Research

MissionDAC unites a diverse team from Northern Arizona University (NAU), ASU and University of Texas at Austin to engage in coordinated fundamental research of CO₂ sorbent materials that release captured CO₂ using moisture (water) rather than energy intensive heat or vacuum pressure. The research will use advanced computer studies ranging from atoms to materials to understand how structural and chemical changes within these materials drive CO₂ capture and release. The models will be informed by advanced experimental techniques using X-rays, electron beams and gas flow systems that reveal how the materials are structurally organized and transport water, ions and carbon species. These investigations will generate a comprehensive knowledge base to enable increasing CO₂ capture capacity, accelerate capture and release kinetics and manufacturable, durable materials. This research also could benefit other energy-related technologies like batteries, fuel cells, and water purification. This project is sponsored by the Department of Energy under award # DE-SC0023343.

ASU’s DAC polymer-enhanced cyanobacterial bioproductivity (AUDACity) project focuses on developing innovative sorbent materials that capture carbon dioxide (CO2) from the atmosphere when dry and deliver it when the material comes into contact with cultivation liquids, thereby enhancing the productivity of cyanobacteria. Cyanobacteria are aquatic, photosynthesizing microorganisms that can be harvested for various valuable products, including food, fuels, fertilizers and biochar. The primary objectives are to engineer cyanobacterial strains for fuel production, creating efficient air-capture materials compatible with cyanobacteria and that resist degradation from the cyanobacteria themselves and nutrients and salts contained within the cultivation liquid, and scaling up CO2 delivery systems for outdoor demonstration in raceway ponds. This transformation of CO2 from a pollutant to a valuable resource adds significant value to the captured CO2. This project is supported by the Department of Energy under award # DE-EE0009274.

The Mechanical Tree™ is a groundbreaking carbon dioxide (CO2) direct air capture (DAC) technology and a pioneering advancement to address climate change. Th first Mechanical Tree ™ in the world was installed by Carbon Collect at ASU, which will enable outdoor, pilot-scale DAC research at ASU CNCE. Natural air flow from wind brings air in contact with specialized materials (sorbents) that remove CO2 without the need for fans or blowers. This passive capture makes the MechanicalTree™ unique by minimizing energy consumption. Once the material has become saturated with CO2, the tree collapses into its “trunk” (right side of figure) where the collected CO2 is removed as concentrated gas for use or permanent storage. Future MechanicalTree™ “farms” will comprise thousands of trees to provide a scalable solution to global climate change mitigation. 

Mineralization is a safe and permanent disposal of CO2. It involves using minerals, such as olivine and serpentine, which contain calcium or magnesium that are reactive toward CO2, and converting them into carbonates. This project is a collaboration between the Arizona Geological Society at the University of Arizona, ASU and Northern Arizona University to evaluate the potential of disposing of CO2 safely within cinder cones (scoria) in Arizona. Researchers will collect samples at several scoria sites, measure reactivity with CO2 and estimate the potential capacity for storing CO2 in Arizona. The team will also evaluate processes that integrate direct air capture (DAC) of CO2 located onsite with the scoria for mineralization and disposal, and engage communities and stakeholders regarding jobs, and business opportunities that could benefit communities nearby the scoria sites. This project is supported by the Department of Energy under award # DE-FE0032252.

This project is investigating fundamental mechanisms of novel sorbent materials that integrate both moisture and thermal swing mechanisms that could increase their capacity for capturing CO2 and reduce energy requirements. The project also is collaborating with Indigenous communities to consider the priorities, values, risks, and burdens of such an emerging technology while also transitioning away from fossil fuels and exploring secondary benefits such as purified water and renewable fuels derived from technology. This project is sponsored by the National Science Foundation under award # 2219247. 

This project is sponsored by SRP (Salt River Project), which is a significant utility company in Arizona with a strong commitment to sustainability, particularly in reducing emissions. ASU CNCE has a long-standing partnership with SRP, which helped develop novel technologies that capture CO2 directly from passive wind flows. This project will design a system that utilizes the heat generated as water is absorbed onto moisture-driven CO2 sorbent materials that further enhances the CO2 release process and can be used to generate heat onsite for other purposes (e.g., water purification, energy production). This approach will allow us to design a comprehensive direct air capture (DAC) system that accounts for local environmental conditions and provide SRP with a powerful tool to combat climate change while advancing clean technology.

SAPDAC (Strategic Approach for Passive Direct Air Capture) is designing three carbon farms across three distinct climates (hot dry, hot humid and cool dry) in the US, each utilizing innovative ‘Carbon Trees’ systems, similar to the Pilot plant located at ASU. The farms will capture, separate, and either store or convert 1,000 metric tons of CO2 daily at each site. This initiative represents a crucial step toward the commercialization of a technology that has the potential to revolutionize our carbon balance on a global scale. With the ability to help meet the world’s carbon budget, facilitate the essential drawdown for limiting global warming to 1.5℃, and provide the carbon needed for synthetic fuels and chemicals, SAPDAC is at the forefront of impactful climate solutions. This project is supported U.S. Department of Energy’s National Energy Technology Laboratory, Office of Fossil Energy and Carbon Management, under Award Number DE-FOA-0002402.

Industries seeking to offset emissions can acquire ‘carbon credits.’ However, the existing carbon markets are plagued by issues like unverifiable claims, fraud, greenwashing, and conflicts of interest, making it essential to establish comprehensive rules for effective certification. The Carbon Removal Certification Project addresses this critical need by focusing on certification processes, potential outcomes, and requirements, with a goal to standardize carbon markets and the removal or sequestration of CO2. The project delves into critical aspects, including accounting methods, storage duration, re-release risk, and safeguards, while also examining the potential for unintentional emissions during the carbon removal process. The growing carbon offset market, with approximately 80% of the world’s emissions falling under carbon neutrality plans that rely on credits, highlights the urgency of this initiative to ensure a transparent and impactful carbon market.

By feeding a plant water and artificial sunlight in an enclosed environment, we can measure the plant’s photosynthesis of CO₂ and maintain a higher moisture content. Continuously adding the sorbent material into the glove box allows us to demonstrate the ability to maintain CO₂ -enriched air of up to 1,000 ppm.

The CNCE develops and utilizes diverse sorbent materials for capturing carbon dioxide (CO₂) directly from the atmosphere and has a comprehensive suite of custom and commercial test equipment for studying fundamentals performance characteristics from the milligram to kilogram scale, using thermal, vacuum, moisture or hybrid swings, including open and close loop setups and a 561 L wind tunnel. Ongoing research aims to enhance standard sorbent characterization, create representative models, and optimize sorbent designs, with insights guiding scalable manufacturing and improving economic feasibility.

This project is a modular and automated approach to capture and generate a stream of CO₂-enriched air using the moisture swing. There are two moving panels: one to capture CO₂, and another to release it into a compartment. Stay tuned for the next generation of this unit, which will be operating outside, continuously providing live data.

For more enriched concentrations (up to almost purity) of CO₂, a second step is required. To this end, one possible approach is to store CO₂ in a carbonate/bicarbonate medium that enables further purification. This project is part of a collaboration with Électricité de France and Columbia University that links closely to the prototype units which will be increasing in scale.

Performing experiments and running molecular-based models on air capture sorbents allow us to understand and predict the behavior of the membrane. This provides the rationale for future design, ultimately maximizing the uptake rate of CO₂.

The CO₂ transport model is a theoretical model which shows the movement of CO₂ in the resin from the dry to wet state as a membrane pump. Verifying and validating this theory involves studying and quantifying the concentration levels of CO₂ during this transition phase, and the time utilized.

In this project, we model and test the reactions of the sorbent at a nano scale to understand how water on the resin governs the interactions between all the ions on the resin. These tests lead to the development of a novel efficient nano-structural CO₂ capture absorbent, driven by low-cost water.   Capturing and concentrating CO₂ from air for enhanced biological growth has several key advantages, including:  

• Eliminating transport costs.
• Removing pollutants.
• Enabling carbon neutrality.
• Scaling to need.

  As we scale up prototypes to remove CO₂ from air, these efforts will optimize for automation, mass production, regeneration of sorbent material, temporary storage and transport media and monitoring of loading states.

This project seeks to integrate a system to capture and deliver a desired level of CO₂ to feed to invigorate micro algae growth for fuels or high-value products. This project is supported by the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy Targeted Algal Biofuels and Bioproducts program under Award Number DE-EE0007093.

The chemical conversion of CO₂ advances our research from CO₂-enriched air to purer concentrations that can turn into a value-added product.

This research explores the topic of making liquid fuels from CO₂ captured from air to create a feedstock for making liquid fuels through the fischer-tropsch process. The high energy density and ability to store and transport liquid hydrocarbons presents a transformative option for a carbon-neutral future.

Without safe and permanent storage of CO₂, negative emissions are not possible. Our research in this area explores the most effective methods for disposing of CO₂ captured from air through transferring the gas into a carbonate. Given the siting challenges posed to carbon storage from public opposition, geologic favorability, and potential infrastructure costs, capturing CO₂ from air for storage permits high degrees of flexibility.

This research explores the reactions of CO₂ in salt water to determine the safety and sequestration of potentially storing CO₂ from air in the oceans. Saline water can also be an advantageous transfer medium to further inform design decisions that require storage buffers.

Mineralization is a safe and permanent disposal of CO₂. It involves using minerals, such as olivine and serpentine, which is a mineral of magnesium silicate, and converting it into carbonates. Because air capture is, by nature, small in relation to carbon capture and storage, which injects CO₂ underground, this approach looks at minerals that exist in abundance to carbonate ex-situ.

Oxygen is a valuable and life-enabling gas. We apply our expertise and interest in modular systems and scaling laws to develop projects that can scale rapidly from mass manufacturing and automation.

This project explores the theoretical possibility to create oxygen from CO₂ to enable life on Mars. This project is supported by a grant from NASA to support the Mars Oxygen ISRU Experiment.

Innovative air separation systems that can reduce the cost of oxygen at all scales will create many more new opportunities for cleaner energy and lower-priced fuels and chemicals. This project is a process that can operate at any scale and can be used to split water molecules into oxygen and harmless gases. Our research focuses on developing noble metal coatings for niobium membranes that minimally interfere with hydrogen transport, but effectively prevent oxidation by air and/or water.