Nature-Inspired Solutions for Climate and Sustainability
Inventing a New Circular Carbon Economy via Carbon Capture, Utilization and Sequestration
Direct Air Capture: Sustainable Materials and Manufacturing for Carbon Capture, Usage and Storage (CCUS)
Moisture-Driven Direct Air Capture
Carbon Capture and Storage
Carbon capture and storage (CCS) (or carbon capture and sequestration or carbon control and sequestration) is the process of capturing waste carbon dioxide (CO2) from large point sources, such as fossil fuel power plants, transporting it to a storage site, and depositing it where it will not enter the atmosphere, normally an underground geological formation. The aim is to prevent the release of large quantities of CO2 into the atmosphere (from fossil fuel use in power generation and other industries).
Climate, water, energy, and sustainability are essential for human well-being, poverty reduction, and sustainable development. Global climate change creates critical challenges by increasing temperatures, reducing snowpack, and changing precipitation patterns for water, energy, and food, as well as ecosystem processes at regional scales. Ecosystem services provide life support, goods, and natural resources from water, energy, and food, as well as the environment. However, knowledge gaps are resulting from a lack of conceptual frameworks and practices to interlink major climate change drivers of water resources with the climate-water-energy-food nexus and related ecosystem processes. The Tang group is part of a multinational collaboration aimed at developing materials that decarbonize the atmosphere. Teaming with diverse researchers, we study solid adsorbent materials that capture carbon dioxide from the air or the exhaust streams of industrial processes.
Direct Air Capture (DAC) faces several scientific challenges that hinder its efficiency and scalability. One of the primary obstacles is high energy consumption, as regenerating sorbents to release captured CO₂ requires significant energy, making the overall process costly and less efficient. Additionally, many sorbents suffer from low selectivity and capacity, which limits their ability to efficiently capture CO₂ from the air and reduces the overall effectiveness of the system. The process is further slowed by slow adsorption and desorption kinetics, where the rates at which CO₂ is captured and released are insufficient to support high throughput, restricting the system's potential for large-scale operation. Lastly, air handling and transport challenges complicate the process, as moving large volumes of air through the capture system while maintaining optimal conditions for effective CO₂ removal presents significant logistical and engineering challenges.
To address these scientific challenges in Direct Air Capture (DAC), I have created solid adsorbent polymer materials that capture carbon dioxide from the air or exhaust streams of industrial processes. I developed and integrated diverse cutting-edge atomic-level toolboxes, including multidimensional and multinuclear quantitative solid-state NMR spectroscopy (1D SS-NMR (13CP/MAS, 1H) and 2D SS-NMR (2D Heteronuclear Correlation Spectroscopy-HETCOR, 2D 1H NMR Spin Diffusion)), atomic engineering, Cryo-EM, S/TEM atomic resolution imaging, electron energy loss spectroscopy (EELS), X-ray spectroscopy/microscopy, and synchrotron-XAS/computed micro-tomography/SAXS techniques, density-functional theory (DFT), molecular dynamics simulation, and gas adsorption methods. These tools were used to investigate how polymers adsorb target gas molecules (CO2) with high affinity and selectivity, as well as to reveal the unique interatomic interactions between CO2 and sustainable materials.
Electrochemical CO2 Capture
Redox-Active Materials Enabled Deep Ocean Carbon Dioxide (DOC) Removal:
Electrochemical Marine Carbon Dioxide Removal in Seawater
Carbon Sequestration and Mineralization for a Sustainable Built and Infrastructure Environment
Carbon-Negative Building Materials for Cement and Concrete toward a Greener Construction Industry
Cement is arguably the most crucial material holding the globalized world together, especially in our cities. However, its production requires vast amounts of fossil fuels and is responsible for up to 8% of global greenhouse gas emissions, according to a 2023 study in Nature. Efforts to tackle this issue have historically focused on fuel and efficiency improvements. However, some companies are exploring a promising alternative that could benefit both the environment and the cement industry: creating carbon-negative building materials by storing excess carbon dioxide in concrete. Paebbl, for instance, captures carbon from the atmosphere and combines it with ground olivine rock to produce a rock powder or slurry. This material can serve as an inert industrial filler or an ingredient in building materials like concrete. The process, known as accelerated mineralization, can be completed within an hour and has the potential to reduce the carbon footprint of concrete by up to 70%.
Globally, cement manufacturing is responsible for about 8% of the world's total CO₂ emissions, and under the current trajectory, emissions from this sector could rise to 3.8 billion tonnes per year. Concrete, the second most consumed material on Earth after water, depends heavily on cement as its primary binding agent. To tackle this challenge, it is essential to explore ways to decarbonize cement, transform CO₂ into carbon-negative cement, and generate co-benefits for other industries. One promising approach is to replace traditional cement with byproducts from the energy industry, significantly reducing carbon emissions across various sectors. These alternatives, which are either low-carbon or carbon-negative, often outperform conventional cement in strength and durability, offering a viable pathway for more sustainable construction.
Buildings themselves account for roughly 40% of total energy consumption in the United States. Achieving energy efficiency in this sector demands not only disruptive technologies but also breakthroughs in material innovation. Energy-efficient building materials can dramatically reduce energy usage while reshaping construction practices toward sustainability. Conventional building materials often carry a high embodied carbon footprint and offer minimal capacity for carbon storage. To combat these limitations, we are advancing the knowledge base required to integrate carbon-negative infrastructure materials into construction.
Our research group is dedicated to the design, processing, and characterization of innovative materials reinforced with cementitious composites to create resilient and sustainable built environments. We focus on decarbonizing the built environment and geologic storage of CO2, with particular emphasis on carbon sequestration, mineralization, and the 3D printing of engineered infrastructure and cementitious composites. We are developing cutting-edge atomic-level, multi-modal synthesis and characterization methods. Our work aims to unravel the geochemistry, materials science, multi-scale structures, and intrinsic mechanical properties of material phases within these systems, bridging the gap between the built and natural environments. These efforts establish a strong foundation for designing sustainable, high-performance materials capable of driving a paradigm shift for permanent carbon removal to reach scale in the construction industry.
3D Concrete Printing
