In order to meet the challenge of transitioning to a carbon negative energy economy, the Center for Negative Carbon Emissions (CNCE) focuses on developing the next generation of carbon management technologies. We have demonstrated a moisture swing sorbent cycle for capturing carbon dioxide (CO2) from air. The sorbent, an anionic exchange resin, has been shown to absorb CO2 when it is dry, and to release it again when exposed to moisture. We aim to advance this technology as it applies to closing the carbon cycle with carbon recycling, reducing atmospheric concentration through CO2 disposal, and the economic and policy considerations from its availability. Our interdisciplinary research approach includes:
- Demonstration and development of prototype technologies to close the carbon cycle and create net negative emissions
- Advancement of fundamental sciences supporting this new technology base
- Systems analysis and engineering studies of rapid transition to new energy infrastructures
- Models of the underlying mechanisms within air capture technology
- Study of the interactions of these new technologies with policy development and of the societal implications of these changes
- Analysis to determine the optimal positioning of these technologies to best serve societal needs.
On the lab scale, we can demonstrate the moisture swing’s ability to increase the concentration of CO2 from the amount that is in ambient air, 400 parts per million (ppm) or 0.04%, to an enriched stream of up to 5%. This passive process uses water to release CO2 and relies on evaporation to regenerate the sorbent. Specific projects to demonstrate this phenomenon are:
- Greenhouse in a Glove Box – 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 1000 ppm.
- Automated Shutter-box – 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 carbon dioxide 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.
- Secondary sorbent – For more enriched concentrations (up to almost purity) of CO2, a second step is required. To this end, one possible approach is to store carbon dioxide 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.
Experimentation and Modeling of Sorbent
Experimentation and Modeling of sorbent
Performing experiments and running molecular based models on air capture sorbents allow us to understand and predict the behavior of the membrane and provides the rationale for future design, ultimately maximizing the uptake rate of carbon dioxide.
- Verifying and validating the CO2 transport model – 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 carbon dioxide during this transition phase and the time it takes.
- Molecular dynamics of the Humidity Swing – 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.
Biological Conversion of Carbon Dioxide
Capturing and concentrating carbon dioxide from air for enhanced biological growth has several key advantages including: eliminating transport costs, removing pollutants, enabling carbon neutrality, and 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.
- Atmospheric Capture, Enrichment and Delivery – This project seeks to integrate a system to capture and deliver a desired level of carbon dioxide 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.
Chemical Conversion of Carbon Dioxide
The chemical conversion of carbon dioxide advances our research from CO2 enriched air to purer concentrations that can turn in to a value-added product.
- Sustainable Hydrocarbons, liquid fuels from air and water – This research explores the topic of making liquid fuels from CO2 captured from air to create a feedstock for making liquid fuels through fischer-tropsch process. The high energy density and ability to store and transport liquid hydrocarbons presents a transformative option for a carbon neutral future.
Safe and Permanent Removal of CO2 from Air with Carbonates
Without safe and permanent storage of carbon dioxide, negative emissions are not possible. Our research in this area explores the most effective methods for disposing of carbon dioxide 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.
- Carb-In-Ocean – 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.
- Small scale mineralization – Mineralization is a safe and permanent disposal of carbon dioxide. 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.
- Making oxygen from carbon dioxide on Mars – This project explores the theoretical possibility to create oxygen from carbon dioxide to enable life on Mars. This project is supported by a grant from NASA to support the Mars Oxygen ISRU Experiment (MOXIE).
- Splitting water into oxygen – 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 cost fuels and chemicals. This project a process that can operate at any scale that 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
Graduate Student Research
Please click this link to read about specific projects available for graduate student research.