By Chantal Cooke, PASSION for the PLANET
Multiple highest-level climate reports published recently (IPCC SR15 & AR5, EASAC, NAS) clearly state that in order to achieve climate targets, not only do we need to do everything we can to reduce emissions; we also need to actively remove CO2 from the atmosphere.
Image: Jump Story
Yet, even if we managed to completely revolutionize the economy, and made every product more energy efficient, we would still have historic CO2 in the atmosphere and we’d still be adding to it, because some sectors, for example, aviation, are hard to fully de-fossilize.
One way to help is by planting trees
Along with finding ways to reduce the amount of carbon dioxide we add to the atmosphere, we also need to find ways to remove unavoidable emissions as well as the CO2 already in our atmosphere. The obvious way to remove CO2 is by planting trees. If done well, afforestation comes with a number of important benefits such as reduced soil erosion and increased biodiversity. However, afforestation is a solution that cannot be scaled indefinitely, because it requires lots of water and surface area. Also, the permanence of the removed CO2 cannot always be guaranteed with trees: wildfires or deforestation can destroy the trees and release the CO2 back into the atmosphere. Because of this, it’s hard to see how tree planting could be the only answer to our carbon dioxide removal needs.
Direct air capture of CO2
Direct air capture is another carbon dioxide removal solution and a complementary approach to planting trees.
Direct air capture is a way of removing CO2 directly from the atmosphere – both new and historic. However, in order to scale direct air capture up to levels that will make a meaningful difference, we need to act now.
Let me explain a bit about direct air capture and how it works. At Climeworks, carbon dioxide is captured directly from the air by sucking it through the company’s CO2 collectors. These collectors contain a patented filter material, which binds the CO2. When the filter material is saturated, the collector automatically closes, and its contents are gently heated. At elevated temperatures, the CO2 is released from the filter material and can be collected.
Subsequently, it can be used as a product or, in the case of Climeworks’ direct air capture and storage plant in Iceland, it can be stored safely and permanently underground where it is naturally turned to stone and thus creates negative emissions.
Once the collected CO2 has been removed from the filter, the collector re-opens and starts the whole process again. This cycle happens thousands of times a year to capture CO2 from the atmosphere.
Climeworks direct air capture plants are powered solely by renewable energy or energy from waste.
A recently published independent life cycle assessment carried out by the RWTH Aachen University, using data from Climeworks, showed that direct air capture has a low carbon footprint when powered by low-carbon energy, such as waste heat or renewable energy. Specifically, it found that Climeworks’ plants can reach a net carbon dioxide removal efficiency of more than 90%. In other words, over its whole lifespan (including construction, operations, and recycling), a typical Climeworks plant re-emits less than 10% of the carbon dioxide it captures. Future scenarios show that this can be further reduced to 4%.
But can direct air capture be scaled? Climeworks shows it can – let’s look at two projects, Orca and Zenid:
Climeworks new large-scale direct air capture and storage plant Orca
“Orca” is the name of Climeworks’ new direct air capture and storage plant in Iceland. Once completed it will take carbon dioxide removal to the next level: it combines Climeworks’ direct air capture technology with the underground storage of carbon dioxide provided by Carbfix on a large scale, capturing 4’000 tons of CO2 per year.
In addition to emissions reduction efforts, climate scientists agree that removing historic emissions is crucial to limit global warming to 1.5°C. And this is where Orca comes in.
By providing accessible, permanent, and fully-measurable CO2 removal, Orca sets high standards for the emerging carbon dioxide removal industry.
Under construction Orca
Orca will permanently remove CO2 from the atmosphere on behalf of corporations or institutions as well as individuals. A unique subscription-based program enables anyone to join the innovative community of more than 4’000 pioneers from 54 countries around the world who are already leading the way to a climate-positive world. To join, visit Climeworks.
Zenid Project and Sustainable Aviation Fuel (SAF)
The aviation industry is responsible for 3% of global manmade CO2 emissions and has the challenging objective to reduce these emissions significantly in the next decade. Unlike road transport, aviation cannot switch to electric or hydrogen propulsion yet and therefore depends on sustainable aviation fuels (SAF). SAF, purely made from the air via direct air capture technology and renewable electricity, offers a carbon-neutral solution suitable to meet the industry’s high demands for renewable fuels in the future.
In February 2021 a high-level conference on synthetic SAF was hosted by the Dutch Minister for Infrastructure and Water Management Cora van Nieuwenhuizen. During this event, Zenid was presented: a consortium consisting of the Rotterdam The Hague Airport (part of Royal Schiphol Group), Rotterdam The Hague Innovation Airport, global leader for SAF SkyNRG, and direct air capture pioneer Climeworks. The partners agreed to further investigate the construction of a demonstration plant producing fully circular SAF with 100% CO2 derived from the air. This is based on the positive outcome of a feasibility study for such a plant conducted earlier.
The demonstration plant will be powered by regionally sourced renewable energy and combines several innovative technologies: a direct air capture plant provides CO2 to a highly efficient co-electrolysis unit, that turns the CO2 and added water into syngas. The syngas is transformed into liquid hydrocarbons by a modular Fischer-Tropsch reactor and then refined into sustainable aviation fuel.
The goal of Zenid is to enable a net-zero aviation industry in the long-term.
As UN Secretary-General António Guterres remarked:
The climate emergency is a race we are losing, but it is a race we can win.
With people and companies from around the world working together on a range of solutions we are making progress.
Chantal Cooke is an award-winning environmental journalist and broadcaster and founder of the UK’s first environmentally-focused radio station, Passion for the Planet.
The views and opinions expressed in this blog post or content are those of the authors or the interviewees and do not necessarily reflect the official policy or position of any other agency, organization, employer, or company.