The world's largest direct air capture (DAC) plant, Mammoth, opened in Iceland on the 8th. It has the capacity to remove 36,000 tons of carbon dioxide annually, equivalent to removing the emissions of approximately 8,600 cars. This is eight times more than the current largest plant of its type.
Capacity jumps, but cost reduction is difficult
In 2021, Swiss startup Climeworks launched its Orca direct air capture plant in Iceland. Located in Iceland, the Orca plant can capture 4,000 tons of carbon dioxide annually. The captured CO2 is then stored by its Icelandic partner, Carbfix. At the time, it was the world's largest direct air capture and storage (DAC+S) plant.
"Orka" comes from the Icelandic word "orka," meaning "energy." Shortly after the Orka plant opened, Climeworks began construction on the Mammoth plant, completing it within two years. The Mammoth plant can capture 36,000 tons of carbon dioxide annually, nine times more than the Orka plant.
With carbon reduction efforts slow and insufficient, many experts are pinning their hopes on carbon-negative technologies. Commonly known as "carbon capture" involves separating and compressing carbon dioxide emitted by thermal power plants and factories, then storing it for storage. Direct air capture, on the other hand, intercepts carbon dioxide in the atmosphere, a process often described by foreign media as a "giant air purifier" or "carbon dioxide vacuum cleaner."
The Guardian explains that the plant uses powerful fans to draw air into a collector, where alkaline filters absorb the carbon dioxide. Once the filter is filled with carbon dioxide, the collector shuts down and heat is used to extract the carbon dioxide. The carbon dioxide is then mixed with water and injected 1,000 meters underground. After a long period of chemical reaction with the basalt, it mineralizes into rock.
The Mammoth plant has a total of 72 collectors, 12 of which were completed in May and began direct air capture. This technology is very energy-intensive, and the energy required is provided by another Icelandic partner, geothermal energy company ON Power.
Climeworks' direct air capture plant, Mammoth, opened in May. Image credit: Climeworks
DAC advantage: easy to verify and calculate carbon reduction benefits
Leveraging the success of these two plants, Climeworks continues its construction plans, aiming for a total production capacity of one million tons by 2030. Christoph Gebald, co-founder and co-CEO of Climeworks, told Bloomberg that the Mammoth plant's costs are only slightly lower than those of the Oka plant, capturing one ton of carbon dioxide at approximately $1,000 (NT$32,000). He hopes to reduce this to $200-300 per ton by 2040 and $100 per ton by 2050.
Energy consulting firm Wood Mackenzie points out that while afforestation can reduce carbon emissions, its effectiveness and verification are highly controversial. Direct air capture offers the advantages of longevity, measurability, and externality, but the most pressing issue is reducing costs. However, this technology is highly energy-intensive, making cost reduction challenging.
David Webb, Chief Sustainability Officer at Boston Consulting Group, believes that the small land area required for direct air capture is also an advantage. Taking the rapidly declining cost of solar photovoltaics as an example, reducing the cost of direct air capture requires not only expanding production capacity, government incentives, and increased investment, but also accelerating the learning curve.
References：
*REUTERS（2024.5.9），Climeworks opens world’s largest plant to extract CO2 from air in Iceland
*Bloomberg（2024.5.8），The World’s Biggest Carbon Removal Plant Comes Online in Iceland
*Washington（2024.5.9），The world’s largest carbon-capture plant just switched on
*Wood Mackenzie（2024.1.18），Low-carbon tech: can direct air capture rise to the challenge? DAC could get the energy transition on track
*World Economic Forum（2023.8.9），Achieving net zero: Why costs of direct air capture need to drop for large-scale adoption
*Climeworks，Mammoth: what it takes to manufacture direct air capture plants at new scales
*Climeworks，Mammoth: our newest facility
*Climeworks，Orca: the first large-scale plant
*The Guardian（2021.9.9），World’s biggest machine capturing carbon from air turned on in Iceland
*Taiwan Sustainability Hub（2021.10.8），從淨零到負碳 – 碳移除技術的前景與挑戰
Sources:
Environmental Information Center
