The U.S. Department of Energy awarded $3.2 million to Solar MEAD, a joint project headed by Sandia National Laboratories, CEMEX and Synhelion, which aims to decarbonize cement production by replacing fossil fuels with concentrated solar thermal technology.

The project, known formally as Solar-Thermal Mixed-Media Enhancement and Decarbonization of Clinker Formation, would use concentrated solar thermal energy in clinker production, a key component in cement.

CEMEX and Synhelion have worked to introduce CST in the cement production process, achieving a successful laboratory-scale pilot in 2022. Sandia Laboratories will contribute research facilities as part of the National Solar Thermal Test Facility, along with subject matter expertise to help accelerate the technology’s adaptation to cement manufacturing.

The DOE award was made last fall and announced by CEMEX in mid-February.

Cement clinker is a solid material produced in the manufacture of Portland cement. It is produced by sintering limestone and aluminosilicate materials such as clay during the cement kiln stage. Fossil fuels are typically used to heat the kiln and are responsible for around 40% of direct CO2 emissions from the process.

Synhelion’s technology delivers process heat beyond 1,500 degrees Celsius to produce clinker without using fossil fuels.

Few renewable technologies are capable of generating heat at the temperatures needed to process raw cement feedstock, said Nathan Schroeder, Sandia researcher and principal investigator for the Solar MEAD project. The project is expected to advance understanding of how to use CST to gather and deliver heat to existing cement production facilities. Techniques could be used in other ore processing industries such as refractory, ceramics, and battery production.

The project is designed to investigate methods to reduce carbon dioxide emissions, lower process temperatures, and increase the efficiency of clinker formation using solar energy. The team will assess the conditions to maximize heat transfer to the raw cement mix.

Successful adoption of this technology in cement manufacturing could allow for the replacement of fossil fuels.

Synhelion evolved from the Swiss Federal Institute of Technology in 2016 in a bid to decarbonize the transportation sector. Synhelion is currently building its first industrial solar fuel plant in Germany. The first commercial production facility is planned for commissioning in Spain by 2025. 

Mexico-based CEMEX offers cement, ready-mix concrete, and aggregates in global markets.