November 2, 2006

PM_2.5 Hot Topic Hour Reveals that Firm Guarantees are being made based on Questionable Monitoring Methods

http://www.mcilvainecompany.com/utility/subscriber/Hot_Topic_Hour_Recordings.htm

This link is for registered subscribers and is free of charge. Even though your company may be a subscriber but you are not a registered additional user, you can still access this recording at $95 for a period of six months. But the cost of becoming an additional user is not much more, so this would be a better option. In any case the link for those interested in individual tape access is

http://www.mcilvainecompany.com/FGDnetoppbroch/hottopichourrecordings.htm

This was a very valuable session because we had insights from the individual at EPA most responsible for the specific development of  PM_2.5 monitors, the executive director of the association of companies which has to make guarantees based on the reliability of these instruments, utilities who were knowledgeable enough to spot some of the potential weaknesses in the designs, consultants who are focused on the PM_2.5 issues, and suppliers of continuous emissions monitors whose results must be correlated with the stack methods.

The undeniable conclusion from this two hour session is that there is a major problem with the time table. Firm guarantees are being made without a reliable method of proving those guarantees. There are many millions of dollars in guarantee risks and hundreds of millions of dollars in risks involving permission to operate contingent on meeting specific limits as low as 0.018 lbs/MMBtu of particulate 2.5 microns and smaller including condensibles.

Method 202 is the method which will be used to validate the guarantees, but EPA is working on an improved method which will eliminate some of the artifacts. It also has a new conditional method using dilution sampling which appears promising, but this new method is not advanced to the point of replacing Method 202.

Here are some highlights from the presentations:

More than 40 people including utilities, government, A/Es, and suppliers participated in a two- hour discussion of the perplexing problem of measuring and controlling fine particulate. The discussion started with a brief tour of the Particulate Decision tree. An extensive analysis in the Decision Tree shows that discrete fine particle emissions from U.S. power plants could be as low as 100,000 tons per year or as high as one million tons per year. When you add in the condensibles you add another 200,000 to 500,000 tons/yr.

There were six semi-formal presentations and two inputs from expert panelists. The semi-formal presentations can be viewed without the audio directly in the Decision Tree through the links provided below. The full recording with all the presentations both video and audio is available through the Utility Environmental Tracking System,

http://www.mcilvainecompany.com/utility/subscriber/Hot_Topic_Hour_Recordings.htm

or the Power Plant Air Quality Decisions.

http://www.mcilvainecompany.com/ppks/subscriber/Hot_Topic_Hour_Recordings.htm

Ron Myers, EPA

Ron provided the very latest data on performance of the dilution sampling system which has been designated as conditional test method CTM 039. This system has been tested on seven sources including utility coal-fired boilers, oil-fired boilers and cement plants. Data correlates well with an improved Method 202 but not will the original method which is referenced in the permits. The designated method has a bias which converts some of the SO₂ and considers it additional particulate.

Dave Foerter, ICAC

Dave reviewed the history of ambient air particulate legislation and pointed out that this year the 24-hour standard has been reduced from 65 ug/m³ to 15 ug/m³. He also emphasized that the air pollution control companies are being required to make PM_2.5 guarantees and are in a difficult situation. Since Method 202 results in reporting erroneously high particulate weights and since it is the designated method, it is a big problem for the suppliers.

Buzz Reynolds, Siemens-Wheelabrator

This potentially interesting presentation was postponed due to some access problem. Due to the security software at some of the big companies it takes a special effort to use Webex.

Bob Crynack, Indigo Agglomerator

Bob presented data to show that the Indigo Agglomerator is effective on fine particles. In a subsequent discussion, the question was raised as to the effectiveness on nanoparticles. One hypothesis is that particles less than 100 nanometers will act more like a gas and pass through a fabric filter, but if these particles are charged they may be captured in the fabric filter.

Editor note:  See discussion of nanoparticles below. But is it possible that precipitators do better on nanoparticles than fabric filters? The problem is that we cannot even count the number of nanoparticles, so proving this hypothesis is not going to be easy.

Craig Clapsaddle, MSI

Craig provided details on the ability of the BetaGuard particulate mass monitor to accurately measure mass emissions following a wet FGD system. Many States are incorporating mass monitoring requirements downstream of wet FGD in their permits for new plants. Craig pointed out that in some cases there is as much as a 90 percent reduction in discrete fine particulate in the scrubber. Several utilities that were having problems with meeting opacity limits after the precipitator were able to demonstrate compliance by installing the BetaGuard and proving the further reductions in the FGD.

Editor note: Since discrete particulate is a surrogate for heavy metals and there is likely to be significant reduction in the wet scrubber if it follows an old precipitator, this wet stack measurement is particularly valuable.

Otakar Jonas, Jonas Inc.

Tests were run at a DuPont incinerator some years ago and showed the inaccuracies of some of the CEMS in continuously monitoring mass. The acoustic emission monitor has some advantages.

Panelists

John McKenna of ETS was one of the panelists. He pointed out that PM_2.5 is defined as all particles of this diameter or smaller. So, he asks, what about nanoparticles? John operates a fabric verification program for EPA. When challenging today’s fabrics with 100 nanometer particles, there is little difference between fabrics.

But if John were to use a particle counter rather than a weight measurement, he would be able to discern performance differences. As Bob Crynack pointed out in his presentation, there are many thousands of particles less than 0.1 micron in each cubic centimeter of flue gas. So measurement with a condensation nuclei particle counter could show differences of thousands or hundreds of thousands of particles in each cubic foot of flue gas passed through one fabric as compared to another.

Bill Ellison was a panelist and addressed the questions posed at the beginning of the session  as follows:

Responding to several of McIlvaine’s nine recently posted sub-topic areas:

(1)    What percentage of PM_2.5 is condensables?  A major proportion, especially in high-sulfur service. H₂SO₄ is the “tail” wagging the “dog” in the current era of low PM_2.5 emission limits out of “sync” with sulfur emission limits.

(2)    Should there be a separate SO₃ measurement? No. That portion of the H₂SO₄ that would be expected to condense in the real-life flue gas treatment train prior to stack exit should (via the sample/test train) be summed-in with the PM_2.5 solids catch. Accordingly, the “back end” of the sample train should be operated at the same temperature as that at the stack-inlet, i.e.:

(a)    A nominal 300ºF for an unscrubbed unit (or, logically, there is no back end catch available to be caught).

(b)   The flue gas wet bulb temperature, e.g. 122ºF for bituminous coal-firing, for wet scrubbed units.

(c)    The above temperature for wet scrubbers plus the unit’s actual amount of temperature approach to wet bulb for dry or semi-dry scrubbers (an appreciable “back end” catch for spray dryers but not for CFB scrubbers.)

Editor’s comments: Bill is recommending an approach which measures the real time particulate. But the SO₃ will convert to H₂SO₄ within a short distance from the stack. (The difference is that all the SO₃ is converted prior to the stack exit when wet scrubbers are used. However, some of the SO₃ is captured.) Therefore EPA is considering this primary particulate as part of PM 2.5. By contrast SO₂ forms compounds much farther from the stack and is therefore considered a source of secondary particulate.  Bill’s approach will make the dry scrubber people happy. But the wet scrubber people will justifiably point out that within a short distance from the stack the H₂SO₄ will be less rather than more. Therefore why discourage more SO₃ removal?

(3)    If I already have a precipitator, how much further reduction will I achieve when I install my wet FGD?  None. Absent a wet ESP mist eliminator and its mitigating effect, PM_2.5 will increase due to each of:

(a)    H₂SO₄(ℓ) formation in the wet scrubber, (i.e. that portion of raw-gas SO₃/H₂SO₄(v) not removed in the scrubber, e.g. 50%).

(b)   The solids component, suspended and dissolved, of the scrubber carryover, less that amount of particulate solids removed (inefficiently) in the wet scrubber, the latter being minimal in the case of an existing upstream precipitator of modern sizing with high solid particulate removal efficiency.

Editor note. However, many of the installations involve new FGD on plants with old precipitators. In general the scrubber can bring emissions down to 0.05 lbs/MMBtu. So if the inlet is 0.15 lbs/MMBtu then the scrubber can achieve a 66% reduction. But if the precipitator outlet emission is only 0.02 lbs/MMBtu the scrubber will not likely have any additional reduction. There is one exception. When there is a precipitator excursion, the scrubber particulate capture will be significant.

Ronald E. Myers (Ron)

Graduated from the University of Tulsa in Engineering Mathematics in 1968 and from the University of Michigan in Industrial Hygiene in 1977.  Was a Bio-Environmental Engineer in the U.S. Air Force from 1968 to 1980 where I was responsible for monitoring Air, Water, Solid Waste, Noise and Radiation programs.  I have been with OAQPS since 1980.  I spent the first 12 years in the Emission Standards Division (ESD). Projects that I participated in while in ESD included Control Techniques Documents for Particulate and Nitrogen Oxides; New Source Performance Standards for Sewage Sludge Incineration, Municipal Incineration, Glass Manufacturing, Portland Cement Plants and Process Heaters at Petroleum Refineries and Chemical Manufacturing Plants; NESHAP Standards for Comfort Cooling Towers, Industrial Cooling Towers, Glass Manufacturing and Municipal Waste Combustors.  The next six years were in the Emission Factors and Inventories Group and was responsible for the AP-42 Chapters dealing with Solid Waste Disposal, Mineral Products Industries, Inorganic Chemical Manufacturing, Metallurgical Industries and the Miscellaneous Source Categories.  From 1998 to 2003, I was in the Emissions Measurement Center (EMC) with responsibilities to develop methods for use in measuring particulate and particulate precursors. While with the EMC I helped develop the sampling method for filterable PM₁₀ and PM_2.5 which is numbered CTM 40 and for the dilution sampling method for filterable and condensable PM_2.5 which is numbered CTM 39.  Since 2003, I have been in the Measurements Policy Group and share responsibilities for the emissions testing and monitoring portions of the PM implementation rule and the reinvention of the emissions factors program.

David C. Foerter, Executive Director, Institute of Clean Air Companies (ICAC) 

David Foerter has 20 years of experience advising the public and private sector on environmental legislation, policy, rules, and technology issues with a focus on air pollution control for stationary and mobile sources. Mr. Foerter has been with Institute of Clean Air Companies (ICAC) since 2000, and it’s Executive Director since 2002. Mr. Foerter served for seven years at the Ozone Transport Commission (OTC) working on the OTC NO_x MOU for Stationary Sources and the National LEV program. Prior to the OTC, Mr. Foerter managed the air program for the Metropolitan Washington Council of Governments (Wash COG), the region’s planning organization, where he coordinated the broad range of regional air pollution assessment, control, and abatement activities for States and local governments.  Mr. Foerter holds a B.S. in microbiology.

James “Buzz” Reynolds

Buzz is Vice-President of Wet Electrostatic Precipitators at Wheelabrator Air Pollution Control Inc., a Siemens Company. Previously, Buzz was President of CR Clean Air Technologies, where he held various executive positions for the past 25 years in the Croll-Reynolds group of companies. He is a Director of the World Pollution Control Association and a member of the Council of Industrial Boiler Owners. He has worked with the EPA, Department of Energy and Electric Power Research Institute on R&D funding of wet ESP technology and is a co-inventor of several patents.

Bob Crynack

Bob is president of Indigo Technologies Inc, the U.S. subsidiary of the Australian based parent company. He is has many decades of particulate control experience, most of it with Wheelabrator

Craig Clapsaddle, MSI

Craig Clapsaddle is the BetaGuard PM sales manager at MSI Mechanical Systems.  His main responsibilities are the sale, start-up and testing of MSI’s continuous particulate emission monitor.  Craig has eight years experience with continuous particulate emission monitors and a total of 17 years experience in the field of source emission monitoring.

Comparison of measurement techniques for PM2.5.

http://www.mcilvainecompany.com/Particulate_Decision_Tree/subscriber/Tree/DescriptionTextLinks/Jonas%20Presentation%2011-02-06.ppt

Otakar Jonas, P.E., PhD. is the President of Jonas, Inc. and a consultant.  He has over forty years experience in corrosion, steam generation, water chemistry, materials engineering, teaching, research and development, and troubleshooting. Dr. Jonas has published over 180 technical articles and has worked for the last 20 years on the development of new instruments for the detection of particles in gas streams. 

Bill Ellison, Ellison Consultants

Since 1966 Ellison has specialized in stack gas  cleaning. He is currently in the forefront of technical and commercial development of optimum means of achieving Nox emissions reduction in existing FGD facilities

John D. McKenna B.S. Ch.E., M.S. Ch.E., M.B.A., Ph.D.

PRINCIPAL, ETS Inc.

A chemical engineer (Manhattan College) with entire career (40 plus years) spent in the field of pollution control with a special emphasis on baghouse technology. Designed, installed & operated the first baghouse on an industrial coal-fired boiler. Recent projects include utility boiler baghouse specification and management of ETV Baghouse Filtration Product lab testing.

Authored the baghouse text along with Jim Turner and currently writing one on fine particle measurement & control. Author of numerous articles & a number of texts including the air pollution control section of Perry's Chem E. Handbook Founder (1973) and principal of ETS Inc. ETS does testing (bags), troubleshooting (baghouses), training (online and in-person baghouse training) & testimony (baghouse expert witness).