Continental Cement Trial Burn Strategy
Director of Environmental Affairs - Continental Cement Company
David L. Constans
Engineering Consultant - Gossman Consulting, Inc.
Operations Consultant - Gossman Consulting, Inc.
Presented at the AWMA International Specialty Conference on Waste Combustion in Boilers and Industrial Furnaces March, 1995
This paper describes the trial burn strategy proposed for Continental Cement's cement kiln. The plan utilizes "data in lieu of" from previous compliance testing for establishing the chlorine and metal feed rate limits, the pumpable/total waste fuel feed, production rate limits, and the various kiln system operating conditions. The plan also addresses the draft trial burn guidance on organic emissions risk assessment. The organic emissions determinations are to be obtained through the execution of testing during two campaigns. These testing campaigns are executed right before and right after the annual kiln maintenance period, corresponding to the minimum and maximum thermal efficiency periods for the kiln.
Continental Cement Company (CCC) is located near Hannibal, Missouri on the Mississippi River. CCC operates a Portland Cement manufacturing facility utilizing hazardous waste as fuel. The kiln utilizes the wet slurry clinkering process. The kiln was constructed in 1966 and produces about 1,800 tons of Portland Cement clinker each day. CCC began utilizing hazardous waste fuel in 1986. Currently, CCC consumes about 5,000 tons each month of liquid hazardous waste fuel and about 2,500 tons each month of solid hazardous waste fuels.
The purpose of the trial burn plan is to document a comprehensive program to supply sufficient information to the agency(s) to allow a facility operating permit to be written. This information must be supplied in conformance to specific regulations, CFR 270.22 and 270.66. Additionally, the EPA has supplied the permit writers with a Trial Burn Guidance Document. This guidance document addresses additional data requirements. The Trial Burn Plan and Submittal Of "Data in Lieu Of" documentation submitted to the agency in July of 1994 attempted to supply the information in accordance with the regulations and the data request generated by the guidance document. This paper is a discussion of the strategy CCC employed to fulfill this goal.
TRIAL BURN PLAN STRATEGY
The applicable regulations are in two parts: CFR 270.22 Specific Part B information requirements for boilers and industrial furnaces (BIF) burning hazardous waste and CFR 270.66 Permits for boilers and industrial furnaces burning hazardous waste. For CCC this second regulation is limited to the provisions stated in section (g), Interim status BIFs.
Specific Regulations Governing Trial Burn Plans
The first of the two regulations, CFR 270.22 Specific Part B information, is a condensation of the BIF regulation, CFR 266. The BIF regulation is heavily referenced throughout these information requirements. The facility must supply documentation that each of the specific emissions standards in BIF have been complied with. That is, the facility can document compliance with the organic emissions standard, CFR 266.104, the particulate emissions standard, CFR 266.105, the metals emissions standard, CFR 266.106, and the chlorine and hydrogen chloride emissions standard, CFR 266.107. There are other Part B information requirements included that are not part of a trial burn, such as: alternate metals implementation, automatic waste fuel cut-off systems and Bevill exclusion requirements. This regulation includes the section on "Data in lieu of trial burn" which will be discussed later.
The second part, Permits for BIFs, CFR 270.66, details specific requirements for designing and executing trial burns. However, since CCC has interim status as a BIF under 266 the only applicable section of 270.66 is (g) which in turn references section (f) Determinations based on trial burns. Section (f) heavily references the BIF regulation CFR 266.
Submittal Of Data In Lieu Of Trial Burn
Both of the specific regulations governing trial burns for cement kilns allow the submittal of "data in lieu of trial burn". The Permits regulation, CFR 270.66, in section (g) states that the applicant must: ". . . either prepare and submit a trial burn plan in accordance with the requirements of this section or submit other information as specified in CFR 270.22 (a) (6)."
The "Data in lieu of trial burn" section in 270.22 allows the submittal of data acquired during "previous compliance testing of the device in conformance with 266.103. In fact, the data in lieu of trial burn can be from a "compliance testing or trial burn or operational burns of similar boilers or industrial furnaces burning similar hazardous wastes under similar conditions." The EPA Director, however, has been given latitude to decide if he shall approve a permit without a trial burn. CFR 270.22 (a) (6) states: "The Director shall approve a permit application without a trial burn if he finds that the hazardous wastes are sufficiently similar, the devices are sufficiently similar, and the data from the compliance tests, trial burns or operational burns are adequate to specify (under 266.102 of this chapter) operating conditions that will ensure conformance with 266.102 (c) of this chapter." This wording would appear to be specifically discussing the use of data from tests of devices other than the device for which the permit is being sought. However, CCC assumed that the data submitted in the plan should address the "sufficiently similar" concept with respect to hazardous waste and operating conditions. Thus, since the beginning, CCC has collected a large volume of analytical data on input feeds and output streams as well as process condition data to know and document the similarity. Additionally, CFR 270.22 (a) (6) included two subsections delineating specific information that must be submitted in the trial burn plan if "data in lieu of trial burn" is included. These subsections, (i) and (ii), require documentation that the waste consumed during the data in lieu of testing and the waste described in the permit application "support the contention that a trial burn is not needed." Similar requirements were specified to document comparable operating conditions and that the selection of the POHC used in the submitted DRE test was an adequate selection to demonstrate DRE conformance for the wastes listed in the permit application.
Although only section (g) of the Permits regulation, 270.66, is applicable to CCC as a BIF interim status facility, the data in lieu of section, 270.22 (a) (6) references 270.66 generally. Stating: ". . . demonstrate conformance with 270.66 by providing the information required by 270.66 from previous compliance testing". Consequently, it was reasonable to supply any information requested in 270.66 that had not already been required by 270.66 (g) and 270.22. It is interesting to note that CFR 270.66(d)(2) appears to support the submittal of data in lieu of trial burn concept. 270.66(d) is entitled "Trial burn procedures", 270.66(d)(2) states: "The Director shall approve a trial burn plan if he/she finds that: . . . (iv) The information sought in the trial burn cannot be reasonably be developed through some other means."
Emissions Data For Which Data in Lieu of Was Not Submitted
Data in lieu of trial burn was not submitted for dioxin/furan emissions. CCC had conducted this emissions testing during the 1992 COC Testing and had demonstrated compliance to the BIF emissions standard. CCC decided however not to submit this data as data in lieu of. The primary reason for this decision was that at the time of the COC Test Burn the kiln was operating under the provisions of the Tier III PICs standard, now however, CCC is operating under the Tier I CO standard. CCC believes that the results of the dioxin/furan testing in 1992 would not be representative of the current operation of the kiln. Since dioxin/furan emissions testing would be part of the products of incomplete combustion (PIC) testing requested by the agency a submittal of dioxin/furan emissions data in lieu of trial burn would be redundant.
Trial Burn Guidance Document
In September of 1993 the EPA issued a draft guidance document to its permit writers on criteria for trial burns. This was followed in April of 1994 with a heavily revised document which included revised attachments. The stated purpose of the document was to provide the permit writer with guidance on the criteria for a trial burn. That is, specific selection of emissions testing and analyses and operating conditions that would supply the data needed to perform an indirect, food chain pathway risk analysis.
EPA's concern, as stated in this document, is primarily the emissions of PICs. While there is some discussion of chlorine and metals, these discussions generally are concerned with their impact on PIC emissions.
The document included specific guidance on determining the list of PICs to be analyzed in the emissions. Also, there is guidance on waste feed selection and rates and trial burn operating conditions. It is not the purpose of this paper to critique the Trial Burn Guidance Document, such a critique has been done by Gossman Consulting and others over the past several months. However, the guidance provided in the document includes contradictory operating conditions and a misunderstanding of cement kiln technology. Consequently, CCC was left to propose a test sequence that would acquire the necessary PIC emissions data.
What CCC had chosen to do was to submit to the agency a test strategy that would provide a set of testing campaigns that accurately represented the realistic operating extremes for this cement kiln. During the course of the year the kiln moves between two extreme operating conditions. The CCC design allows one testing campaign at the extreme condition experienced immediately before the facility performs the annual major maintenance on the kiln. The second campaign is conducted during the operating conditions that exist immediately after this major kiln maintenance. In the Trial Burn Plan submitted to the agency the two conditions were described as follows:
Kiln Conditions After a Major Maintenance Shutdown. During a major kiln shutdown, the necessary refractory brick will be replaced in the various zones of the kiln and worn pieces of chain will be replaced. Additional chain may also be added to improve heat transfer, if necessary. After a major shutdown, the kiln refractory will be at its maximum thickness and the mass of the chains will be at a maximum. Less heat will be lost through the refractory to the kiln shell. More efficient heat transfer will occur between the chains and the raw materials, thereby decreasing the temperature of the exit gas stream. Under the conditions that exist after a shutdown, fuel usage will be reduced as the thermal efficiency of the kiln is maximized. The kiln conditions after a major maintenance period represent one of the campaign conditions under which CCC proposes PIC testing. The campaign test periods will reflect two extremes of the normal cycle of operating conditions, instead of subjecting the kiln to extreme conditions and stressing the kiln unnecessarily, regardless of its thermal condition during the test.
Kiln Conditions Prior to a Major Maintenance Shutdown. During the normal operations of the kiln, the refractory and the chains will experience wear. More heat will be lost through the kiln shell and less heat will be transferred between the gases and raw materials in the chain zone, as the mass of the chain decreases. Fuel consumption will increase to meet the reaction needs. Since heat transfer between the chains and the raw materials is at a reduced efficiency, the exit gas temperature will be at a maximum. The kiln conditions prior to a major maintenance period represent a second set of campaign conditions under which CCC proposes to perform PIC testing. Again, the campaign test periods reflect the extremes of the normal cycle of operations conditions without unnecessarily subjecting the kiln to artifically extreme conditions.
The kiln emissions during each of these tests will be sampled for dioxin/furans and semivolatile and volatile PICs. These samples will be subjected to gas chromatographic/mass spectrometry analysis. Identification of the largest ten peaks for each of the semivolatile and volatile samples will be attempted. Dioxin/furans will be analyzed separately using EPA Method 23. CCC currently has certified compliance and complies with the Tier I CO standard, i.e. less than 100 ppmv of CO in the stack emission, normally operating in the range of 20 to 50 ppm of CO in the stack gas. It is expected that volatile and semivolatile hydrocarbon emissions will be very low, one to five ppm THC. Nor is it expected that these constituents will be chemically complex or especially toxic.
OVERVIEW OF THE TRIAL BURN PLAN AND SUBMITTAL OF DATA IN LIEU OF
Attachment A, is an outline of the document submitted to the agency. This outline generally follows the outline of other trial burn plans that have been submitted to the agency. There are, however, some differences that should be noted.
Section 1.5 includes discussions on metal volatility, metals partitioning and the insensitivity of system removal efficiencies (SRE) to most operating parameters. These discussions were included to demonstrate the knowledge gained during the 1992 COC Testing of metals emissions under various kiln operating conditions of 24 different kilns. CCC felt this information was important in demonstrating that although each kiln may be unique the cement clinkering process overwhelmingly predetermines the fate of metals that enter the system. Graphs supporting these statements were included in Appendix D of the submittal.
As noted earlier the specific regulations governing trial burns requires that the data in lieu of trial burn include a demonstration that the device and wastes for which this data was generated and the devices and wastes for which the permit is requested be "sufficiently similar." Sections 2 and 3 address these requirements. It is important to also note that CCC is not seeking to expand operating conditions while submitting data in lieu of.
Section 4 is straight foreword. The operating limits are those established during the COC Testing and proposed as the permit operating limits. These proposed limits have not changed.
Section 5 is the submittal of data in lieu of trial burn. The data is presented in the same order as the emissions standards in BIF. That is, CFR 266.104, standards to control organic emissions through, CFR 266.107, standards to control chlorine and hydrogen chloride emissions. This data is provided in an abridged format to make the section readable. Section 5.1 discusses the suitability of the selection of the POHCs in the submitted data versus the list of wastes included in the permit application. Section 5.5 is a summary of the kiln operating limits and metal/chlorine input limits established by the COC Test data. This is sufficient data to establish permit limits on feed rates and operating conditions.
Section 6 reiterates the statement noted earlier that the risk analysis for the dioxins/furans will be completed based on the data acquired during the proposed PIC testing.
Section 7 details the proposed timing and plan of execution of the PICs emissions testing. That is, one campaign conducted just before the annual kiln maintenance and one campaign immediately after. No specific date had been proposed as this is dependent on the timing of the annual maintenance following agency approval of the plan.
Attached to the Plan is a Quality Assurance Project Plan and a document describing the test personnel qualifications and organization. Both are typical for these type of submittals. Also included are four appendices. The first is an extensive document demonstrating the manner in which the Waste-Derived Residue Compliance Program has been conducted by CCC. This document demonstrates continued compliance with the Bevill exemption provisions in CFR 266.113 for CCC's CKD. The second appendix demonstrates compliance with the Tier I CO standard and the third a set of Revised COC forms documenting the change in the CO standard. The fourth appendix contians a number of graphs supporting the statements made in Section 1.5 regarding the insensitivity of metal SRE's to kiln operating conditions.
INVOLVEMENT OF THE PUBLIC
In an effort to keep CCC's neighbors and other interested parties informed of their ongoing efforts to comply with the various and numerous regulations, as well as the changing interpretation and guidance regarding the use of hazardous wastes as fuel in the kiln, CCC has conducted a number of information programs, meetings and a facility "open house." In all, CCC has conducted about 16 meetings including talks and question/answer periods by management personnel and experienced consultants. There have been several mailings intended to inform on such subjects as: waste as fuel, risk and risk assessment, EPA's CETRED document and RCRA permitting. In September of 1994, CCC conducted an "open house" during which over 900 people viewed the facility and asked questions. The response to all of this effort has been quite gratifying as demonstrated by the 518 favorable responses received by the agency in response to the RCRA permit public notice.
The Trial Burn Plan was submitted in July of 1994, to date the agency has requested only minor additional information on an analytical procedure used in the COC Testing. CCC believes that the plan as submitted, to the best of our understanding of these regulations, meets the regulatory requirements and the request for the PIC emissions data necessary to conduct an indirect risk assessment. However, as in all such submittals CCC fully expects to be required to respond to the agencies information requests. Based on past experience, the majority of these responses will be to differences in interpretation of the regulations or lack of understanding of clinkering technology by the contractor or person the EPA assigns to review the Plan.
Indications are that the current status of the Trial Burn Plan submittal, based on conversations with the agency handling the permit application, is very good. The preliminary review has been completed and there appear to be few if any additional questions.
OUTLINE OF TRIAL BURN PLAN AND SUBMITTAL OF DATA IN LIEU OF
1. GENERAL INFORMATION
1.1 Name and Location of Facility
1.2 Scope and Objectives
1.3 PIC Emissions Testing Schedule
1.4 HCl/Cl2 Emissions Data in Lieu
1.5 Metals Emissions Data in Lieu
1.6 POHC DRE Data in Lieu
2. ANALYSIS OF EACH FEED STREAM
2.1 Heating Value, Metals, Total Chlorine/Chloride, Viscosity or Form, and Ash
2.2 COC Test Process Sample Analysis
2.3 Current Process Sample Analysis
2.4 CKD Analysis
3. ANALYSIS OF EACH HAZARDOUS WASTE AS FIRED
3.1 Identification of Appendix VIII Hazardous Constituents
3.2 Approximate Quantification
3.3 Description of Blending Procedures
3.4 Selection And Description of POHCs and Metals Spiked During the
4. DETAILED ENGINEERING DESCRIPTION OF KILN
4.1 General Information
4.2 Manufacturer's Name and Model Number
4.3 Type of Industrial Furnace
4.4 Maximum Design Capacity
4.5 Description of All Kiln Feed Systems
4.5.1 Raw Material Preparation and Feed
4.5.2 Furnace Fuel Supply
4.6 Capacity of Hazardous Waste Feed System
4.7 Description of Automatic Waste Feed Cut-Offs (AWFCs)
4.8 Description of Air Pollution Control Device
4.9 Description of Stack and Continuous Emission Monitoring Systems
4.9.1 CEM System - Process Description
4.9.2 Additional Emissions Monitoring Equipment
4.10 Procedures for Rapid Waste Feed Cut-Offs
5. SUBMITTAL OF DATA IN LIEU OF TRIAL BURN
5.1 Standards to Control Organic Emissions
5.1.1 Description of Testing
5.1.2 Summary of Data
5.1.3 Selection and Description of POHCs and Method of Injection
5.2.1 Description of Testing
5.2.2 Summary of Data
5.3.1 Description of Testing
5.3.2 Summary of Data
5.3.3 Spiked Metals Selection and Method of Injection
5.4.1 Description of Testing
5.4.2 Summary of Data
5.4.3 Discussion of Metal Halide Salts in the Impinger Solutions of the Method 26 HCl
Emissions Measurement Train
5.5 Summary of Operating Limits
6. RISK ANALYSIS FOR PCDD/PCDF
7. ADDITIONAL TESTING TO ACQUIRE DATA FOR INDIRECT RISK
7.1 Purpose of PIC Emissions Testing
7.2 Protocol for PIC Testing
7.2.1 Maximum Kiln Exit Temperature Test Sequence - First Campaign
7.2.2 Maximum Thermal Efficiency Condition Test Sequence - Second Campaign
7.3 Detailed Test Schedule and Test Duration
7.3.1 First Campaign
7.3.2 Second Campaign
8. QUALITY ASSURANCE PROJECT PLAN FOR THE PIC EMISSIONS TESTING
9. PERSONNEL QUALIFICATIONS AND ORGANIZATION
Appendix A Waste-Derived Residue Compliance Program For Beville Exemption
Appendix B Documentation Demonstrating Compliance with Tier I CO Standard
Appendix C Revised Certification of Compliance
Appendix D Multi-kiln System Removal Efficiencies Graphs
"Data in Lieu of"