At CE, we have been developing our direct air capture technology since 2009. We have 8 core patent families, and we have proven the technology with a full end-to-end pilot plant.
We have built our direct air capture (DAC) technology upon established chemical processing industry equipment and techniques, augmented by our own innovations and IP throughout. Our DAC system has four major unit operations that comprise a closed chemical loop, which continuously captures CO2 from atmospheric air, and delivers a purified compressed stream of CO2, using only water and energy as inputs.
Our DAC process starts with a “wet scrubbing” air contactor which uses a strong hydroxide solution to capture CO2 and convert it into carbonate. This occurs within an air contactor structure modelled on industrial cooling tower design, which effectively contains the liquid hydroxide solution. Our second step is called a “pellet reactor” which precipitates small pellets of calcium carbonate from the aqueous carbonate solution. This calcium carbonate, once dried, is then processed in our third step, a circulating fluid bed calciner, which heats it to decomposition temperature, breaking it apart into CO2 and residual calcium oxide. The calcium oxide is hydrated with our make-up water stream in our fourth step, called a slaker, and is returned into the pellet reactor to precipitate calcium carbonate, and close the chemical loop.
In our baseline design, our calciner is heated by oxy-fired natural gas, so that the calciner contains CO2 originally captured from air and liberated by the pellets, CO2 from natural gas combustion, and water vapour. This gas stream is sent for clean up, compression, and water knock-out, in order to produce a stream of pure CO2. This configuration avoids emission of CO2 from natural gas usage, and we also have technical variants that reduce or eliminate natural gas requirements by substituting biogas or clean electricity.
More process details are available in our papers and publications, but this overall DAC approach pairs a wet scrubbing air contactor with a calcium re-generation cycle similar to what is used by the pulp and paper industry. The industrial precedent behind our choices of equipment and process chemistry means that we have a scaleable, low-risk air capture technology that is now ready for commercial deployment.
As we move to commercialization, we envision industrial-scale air capture facilities, sited outside of cities and on non-agricultural land, that supply CO2 for fuel synthesis, and eventually for direct sequestration to compensate for emissions that are too challenging or costly to eliminate at source. At this large scale, our technology will be able to achieve costs of $100-150 USD per tonne of CO2 captured, purified, and compressed to 150 bar.