Researchers from the University of Texas at Austin have developed a new method for storing carbon captured from the atmosphere. This innovative approach works significantly faster than existing methods and does not rely on harmful chemical accelerants. This research was published in the journal ACS Sustainable Chemistry & Engineering.
Image Credit: The University of Texas at Austin
In the new research, the team developed a technique for the ultrafast formation of carbon dioxide hydrates. These unusual substances, which resemble ice, can sequester carbon dioxide in water, stopping it from entering the atmosphere.
We are staring at a huge challenge finding a way to safely remove gigatons of carbon from our atmosphere and hydrates offer a universal solution for carbon storage. For them to be a major piece of the carbon storage pie, we need the technology to grow them rapidly and at scale, we have shown that we can quickly grow hydrates without using any chemicals that offset the environmental benefits of carbon capture.
Vaibhav Bahadur, Professor and Study Lead, Walker Department of Mechanical Engineering, The University of Texas at Austin
Carbon dioxide is the most prevalent greenhouse gas and a leading contributor to climate change. Carbon capture and sequestration (CCS) remove CO2 from the atmosphere and store it permanently, playing a crucial role in efforts to decarbonize the planet.
Currently, the most widespread method for carbon storage involves injecting CO2 into underground reservoirs. This technique not only traps carbon but also boosts oil production. However, it presents several challenges, including the risk of CO2 leakage and migration, potential groundwater contamination, and seismic risks related to injection. Additionally, many regions lack the appropriate geological features required for reservoir injection.
Hydrates are considered a "plan B" for gigascale carbon storage, according to Bahadur, but they could become "plan A" if key issues are addressed. The traditional process of forming these carbon-trapping hydrates has been slow and energy-intensive, limiting their potential as a large-scale carbon storage solution.
In this new study, researchers achieved a sixfold increase in the rate of hydrate formation compared to previous methods. This faster, chemical-free process simplifies the use of hydrates for large-scale carbon storage.
Magnesium serves as the "secret sauce" in this research, acting as a catalyst that removes the need for chemical promoters. This is further enhanced by the high flow rate bubbling of CO2 in a specialized reactor configuration. The technology is compatible with seawater, which simplifies implementation by sidestepping the need for complex desalination processes to produce fresh water.
Hydrates are attractive carbon storage options since the seabed offers stable thermodynamic conditions, which protects them from decomposing. we are essentially making carbon storage available to every country on the planet that has a coastline; this makes storage more accessible and feasible on a global scale and brings us closer to achieving a sustainable future.
Vaibhav Bahadur, Professor and Study Lead, Walker Department of Mechanical Engineering, The University of Texas at Austin
The implications of this breakthrough extend beyond carbon sequestration. The ultrafast formation of hydrates holds potential applications in desalination, gas separation, and gas storage, offering a versatile solution for various industries.
The researchers and The University of Texas at Austin have filed for two patents related to this technology, and the team is contemplating launching a startup to commercialize it.
Journal Reference:
Bhati, A., et al. (2024) Ultrafast Formation of Carbon Dioxide Hydrate Foam for Carbon Sequestration. ACS Sustainable Chemistry & Engineering. doi.org/10.1021/acssuschemeng.4c03809