century we have been speculating that methane is being created through an abiotic process. But it is hard to enter the Earth’s crust. And the conditions there are even hard to imagine. But guess, what happens when you put hot hydrogen onto compressed diamonds?
Image by Colin Behrens from Pixabay
@kralizec and subscribe to my Youtube channel at Kralizec Gaming Youtube ChannelOur world is obsessed with carbon. In both good and bad. The interesting thing is that the vast majority of the carbon cycle takes place deep within the Earth. And you will probably not be surprised that we know little about the carbon cycle. But it is truly important to understand it.
When it comes to the fate of carbon deep beneath us one of the key mysteries is the role of diamonds. As Alberto Vitale Brovarone from the Alma Mater Studiorum – Universitá di Bologna says we have suspected for some time that when methane decays diamonds could be created. But we have no idea whether the process could also go the other way around.
The theory that methane is created through abiotic processes deep in our Earth has been propping up for more than a century. So, Brovarone and his colleagues decided to take a look at it. Sadly, we cannot just visit the Earth’s depths so they had to do it in the laboratory.
The researchers used the popular diamond anvil cell. This device is made from diamonds and something that presses them together. The scientists created a pressure of 0.5 – 3 GPa which corresponds to the conditions that can be found at the depths of 70 kilometers and deeper. Then they put gaseous hydrogen at a temperature of 300° Celsius. The result was the quick creation of methane molecules. When the temperature rose to 500° Celsius ethane and other light carbohydrates also started to appear. The experiments were evaluated using Raman spectroscopy.
According to Brovarone, they created a model of conditions in the upper crust when it comes to temperature and pressure. Then they witnessed how compressed diamond reacts to with hydrogen and turns into methane in a few seconds. The scientists are convinced that methane and similar carbohydrates can truly be created in the Earth’s depths through abiotic processes and that this mechanism could play a key role in the carbon cycle.
