UH physics department researches waste heat
The UH Physics Department and the Texas Center for Superconductivity are getting closer to finding the right material to boost the efficiency in waste heat recovery.
“Some materials can recover some of the heat (wasted in the conversion) into electricity,” said M.D Anderson Chair Zhifeng Ren. “The only problem has been that the materials and the material properties are not good enough (for commercial use). So that is why there is so much research effort in trying to improve the materials, to the point where it economically makes sense.”
Originally, lead telluride was studied for the purpose of improving efficiency in the heat conversion process, but the issues lie in the health repercussions that could arise with real world innovations. However, tin telluride may be a step in the right direction.
“(Tin telluride) can replace lead telluride without the concern of toxic lead if it could have higher ZT (efficiency to produce thermoelectric power),” said research associate Qian Zhang. “In this paper, we increase the ZT significantly. We will continue working on it.”
This research could lead to real-world applications that could economically impact many modern issues. These applications include increasing gas mileage, cooling down car seats faster and helping power plants generate more electricity.
“The only purpose of a car is to get you from point A to point B, but you are really only using about 30 percent of the gas for that purpose,” Ren said. “The reason is because of the burning process involved. There is a lot of heat wasted. For power plants, it is the same thing. You burn coal or oil or whatever, you burn to generate electricity. The overall efficiency is about 40 percent; 60 percent is wasted.”
The goal in Ren’s research is to find a material good enough to be economically efficient and to generate more electricity by wasting less heat in the conversion process. However, the researchers are also working to reduce any potential health risk associated with these materials.
“Current approaches rely on the use of chalcogenides, which contain lead,” said physics department chairman Gemunu Gunaratne. “Researchers in professor Ren’s group have designed a possible replacement for chalcogenides, by ‘doping’ the telluride with indium. Their applications could significantly reduce health hazards caused by lead emissions.”
Ren’s research on waste energy recovery has recently been published in PNA. He has also done research in other areas regarding environmental issues.
“Professor Ren leads one of the world’s leading research programs to design minimally damaging nano-scale materials with desirable feautures,” Gunaratne said. “Examples include ingenious designs used for high efficiency solar energy conversion and water purification.”
Ren and his research group, including Zang, were recruited to UH from Boston University, according to a press release.