The manufacture of Portland cement – the most common type of cement used for structural concrete – presently accounts for roughly 5% of global energy usage and 8% of carbon dioxide greenhouse gas emissions. The current manufacturing process has not changed substantially over the past 140 years, and requires temperatures above 1400 degrees Celsius with heat provided by the combustion of fossil fuels. This Future Manufacturing seed project explores the potential of substituting an electrochemical process for the combustion process, thus opening the door to eco-manufacturing utilizing renewable electricity from sources such as wind and solar energy. The project includes broader elements aimed at preserving U.S. leadership in efficient, low-carbon-emission manufacture of cement while developing a highly-trained workforce skilled in renewable, energy-efficient technologies.
The project will enable future manufacturing of cement by transforming the chemical process of converting calcite (i.e. limestone) to calcium oxide (CaO) via calcium hydroxide (Ca(OH)2) formation, the latter being produced in an electrolyzer rather than direct limestone calcination in a conventional fossil-fuel fired kiln. This approach offers a new, chemical pathway to produce cement with much reduced carbon footprint and energy usage, while enabling the use of electricity from renewable resources. This project will advance knowledge in several different fields, including electrolysis, cement chemistry, advanced manufacturing, and system-level assessment of the economic and environmental impacts of cement industry processes. Specifically, the research efforts will (1) provide fundamental insight into the lower-temperature chemical process of cement manufacturing, (2) assess the scalability of the electrochemical method of value-added products and chemical process of Ca(OH)2 co-production and its overall efficiency, (3) assess and understand the chemical composition, reaction chemistry and resulting properties (mechanical strength and durability) of cement manufactured through this new versus conventional approach, and (4) quantify economic and environmental advantages of this new cement manufacturing process through system-level analysis. Three electrolyzer designs with various redox couples will be investigated to advance knowledge of cement manufacturing and efficiency of co-production of value-added products. Multi-techniques characterization will generate new understandings on the chemistry of the cement synthesis, formation of various phases, efficient separation processes, and resulting composition and properties that are instrumental to construction materials. Educational and outreach activities will focus on training next generation students on renewable manufacturing of cement. A workshop and seminar series will introduce underrepresented minority students and faculty from two-year colleges to industrial stakeholders. In addition, the workshop/seminar series will explore opportunities for collaborative R&D between the academic community, the electrochemical industry, and cement manufacturers.
This project is jointly funded by the Division of Chemical, Bioengineering, Environmental and Transport Systems (CBET), the Division of Chemistry (CHE), and the Division of Undergraduate Education (DUE).
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.
