As global momentum accelerates toward net-zero targets, it’s clear that reducing emissions alone won’t be enough. To curb climate change, we must also remove existing carbon dioxide (CO₂) from the atmosphere, especially the legacy emissions accumulated over decades. That’s where Direct Air Capture (DAC) comes in, which can also feed the ongoing clean fuels production revolution..
DAC is no longer an experimental technology. It’s emerging as a critical player in the suite of Carbon Dioxide Removal (CDR) solutions supported by the Intergovernmental Panel on Climate Change (IPCC) and the International Energy Agency (IEA). Unlike traditional carbon capture, which is tied to point-source emitters like power plants, DAC captures CO₂ directly from the air—making it location-flexible and able to address diffuse emissions. That flexibility allows it to be deployed near renewable energy sources or CO₂ storage sites, cutting transportation costs and improving efficiency.
From Clean Air to Clean Fuel
One of the most promising applications of captured CO₂ is its use in synthetic fuel production—particularly Sustainable Aviation Fuel (SAF). When CO₂ from DAC is combined with hydrogen through a process known as Power-to-Liquids (PtL), the result is a carbon-neutral fuel. The hydrogen can be sourced cleanly from waste methane (CH₄) using methods like methane pyrolysis or steam methane reforming (SMR), which split CH₄ into hydrogen (H₂) and solid carbon (C). This opens the door to new, cleaner fuel pathways for hard-to-decarbonize sectors like aviation and shipping.
There’s a strong connection here to geothermal energy—an area I recently wrote about—because methane is often a byproduct of geothermal drilling. With the proper setup, DAC and geothermal can work in tandem to produce both clean power and clean fuel.
Two Leading DAC Approaches
Several technical approaches are evolving, but two methods have seen the most commercial traction:
- Liquid Solvent DAC (L-DAC): This method passes air through a liquid solution (often potassium hydroxide), which binds with CO₂ to form carbonate pellets. These are then heated—between 300°C and 900°C—to release the concentrated CO₂. L-DAC is proven to handle large air volumes but is energy-intensive and involves solvent degradation risks.
- Solid Sorbent DAC (S-DAC): Instead of a liquid, this method uses materials like amines or zeolites to absorb CO₂. When heated to just 80°C–120°C (or vacuumed), the CO₂ is released. S-DAC typically requires less energy and can be scaled modularly, though it may capture less CO₂ per unit and requires sorbent maintenance over time.
Other experimental technologies are also in development—such as using ultra-fine mist to bind with CO₂ midair, forming pellets that can be collected and reused. Spray technologies have become very impressive in recent years. Particle size and flow rate are critical parameters for this to work, plus it needs a lot of power, which is a significant cost contributing to its price.
What’s Holding DAC Back?
Despite its promise, DAC remains expensive. Current costs range from $250 to over $1,000 per ton of CO₂ captured, and the energy input required is significant. Scaling the infrastructure for CO₂ capture, transportation, and storage will require substantial investment.
However, innovation is moving fast. Researchers are working on advanced sorbents, low-temperature regeneration methods, and electrified processes. With government incentives like the U.S. Inflation Reduction Act, the EU Green Deal, and increasing corporate investment, DAC deployment is expected to grow substantially over the next decade.
A Circular Carbon Future
DAC isn’t just about cleaning the atmosphere. It’s about creating a circular carbon economy—where CO₂ isn’t just captured and buried but reused to produce fuels and materials, closing the loop. This approach is especially attractive for industries with few decarbonization options and where renewable electricity isn’t yet a viable solution.
Final Thoughts
Direct Air Capture represents a major leap forward in our ability to reverse carbon buildup. While there’s still work to do—especially in lowering costs and energy use—the foundation is strong. With continued innovation, policy support, and cross-sector collaboration, DAC could soon become a cornerstone of climate strategy and fuel transformation.
If you’re exploring the future of DAC, clean fuels, or the intersection of carbon capture and geothermal innovation, I’d love to connect. I’m especially interested in hearing from leaders in clean energy, infrastructure, and emerging technologies who are navigating similar challenges or opportunities. Let’s exchange insights and explore where this evolving space might take us.