Hot Topic Hour March 15 had new insights on Mercury Measurement and Control

The Hot Topic Hour on Thursday was about new ways to control mercury and to measure it. Sorbent traps were discussed as an alternative to CEMS. Three alternatives to activated carbon were claimed to be more cost effective.

Jim Wright, Director of Source Testing Mercury at Clean Air Engineering, Inc., discussed mercury measurement, specifically continuous monitoring at very low levels using sorbent trap technology. The sorbent trap can accurately measure very low mercury levels. It may be the only way to accurately measure at the levels mandated by New Source Performance Standards (NSPS).  A number of sorbent trap systems are operating in states which now require monitoring. Utilities are replacing the traps themselves. Thus the operating costs are comparable to CEMS. The disadvantage is lack of process control. You only find out the results every hundred hours. But this device could be coupled with a CEMS if process control is also needed. The CEMS could be configured just for process intelligence without constraints about operation for compliance demonstration. 

John Darrow, Associate, and Jeff Kolde of the Mercury Control Technology Team at W. L. Gore & Associates, Inc. described a new fixed-bed sorbent technology for controlling mercury emissions from combustion applications. This “end-of-pipe” solution provides a simple and effective way to continuously capture both elemental and oxidized mercury from flue gas streams for typically several years at a time without requiring regeneration. Drawbacks of activated carbon injection such as flyash contamination and interference by SO₃ are completely avoided.  In addition to very high mercury removal efficiency, SO_x emissions are reduced as a co-benefit.  Cost comparisons to activated carbon were provided. The Gore approach showed economic advantages in several cases analyzed. It appears to also be attractive as an add-on technology in case higher efficiencies are needed in the future. If a power plant is installing an FGD system, it can leave additional height above the mist eliminator for eventual installation of the Gore modules.

Bobby IT. Chen, Client Program Manager of Integrated Emissions Solutions at Shaw Environmental & Infrastructure Group, presented some very up-to-date information on the control of mercury from power plants burning lignite coal using a special brominated compound. He advised participants that

• EMO™ injection successfully demonstrated Hg compliance to the final EPA EGU MACT (>90% plus stack Hg oxidization and Hg removal efficiency)
• EMO™ yielded no impact to the stack particulate and HCl emissions
• EMO™ injection does not create flyash disposal problems (No metal leaching issues observed)
• Some applications require a combination of EMO and PAC for efficient Hg control and to be cost-effective.

Marc Sylvester, Vice-president for Sales at Midwest Energy Emissions Corp (ME2C), discussed control of mercury emissions from major utility and industrial boilers utilizing patented technologies. ME2C has worked closely with the Energy & Environmental Research Center (EERC) at the University of North Dakota to develop and deploy cost effective mercury control technologies in the world.  The technology combines enhancement additives with sorbents at two injection points. Details on performance at a 700 MW power plant were provided. 90 percent capture was achieved with enhancement additives of 0.3 lb/MACFM and sorbent of 1.2 lb /MACFM. Brominated activated carbon was only able to obtain 80 percent capture at 3.2 lb/MACFM. Another difference was that ME2C had no impact on flyash sales whereas the brominated activated carbon created an unsalable flyash.

The Bio and Abstract information is linked below.
BIOS, ABSTRACTS, PHOTOS - MARCH 15, 2012.htm