A Quartz Thermal Trap Harnessed the Sun—and Is About to Change Smelting Forever
"Hearst Magazines and Yahoo may earn commission or revenue on some items through these links."
Many argue that the best way to solve climate change is to build our way out of it with solar panels, wind turbines, and other green technologies.
But those projects require cement and steel—some of the dirtiest industrial materials in the world. Luckily, a new study highlighting a solar-powered thermal trap could help decarbonize the industry.
A thermal receiver built with a quartz shield achieved temperatures beyond 1000 degrees Celsius, exceeding previous efforts and offering a glimpse into cement and steel industries that can finally ditch coal and natural gas.
Fighting against climate change means building, whether that’s large solar arrays, sprawling wind farms, or powerful fission reactors. However, therein lies a problem—smelting the very materials needed for those projects isn’t exactly the most sustainable of enterprises.
Because the industrial processes that creates cement and steel require burning coal or oil, the two industries are some of the biggest CO2 emitters (producing 6.5 percent and 7 percent of global emissions, respectively). There are many ways researchers have investigated possibilities for lowering this carbon footprint, including reinvention of the materials themselves, CO2 storage during the manufacturing process, and lower reliance on these high-cost materials entirely. But a study from researchers at ETH Zurich in Switzerland highlights another approach—just use renewable energy to power the manufacturing process in the first place.
In a paper published last week in the journal Device, the researchers highlighted a new thermal trap technique that uses solar radiation to reach temperatures of 1,050 degrees Celsius (1,922 degrees Fahrenheit). The trap is made from a quartz rod and a ceramic absorber, which effectively transfers the Sun’s radiation to heat. During the experiment, the research team subjected the thermal trap to the energy flux of 136 Suns, and the absorber reached groundbreaking temperatures while the other end of the quartz rod remained a balmy 600 degrees Fahrenheit—successfully demonstrating the material’s heat-trapping effects.
“Previous research has only managed to demonstrate the thermal-trap effect up to 170°C (338°F),” Emiliano Casati, a co-author of the study, said in a press release. “Our research showed that solar thermal trapping works not just at low temperatures, but well above 1,000°C. This is crucial to show its potential for real-world industrial applications.”
But reaching those intense temperatures is only part of the battle—you also have to achieve high-levels of efficiency as well. According to the ETH Zurich researchers, this new solar receiver, encased in quartz, has a much higher efficiency that an unshielded solar receiver. That means it can achieve higher temperatures with less radiation input and maintain a certain temperature with better results.
After crunching the numbers, the researchers discovered that a normal, unshielded receiver has an efficiency of only 40 percent at 1,200 degrees Celsius, which is the equivalent of 500 Suns. The quartz thermal trap operates at 70 percent efficiency—it would take a whopping 1,000 Suns for an unshielded thermal trap to achieve the same performance.
“To tackle climate change, we need to decarbonize energy in general,” Casati said in a press statement. “People tend to only think about electricity as energy, but in fact, about half of the energy is used in the form of heat...solar energy is readily available, and the technology is already here.”
With concrete and steel industries previously seen as particularly tricky to decarbonize, this technology could lead to high-temperature solar plants that don’t rely on planet-choking coal and natural gas to create concrete and steel. This is certainly good news for humanity's ongoing quest toward decarbonization, but the technology is currently only a proof of concept. However, should serve to give us a little bit of hope that what was once considered impossible is now more possible than ever.
You Might Also Like
