ECO-CBET: GOALI: CAS-Climate: Expediting Decarbonization of Cement Industry through Integration of CO2 Capture and Conversion

The overall goal of this project is to deliver an innovative, integrated, and adaptable CO2 capture-conversion system to enable decarbonization of the cement industry while producing valuable cement supplements from waste CO2. In transitioning to a net-zero emission and circular economy, waste CO2 in industrial flue gases is considered as a valuable resource for production of a wide range of value-added products. Cutting America’s CO2 emissions in half by 2030 requires investment in industry sectors like cement that cannot shift entirely to carbon-free energy sources just yet. The U.S. is currently producing ~90 million tons of cement every year, emitting nearly the same amount of CO2. If no eco-efficient alternative cements can be invented to completely replace Portland cement, a promising strategy to decarbonize the cement industry in the foreseeable future is to transform Portland cement into blended cement. In this project, the approach is to capture CO2 from cement flue gas and use it as a renewable feedstock to produce blended cement using carbon-negatively processed industrial wastes. The proposed capture-conversion technology will be integrated into a cement production unit, where the CO2 comes from the flue gas of the cooler end of the kiln, and the waste materials and waste heat from the cement plant can be used to run the CO2 conversion process. The project team will explore the fundamental chemistry needed to develop economically viable technology to convert the captured CO2 to blended cement. The fundamental findings at the molecular level (reaction chemistry and sorbent development) will be merged with extensive process modeling, simulation, and design optimization, along with techno-economic analysis (TEA) and rigorous life cycle assessment (LCA) of representative cement manufacturing facilities with and without the integration of the CO2 capture-conversion process. The team will leverage convergence science principles to advance the scientific, technological, and socio-economic knowledge needed to overcome challenges associated with: 1) CO2 capture, 2) CO2 conversion, 3) process systems engineering and integration, and 4) environmental sustainability assessment for expediting the decarbonization of the cement industry. The project has the potential to open new opportunities for achieving net-zero CO2 emissions from the cement industry while producing a valuable cement supplement from waste resources (e.g., alkali industrial wastes such as off-specification coal ashes). Assuming broad technology adoption and replication, potential profitable CO2 emission reductions of >50 Mt/year are projected for U.S., the possibility of which is enhanced by collaboration with the Ash Grove Cement Company. Components of the collaboration with the Ash Grove partner include graduate student summer internships and seminars on CO2 capture-conversion by both University researchers and Ash Grove engineers. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.