1、 Comparison of API and EPA Toxic Air Pollutant Emission Factors for Combustion SourcesRegulatory Analysis and Scientific AffairsPUBLICATION NUMBER 4720SEPTEMBER 2002Comparison of API and EPA Toxic Air Pollutant Emission Factors for Combustion SourcesRegulatory Analysis and Scientific AffairsAPI PUBL
2、ICATION NUMBER 4720SEPTEMBER 2002PREPARED UNDER CONTRACT BY:Edward SaboPES, a MACTEC Company560 Herndon Parkway, Suite 200Herndon, Virginia 20170FOREWORDAPI publications necessarily address problems of a general nature with respect to particularcircumstances, local, state, and federal laws and regul
3、ations should be reviewed.API is not undertaking to meet the duties of employers, manufacturers, or suppliers to warnand properly train and equip their employees, and others exposed, concerning health andsafety risks and precaution, nor undertaking their obligations under local, state, or federallaw
4、s.Nothing contained in any API publication is to be considered as granting any right, byimplication or otherwise, for the manufacture, sale, or use of any method, apparatus, orproduct converted by letters patent. Neither should anything contained in the publication beconstrued as insuring anyone aga
5、inst liability for infringement of letters patent.API publications may be used by anyone desiring to do so. Every effort has been made bythe Institute to assure the accuracy and reliability of the data contained in them; however, theInstitute makes no representation, warranty, or guarantee in connec
6、tion with this publicationand hereby expressly disclaims any liability or responsibility for loss or damage resultingfrom its use or for the violation of any federal, state, or municipal regulation with which thispublication may conflict.Suggested revisions are invited and should be submitted to Reg
7、ulatory and Scientific AffairsDepartment, American Petroleum Institute, 1220 L Street, N.W., Washington, D.C. 20005.All rights reserved. No part of this work may be reproduced, stored in a retrieval system, or transmitted by any means, electronic, mechanical, photocopying, recording, or otherwise, w
8、ithout prior written permission from the publisher. Contact the Publisher, API Publishing Services, 1220 L Street, N.W., Washington, D.C. 20005.Copyright 2002 American Petroleum InstituteABSTRACTBoth the U.S. Environmental Protection Agency (EPA) and the American Petroleum Institute (API) havepublis
9、hed toxic air pollutant emission factors for combustion sources. This study compared the publishedemission factors, identified and explained differences in the factors, and recommended priorities forgathering additional information to improve the quality and reliability of published factors. This st
10、udy revealed the following major gaps and inconsistencies in air toxic emission factors forcombustion sources: There is the lack of data for metals emissions for reciprocating internal combustion engines and gas-fired gas turbines. While it is likely that metal emissions from these sources are small
11、, there are nopublished emission factors to confirm this assumption. There is no consistent list of target compounds in the emission factor databases and not all hazardousair pollutants were targeted in all tests. This results in isolated gaps for specific organics and metalsthroughout the databases
12、. There are several inconsistencies in the emission factors reported by EPA and API. The primary rea-sons for these inconsistencies are: (1) differences in source populations and operating conditions, (2)differences in sampling and analytical methods, and (3) differences in the treatment of detectio
13、n lim-its. For most source categories, there are no factors for dioxin/furan emissions. A literature search revealed several potential sources of new information that could be used to update theEPA or API emission factor databases. These sources include EPA-sponsored testing of reciprocatingengines,
14、 the Industrial Combustion Coordinated Rulemaking databases, the Petroleum EnvironmentalResearch Forum study, and a study by the Gas Technology Institute. A preliminary review of these sourcesshowed that they did not contain the data needed to fill the gaps for dioxins and furans, but could be used
15、toaddress other gaps and inconsistencies.Several areas of additional research are recommended: Determine the extent to which information available in recent literature is sufficient to verify EPA/APIemission factors or fill in existing data gaps. Collect additional data for gas-fired boilers/heaters
16、 to develop emission factors for polycyclic com-pounds, metals, and organic hazardous air pollutants. Collect additional data for fuel oil-fired boilers and IC engines to develop emission factors for polycy-clic compounds, metals, and organic hazardous air pollutants. Initiate the process with EPA f
17、or the updating of the AP-42 fuel oil and natural gas external combus-tion sections. Where possible, consider adding sampling and analysis for hazardous air pollutants to existing fielddata collection efforts.iiiACKNOWLEDGMENTSAPI STAFF CONTACTKarin Ritter, Regulatory Analysis and Scientific Affairs
18、 DepartmentMEMBERS OF THE STATIONARY SOURCE EMISSIONS TASK FORCE PROJECT WORKGROUPJeff Siegell, ExxonMobil Research and Engineering, ChairpersonKarl Loos, Equilon Enterprises LLCLee Gilmer, Equilon Enterprises LLCLyman Young, Chevron TexacoGary Kizior, BPPREPARED UNDER CONTRACT BY:Edward SaboPES, a
19、MACTEC Company560 Herndon Parkway, Suite 200Herndon, Virginia 20170TABLE OF CONTENTSPageSection1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 COMPARISON OF PUBLISHED EMISSION FACTORS . . . . . . . . . . . . . . . . . . .
20、. . 13 PRIORITIZATION OF GAPS AND INCONSISTENCIES . . . . . . . . . . . . . . . . . . . . . 34 LITERATURE SEARCH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44.1 AP-42 Section Updates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
21、. . . . . . . . . . . . . 44.2 Industrial Combustion Coordinated Rulemaking (ICCR) Databases. . . . . . . . . . 44.3 Petroleum Environmental Research Forum (PERF) Study . . . . . . . . . . . . . . . . . 44.4 Gas Technology Institute (GTI) Study . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22、 . . . . . 55 RECOMMENDATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5APPENDIX A COMPARISON OF AP-42 ANDPATEF 2.02 EM
23、ISSION FACTORS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7APPENDIX B IDENTIFICATION OF HAP GAPS AND INCONSISTENCIES. . . . . 39Figures1 Identification of HAP Gaps and Inconsistencies . . . . . . . . . . . . . . . . . . . . . . . . . . . 3Tables1 Key to Fields Contained in Tables A-1 t
24、o A-13 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8A-1 Comparison of EPA and API Emission FactorsExternal Combustion, No. 6 Fuel Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14A-2 Comparison of EPA and API Emission Factors
25、External Combustion,Refinery Gas/Natural Gas-Refinery Gas-fired Boilers, Refineryand Natural Gas-fired Process Heaters, Natural Gas/CVR-fired Steam Generators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17A-3 Comparison of EPA and API Emission
26、FactorsExternal Combustion,Crude Oil/Pipeline Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19A-4 Comparison of EPA and API Emission FactorsInternal Combustion, Reciprocating Engine, Diesel-fired, Oxygen 600 hp . . . . . . . . . . . . . . . . 22A-5 C
27、omparison of EPA and API Emission FactorsInternal Combustion, Reciprocating Engine, Diesel-fired, Oxygen 13%, 13% Internal Combustion, Reciprocating Engines, Gas-fired, 2-Stroke, Lean-burn Internal Combustion, Reciprocating Engines, Gas-fired, 4-Stroke, Lean-burn Internal Combustion, Reciprocating E
28、ngines, Gas-fired, 4-Stroke, Rich-burn Internal Combustion, Gas Turbines, Refinery/Natural Gas-fired, Duct Burners Internal Combustion, Gas Turbines, Refinery/NaturalGas-fired, No Duct Burners Direct Combustion, Asphalt Blowing, Blow Cycle Direct Combustion, Asphalt Blowing, No Blow Cycle Direct Com
29、bustion, Coke CalciningFor each of these 13 source categories, PES prepared a table that compares the API and EPA emission factors. These tablesare contained in Appendix A. Each table identifies the chemicals for which emission factors are available, EPA emissionfactor information, and API emission
30、factor information. Each table is accompanied by a narrative discussion of the gapsand inconsistencies that were found for each source category. Using the data in these 13 tables, PES prepared a color-coded scheme to visually identify data gaps and inconsistenciesusing the following indicators: A gr
31、een code indicates that the emission factors are of reasonable quality and there is consistency between the EPAand API databases. The specific criteria are that either the API or EPA emission factor has a data quality rating of A(excellent), B (above average), or C (average), and there is good agree
32、ment (within a factor of 5) between the EPAand API factor.2 API PUBLICATION4720 A yellow code indicates some concern about the quality of the emission factors, either because of inconsistenciesbetween the EPA and API factor or because of a small data set. The specific criteria are: (1) either the AP
33、I or EPAemission factor had a data quality rating of A, B, or C, but there is disagreement greater than a factor of 5 betweenthe EPA and API factor; or (2) the emission factor had a data quality rating of D below average and there is goodagreement within a factor of 5 between the EPA and API factor.
34、 A red code indicates the emission factors are of poor quality or based on a single test. The specific criteria are: (1) theemission factor had a data quality rating of D, but there is disagreement greater than a factor of 5 between the EPAand API factor; or (2) the emission factor had a data qualit
35、y rating of E poor. A gray code indicates that there is no emission factor available from either EPA or API.Detailed graphical summaries of gaps and inconsistencies for each source category and pollutant are presented in Appendix B.Figure 1 summarizes the information in Appendix B by assigning a sin
36、gle color code for each source and pollutant category.Major gaps in air toxic emission factors for combustion sources include: A lack of data for dioxin/furan emissions for most source categories. This gap may be important because EPAs Per-sistent Bioaccumulative Toxic regulation is focusing attenti
37、on on these chemicals. The reporting threshold for thedioxin and dioxin-like compounds is 0.1 grams per year. While the relative potential for dioxin emissions from gas-fired heaters is generally considered very low, the industry needs a reasonable and defensible position regarding theirpotential to
38、 emit dioxin. A lack of data for metals emissions for reciprocating internal combustion engines (RICE) and gas-fired gas turbines.While it is likely that metal emissions from these sources are small, there are no published emission factors to con-firm this assumption. No consistent list of target co
39、mpounds used in the emission testing. Not all HAPs were tested for in all tests. Forexample, newer testing of reciprocating engines using Fourier Transform Infrared (FTIR) techniques included manymore individual organic HAP compounds than older testing, which tended to focus on aldehydes, benzene, t
40、oluene,and xylene. Thus, there is a lack of data for certain organic HAP emissions from certain source categories such as gas-fired and fuel oil-fired boilers and heaters. Similarly, not all metals or polycyclic compounds were tested for in all tests.This results in isolated gaps for specific organi
41、c HAPs, polycyclic compounds, and metals throughout the database.There are several inconsistencies in the reported emission factors. For example, several metal EPA emission factors for gas-fired boilers/heaters are 10-50 times lower than the API emission factor. There are many factors that contribut
42、e to theseinconsistencies, including: Differences in source populations and operating conditions. Differences in the design, operation, and maintenance ofsources may contribute to emissions factor inconsistencies. For example, the EPA external combustion emission fac-tors based primarily on tests at
43、 large electric utility boilers, while the API factors based on petroleum industry boilersand process heaters. Differences in sampling and analytical methods. Measurement methods are continually improving. Different mea-surement methods may contribute to emission factor inconsistencies. For example,
44、 formaldehyde may be measuredusing CARB method 430, EPA method SW-846, or the FTIR method. These different methods can have differentbiases in the methods, different detection limits, and different data reduction procedures. Differences in the treatment of detection limits. Many tests of combustion
45、sources result not in an emission rate but inknowledge that the pollutant was not present at or above the limit of detection of the test method used. How themethod detection limits are reported and used to develop composite emission factors may contribute to emission fac-tor inconsistencies. An assi
46、gned value of 1/2of the minimum detection limit is generally used in calculating emissionfactors. For example, the detection limit for benzo(a)pyrene is a factor of 200 lower if the sample is analyzed usinghigh resolution gas chromatography/high resolution mass spectrometry rather than low resolutio
47、n gas chro-matographe/low resolution mass spectrometry. If two similar sources are tested for benzo(a)pryrene, one using thehigh resolution technique and one using the low resolution technique, and benzo(a)pyrene is not detected in eithersample, the reported emissions will be 200 times higher for th
48、e source tested with the low resolution technique3.In addition to these factors, other factors such as contamination problems during sampling and variability in qualityassurance procedures may be causes of inconsistencies among the emission factors.COMPARISONOFAPI ANDEPA TOXICAIRPOLLUTANTEMISSIONFAC
49、TORSFORCOMBUSTIONSOURCES33 PRIORITIZATION OF GAPS AND INCONSISTENCIESWe made a qualitative prioritization of the relative importance of the gaps and inconsistencies identified above. Theprioritization considered five factors: Emission Factor Quality. We evaluated the relative quality of emission factors based on the data quality rating of thePATEF and EPA factors. Toxicity. We evaluated the relative dose that causes adverse health effects of a given pollutant. We considered therisk-based Concentrations (RBCs) that were used as a surrogate
