Susteon Inc., with project management from NETL, is working to develop and deploy direct air capture (DAC) technologies by conducting fundamental research and bench-scale testing of new materials and processes that could result in integrated systems capable of continuous atmospheric carbon dioxide (CO₂) capture and conversion to valuable products.

DAC technologies can reduce legacy CO₂ pollution by removing it directly from the atmosphere and can counter-balance emissions from hard-to-abate sectors such as aviation and shipping, among others. Susteon’s DAC work, which spans five projects funded by the U.S. Department of Energy (DOE), supports the Department’s Carbon Negative Shot target of reducing the cost of capturing and storing CO₂ at gigaton scales to less than $100 per net metric ton of carbon dioxide equivalent.     

Susteon’s first project, which was funded by a Small Business Innovation Research grant, laid the ground work for its process and materials breakthroughs by developing dual function materials (DFMs) for both CO₂ capture and conversion to valuable products. The DFMs were originally developed for treating flue gas from large point sources, but the project team optimized them for DAC applications. The DFM porous solid material, consisting of a novel combination of an adsorbent and a catalyst, demonstrated high CO₂ capacity under DAC conditions and even greater capacity in the presence of atmospheric moisture in laboratory experiments.

Building from this work, Susteon embarked on a project that developed a novel DAC technology using high-capacity structured sorbents. This project focused on addressing key challenges for practical DAC implementation, such as increasing CO₂ capacity and absorption rates, developing a process for structured supports, and creating a bench-scale testing unit. The successful completion of this project resulted in a validated process model and crucial engineering data for future scale-up.

The project team has since turned its attention to scaling up continuous operation to an integrated bench-scale system. This work is designed to demonstrate the continuous operation of Susteon’s DAC technology under real-world conditions, utilizing ambient air and accounting for varying climate conditions. The focus on optimizing the structured material assembly performance for CO₂ production highlights the crucial link between technological advancement and economic viability. This research effort is still ongoing.

While scaling up the integrated system, Susteon continues to refine the core component of its technology — the high-capacity structured sorbents. This project emphasizes the critical role of sorbent optimization in achieving the cost targets set by the Carbon Negative Shot. The development and rigorous testing of novel sorbents and structured form factors represents continuous improvement for the technology. The exploration of various regeneration options, including steam and Joule heating, further demonstrates the comprehensive nature of their approach.

The project team is also focusing on using CO₂ captured from DAC along with carbon-free hydrogen production to create a carbon-negative methanol production system. Methanol is an important renewable fuel source, and this project exemplifies Susteon’s vision of a circular carbon economy, where captured CO₂ is transformed into valuable products. The development of a detailed process model, incorporating various subsystems, highlights the complexity and innovation driving this project.

Susteon’s interconnected projects represent a strategic and comprehensive approach to DAC development, clearly aligning with the goals of DOE’s Carbon Negative Shot. The progression from fundamental research to integrated systems demonstrates a commitment to both scientific rigor and practical application. By tackling key challenges such as sorbent optimization, process design and cost reduction, NETL is enabling companies like Susteon to pave the way for a future where DAC plays a pivotal role in mitigating climate change.

NETL is a U.S. Department of Energy national laboratory that drives innovation and delivers solutions for a clean and secure energy future. By leveraging its highly skilled innovators and state-of-the-art research facilities, NETL is advancing carbon management and resource sustainability technologies to enable environmental sustainability for all Americans.