Orca: The World’s First Large-Scale Carbon Dioxide Removal Plant

Alexia Gerogiannis, , ,

The capabilities and shortcomings of a novel climate change prevention technology. 

As scientists search for methods of achieving zero net carbon emissions, an innovative new technology leads the way: Orca, the world’s first and largest direct air capture and storage plant (1). Launched by the Swiss company Climeworks on September 8th, 2021, Orca is designed for carbon capture, the process of extracting CO2 from the air and reusing or storing it so that it cannot reenter the atmosphere (1, 2). This new technology has been the subject of much conversation and debate in the world of climate change prevention for its many capabilities—and shortcomings (2).

The Orca structure is built from eight collectors—each the size of shipping containers—with an annual carbon capture capacity of 500 tons per unit (1, 3). Within each container, large fans draw atmospheric air into the collectors. Inside, CO2 from the air binds to molecules on a filter material until maximum capacity is reached. The collector then closes, and heaters increase the internal temperature to release the carbon dioxide from the filter material, creating a highly concentrated gas. The pure gas is then mixed with water and pumped 1000 meters below the Earth’s surface, where it solidifies to create stone. The containers then release carbon-free gas back into the atmosphere (2).

A diagram of Orca’s carbon capture process. https://climeworks.com/glide/containers/images/orca/test-image-6.jpg/933f6d460bdf88a4f8380c5bc8825782.jpg

In order to create Orca, Climeworks partnered with Carbfix, a carbon storage start-up, to tackle the carbon disposal process (3). Carbfix’s strategy mimics the natural process of CO2 and reactive rock formations interacting to create thermodynamically stable carbonate minerals, which are permanent, environmentally benign states of carbon within the earth (3). When Orca pumps the carbon dioxide and water mixture below ground, it reacts with volcanic basalt rock to form calcium carbonate. Researchers have found that within two years, the basalt turns the carbon dioxide into solid rock, permanently storing it below ground (2). Orca is located in Hellisheidi, Iceland, which was selected for its geothermal energy supply and compatible underground geology. Positioned next to the Hellisheidi power plant, Orca draws its necessary power from a renewable geothermal energy source (3).

The Orca carbon capture plant.

While Orca has revolutionized the field of direct air capture, Climeworks has made similar attempts to minimize net carbon emissions in the past. In Switzerland, Climeworks built plants to collect carbon dioxide to later sell to carbonated beverage companies. However, these facilities captured only 900 tons of carbon annually—a fraction of Orca’s 4000—and were not capable of permanently disposing of the CO2 as Orca is, instead just recycling it (3). Yet, while Orca’s 4000 ton annual capture capacity appears impressive (quadrupling the numbers of its predecessors), it has left many climate change prevention researchers underwhelmed (4). When compared to this year’s estimated 33 billion tons of global CO2 emissions, the 4000 tons captured by Orca is barely impactful (2). Coupled with the high price of $800 to $1084 per ton, Orca is not yet an economically viable means of achieving zero net carbon emissions (3).

However, Climeworks developers call Orca a “blueprint,” not a solution, yet (4). In order to increase Orca’s impact, developers have been working to reduce its price and enhance its capture capacity. In 2024, Climeworks launched a new working carbon capture plant, “Mammoth,” with a capture projection of almost ten times Orca’s capabilities (5). Developments in the field of direct air capture leave scientists both hopeful and apprehensive: will this technology prove impactful, or should developers take a new approach to climate change prevention?

Sources

  1. (n.d.). Orca: the first large-scale plant. Climeworks. Retrieved from https://climeworks.com/plant-orca.
  2. Graves, I. (n.d.). Orca: the future of carbon capture? InterClimate Network. Retrieved from https://interclimate.org/orca-the-future-of-carbon-capture/. 
  3. (2021, September 16). Is Orca a new carbon predator? Australian Energy Council. Retrieved from https://www.energycouncil.com.au/analysis/is-orca-a-new-carbon-predator/.
  4. (2021, September 17). What is Orca? A way of turning captured atmospheric C02 into rock. Negative Emissions Platform. Retrieved from https://www.negative-emissions.org/orca-launch-and-dac-summit-2021.
  5. Paddison, L. (2024, May 8). The ‘world’s largest’ vacuum to suck climate pollution out of the air just opened. Here’s how it works. CNN Climate. Retrieved from https://www.cnn.com/2024/05/08/climate/direct-air-capture-plant-iceland-climate-intl/index.html.