The photo is sourced from climeworks.com
Each collector is a kind of box equipped with a filter and a fan: the fan extracts carbon dioxide from the ambient air, after which carbon dioxide gets absorbed by the filter. Once the filter is completely saturated, the box is closed and heated to 100 degrees Celsius using waste heat from the nearby geothermal unit, which results in the desorption of carbon dioxide. At the final stage, carbon dioxide is mixed with geothermal water and pumped into the ground, where through the process of mineralisation it reacts with basalt rock and gradually turns into carbonates, i.e., carbonic acid salts. This makes it possible to safely store CO2 for centuries.
Once all 72 collectors are operational, the Mammoth project will become the world’s largest site for direct air capture. Earlier, a similar site was built as part of the Orca project, which was also implemented through the efforts of Climeworks, but its capacity is ten times less than that of Mammoth. Return on investment will likely be achieved through the resale of so-called carbon credits, the value of which will be directly proportional to the amount of CO2 captured as part of the Mammoth project. Carbon credits will be purchased by major emitters of CO2, including steel and cement producers, which will use them to improve their non-financial reporting indicators.
S&P Global Platts estimates that the cost of carbon credits for DAC projects is between $300 and $2,000 per ton, a multiple of current stock exchange prices for carbon dioxide in Europe. However, DAC projects tend to be quite costly: the operating costs for capturing one ton of CO2 using DAC units range from $400 to $700, while those of CCS projects, which involve the absorption of carbon dioxide from flue gases of power plants and industrial enterprises, range between $50 and $250 per ton.
