Georgetown Researchers Aim to Clean Up U.S. Cement Production with Policy Solutions for Technological Upgrades

A team of Georgetown researchers from across disciplines are collaborating to investigate a set of technology solutions and policy proposals that can drastically reduce the cement industry’s carbon footprint. The lead researcher, Ankita Gangotra, a postdoctoral fellow, has been working with  Emanuela Del Gado, a professor in the Department of Physics, and Joanna I. Lewis, a professor in the School of Foreign Service and director of the Science, Technology and International Affairs (STIA) program. Gangotra’s position is the first postdoctoral fellowship at Georgetown to span the Physics Department and the School of Foreign Service.

Cement manufacturing in the United States, on average, creates more CO₂  emissions per ton than in peer nations. Despite an 18% reduction in CO₂ emissions intensity since 1990, American CO₂ emissions per ton of cement are 20-30% higher than in China, India and the European Union. That’s a huge problem, compounded by both the demand for cement and anticipated growth in population. Currently, cement and concrete are the second-most used resource in the world – behind only water. Due to population increases and continued urbanization, global demand for cement is expected to nearly double by 2060. 

“There’s a lot of potential within the United States,” says Gangotra. “To upgrade our technologies. To make them greener and bolster the cement sector, making it more competitive within domestic and international markets as demand for low-carbon products rises.”

While there’s exciting theoretical work being done on new and greener cements, Gangotra’s team is proposing near-term adaptations that are already widely used in the rest of the world. 

Material Substitution

To slash carbon emissions, the team has focused on increasing the production of blended cements in the United States. Around 83% of cement CO₂ emissions come from the production of clinker, the main binding agent in cement. Reducing the total amount of clinker and substituting it with other materials produces less pollution and reduces the carbon footprint of the entire cement production process. The average clinker content in the cement produced in the United States is 88% compared to 64-76% in China, India and the European Union. For Gangotra and her team, substituting clinker is a simple step with a relatively low cost. 

Energy Efficiency 

Thermal and electrical energy make up, respectively, 40% and 10% of cement CO₂ emissions. Generally speaking, thermal energy is needed to heat up the raw materials during the production process and electrical energy is needed to transform those materials through crushing and blending. Given that the average age of a cement manufacturing facility in the United States is older than those in peer countries, especially India and China, upgrading facilities could reduce CO₂ emissions through combined thermal and electrical efficiency. 

“Just deploying these basic technologies, to bring us on par with the other major cement producing parts of the world, could enable the United States to have a significant one-time CO₂ emissions reduction from annual domestic cement production,” Gangotra says.

To achieve substantial change in the cement industry, Gangotra’s team has analyzed multiple policy levers, including performance standards, financial incentives, government procurement policies and sectoral agreements that should be implemented. While the team acknowledges that creating political change in the United States isn’t easy, it may be immediately feasible and can provide considerable near-term benefits.. 

In March, Gangotra will present her team’s work at the 2022 American Physical Society Meeting. A paper on this research is currently under review.