Subject: Solutions to mercury and condensibles measurement and control

Base Condensibles on an Aggregation of Individual Pollutant Measurements

Condensibles are an integral part of PM₁₀ measurements. The problem with Method 202 is that it tends to overstate the amount of particulate which would actually be present in ambient air.  Coal-fired boilers have only a few significant sources of condensibles.  In fact, SO₃ and VOCs are the only really significant compounds which are vapors at 250°F but particulate at ambient temperatures.  So why not run a Method 5 front half train for discrete particles.  Then run Method 8 for SO₃ and Method 25 for VOCs, and add the three together to get total particulate including condensibles.  A number of organizations including ICAC and CIBO are exploring ways, including the above aggregation, in which a truer representation of ambient particulate can be obtained.

McIlvaine is not only reporting but also offering new solutions to regulate and remove power plant air contaminants

The above suggestion that total particulate be measured by aggregating several individual measurements is consistent with another McIlvaine recommendation.  McIlvaine recommends that an “audit” concept be used for measuring mercury.  The CEM, by itself, is likely to provide an accuracy range of plus or minus 50 percent.  However, if the CEM results are weighed against other data such as periodic sorbent trap sampling, particulate mercury testing, and material balances, the inaccuracy range can be reduced to just a few percent.

The Power Plant Knowledge System provides a way for regulators to keep up with the latest technologies for mercury and other contaminant removal as well as with analyses of regulatory routes.  For more information, on the Power Plant Knowledge System, click on: http://www.mcilvainecompany.com/energy.html#44I .

Five Initiatives Eliminate the Mercury Controversy

Cost effective mercury reduction can be quickly applied without controversy by adopting five initiatives.

1. A destination based early mercury reduction option.  A one percent rate increase would create the fund which would pay early reducers.

2. Audit bases for mercury measurement. The audit would reduce mercury inaccuracy from plus or minus 50 percent to plus or minus five percent.

3. Equipment guarantees based on equipment performance and not process variables.  Efficiency of miniature systems would be increased until a level is achieved to cover most extreme process variables.  Suppliers of full scale systems have only to match the performance of the miniature system which is operated in parallel.

4. Greater effort on a variety of mercury reduction options.  More mercury is presently removed in chloride pre-scrubbers than by activated carbon, but no effort has been made to utilize this technology.  There are other promising options which are not being pursued.

5. Place mercury in the proper perspective through harm factor index.  Every air pollution control decision should be made with consideration for the total harm factor which is the aggregate weight of each pollutant including heavy metals multiplied by its individual harm factor.

See further discussion at:

http://www.mcilvainecompany.com/comments_to_neshap_for_utilities.htm

Bob McIlvaine

847-784-0012

www.mcilvainecompany.com