Carbyon, a Netherlands-based company founded in 2019, develops direct air capture (DAC) technology that removes carbon dioxide (CO₂) directly from the air. Carbyon’s technology uses a fast swing process by means of a continuously rotating drum that consists of activated carbon fibers functionalized with amines. The fast swing process is the key to lower the energy consumption as well as the cost of the machine. The company’s goal is to turn direct air capture into an affordable and scalable technology that can be used to stop climate change. Carbyon has won XPRIZE Milestone Award for Carbon Removal in 2022.
(This article contains 7 diagrams and 1795 words.)
Challenges: carbon emissions and Direct Air Capture
Carbon emissions
Since the early 1900s, carbon dioxide (CO₂) levels in the atmosphere have increased by 50% due to human activities. When fossil fuels (such as coal, oil, and natural gas) are burned for energy production, transportation, and industrial processes, CO₂ is released into the atmosphere. This excess CO₂ acts as a greenhouse gas, trapping heat and causing the air and ocean temperatures to rise. CO₂ emissions play a crucial role in driving climate change.
This warming effect has caused the global average temperature to rise by about 1.1 ºC since the pre-industrial period. This has led to rising in the frequency and intensity of extreme weather events, melting of polar ice caps and glaciers and rising sea levels, shifts in species ranges and increased risk of species extinction, agriculture and food security, and ocean acidification.
To mitigate these impacts, the Paris Agreement aims to limit global warming to well below 2 ºC above pre-industrial levels. The Intergovernmental Panel on Climate Change (IPCC) estimates that a “carbon budget” of about 500 GtCO₂, which corresponds to about ten years at current emission rates, provides a 66% chance of limiting global warming to 1.5 ºC.
Direct Air Capture
Direct Air Capture (DAC) is a process that extracts CO₂ directly from the atmosphere, as opposed to industrial emissions with a high CO₂ content. The captured CO₂ can then be either permanently stored in deep geological formations, thereby achieving CO₂ removal (CDR), or used as a climate-neutral feedstock for a range of products that require a source of carbon.
The basic principle of DAC involves using large-scale machines or facilities equipped with specialized filters or sorbents which are designed to attract and bind with CO₂ molecules from the air while allowing other gasses, such as nitrogen and oxygen, to pass through. After the CO₂ is captured, it is separated from the sorbent through a regeneration process, resulting in the release of CO₂.
DAC technology employs a variety of methods, but chemical sorbents or solvents are typically used to capture CO₂. These sorbents can chemically react with CO₂ to form solid compounds or dissolve the CO₂ in a solvent. The captured CO₂ is then released from the sorbent or solvent via heating or other processes, allowing for its storage or utilization.
Direct air capture technology challenges
DAC plays an important and growing role in net-zero pathways. Capturing CO₂ directly from the air and permanently storing it removes the CO₂ from the atmosphere, providing a way to balance emissions that are difficult to avoid, including from long-distance transport and heavy industry. DAC has seen a surge in interest and investment over the past few years, and a growing number of companies are entering the market due to the realization that carbon removal will increasingly be needed to meet national and global climate goals, as well as the advantages of DAC relative to other carbon removal technologies.
However, this technology is still in its infancy and faces several challenges that are stunting its global adoption and deployment.
One of the main challenges is that CO₂ is present in the air at a much lower concentration than other commonly targeted sources, such as flue gasses resulting from energy generation and industrial processes. This makes it technically challenging and requires a lot of energy.
As carbon dioxide removal from ambient air is an energy-intensive process, DAC technology is more expensive per ton of CO₂ removed than many mitigation strategies and natural climate solutions. Today, the price range for DAC ranges between $250 and $600. By the end of this decade, however, the cost of DAC technology is projected to fall to $250-$300 per ton for a multi-megaton capacity range. If further industrialization is accomplished within the ecosystem of this emerging industry, prices may fall to between $100 and $200.
The sociopolitical acceptance of DAC is also a challenge. Currently, there is no established market for carbon removal, and the demand for carbon removal is not yet sufficient to support the large-scale deployment of DAC. Some advocates worry the carbon capture process may not be scaled up fast enough to make an impact. However, the demand for carbon removal is expected to increase as more countries and companies set net-zero targets and seek to offset their emissions. In addition, governments and other stakeholders must provide substantial funding and support.
Carbyon Technology
Carbyon develops a low-cost, energy-efficient DAC technology that uses a fast swing process by means of a continuously rotating drum. The rotating drum comprises activated carbon fiber membranes. The surface of fibers are functionalized with a monolayer of amines that are used as CO₂ adsorbents. Such a thin surface sorbent allows a rapid CO₂ absorption at ambient temperature and fast regeneration below 100 ºC. Thereby, one cycle of absorption and regeneration occurs in less than 5 seconds. The fast swing CO₂ capture process is the key to lower the energy consumption as well as the cost of the machine.
Carbyon direct air capture
The diagram below depicts the system of the DAC technology developed by Carbyon.
The system comprises a drum containing porous CO₂ sorbent materials, at least one sorption chamber, at least one regeneration chamber, and a mechanism for rotating the drum from the sorption chamber to the regeneration chamber and back. The sorption chamber has inlets and outlets for the airflow that passes over the porous carbon fiber support structure. For regeneration of sorbents, the regeneration chamber is heated to a moderately high temperature by heating elements. The regeneration chamber also has outlets for discharging CO₂.
The diagram below depicts Carbyon’s carbon fiber membrane with microporous structures, which offers a large surface area for coating a monolayer of amine sorbents. The amine sorbents coat the surface of carbon fiber via a wet impregnation method.
The process for CO₂ absorption by the monolayer of sorbents is depicted in the diagram below.
During operation, air enters the micropores and largely stands still, whereas air outside the opening of the pores flows. The amine absorbs CO₂ from the air in the micropores, resulting in a decrease in CO₂ concentration and CO₂ partial pressure. Therefore, mainly CO₂ molecules diffuse into the pores and are absorbed by the amines until the sorbent is saturated. Other molecules in the airflow that are not adsorbed by the sorbent hardly diffuse into the pores because their partial pressure is not reduced in the pores.
Therefore, CO₂ molecules are selectively sucked out of the airflow and captured by the sorbent. Moreover, the process avoids the need for large pressure differences of the airflow passing through the sorption chamber, as is required by conventional DAC technologies, thereby minimizing the energy input.
When only surface adsorption takes place, the surface adsorption is much quicker than bulk absorption, as it avoids solid or liquid state diffusion. In addition, the capacity of a certain volume of sorbent is significantly reduced. Therefore, the sorbent is saturated with CO₂ faster, resulting in a higher adsorption rate. To liberate the CO₂ molecules from the monolayer sorbents during sorbent regeneration, only a short heat pulse is required. The regeneration temperature is below 100 ºC, which reduces the energy input significantly.
Thus, the surface sorbent enables shorter cycle times for the sorbent to switch between a sorption stage and a regeneration stage and minimizes the energy requirement.
How does Carbyon direct air capture technology work?
Air flows through the sorption chamber over a microporous structure coated with a monolayer of amine sorbents. CO₂ is selectively captured at ambient temperature, as described previously. Due to the thinness of the sorption layer in the microporous structure, the residence duration of the sorbent within the sorption chamber is less than 5 seconds.
The CO₂-saturated amine sorbents are rotated from the sorption chamber to the regeneration chamber, where they are regenerated at temperatures between 65 and 100 ºC by liberating CO₂ from the sorbent. The process typically occurs at the same time scales of less than 5 seconds. The released CO₂ is extracted from the regeneration chamber and either stored for utilization or buried underground.
The regenerated sorbent is then rotated towards the sorption chamber and used again for capturing CO₂ from air. Absorption and regeneration processes are continuous.
Carbyon Patent
- WO2022013456A1 Device and process for the direct carbon dioxide capture from air
Carbyon Technology Applications
- Carbon dioxide removal
Carbyon offers a modular machine that contains thin membranes to efficiently capture CO₂ out of air by using a fast swing process. The thin membrane design minimizes the energy consumption. The fast swing process allows for a very compact and reproducible machine design, lowering the manufacturing cost.
Carbyon Products
The company aims to reach gigaton scale in the 2030s and substantially contribute to mitigating climate change. The company’s target is a cost of 50 euros/ton for CO₂ capture, and its approach is radically distinct from competing technologies. The company has developed prototypes and is developing outdoor piloting systems.
Carbyon Technology Readiness Level (TRL)
In 2023, Carbyon commissioned two fully integrated prototypes at their testing facilities in Eindhoven. These prototypes are capable of capturing CO₂ directly from outside air, which aligns with the TRL 6 definition of a “fully integrated pilot (prototype) tested in a relevant environment”.
Carbyon Funding
Carbyon has raised a total of $19.9M in funding over 3 rounds:
Their latest funding was raised on Sep 3, 2024 from a Series A round.
Carbyon Investors
Carbyon is funded by 8 investors:
- Innovation Industries
- XPRIZE
- Lowercarbon Capital
- Omnes Capital
- Invest-NL
- Siemens Financial Services
- Global Cleantech Capital
- Brabant Development
Lowercarbon Capital and Invest-NL are the most recent investors.
Carbyon Founder
Hans de Neve is Founder.
Simon Bambach is Co-Founder.
Carbyon CEO
Hans de Neve is CEO.