Technology
TerraFixing's Key to Affordable and Scalable Direct Air Capture
Lowest Cost, IP Protected, Proven, & Validated
At TerraFixing, we are distinctive in our strategy to capture, concentrate, and permanently store CO2 with a mission to reach net zero and going beyond. We use a unique adsorption based process using readily available industrial materials, and by placing our process in desirable cold dry climates, we can achieve the lowest operating and capital costs in the DAC industry. The working material of our process are zeolites, which are inexpensive, industrially available, robust, and highly effective at capturing CO2 from the air. Zeolites are supermaterials with surface areas of over 800 m²/g and work via adsorption whereby the CO2 is selectively captured on the surface. We employ our proprietary zeolites in a temperature vacuum swing adsorption cycle where CO2 is captured at environmental conditions and then isolated with temperature and a vacuum at high purities for durable storage. This process is simple; with only 5 unit operations and operating energies as low as 1 MWh/tCO2 in cold dry climates, we can achieve the lowest capital and operating costs for DAC.
Simple process with readily available industrial materials
Our technology uses a 5-step temperature vacuum swing adsorption (TVSA) cycle that captures the CO2 from the air, purifies it, and yields high purity CO2. The working materials, zeolites, have been proven over 20 years in industry for similar air pre-purification separations, and our proprietary zeolites are ideally suited for DAC. Zeolites are already commercially available allowing us to scale to gigatonne capture today. Finally, we've designed a simple process needing only 5 unit operations to capture and concentrate the CO2 compared to competitors which need 9-22 unit operations - this reduces our CAPEX significantly.
TerraFixing's Fundamental Technological Advantage
At TerraFixing, we have a technological advantage that will enable us to offer the lowest $/tCO2 in the DAC space. Our technology uses adsorbents that physically adsorb the CO2 quickly, with very high CO2 loadings in cold climates. These fast kinetics combined with our simple process that takes advantage of commercially available industrial materials, allows for low CAPEX and OPEX.
Separation are thermodynamically more efficient in cold climates
This figure shows the minimum work required (i.e., energy) to capture and concentrate CO2 from a feed stream at a particular concentration - for air, that's 420 parts-per-million (ppm). The equation at the top, derived from the second law of thermodynamics, demonstrates that temperature (T) impacts the minimum work (Wmin) required to separate and concentrate CO2 to 100%. As the temperature decreases, Wmin decreases substantially. For example, the minimum work required is 45% lower at -50°C relative to 50°C. Therefore, a DAC plant operating in cold climates has a thermodynamic advantage over a process happening in a comfy warm climate. Adsorbents like TerraFixing's zeolites (trade secret!) are able to operate in these cold climates and take advantage of easier CO2 separations from air. Amines and hydroxyl solutions physically cannot operate in freezing conditions and can therefore not take advantage of these fundamental thermodynamic principles.
Zeolites are the ideal DAC materials: Higher CO2 capacity and lower CO2 heat of sorption
When considering some key metrics for sorbents, having a low CO2 heat of sorption and a high CO2 sorption capacity at 420ppm are desired. Having a low CO2 heat of sorption is advantageous because it reduces the energy required to regenerate the sorbent. For instance, the material that Heirloom uses, CaO, has a high heat of sorption that requires 1.13 MWh/tCO2 just to break the CO2-CaO bond. TerraFixing's zeolite requires just 0.28 MWh/tCO2. This energy is also 2/5ths of that of Climeworks & Global Thermostat's sorbents which are amines (MEA & TRI-PE). In addition, TerraFixing's zeolites, in cold conditions, have the highest sorption capacity, meaning that they can adsorb more CO2 for the same mass of material. This translates into CAPEX saving and energy savings, allowing our technology to have the lowest DAC energy requirements, around 1 MWh/tCO2 in favourable climates.
Zeolites are the ideal DAC materials: Faster rate constant and lower CO2 heat of sorption
Another key metric for a DAC process is the kinetics of how fast the CO2 reacts or uptakes into the sorbent, which is known as CO2 rate constant. Slow kinetics equals larger equipment and/or slower cycle times, thereby increasing the CAPEX. Traditional DAC materials like Carbon Engineering's hydroxyl solutions or Climeworks' amines either have a moderate sorption enthalpy, or fast sorption rate - and companies using CaO (like Heirloom) have neither. TerraFixing's zeolite however, has both a fast sorption rate as well as moderate sorption enthalpy which fits into the ideal material zone. This ideal material zone was highlighted in 2011 by the DAC community in the APS report with committee members including Jennifer Wilcox, Peter Eisenberger (Global Thermostat), David Keith (Carbon Engineering), Klaus Lackner, and 30 other renown academics.
Ideal Location Advantage
Ideal Locations
At TerraFixing, we locate our DAC plants in cold dry climates like Canada, Norway, Alaska, Russia, Finland, Greenland, and Antarctica which have optimum conditions for our process. We also ensure that we are located next to clean cheap abundant energy sources as well as a sequestration site to allow us to capture the CO2 for the lowest $/tCO2. This formula will allow our technology to outcompete other DAC technologies and offer the most affordable DAC.
Unlimited Scalability
Our modular units and integration with renewable energy gives us a scalability advantage. The locations that we place our technology will accommodate nearly unlimited scalability without NIMBYism, and without significantly effecting flora and fauna.