BIF Testing - Is There Anything Else To Learn?
ABSTRACT
The paper examines cement kiln BIF recertification of compliance tests and compares them to previous certification of compliance tests. This paper also discusses various papers that have examined cement kiln emission data and whether there is any further information that can be obtained from additional ROC tests or trial burns.
INTRODUCTION
Is there anything else to learn from BIF testing of cement kilns? The short answer is "no". The underlining physical and chemical characteristics and operations control of cement kilns ensure consistently low emission rates at normal operating conditions. Repetitive tests simply demonstrate this ability but add nothing to our store of knowledge. Recertification test protocols should be reformulated to confirm facility compliance rather than repetitively prove well documented physical/chemical principals.
METALS TESTING/METALS FATE
The centerpiece of the BIF regulation has been the setting of metals emissions rates and metals input limits. All other BIF emission regulatory requirements pale in comparison to the effort and expense of determining these emission rates and limits.
Beginning with the first certification of compliance (COC) tests in 1992, this testing has involved the careful measurement of all of the metal inputs and outputs to the kiln and the purposeful augmentation of metal inputs (spiking). In 1995, recertification of compliance (ROC) tests were conducted at most plants and now in 1998 another round of ROC's will be conducted at many facilities. Some kilns have managed to conduct permit trial burns in place of ROC's or plan to do so for pending ROC's. In each case, with rare exceptions, the testing included the same metal input/output measurement and spiking that the original COC tests in 1992 required.
Reports on each of the tests that have already been conducted should have included a metals balance and a system removal efficiency (SRE). Such reports provide more than enough data to determine the source and fate of each of the metals. Indeed there have been at least eight papers presented at these A&WMA BIF conferences alone that present data and discuss metals testing, emissions results, or metal fates. These papers discussed a wide range of issues related to metals testing and metals fates.(1) ,(2) ,(3) ,(4) ,(5) ,(6) ,(7) ,(8) ,(9) ,(10)
Does the available data indicate that there is more to learn regarding metals emissions or emission input limits? Will future BIF tests of this nature provide helpful data?
These ROC tests invariably demonstrate that the facilities comply with the metals emissions limits, that the kiln and the air pollution control devices (APCD) are being operated properly even at worst case conditions. None of this should be surprising as this information has been pointed out in several of the above referenced papers.(3),(4),(5),(8)
However, the BIF testing requirements do not, indeed cannot, address other issues. Currently BIF requires that metal emissions are assumed to be emissions of the most toxic species of that metal. With the exception of the occasional determination of hexavalent chromium emissions, no one has bothered to speciate metals emissions. There is no need to do so as emission rates are well below, habitually by orders of magnitude, the conservative limits set by the EPA.(11)
As currently configured, additional BIF metals emissions tests will add no new knowledge of a cement kiln's capabilities, or of cement chemistry with respect to metals.
PIC AND DIOXIN FORMATION
In addition to metals, the EPA was concerned with the destruction of organic constituents and the production of products of incomplete combustion (PIC's). There were some problems with the implementation of these regulations which stemmed largely from EPA's poor understanding of cement kiln operations. Indeed most of the PIC and dioxin papers presented at the A&WMA BIF conferences focus on the differences between EPA's conventional wisdom regarding waste combustion and the documented combustion of wastes in cement kilns.(12) ,(13) ,(14) ,(15) ,(16) ,(17) ,(18) ,(19) ,(20)
The data from these COC and ROC tests demonstrate that carbon monoxide and hydrocarbon emissions from the kiln stack are not a reliable indicator of the combustion in the firing zone of a cement kiln. Nor does this data support the majority of EPA's theory of PCDD/PCDF formation. There appears to be no correlation between HCl and Cl2 concentrations in the stack gas and PCDD/PCDF concentrations14 and only a weak correlation between APCD temperature and PCDD/PCDF emissions.15,16,17,18 As for EPA's belief that carbon injection could reduce PCDD/PCDF emissions from cement kilns, Continental Cement reports conducting a carbon injection test and documenting an increase in PCDD/PCDF emissions.(18)
EPA's concern with PIC's has evolved into an elaborate examination of PIC emissions as expressed in EPA's draft Trial Burn Guidance document. Indeed, the EPA has discussed requiring facilities to conduct comprehensive PIC analysis that identifies the organic compounds being emitted. The basis of this request is the belief that these PIC's "may reasonably be expected to consist of thousands of individual compounds."(21)
Not satisfied with the data generated by cement manufacturers, the
EPA conducted a comprehensive PIC analysis of a hazardous waste
co-fired cement kiln.21 The testing included VOST and SVOST (including
dioxins), aldehydes/ketones and on-line GC. This testing documents the
identification of nearly all of the organic emissions from this kiln.
What the testing shows is that benzene is the most common compound at
25% (as carbon) with methane at 18% (as carbon) a close second.
Clearly, this confirms the data from cement kiln operators who have
performed SVOST sampling and analysis on their kiln's emissions. What
is also clear is that EPA's belief that there are "thousands of
individual compounds" in cement kiln PIC emissions is also erroneous.
Additional testing will provide no further insight into how PIC's or
PCDD's/PCDF's are formed in cement kilns as a group of combustion
devices. However, testing and operations protocols can be devised on a
facility specific basis that will help define the conditions that will
minimize PIC or PCDD/PCDF emissions.17 Unfortunately, such conditions
are unlikely to be those required by the BIF COC protocol.
PERFORMANCE CONFIRMATION - AND THAT'S ALL
At this point the ROC testing is no more than an elaborate and costly performance confirmation test. Individual facilities may be able to tinker with the protocol or add runs at different conditions, at additional cost, to glean some added insight into their process, but for the most part the ROC tests will provide little new information.
As a performance confirmation, the ROC test protocol is overkill. Clearly there is a need to demonstrate that the combustion device's capabilities have been maintained. However, it should be unnecessary to repeatedly demonstrate well documented cement kiln chemistry or to repeatedly test an unchanged facility as if its emissions were erratic and unpredictable, which decidedly they are not. The most dramatic illustration of this is Table 1 showing the emission rates for the volatile metals cadmium and lead for 24 cement kilns which conducted COC's in 1992 and ROC's in 1995 and 1996.
Comparing the 1992 COC emission rates for each of the metals to the ROC tests clearly shows how replicable these emission rates are. In many cases, the difference from test to test is less than the value attributable to analytical error. Where there are larger differences in this table some of them are denoted as alternate operating conditions, others are likely to be significant changes in feed rates. What is the cost of a standard ROC test? Substantial, easily $150,000, not counting the disruption the test inflicts on the facility. But the hidden costs and the potential costs are of even more concern. This too has been the subject of discussion at A&WMA BIF conferences and was addressed in a paper presented at the 1995 BIF conference.(22)
The thrust of the paper was that the added risk to human health and
the environment due to the BIF regulation, particularly from metal
spiking, was substantial. The proposed Hazardous Waste Combustor
regulation acknowledged this risk as well.(23)
CONCLUSION
Clearly, the extensive database accumulated over the last six years on cement kiln emissions in conjunction with the numerous papers presented at such conferences as A&WMA's BIF conference and in a variety of journals have established that cement kiln emission rates are predictable and replicable at the established operating parameters. PIC and dioxin emissions are impacted much more by the naturally occurring hydrocarbons in the raw feed materials than by any other factor, except for in some instances the APCD temperature.
Metals spiking can be eliminated, there is more than enough data to enable the setting of input limits without the need for this "what you spike is what you get" concept. As for PIC's and dioxin, the EPA should acknowledge that reasonable hazardous waste fuel input rates have virtually no impact and allow these tests to be conducted at normal operating conditions, thereby generating useful data that can be used in realistic risk assessments.
Conducting additional testing using the BIF ROC test protocol will add no useful information to the already immense store of data. Indeed, such additional testing is a threat to the human health and environment for no discernible future improvement in the environmental health of the nation. EPA should quickly move forward under RCRA with an emergency rule-making to modify these testing requirements and reduce this risk to human health and safety. Waiting for the conclusion of the MACT rule-making process would be unjustified. Furthermore, permit writers, under the omnibus authority should take these factors into account when prescribing the frequency and extent of testing required after a permit is issued.
| Table 1. Cadmium and Lead Emission Rates | ||||||||
| CT ID/YR | Kiln | Cd | Pb | CT ID/YR | Kiln | Cd | Pb | |
| g/hour | g/hour | g/hour | g/hour | |||||
| AGFORE1 92 | 1 | 2.62e+00 | 1.09e+00 | LAFALPEN 0595 | 22 | 1.77e-01 | 1.20e+00 | |
| AGFORE12 1194 | 1 | 7.48e+00 | 1.45e+02 | LAFALPEN 92 | 23 | 3.67e-01 | 9.93e-01 | |
| AGFORE2 92 | 2 | 9.15e-01 | 3.31e+01 | MEDDEMOP 0695* | 1 | 8.50e-02 | 1.30e+00 | |
| AGFORE3 92 | 3 | 6.22e-01 | 9.36e+00 | LAFDEMOP 92* | 1 | 2.33e-01 | 5.73e+00 | |
| AGFORE3 0195 | 3 | 9.76e-01 | 1.34e+01 | LAFFRED1 92 | 1 | 9.53e-01 | 1.12e+01 | |
| CCCHANNI 0296 | 1 | 4.09e+01 | 2.42e+02 | LAFFREDO 0995 | 1 | 2.93e+00 | 1.87e+01 | |
| CCCHANNI 92 | 1 | 3.28e+01 | 1.53e+02 | LAFFRED2 92 | 2 | 5.50e+00 | 9.03e+01 | |
| ESSLOGAN 0595 | 2 | 3.84e+00 | 1.25e+02 | LAFFREDO 0995 | 2 | 3.81e+00 | 3.80e+01 | |
| ESSLOGAN 92 | 1 | 2.12e+00 | 2.18e+02 | LAFPAULD 0795 | 2 | 3.50e+00 | 3.23e+01 | |
| GIAHARLE 0595A | 4 | 4.23e-01 | 1.37e+00 | LAFPAULD 92 | 2 | 8.37e+00 | 1.21e+02 | |
| GIAHARLE 0595B | 4 | 1.42e-01 | 6.78e-01 | LSICAPEG 1095 | 1 | 4.10e-01 | 1.52e+00 | |
| GIAHARLE4 92 | 4 | 4.47e-01 | 3.89e+00 | LSICAPEG 92 | 1 | 2.68e+00 | 8.31e+00 | |
| HCINDEP 0796 | 1 | 4.17e+00 | 1.58e+01 | LSIGCAST 0795 | 1 | 1.11e+01 | 1.39e+02 | |
| HCINDEP 92 | 1 | 2.26e+00 | 1.06e+01 | LSIGCAST 92 | 1 | 2.68e+01 | 1.14e+02 | |
| HOLCLARK 0296A | 1 | 3.54e-01 | 1.46e+01 | MEDWAMP1 92 | 1 | 2.72e-01 | 1.09e+02 | |
| HOLCLARK 0296B | 1 | 1.25e+01 | 2.17e+02 | MEDWAMP3 92 | 3 | 9.00e-02 | 5.96e+01 | |
| HOLCLARK 92 | 1 | 1.97e+01 | 2.00e+02 | MEDWAMPU 0695 | 2 | 2.05e+01 | 7.77e+01 | |
| HOLHH1 0695 | 1 | 9.72e-01 | 1.00e+01 | MEDWAMPU 0695 | 3 | 3.72e+00 | 3.59e+01 | |
| HOLHH1 92 | 1 | 1.85e+01 | 1.73e+02 | NATLEBEC 0695 | 1 | 3.50e-01 | 1.20e+00 | |
| HOLHH2 0595 | 2 | 8.59e+00 | 1.30e+02 | NATLEBEC 92 | 1 | 4.67e-01 | 2.57e+00 | |
| HOLHH2 92 | 2 | 4.93e+00 | 6.04e+01 | RCFESTU 0596 | 1 | 2.54e+01 | 2.73e+02 | |
| KEYBATH1 0595 | 1 | 2.89e+00 | 2.95e+01 | RCFESTU 92 | 1 | 4.96e+00 | 2.25e+02 | |
| KEYBATH1 92A | 1 | 1.17e+01 | 1.28e+01 | TXIMIDLO 0395 | 2 | 4.67e-01 | 2.47e+00 | |
| KEYBATH1 92B | 1 | 7.50e+00 | 5.87e+00 | TXIMIDLO 92 | 1 | 5.86e-01 | 1.29e+01 | |
| KEYBATH2 0595 | 2 | 3.64e+00 | 4.66e+01 | * Medusa purchased the | ||||
| KEYBATH2 92A | 2 | 5.15e+00 | 1.14e+01 | Demopolis facility from | ||||
| KEYBATH2 92B | 2 | 3.06e+00 | 1.14e+01 | Lafarge | ||||
| Data taken from GCI's Combustor Database | ||||||||
REFERENCES
1. Gossman, David; Constans, David; Woodford, Jim; et al, "Metal Equilibration and Process Capture Efficiencies in Cement Kilns", In Waste Combustion in Boilers and Industrial Furnaces conference, Air & Waste Management Association: Clearwater, FL, March 1993, pp 247-252.
2. Constans, David; Woodford, Jim; Gossman, David, "Comparison of Metals Spiking Systems and Metals Compounds Selection Among the Cement Kiln Conducting Compliance Tests", In Waste Combustion in Boilers and Industrial Furnaces conference, Air & Waste Management Association: Clearwater, FL, March 1993, pp 253-258.
3. Woodford, Jim; Gossman, David; Jameson, Rex; Gossman, Susan, "The Effects of Process Differences on System Removal Efficiencies (SREs) and the Fate of Metals in Cement Kilns", In Waste Combustion in Boilers and Industrial Furnaces conference, Air & Waste Management Association: Kansas City, MO, March 1995, pp 191-215.
4. Woodford, Jim; Gossman, David; Johnson, Norris, "A Comparison of Normal and Worse Case Cement Plant Emissions", In Waste Combustion in Boilers and Industrial Furnaces conference, Air & Waste Management Association: Kansas City, MO, March 1996, pp 65-68.
5. Schreiber, Robert J.; Kellerman, Scott J.; Schreiber, Carol, "Comparison of Criteria Pollutants for Cement Kilns Burning Coal and Hazardous Waste Fuels", In Waste Combustion in Boilers and Industrial Furnaces conference, Air & Waste Management Association: Kansas City, MO, March 1996, pp 69-87.
6. Moscati, Anthony F., "Characteristics and Trends in the Burning of Hazardous Waste in Cement Kilns", In Waste Combustion in Boilers and Industrial Furnaces conference, Air & Waste Management Association: St. Louis, MO, April 1997, pp 94-105.
7. Graf, Brian, "Trends and Characteristics of Hazardous Waste Derived Fuel Burned for Energy Recovery in Cement Kilns: An Essroc Perspective", In Waste Combustion in Boilers and Industrial Furnaces conference, Air & Waste Management Association: St. Louis, MO, April 1997, pp 106-117.
8. Johnson, Norris; Kluesner, Mark, "Advantages and Disadvantages of Burning Hazardous Waste in a Precalciner Kiln", In Waste Combustion in Boilers and Industrial Furnaces conference, Air & Waste Management Association: St. Louis, MO, April 1997, pp 185-189.
9. Gossman, David; Black, Myron; Ward, Mark, "The Fate of Trace Metals in the Wet Process Cement Kiln", In Waste Combustion in Boilers and Industrial Furnaces conference, Air & Waste Management Association: Kansas City, MO, April 1990, pp 70-93.
10. Chadbourne, John, "Cement Kilns and Hazardous Waste", In New RCRA Regulations for Industrial Boilers, Furnaces and Incinerators conference, Air & Waste Management Association: Orlando, FL, March 1992, pp 185-197.
11. Gossman, David, "Metals Emission Rates vs. Limits, Combustor Database", Gossman Consulting, Inc., 1997.
12. Schreiber, Robert J.; Strubberg, Kathleen, "Hydrocarbon Emissions from Cement Kilns Burning Hazardous Waste", In Waste Combustion in Boilers and Industrial Furnaces conference, Air & Waste Management Association: Clearwater, FL, March 1993, pp 275-286.
13. Woodford, Jim; Jameson, Rex; Buckelew, Carlos, et al, "Suitability of Hydrocarbon and Carbon Monoxide Measurements as Combustion Indicators in Cement Kilns", In Waste Combustion in Boilers and Industrial Furnaces conference, Air & Waste Management Association: Clearwater, FL, March 1993, pp 287-298.
14. Schreiber, Robert J.; Gossman, David, "2,3,7,8-TCDD Equivalent Emissions from Cement Kilns Burning Hazardous Waste", In Waste Combustion in Boilers and Industrial Furnaces conference, Air & Waste Management Association: Kansas City, MO, April 1994, pp 127-134.
15. Hansen, Eric; Pershing, David W.; Sarofim, Adel F.; Heap, Michael P.; Owens, Warren D., "An Evaluation of Dioxin and Furan Emissions from a Cement Kiln Co-firing Waste", In Waste Combustion in Boilers and Industrial Furnaces conference, Air & Waste Management Association: Kansas City, MO, April 1994, pp 135-176.
16. Dellinger, Barry and Sukh, "Contribution of Cement Kilns Raw Metal Organics to PIC Emissions", In Waste Combustion in Boilers and Industrial Furnaces conference, Air & Waste Management Association: Kansas City, MO, March 1995, pp119-130.
17. Denizeau, Jaques, "Is the Dust Collector Temperature the Magic Answer to PCDD/PCDF Emission Control?", In Waste Combustion in Boilers and Industrial Furnaces conference, Air & Waste Management Association: Kansas City, MO, March 1995, pp 131-141.
18. Schreiber, Robert J.; Evans, Jeffrey J.; Winders, Henry, "Dioxin Emissions and Cement Kilns Operations", In Waste Combustion in Boilers and Industrial Furnaces conference, Air & Waste Management Association: Kansas City, MO, March 1995, pp 157-161.
19. Trenholm, Andrew; Hlustick, Dwight, "Organic Emissions From a Cement Kiln Burning Hazardous Waste", In Waste Combustion in Boilers and Industrial Furnaces conference, Air & Waste Management Association: Kansas City, MO, April 1990, pp 49-62.
20. Hastings, Kevin; Hereth, Mark, "Factors Influencing Hydrocarbon Emissions From Cement Kilns", In New RCRA Regulations for Industrial Boilers, Furnaces and Incinerators conference, Air & Waste Management Association: Orlando, FL, March 1992, pp 69-80.
21. "Products of Incomplete Combustion (PICs) from a Hazardous Waste Co-fired Cement Kiln", USEPA Contract 68-DZ-016, EER at Holnam's Holly Hill Facility.
22. Constans, David; Gossman, David, "The Added Risks to Health, Safety and the Environment Due to the BIF Regulation", In Waste Combustion in Boilers and Industrial Furnaces conference, Air & Waste Management Association: Kansas City, MO, March 1995, pp 22-26.
23. Federal Register, Volume 61, No. 77, US Government Printing Office, page 17429.