ETH Zurich Experts Develop Thermal Trap to Absorb Concentrated Sunlight, Generating Extreme Heat for Production
The production processes for cement, metals, and various chemical products require extremely high temperatures, exceeding 1,000 degrees Celsius. Currently, this temperature is typically achieved by burning fossil fuels such as coal or natural gas, resulting in significant greenhouse gas emissions. Utilizing renewable electricity is not a suitable alternative as it is inefficient at such high temperatures.
A team of scientists at the Swiss Federal Institute of Technology Zurich (ETH Zurich) has developed a method that allows these industries to reduce their reliance on fossil fuels, which has already been validated in laboratory settings, as reported by SciTechDaily on May 28. The new research was published in the journal Device.
The main component of the thermal trap consists of a quartz tube, achieving a temperature of 1,050 degrees Celsius during experiments and glowing. (Photo: ETH Zurich/Emiliano Casati)
Using solar radiation, the research team led by scientist Emiliano Casati and Professor Aldo Steinfeld developed a thermal trap capable of providing the extremely high temperatures necessary for production processes. The device includes a quartz tube connected to a ceramic absorber. Thanks to its optical properties, this absorber can efficiently capture sunlight and convert it into heat.
In laboratory experiments, the research team utilized a 30 cm long quartz tube with a diameter of 7.5 cm. They exposed this tube to artificial light with an intensity 135 times that of sunlight, reaching temperatures of up to 1,050 degrees Celsius. Previous research by other groups had only achieved a maximum temperature of 170 degrees Celsius with similar thermal traps.
Industrial-scale concentrated solar power systems have been established to produce solar electricity in various locations such as Spain, the United States, and China. They typically operate at maximum temperatures of 600 degrees Celsius. At higher temperatures, thermal losses due to radiation increase, reducing plant efficiency. A significant advantage of the thermal trap developed by the ETH Zurich experts is its ability to minimize radiative heat loss.
“Our approach significantly improves the efficiency of solar energy absorption. Therefore, we are confident that this technology will help promote the deployment of high-temperature solar power plants,” Casati stated. However, he noted that further detailed economic and technological analyses are still needed.
Casati is continuing his research to optimize the process. In the future, this technology could enable the use of solar energy not just for electricity generation but also for large-scale carbon reduction in energy-intensive industries. “To combat climate change, we need to decarbonize energy in general,” Casati commented.
