Researchers from the University of Texas and ExxonMobil have discovered a new way to store carbon dioxide. Currently, the most popular ways to capture carbon include direct air capture and planting trees. Scientists have now found that burying carbon dioxide beneath the ocean floor could also have promising results.
We’re now in a race against the clock to fight climate change. The latest IPCC report revealed that the effects of global warming have begun to intensify rapidly in recent years. In fact, scientists have observed widespread changes in Earth’s climate in every region.
Since the Industrial Revolution, greenhouse gas emissions from human activities have warmed the Earth approximately 1.1 degrees C. Over the next 20 years, scientists anticipate that global temperatures will reach or surpass 1.5 degrees C. We would experience more frequent heatwaves, longer warm seasons, and shorter cold seasons at these temperatures.
Encouragingly, the report says that “strong and sustained reductions in emissions of carbon dioxide (CO2) and other greenhouse gases would limit climate change. While benefits for air quality would come quickly, it could take 20-30 years to see global temperatures stabilize, according to the IPCC Working Group I report.”
That’s why it’s imperative to tackle climate change before it gets any worse. Capturing and sequestering carbon are the most promising ways to mitigate the effects of the climate crisis. However, current methods to store carbon dioxide safely have barely made a difference in CO2 levels. The latest findings by UT researchers could help scale and improve the efficiency of carbon capture.
Researchers Find an Innovative Way to Store Carbon Dioxide Safelycarbon dioxide safely under the ocean floor for centuries, perhaps indefinitely. In addition, they found that including magnesium in the reaction increased hydrate formation by 3,000x. So, instead of waiting days or even hours for the response to occur, the hydrates formed in mere minutes.
“I consider carbon capture as insurance for the planet,” said Vaibhav Bahadur (VB), an associate professor in the Cockrell School of Engineering’s Walker Department of Mechanical Engineering and the lead author of the research paper published in ACS Sustainable Chemistry & Engineering. “It’s not enough anymore to be carbon neutral, we need to be carbon negative to undo damage that has been done to the environment over the past several decades.”
The hydrates form when carbon dioxide combines with water at low temperatures and high pressure. During this process, the structure of the water molecules transforms, resembling cages that capture CO2 molecules. However, the process occurs typically over the course of hours or days, making it inefficient for storing carbon dioxide.
Researchers found that adding magnesium to the reaction sped up hydration formation by 3000x, however. In fact, this method is the fastest hydrate formation ever recorded, with some reactions occurring in just one minute. Not to mention, the reaction doesn’t produce any toxic byproducts, unlike other methods currently used.
“The state-of-the-art method today is to use chemicals to promote the reaction,” Bahadur said. “It works, but it’s slower, and these chemicals are expensive and not environmentally friendly.”
How the Hydrates Capture CO2Waste
The researchers use reactors in order to produce hydrates. To capture and store carbon dioxide safely, scientists would place the reactors on the ocean floor. Current carbon capture technology would suck carbon from the air and send it to these underwater reactors. There, the hydrates would form, storing carbon under the ocean for centuries.
These hydrates have a clear advantage over other forms of carbon storage. Injecting carbon as a gas into abandoned gas wells, for example, poses a risk of leaking into the environment. By storing the carbon dioxide deep in the ocean, however, it’s unlikely to travel back into the atmosphere.
For many researchers and scientists around the world, finding ways to reduce atmospheric carbon is a top priority. However, Bahadur says that only a handful of research groups have considered CO2 hydrates as a carbon storage method.
“We are only capturing about half of a percent of the amount of carbon that we’ll need to by 2050,” Bahadur said. “This tells me there is plenty of room for more options in the bucket of technologies to capture and store carbon.”
Since his arrival at UT Austin in 2013, hydrate research has been the focus of Bahadur’s work. The project was part of a research partnership between ExxonMobil and the Energy Institute at UT Austin.
Researchers from both organizations have filed a patent application to bring their discovery to energy markets. Next, they work on ways to increase the amount of CO2 being converted to hydrates during the reaction to boost efficiency. This would ensure constant production of hydrates, and therefore the ability to store carbon dioxide safely.
Other Ways to Store Carbon Dioxide Safely
In addition to storing carbon in hydrates beneath the ocean, other methods exist to sequester carbon. Some of the most popular carbon capture technologies include:
- Simply by planting more trees, we could remove over half a gigaton of carbon dioxide per year from the atmosphere. This equates to the annual emissions of the entire U.S. agricultural sector.
- Direct air capture. While this technology is relatively new, it shows promise in combating climate change. An Iceland-based company called Carbfix recently opened the world’s largest facility to capture and store carbon dioxide safely. Currently, it can pull 4,000 metric tons of carbon from the atmosphere annually.
Scientists all over the world have ramped up their efforts to develop carbon capture technologies. Recently, researchers from UT and ExxonMobil discovered that CO2-based crystal structures called hydrates could store carbon safely on the ocean floor. The carbon would remain there for centuries, if not forever. Unlike other carbon capture technologies, hydrates don’t produce any toxic byproducts. Since they can form rapidly, sometimes in one minute or less, it could provide a scalable, continuous carbon capture method.