Global energy players are currently facing the increasing pressure from governments and shareholders to decarbonize their operations. More and more energy companies are committing to help stop climate change by reducing their own greenhouse-gas (GHG) emissions as much as they can. One potential solution is the direct air capture (DAC), a technology that extracts carbon dioxide (CO2) from the atmosphere and does not require to be close to a CO2 emission source. In recent years, startups in the DAC sector have begun to scale up their operations, attracting larger companies like Occidental Petroleum and ExxonMobil to help fund those efforts.
The picture below shows 3 key steps to direct air capture that produce 2 different outputs: concentrated carbon dioxide and filtered CO2-free air.
During the initial step, whirring fans (there is normally one or two dozen per DAC unit) draw in air from the atmosphere. Then, captured air passes through the filters that “grab” and concentrate carbon dioxide. These filters capture CO2 by using solid sorbents or liquid solvents. Capturing CO2 from the air is very energy intensive and more expensive than capturing it from a point emitter source. Carbon dioxide in the atmosphere is much more dilute (about 0.04% of the atmosphere) and more energy is needed to capture it. That is why DAC facilities are more costly comparing to other CO2 capture applications and technologies.
When it comes to the traditional carbon capture, utilization and storage (CCUS), capture cost varies by CO2 source, from $15-25/t CO2 for industrial processes producing “pure” or highly concentrated CO2 (e.g. ethanol production, natural gas processing) to $40-120/t CO2 for processes with “dilute” gas streams, e.g. cement production, power generation. As of today, DAC costs are prohibitively high. The range of costs vary between $250 and $600/t CO2 depending on the chosen technology. Some DAC companies offer a subscription service to their customers, where costs range from $600-1,000/t, according to the IEA (International Energy Agency). DAC must undergo significant cost reductions if it is to play a role in the Global Energy Transition. The upside of DAC vs traditional CCUS is that DAC removes CO2 from the atmosphere, meaning a net removal, rather than just avoided emissions.
After the CO2 was captured, DAC facilities heat the filter material to release carbon dioxide. The amount of heat required for this process affects how the DAC facilities are powered. If solid sorbents are used, then DAC facilities can utilize renewable energy sources. Liquid solvents require higher energy levels. In that case, DAC facilities can rely on natural gas-to-power energy generation.
The two main outputs of the DAC process are captured CO2, which can be permanently stored in underground reservoirs and deep geological formations or used to make other goods (utilization); and filtered CO2-free air, which is released back into the atmosphere. The captured CO2 can also be utilized in food processing or combined with hydrogen to produce synthetic fuels.
According to the IEA, there are currently 18 direct air capture facilities operating Globally (Europe, the US and Canada), capturing almost 0.01 Mt CO2/year. All these DAC plants are small scale, and the majority of them capture carbon dioxide for utilization. Only a few commercial agreements are in place to sell or store the captured CO2, while the remaining plants are operated for demonstration and testing/pilot purposes.
Companies with the most developed technologies today include Climeworks (Switzerland), Carbon Engineering (Canada) and Global Thermostat (USA). Climeworks opened its first DAC plant in 2017 and now has 15 machines in operation. Canada-based Carbon Engineering and Oxy, subsidiary of Occidental Petroleum, are building the world’s largest DAC facility in the US Permian Basin. Their plant will capture up to 500,000 tons of CO2 each year and store it in rocks deep underground. Occidental Petroleum communicated an impressive plan to build 70 carbon capture facilities Globally by 2035. And each facility should be able to remove around 1 million of CO2/year directly from the atmosphere.
Oxy & Carbon Engineering’s plant is planned to be much bigger than the other largest DAC facility called “Mammoth” in Iceland, run by Swiss Climeworks. When finished, Mammoth will remove around 36,000 tons of CO2/year.
Today, DAC deployment at a large scale relies on the availability of low-carbon energy sources and CO2 storage. DAC needs technology development support, as well as better local policies and regulations. The most advanced federal policy supporting DAC today is the recently passed Inflation Reduction Act (IRA). The US’s IRA, signed into law in August 2022, enhanced 45Q tax credit, offering companies $85/ton for point source and $180/ton for DAC. This is an impactful example that should drive the capital required to bring mass commercial & large-scale projects to financial investment decision (FID).
Carbon Capture, Utilization and Storage (CCUS) and DAC are both vital for achieving the Global net-zero goals. At Schneider Electric, we address the entire CCUS value chain, optimize and secure related processes by combining hardware and software, to deliver reliable and sustainable operations. We can also provide automation around carbon capture, process optimization and simulation, as well as energy efficiency improvement. We support CCUS projects, from design to FID and CO2 transportation, and storage.
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