6-12-08

Mercury Monitoring Webinar reflects both Uncertainties and Progress

There are some State regulations for mercury monitoring of coal-fired power plants but with the elimination of CAMR there is a big void in terms of monitoring method validation as well as clarity on the need. Expert speakers from major supply companies were able to add what clarity there is to this confusing situation.

Biographies and pictures are shown at Bios and Photos

Karl Wilber of Tekran described the “book end” analysis. The left book end is a CAMR replacement which could be months away but at least is possible in the near term. There could be lots of books in between but the right book end is MACT type regulation. In the meantime states are driving the mercury monitoring requirements.

Jim Downey of McIlvaine asked Karl about delays or cancellations of any of the 120 monitoring systems which Tekran has sold. Karl said only a few have delayed using the systems but did take possession of the instruments. Jim says that in his phone calling some of the utilities which had not ordered monitors are now waiting rather than moving ahead as originally planned.

Karl talked about the advantages of independent inlet Hg and stack monitoring systems to provide the process control of the activated carbon. He pointed out that with $125,000 additional investment the benefit could be some percentage of $1 million/yr spent for carbon.

Forty-five of the 120 systems have completed RATAs with many results within 10 percent. If MACT becomes 94 percent reduction as in the case of PA, the measurement requirement may be as low as 0.1 ug/m³.

Jim Wright of Clean Air Engineering (CAE) talked about sorbent traps and the 50 systems which CAE has provided. Sorbent traps are only half the cost of CEMS and the operating costs are possibly lower rather than higher. So far data is being manually integrated with the plant operating systems but there are opportunities for more DAHS integration. Weekly trap changes are proving desirable.

Jeremy Whorton of ThermoFisher covered the lessons learned in certification preparations for mercury CEMS. The talk was based on a joint paper with Cave Darnell of NPPD which was presented at the CEM User Conference. Sheldon 1 is 120 MW and 2 is 135 MW. Pulse Jet baghouses were added in 2000. Hot side precipitators were de-energized but are still in the gas stream to capture large particles. The existence of this precipitator is thought to be a factor in mercury stack concentration variations from 0.9 ug/m³ to 2.4 ug/m³. The method 30B QA is very specific to the initial concentration values when choosing sampling parameters. So big variations present a challenge.

Ravi Narayan of Cemtrex talked about their mercury monitor which has been used extensively in industrial applications but is now just being applied to coal fired stacks. The monitor was successfully used at the Valmy Station to check the performance of the “REACT” system. Outlet emissions are 0-0.1 ug/m³, so the unit demonstrated its ability to measure at low levels. Cement and other applications have higher mercury levels than does coal.

You can go directly to the power points in the Mercury Decision Tree as follows:

Karl Wilber - Tekran

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