Korall Carbon Capture (Develop low-cost Direct Air Capture by turning industrial waste into construction materials)

Korall Carbon Capture, a Swedish startup founded in 2024, develops Direct Air Capture (DAC) technology for atmospheric carbon dioxide (CO₂) removal. The company uses industrial waste as the CO₂ capture agent and sequesters CO₂ into carbonate-based compounds, which can be used in construction materials.

(This article contains 2 diagrams and 1137 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.

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 (DAC)

Direct Air Capture (DAC) operates by extracting CO₂ directly from ambient air. Once captured, the CO₂ has two primary applications: it can be stored permanently in deep geological formations, qualifying as CO₂ removal (CDR), or utilized as a carbon source for manufacturing, serving as a climate-neutral feedstock.

The core principle of DAC involves passing ambient air through large-scale facilities equipped with specialized sorbents. These materials are specifically engineered to attract and chemically bind with CO₂ molecules, while allowing other atmospheric gases like nitrogen and oxygen to pass through unimpeded.

Most DAC technologies rely on solid or liquid sorbents. These substances either chemically react with the CO₂ to form solid compounds or dissolve it in a solution. Once the CO₂ is saturated, a regeneration process (typically involving heating or a pressure swing) is initiated to separate and release the captured CO₂ from the sorbent/solvent, preparing it for storage or utilization.

Since the concentration of CO₂ in ambient air is  low compared to high-concentration industrial flue gases, extracting CO₂ from this dilute source is highly energy-intensive. In addition, the regeneration of sorbent in most DAC technology requires a high temperature process. Because of the requirement of significant energy, DAC is currently more expensive per ton of CO₂ removed than many conventional mitigation strategies and natural climate solutions.

Projections indicate that with increased industrialization and scaling, the cost of DAC technology is expected to drop significantly, potentially making it competitive with other solutions in the future.

Korall Carbon Capture Technology

Korall has developed a unique alkaline solution produced from industrial waste for atmospheric CO₂ capture. CO₂ in the air reacts chemically with the alkaline agent, forming a solid carbonate-based compound. That solid is insoluble in the solvent, so it separates easily. Later, the carbonate-based compound can be used as construction materials.

Korall’s CO₂ capture technology reduces the consumption of energy and simultaneously provides a solution for treating and utilizing industrial waste stream, further enhancing the process's economic and environmental efficiency.

How Korall Captures CO₂

The diagram below depicts the system of the Korall DAC technology.