The world’s first commercial supercritical carbon dioxide (SCO2) power generator has begun operation in a steel factory in Guizhou province, China.
The Chaotan One demonstration project comprises two 15MW CO₂ waste-heat power generators, jointly developed by the Nuclear Power Institute of China (NPIC) of the China National Nuclear Corporation (CNNC) and partners.
It is designed to address global technical bottlenecks in the efficient utilisation of medium- and high-temperature heat sources in small to medium power projects.
Source: CNNC
Its commercial operation marks the first move on SCO2 power technology, shifting from laboratory research to commercial deployment.
Compared with conventional waste-heat steam power generation technologies, Chaotan One has said it delivers over 85% higher generation efficiency and more than 50% higher net power output. For over 100 years, power plants have relied on steam for electricity generation.
The project also features a simplified system architecture, reduced equipment requirements, easier operation and maintenance, and a 50% reduction in site needs.
CNNC launched a molten salt energy storage and SCO2 power generation demonstration project in 2024, which is expected to be deployed by 2028.
The main challenges to using SCO2 are material durability, since materials must withstand high temperatures and pressures, and system complexity, dealing with fluctuating temperatures.
SCO2 is used as the working fluid in high-efficiency water heat pumps for domestic and business heating and cooling applications. It is in vogue as an emerging natural refrigerant in novel low-carbon solutions.
Speaking on China Global Television Network, Gong Houjun, Researcher, NPIC and CNNC, said liquid CO2 enters a supercritical state when its temperature is increased to 31°C and 73 atmospheric pressures.
The technology is not new – the US ranked it as the second strategic frontier technology back in 2017 – but it is now starting to make headway across industries.
To read how SCO2 is enabling the move away from chemical solvents in food and beverage manufacturing, click here.