The U.S. Department of Energy (DOE) has announced that it will award up to $1.2 billion to two projects that aim to directly remove carbon dioxide (CO2) from the air, a technology that could help mitigate climate change by reducing the amount of greenhouse gases in the atmosphere. The projects, which will be located in Texas and Louisiana, are expected to capture and store at least 1 million metric tons of CO2 per year each, equivalent to the emissions of more than 200,000 cars.
What is direct air capture and why is it important?
Direct air capture (DAC) is a process that uses large fans to draw in ambient air and then trap CO2 molecules using liquid solvents or solid sorbents. The captured CO2 can then be stored underground, used for enhanced oil recovery, or converted into useful products such as fuels, chemicals, or building materials.
DAC is different from carbon capture and storage (CCS), which captures CO2 as it is being produced by a power plant or an industrial facility before it reaches the atmosphere. While CCS can prevent new emissions from entering the atmosphere, DAC can remove existing emissions that have already accumulated over time.
According to the Intergovernmental Panel on Climate Change (IPCC), DAC is one of the negative emission technologies (NETs) that will be required to limit global warming to 1.5°C above pre-industrial levels, the goal of the Paris Agreement. The IPCC estimates that NETs will need to remove 100-1000 gigatons of CO2 from the atmosphere by 2100.
How will the DOE support DAC development?
The DOE has allocated $3.5 billion under the Bipartisan Infrastructure Law to establish at least four regional DAC hubs across the country. The hubs will serve as demonstration projects that will test the technical and economic feasibility of DAC at scale, as well as create jobs and stimulate innovation in the emerging sector.
The first two recipients of the DOE funding are:
- Project Cypress: A partnership between Battelle, Climeworks, and Heirloom that will build a DAC facility in Calcasieu Parish, Louisiana. The project will use a modular design that can be replicated and deployed in other locations. The captured CO2 will be stored in saline formations or used for enhanced oil recovery.
- South Texas DAC Hub: A project led by Occidental Petroleum that will construct a DAC facility in Kleberg County, Texas. The project will use a proprietary technology developed by Carbon Engineering, a Canadian company that has been operating a pilot plant in British Columbia since 2015. The captured CO2 will be used for enhanced oil recovery or stored in geological formations.
The DOE will provide up to $580 million for each project, covering about half of the total cost. The projects are expected to start construction in 2024 and begin operations in 2026.
What are the challenges and opportunities for DAC?
DAC is still a nascent technology that faces several challenges, such as high capital and operating costs, low energy efficiency, and uncertain environmental impacts. The current cost of DAC ranges from $94 to $232 per ton of CO2 removed, depending on the technology and the end-use of the CO2. To make DAC more competitive and scalable, further research and development, policy support, and market incentives are needed.
On the other hand, DAC also offers some unique opportunities, such as:
- Flexibility: DAC can be deployed anywhere with access to air, power, and CO2 storage or utilization options. This means that DAC can operate independently of emission sources and sinks, unlike CCS which requires proximity to both.
- Permanence: DAC can achieve permanent removal of CO2 from the atmosphere if the captured CO2 is stored securely underground or converted into durable products. This can help offset emissions that are difficult or impossible to eliminate, such as those from aviation or agriculture.
- Innovation: DAC can stimulate innovation and entrepreneurship in various sectors, such as renewable energy, biotechnology, materials science, and engineering. DAC can also create new markets and revenue streams for CO2-based products and services.
How does DAC fit into the broader climate strategy?
DAC is not a silver bullet that can solve climate change on its own. It is one of many tools that need to be deployed in conjunction with other mitigation measures, such as reducing fossil fuel use, increasing energy efficiency, expanding renewable energy sources, and enhancing natural carbon sinks.
DAC should not be seen as an excuse to delay or avoid emission reductions, but rather as a complement to them. As Jennifer Granholm, the U.S. Secretary of Energy, said: “If we deploy this at scale, this technology can help us make serious headway toward our net-zero emissions goals while we are still focused on deploying, deploying, deploying more clean energy at the same time” .