SwRI sets new benchmark in high temperature pressure testing for sCO2 turbines

SwRI sets new benchmark in high temperature pressure testing for sCO2 turbines
by Clarence Oxford
Los Angeles CA (SPX) May 21, 2025

Southwest Research Institute (SwRI) has established a new high mark in materials testing by reaching 1,150 degrees Celsius at 300 bar pressure during supercritical carbon dioxide (sCO2) turbine development. This surpasses previous benchmarks and represents the highest recorded temperature and pressure ever published for sCO2 environments.

The achievement stems from a $6.4 million U.S. Department of Energy project initiated in 2020, focused on developing a direct-fired sCO2 oxy-fuel turbine. The effort, led by Senior Research Engineer Michael Marshall and Institute Engineer Dr. Jeff Moore, required advanced testing of materials under severe conditions.

"We evaluated turbine materials at constant temperatures and pressures with 100% sCO2. We assessed the performance of different materials and coatings under extreme conditions," said Dr. Florent Bocher, who directed materials engineering for the project.

Earlier records in the field cited a maximum of 800 degrees Celsius at 300 bar. SwRI's target was to exceed that by 350 degrees to match the operational goals of its turbine. However, traditional designs posed limitations, as vessel materials weaken at elevated temperatures.

To overcome this, SwRI engineered a novel solution by modifying an autoclave. They incorporated an internal induction heating coil while maintaining active external cooling. This configuration enabled the internal chamber to reach 1,150 degrees Celsius while preserving the vessel's pressure integrity.

"The new setup allows us to reach up to 1,150 degrees Celsius at 300 bar, significantly enhancing our capability to conduct tests under extreme conditions," Bocher said. "This advancement provides additional opportunities to support testing of other types of turbine materials."

Beyond sCO2 turbine work, this innovation is poised to benefit other high-demand applications, including molten salt systems, hypersonic technologies, and SwRI's own STEP Demo project-a $170 million, 10-megawatt sCO2 demonstration facility.

"This is a major accomplishment. SwRI's superior capabilities push the boundaries of what's possible in this field," Bocher said. "This new capability is crucial for both current and future research areas and technologies that demand extreme testing conditions."