With a $1.2 billion subsidy from the U.S. government, will this technology be a carbon reduction tool?

The U.S. Department of Energy will spend $1.2 billion to subsidize two direct air carbon capture (DAC) projects in response to global warming, the plan was announced on August 11.

The two projects are located in Texas and Louisiana, respectively. According to the U.S. Department of Energy, the project is expected to remove more than 2 million tons of carbon dioxide from the atmosphere each year, equivalent to reducing the annual emissions of about 445,000 fuel vehicles and creating 4,800 jobs in both regions.

Industrial carbon capture technologies include carbon capture and storage (CCS) and direct air capture (DAC). CCS separates carbon dioxide from fossil fuel power plants and heavy industry exhaust gases, while DACs use adsorbents to capture carbon dioxide directly from the air.

The Texas DAC Center is operated by Occidental Petroleum and its subsidiary 1PointFive, which leases 106,000 acres of land locally for project construction that will eventually store up to 1 billion tons of carbon underground. Occidental Petroleum CEO Vicki Hollub said that when the center is fully operational, it will eliminate up to 30 million tonnes of carbon dioxide annually through direct air capture in the future.

According to the journal Science, the Texas Center will use technology developed by Carbon Engineering to capture carbon dioxide using liquid adsorbents, which can be heated to restore their original shape and used to recapture, while pure carbon dioxide is extracted and stored for use in concrete or other products.

The Louisiana DAC Center, operated by Battelle, uses technology from Climeworks and Heirloom that uses solid adsorbents to capture carbon dioxide, which is then released and stored underground. Headquartered in Zurich, Switzerland, Climeworks currently has the world's largest DAC project in Iceland, capturing around 40 million tonnes of CO2 per year.

Heirloom is a California-based startup that is currently using limestone to remove carbon from the air. The company has received $54 million in venture capital funding, including Bill Gates' Breakthrough Energy and Microsoft.

According to the Bipartisan Infrastructure Act, the U.S. plans to establish four DAC centers over the next decade, with $1.2 billion in federal government subsidies to support $3.5 billion. According to the U.S. Department of Energy, DACs, when deployed on a large scale, could help the U.S. achieve its goal of neutralizing greenhouse gas emissions by 2050.

The strategy has also been subject to some controversy, including capital costs, energy consumption, and uncertain risk factors.

According to Science magazine, atmospheric scientist Mark Jacobson called the program "extravagant" and a "complete waste of money." He argues that DAC is one of the most expensive and inefficient ways to sequester carbon because it requires a lot of energy to capture, purify and pump carbon dioxide underground for permanent storage.

"A better climate strategy is to spend money on renewable energy. Mark Jacobson proposed.

The cost of carbon capture is $15 to $20 per tonne for industrial processes with higher CO2 concentrations and $40 to $120 per tonne for more diluted gas streams. DAC technology is in its infancy and relatively costly, currently costing between $600 and $1,000 to capture a tonne of CO2.

Reuters noted that while most environmentalists acknowledge that carbon removal is necessary to meet global climate reduction targets, they are also concerned that the development of carbon removal technologies will provide cover for fossil fuel companies to maintain production.

According to the International Energy Agency, 27 DAC projects are in operation so far in Europe, North America, Japan and the Middle East, but all are small in scale, and only a few have commercial agreements to sell or capture and store CO2.

At present, there are no DAC projects in China, but there is a wide range of CCS projects. According to the China Annual Report on Carbon Capture, Utilization and Storage (2023) released in July this year, there are currently nearly 100 carbon capture, utilization and storage demonstration projects planned and operated in China, covering multiple industries such as power, oil and gas, chemicals, cement, and steel. More than half of the projects have been completed and put into operation, with a CO2 capture capacity of more than 4 million tons per year.