CO2 Capture Advancements

Addressing Atmospheric Carbon: A Novel Approach in Iceland

The composition of the air we breathe is increasingly affected by carbon levels. However, in Hellisheidi, Iceland – a geothermally active region near Reykjavik – an innovative technology is being implemented to address this issue.

Introducing the Orca Facility

The Orca plant, constructed by Climeworks, represents a pioneering effort. It is the world’s first installation designed to extract CO₂ directly from the atmosphere and ensure its long-term storage beneath the surface.

The Technology Behind Carbon Capture

Orca’s carbon capture units have a distinctive appearance, reminiscent of large transistor radios. These devices are seamlessly integrated into the expansive Icelandic terrain, characterized by strong winds and glistening icy peaks.

A Shift in Perspective on Direct Air Capture

Although operational since September, the direct air capture technology employed by Orca has been a subject of debate within environmental circles for some time. Previously viewed as a measure of last resort, extracting carbon dioxide is now increasingly recognized as a necessary component of future climate strategies.

Meeting Global Climate Goals

According to Jan Wurzbacher, CEO and co-founder of Climeworks, “The integration of direct air capture with permanent storage is highly probable to be essential on a large scale globally, if adherence to the Paris climate agreements is to be achieved.”

This suggests a growing acceptance of technologies like Orca as vital tools in mitigating climate change.

Carbon Dioxide Removal: A Mathematical and Technological Approach

The “Paris” targets referenced by Wurzbacher pertain to the internationally agreed-upon objective of limiting global warming to two degrees Celsius, with a preference for 1.5 degrees Celsius, as outlined in the 2015 Paris Agreement. Achieving this necessitates the removal of approximately 10 billion tons of carbon dioxide from the atmosphere annually by the year 2050, according to United Nations estimates. This figure represents an optimistic scenario, contingent upon substantial reductions in emissions through alternative strategies. Insufficient emission cuts could significantly increase the required amount of carbon removal.

Wurzbacher clarified the situation during a virtual discussion from Climeworks’ headquarters in Zurich, Switzerland, stating, “The climate calculations are fairly straightforward.” He continued, “By the middle of the century, a removal of 10 billion tons of CO₂ will be necessary, assuming optimal progress elsewhere. However, we may need to remove as much as 20 billion tons, due to potential delays in phasing out coal-fired power plants and similar sources.”

Direct air capture represents one of several potential methods for mitigating excess CO₂. Alongside natural approaches, such as afforestation, and technologies focused on capturing CO₂ from point sources like smokestacks, direct air capture offers a unique advantage. While more challenging and expensive than source-capture, it doesn’t rely on identifying and curtailing every individual polluter, providing a globally applicable solution.

“The benefit of direct air capture lies in its universality,” Wurzbacher explained. “Because air is ubiquitous, you don’t need to locate the CO₂ source.”

The Orca facility comprises eight collectors, each housed within a shipping container. These collectors feature slats on their exterior, resembling large venetian blinds, and incorporate 12 fans to draw air through the structure. Inside, CO₂ molecules interact with a specifically engineered filter material containing amines, which selectively bind to them.

This interaction marks a pivotal moment. While the remaining air passes through the collectors, the carbon remains firmly attached to the amines. At this stage, CO₂ transitions from the dispersed state of the atmosphere to controlled containment by human technology, potentially for millennia. Applying heat releases the CO₂ from the amines, after which it is injected into subsurface volcanic rock formations, where it undergoes mineralization into stable carbonate compounds.

Currently, the cost of removing one ton of CO₂ at Orca ranges from $600 to $800, making it financially inaccessible for many. Initial clients include organizations and individuals prepared to pay a premium, such as Microsoft, Stripe, Swiss Re, and the musical group Coldplay, who engaged Climeworks to offset emissions from their upcoming global tour.

Climeworks aims to reduce this cost to between $100 and $200 per ton. The US Department of Energy shares this objective, targeting a cost of under $100 per ton for technological carbon removal. Achieving these lower price points would position direct air capture competitively with other ambitious emission reduction strategies.

Despite the current expense, the capture process demonstrably functions. “Orca has successfully moved from concept to reality,” said Dr. Julio Friedmann, a senior research fellow at Columbia University. “We now know that, if required, we can replicate Orca’s capabilities. We anticipate cost reductions and performance improvements, but we have a working unit that removes four thousand tons of CO₂ annually.”

Critics have pointed to the relatively small amount of CO₂ captured by Orca, alongside its high cost. Four thousand tons is a negligible amount compared to the 10 billion tons required within the coming decades. At current emission rates, humanity effectively negates Orca’s annual efforts every three seconds.

However, a more useful perspective involves comparing this quantity to other carbon removal methods. An acre of redwood forest also sequesters approximately 4,000 tons of CO₂, but this process takes considerably longer than a year and is geographically limited.

Friedmann succinctly summarized the value proposition of direct air capture: “It achieves the carbon removal equivalent of two hundred thousand trees, utilizing one thousand times less land area.”

While some activists, like Greta Thunberg, have expressed skepticism towards engineered solutions like direct air capture, favoring nature-based approaches, a combined strategy is feasible. If the United Nations’ projections are accurate, multiple solutions will be necessary to address the excess carbon.

Wurzbacher concluded, “The scale of the challenge will necessitate solutions measured in billions of tons, of that I am certain.”

The Advantages of a Gradual Approach to Direct Air Capture

Concerns regarding the limited scale of Orca, Climeworks’ direct air capture facility, overlook a crucial benefit: initiating with a smaller footprint provides invaluable learning opportunities.

As with all emerging technologies, direct air capture (DAC) is subject to improvement through iterative development, leading to increased efficiency and reduced expenses over time. Climeworks’ CO₂ collectors are designed with modularity in mind.

This means scaling up CO₂ removal involves adding more units, rather than attempting to construct significantly larger, more complex collectors. A modular design facilitates cheaper and more streamlined iteration compared to larger, bespoke systems.

Iterative Development and Scalability

“By the time we commence construction on larger facilities, or multiple installations like the current one, we will have a strong understanding of its functionality and operational sustainability,” explains Nathalie Casas, Head of Technology at Climeworks. “This is the core advantage of a modular methodology.”

Plans are already underway for a larger plant, as noted by Wurzbacher, though the precise location remains undecided. This facility will be ten times the size of Orca, utilizing 80 shipping container-sized collectors to capture 40,000 tons of CO₂ annually.

A key benefit of starting with a plant the size of Orca is that any necessary adjustments to the collector design only require replication across eight units.

“Scaling that up to eighty containers presents a considerably different challenge,” Wurzbacher points out.

Comparing Approaches to Direct Air Capture

Climeworks’ strategy of small-to-medium scale development contrasts with that of Carbon Engineering, another prominent company in the DAC space. Carbon Engineering is currently constructing a plant in Texas with a projected capacity of half a million tons of CO₂ capture per year, scheduled for operation mid-decade.

“Climeworks is entering the field incrementally, while Carbon Engineering is taking a more ambitious, all-in approach,” observes Colin McCormick, Chief Innovation Officer at Carbon Direct, a carbon removal investment and advisory firm.

Whether one, both, or neither of these strategies will ultimately succeed in achieving cost-effective, large-scale carbon removal remains to be seen. While still in its early stages, direct air capture shares similarities with established sustainable technologies.

Both solar photovoltaic (PV) panels and wind turbines began as unproven concepts decades ago, but have since evolved into major, rapidly expanding industries driving the energy transition.

Lessons from Solar and Wind Energy

The parallel with solar energy is particularly relevant, as both technologies initially relied on novel materials to achieve a theoretically possible, yet commercially unproven outcome.

McCormick notes that a minimum energy input is required to capture carbon dioxide from the atmosphere, and this amount is substantial. However, both Climeworks and Carbon Engineering currently utilize approximately ten times more energy than this theoretical minimum, indicating significant potential for improvement.

“We are far from achieving 100% efficiency, and that’s acceptable,” he states. “Early solar panels also exhibited very low efficiency rates.”

Focus on Efficiency and Cost Reduction

Climeworks is actively pursuing several avenues to enhance efficiency and lower costs. A primary focus is improving the filter material to maximize CO₂ capture and extend its lifespan.

The company is also streamlining production processes to reduce the cost of manufacturing the modular units. Furthermore, fixed costs, such as CO₂ pipelines, will naturally decrease as plant sizes increase.

Despite the significant technical hurdles, the Climeworks team remains optimistic. Wurzbacher believes the current state of direct air capture is more favorable than that of wind and solar technologies in the 1970s and 1980s.

“Compared to the cost reductions required for solar PV or wind energy, our challenge is comparatively smaller,” says Wurzbacher. “It’s encouraging that we only need to achieve a factor of ten reduction.”

Real-world learning is essential to achieving these cost reductions, surpassing the limitations of laboratory or office-based research.

“This isn’t a software startup,” Wurzbacher emphasizes. “We’re deploying robust infrastructure in challenging environments. Unexpected issues inevitably arise, and while we can anticipate approximately ninety percent of them, the remaining ten percent require practical experience to resolve.”

Why Iceland?

Finding a more visually striking location for a research facility than Orca would be a challenge. The installation is positioned at the base of rugged, snow-capped black peaks, overlooking a verdant plain. However, the Climeworks team’s decision to construct Orca at this specific site wasn’t based on aesthetics. The Hellisheidi location provides two crucial components for direct air capture technology: affordable renewable energy and a viable means of CO₂ storage. Both of these advantages stem from Iceland’s distinctive volcanic geological characteristics.

Orca is situated adjacent to the Hellisheidi Geothermal Power Plant, a major provider of geothermal energy in Iceland. This plant extracts hot water from depths exceeding a mile, naturally heated by an underlying volcanic hotspot. The geothermal process generates both heat and electricity, both of which are essential for the direct air capture process.

The electricity powers the airflow through the collection system, while the heat facilitates the release of captured CO₂ from the filter material, a process requiring approximately 100 degrees Celsius – the temperature of boiling water.

Wurzbacher explained, “Geothermal energy is particularly advantageous as a starting point due to its consistent 24/7 availability, providing both heat and electricity, making it ideally suited for our operations.”

The handling of CO₂ is also streamlined. The bedrock beneath Hellisheidi consists of porous basalt, geologically young – less than one million years old. Carbfix, a specialized company, has developed a method for injecting CO₂ into this young rock, triggering a reaction that forms stable carbonate minerals.

Carbfix operates as a subsidiary of Reykjavik Energy, the municipal utility managing the geothermal plant. For over five years, they have utilized this technique to sequester the CO₂ byproduct of geothermal energy production, meaning the infrastructure for storing CO₂ from Orca was already established.

McCormick emphasized, “A key reason for Orca’s location in Iceland is the availability of waste heat and carbon-free power from the geothermal field. They already have drilled injection wells and favorable geology for CO₂ injection, making this location comprehensively ideal.”

Effective carbon storage is a vital component of carbon removal strategies. While numerous methods exist, Carbfix’s approach is particularly promising due to the rapid conversion of carbon dioxide into rock. This mineralization occurs within two years, and often within just a few months, ensuring long-term stability for thousands of years.

“Once the CO₂ is underground, it remains there permanently,” stated Kari Helgason, head of research and innovation at Carbfix.

This timeframe offers a significant advantage over alternative methods, such as storage in depleted oil wells, which necessitate continuous monitoring to prevent CO₂ leakage.

Furthermore, the Carbfix method is remarkably cost-effective, especially when contrasted with the substantial expenses associated with carbon capture itself.

Helgason noted, “When we receive pure CO₂, the process is highly economical. Our collaboration with Climeworks makes it exceptionally affordable.”

Iceland’s predominantly basaltic composition provides virtually limitless storage potential. Helgason estimates that each cubic kilometer of basalt can store an impressive one hundred million tons of CO₂.

“The storage capacity is truly immense,” he added.

This storage capacity isn’t limited to Iceland. Carbfix has created an online atlas detailing regions worldwide with potential for geological carbon storage.

Wurzbacher acknowledged the suitability of Hellisheidi and Carbfix for the Orca plant, but indicated Climeworks is open to considering alternative locations for future projects.

“The Icelandic weather and wind conditions are not ideal,” he said. “Our commissioning team might prefer a location like Hawaii, or another area with abundant volcanic rock, for the next plant.”

Collective Effort is Key to Carbon Capture Success

Successful carbon removal hinges on collaborative innovation, as exemplified by the partnership between Climeworks and Carbfix. To encourage similar ventures, the United States has designated $3.5 billion for the establishment of four direct air capture “hubs.” These hubs will facilitate cooperation between multiple companies in the capture and storage of CO₂, a provision included within the recently approved infrastructure bill.

Rory Jacobson, deputy director of policy at Carbon180, a carbon removal-focused think tank, emphasized that “considering direct air capture as a collaborative effort involving numerous stakeholders is crucial.”

Direct air capture projects frequently involve oil and gas companies, typically as financial contributors. Carbon Engineering is collaborating with Occidental Petroleum on a project in Texas, while Global Thermostat is partnering with Exxon Mobil on several smaller-scale initiatives across the US.

While partnering with larger corporations provides carbon capture startups with substantial funding and geological expertise, these alliances have also sparked concerns that carbon capture may serve as a pretext for ongoing pollution.

Jacobson highlighted the significance of the Orca project, noting “the complete absence of fossil fuel industry involvement is particularly encouraging.”

Regardless of participation from the fossil fuel sector, the scalability of direct air capture is likely to be constrained without supportive government climate policies. Currently, no inherent market exists for atmospheric carbon removal, unlike the established market for electricity generated from renewable sources like wind and solar. Funding for direct air capture must therefore come from voluntary purchases – as seen with Climeworks – or through governmental incentives and regulations.

Wurzbacher stated, “The voluntary market for carbon removal can potentially reach millions of tons, perhaps even ten million tons, or more.” He continued, “However, achieving removals in the tens of millions to billions of tons range will necessitate public instruments.”

Existing incentives include the US 45Q policy, which provides $50 per ton for carbon capture and storage. The Build Back Better bill, recently passed by the House of Representatives but currently stalled in the Senate, proposes increasing this payment to $180 per ton.

A significantly larger market for direct air capture would emerge if governments implemented substantial carbon taxes or enacted regulations compelling industries to drastically reduce or eliminate their emissions immediately. At the recent United Nations climate conference in Glasgow, however, world leaders did not announce such decisive measures. This situation may evolve as both public demand for action and the impacts of climate change continue to escalate, neither of which appear to be diminishing.

Should more robust policies be enacted in the future, Climeworks will be prepared, possessing direct air capture technology projected to become considerably more affordable. While the cost will remain substantial, the cost of inaction could prove far greater.