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The world is in a race to reduce harmful gases in the atmosphere and slow climate change. One way to do this is carbon capture and sequestration. This involves taking carbon out of the air and then burying it. We are currently capturing just a small fraction of carbon required to reduce climate change.
ExxonMobil and The University of Texas at Austin have made a breakthrough that could change that. Researchers have discovered a way to supercharge carbon dioxide-based crystal structures, which could one day store billions of tonnes of carbon below the ocean floor for decades, if that is possible.
Vaibhav Bahadur, an associate professor at the Cockrell School of Engineering’s Walker Department of Mechanical Engineering and lead author of a paper in ACS Sustainable Chemistry & Engineering, stated that carbon capture is "insurance for the planet." "It is not enough to be carbon neutral anymore, we must be carbon negative in order to undo the damage that has been done over the past few decades to the environment."
These structures are known as hydrates and form when carbon dioxide is combined with water at high temperature and pressure. The water molecules act as a cage to trap CO2 molecules and reorient themselves.
The process can take several hours, if not days to start. Researchers discovered that magnesium was added to the reaction and hydrates formed three times faster than any other method currently in use. They were formed in less than one minute. This is the fastest known hydrate formation speed.
Bahadur stated that chemicals are the current state-of-the art method to stimulate reaction. It works, but it takes longer and the chemicals are costly, which is not good for the environment.
Reactors can produce hydrates. These reactors could be deployed on the ocean floor. Existing carbon capture technology would allow CO 2 to be extracted from the air and transported to the underwater reactors, where it would grow. These hydrates are stable and less likely to leak than other methods of carbon storage like injecting it into old gas wells.
The problem of reducing carbon dioxide in the atmosphere is as big as the one facing the planet right now. Bahadur states that there are very few research groups around the world who are looking into CO2 hydrates as a possible carbon storage option.
Bahadur stated that only half of the carbon we are capturing is needed to meet our 2050 carbon emission goals. This tells me that there are plenty of options for carbon storage and capture technologies.
Bahadur has been involved in hydrate research ever since he arrived at UT Austin back in 2013. This is part of a partnership between ExxonMobil, the Energy Institute at UT Texas and Bahadur.
ExxonMobil and the researchers have filed a patent application in order to commercialize their discoveries. Next, the researchers plan to address issues such as efficiency.
Bahadur was the leader of the team that also included Filippo Mangolini (an assistant professor at the Walker Department of Mechanical Engineering). The Walker Department of Mechanical Engineering also had Aritra Kar and Palash Vadiraj Acharya, and Awan Bhati. Hugo Celio, from Texas Materials Institute at UT Texas, was part of the team, as well as researchers from ExxonMobil.
Continue reading The challenge of capturing carbon
More information: Aritra Kar et al., Magnesium Promoted Rapid Nuclear Claims of Carbon Dioxide Hydrates. ACS Sustainable Chemistry & Engineering (2021). Aritra Kar et al., Magnesium Promoted Rapid Nuclear Nucleation Carbon Dioxide Hydrates (2021). DOI: 10.1021/acssuschemeng.1c03041
