Next frontier: mercury sensors
Software vendors and magazine editors can sometimes be guilty of oversimplification when discussing “compliance.” The one-word shorthand is meant to encompass the wide array of U.S. government regulations aimed at manufacturers and the often-complex rules for complying with them. Luckily for industry, and for the consumers these regulations are trying to protect, engineers and researchers more comfortable with complexity are focusing on the details.
Hank Hogan’s article in this issue (page 68) focuses on cutting the cost of compliance in general, and an online-only news story tells how American Electric Power (AEP) is working to comply with the Environmental Protection Agency’s new Clean Air Mercury Rule (CAMR). Issued in March 2005 and scheduled to take effect in 2009, CAMR seeks to cap and reduce mercury emissions from coal-fired power plants and allow utilities to trade their “excess” reductions. The EPA expects to reduce utilities’ mercury emissions by nearly 70%. What’s still being worked out is exactly what to measure, how to measure it, and what the reporting rules are.
Phil Sawich, senior engineer in charge of AEP’s continuous emission monitoring system project, says more accurate measurement of mercury emissions “means that you can ensure you are in compliance without having to surrender excess allowances.” He says AEP plans to reduce its mercury emissions by 55% by 2010, primarily as a cobenefit of operating selective catalytic reduction systems to reduce nitrogen oxide emissions and flue gas desulfurization systems for removing sulfur dioxide. He also cites continuing development of new devices, such as an oxidized calibrator.
Mercury measurement and control techniques are relatively new, so methods are being investigated elsewhere as well. The U.S. Department of Energy’s Combustion Research Facility is developing a portable, laser-based, short-range system to remotely and noninvasively detect mercury emissions. Also under development is a fiber-based ultraviolet laser for use with a fieldable instrument that can simultaneously detect elemental mercury and mercury compounds.
The EPA’s “cap-and-trade” approach to mercury emissions management depends on an accurate, real-time and ongoing inventory of mercury emitted from smokestacks, per ton of fuel burned. That data is hard to come by. Control Engineering readers and researchers, however, are just the people to figure it out. Be sure to let us know of your progress.