Our Direct Air Capture (DAC) technology does this by pulling in atmospheric air, then through a series of chemical reactions, extracts the carbon dioxide (CO2) from it while returning the rest of the air to the environment. This is what plants and trees do every day as they photosynthesize, except Direct Air Capture technology does it much faster, with a smaller land footprint.
The process starts with an air contactor – a large structure modelled off industrial cooling towers. A giant fan pulls air into this structure, where it passes across thin plastic surfaces that have potassium hydroxide solution flowing over them. This non-toxic solution chemically binds with the CO2 molecules, removing them from the air and trapping them in the liquid solution as a carbonate salt.
The CO2 contained in this carbonate solution is then put through a series of chemical processes to increase its concentration, purify and compress it, so it can be delivered in gas form ready for use or storage. This involves separating the salt out from solution into small pellets in a structure called a pellet reactor, which was adapted from water treatment technology. In this chemical reaction, in addition to precipitating out the calcium carbonate pellets, the original capture chemical to be used in the air contactor is regenerated.
These pellets are then heated in our third step, a calciner, in order to release the CO2 in pure gas form. This step also leaves behind calcium oxide which is mixed with water in the slaker to rehydrate it, and then it is fed back into the pellet reactor, beginning the cycle again.
DAC is most efficiently placed in locations where there is abundant, low-cost renewable energy to power the facility and easy access to sequestration sites to store the captured CO2 (e.g., proximate to existing pipelines and storage sites). Other key location factors include proximity to ports for easy of delivery of construction materials, near sea level for higher air density, at warmer temperatures (i.e., above 5 degrees Celsius) and where large acreage is available to maximize the number of megatonne trains that can be installed in a single location.
DAC can be built on non-arable land, avoiding competition for areas needed to grow food. In addition, water usage is dependent on climate conditions and can be minimized by location flexibility.
Interested in building out DAC projects? Contact our team for more details.
CE is focused on two types of plants.
Direct Air Capture and storage plants deliver the captured atmospheric CO2 to durable forms of storage. There are a number of forms of CO2 storage, but CE’s main focus is to create permanent carbon removal by burying the CO2 deep underground through secure geologic storage.
AIR TO FUELS™ plants combine CE’s Direct Air Capture technology with hydrogen generation and fuel synthesis capabilities to deliver low carbon intensity synthetic fuel.