Scientists discovers potentially groundbreakingly energy efficient method of carbon capture

"We can capture types of emissions that would be hard to cap in other ways."

The concept of scrubbing CO2 from the atmosphere to stop climate change divides the scientific and environmental communities, primarily because of the energy the process traditionally takes. Now, researchers have discovered a clean and relatively inexpensive way to capture planet-warming carbon from the atmosphere.

A team from The Ohio State University has developed a method to combine direct air carbon dioxide capture (DACC) technologies with geothermal energy, and it says the process could help create large-scale carbon dioxide capture and storage systems. The researchers outlined their findings in Environmental Research Letters, as reported by The Cooldown.

Though a potentially planet-saving technology, DACC can be expensive, as explained in a report by the university posted on Tech Xplore. It also requires energy to operate — if the system uses traditional fossil fuel power, this just adds more Earth-heating gas to the atmosphere.

The new method, called Direct Air CO2 Capture with CO2 Utilization and Storage (DACCUS), proposes to use heat stored underground within deep saline aquifers to produce renewable energy for DACC systems, per the Tech Xplore post.

The system would isolate the captured carbon from the air into these geologic formations — some of the carbon dioxide can be circulated to extract the geothermal heat, which can be used directly or converted to electricity, according to the report.

DACC, along with other techniques like carbon capture and storage (CCS), is a way scientists are working on reducing the amount of this planet-warming gas in the atmosphere.

For instance, one Icelandic startup is injecting carbon dioxide from a nearby power plant into basalt rock after mixing it with groundwater, speeding up a process that normally takes thousands of years into just two years.

Similarly, nature-based solutions can help do the job. Some scientists are turning to carbon farming to manage agricultural land with the aim of improving how much of the gas is stored in soils. Others are looking to seagrass, which provides roughly $88.3 billion worth of carbon storage services every year.

"Carbon removal technologies are especially helpful in mitigating climate change because we can capture types of emissions that would be hard to cap in other ways," said Martina Leveni, lead author of the study and a postdoctoral scholar at Ohio State, per Tech Xplore. "So we thought, could we combine technologies that could be beneficial to one another to meet this goal more efficiently?"

The authors also designed a case study to demonstrate how their technology might work in the U.S. Gulf Coast Region, which they say has the right geology to make it work safely.

The team says their system could be operational by 2025 and that the method could start removing carbon by 2030, according to the Tech Xplore report. They also estimate that up to 25 DACCUS systems will be operating in just one of the 27 geologic formations in the Gulf Coast by 2050.

Are carbon capture projects realistic?

As CTIF.org reported last year, many doubt the realistic future for carbon capture projects. Some believe that even if the carbon capture plants would to become energy efficient, they would make us all relax our attitudes too much about emissions and the result would be that the carbon capture technology would never keep an even keel with emissions.   

According to a November 2022 article on Pachama.com, forest-based carbon-capturing projects are more realistic and effective in the long run, especially since they do not consume external (generated) energy once planted and growing. 

The article outlines three types of projects for forest-based carbon-capture: 

• Reforestation: planting of new trees, often reverting degraded land back to forest 
• Forest conservation: protecting existing forests that are at risk of deforestation
• Improved forest management: employing forest management activities that result in increased carbon storage and/or reduce emissions from forestry activities 

The article then takes a closer look at the unique qualities of each project type. 

Photo Credit: Photo uploaded by SaskPower. 

Public image on Flickr. THIS ILLUSTRATION IS NOT ASSOCIATED WITH THE SUBJECT OF THE TEXT. 

Carbon Capture and Storage at a Glance

At Boundary Dam Power Station, the carbon capture-equipped unit 3 will emit 100,000 tonnes of CO2 into the atmosphere per year, as opposed to 1.1 million tonnes before.