Anbo Wang, CPT director, and Gary Pickrell, associate director, lead the six-year project, which began in 1999. Wang and his colleagues are developing single-crystal sapphire-based high-temperature sensors that can operate reliably in the high temperature and corrosive environment of integrated gasification and combined cycle (IGCC) plants.
Developed by government and industry under the Clean Coal Technology program, IGCC plants convert coal into electricity. This happens in two ways: by converting the coal into a combustible gas, which generates electricity by powering a gas turbine; and by using the gas turbine exhaust to produce steam to drive a steam turbine, which also generates electricity. This process has been demonstrated to have a high thermal efficiency, with significant reductions in carbon dioxide, nitrogen dioxide, and sulfur emissions. Another advantage of IGCC plants is their ability to make use of a wide range of feedstocks, including coal, biomass, and wood wastes.
Coal gasifiers must be operated at temperatures high enough for the ash in the coal to melt and become fluid, but not so high as to damage the gasifier. In some areas of a coal gasifier the temperature can reach as high as 3500 degrees Fahrenheit. The sensors that CPT will develop with DOE funding will be based on single-crystal sapphire, which has been shown to be an excellent material for such high-temperature applications due to its high melting point, superior transparency, and ability to resist corrosion.
The CPT is a research and education center of the Bradley Department of Electrical and Computer Engineering (www.ee.vt.edu/~photonics/).
For technical information, contact Anbo Wang at (540)231-4355; email awang@vt.edu.
PR CONTACT: Liz Crumbley (540)231-9772 lcrumb@vt.edu