||Gossman Consulting, Inc.|
Changes Required in Hazardous Waste Incinerator Trial Burns and Waste Analysis Plans to Fully Implement "BIF" Requirements
Gossman Consulting, Inc.
Over the past several years, many comparisons have been made between thermal treatment in hazardous waste incinerators and thermal treatment in cement kilns. [Regulated under 40CFR Part 266 - boiler and industrial furnace regulations (BIF).] These comparisons have not always been particularly technical in nature. One such argument claims that just because a hazardous waste incinerator is designed to destroy hazardous waste (as built) this somehow makes it the better thermal treatment option. A companion argument is that incinerators are more stringently regulated. (Interesting enough, page 7188 of the BIF preamble states that BIF is more stringent than incinerator regulations.) This paper examines changes required by trial burns and waste analysis plans for waste incinerators in order to comply with regulations currently only applicable to BIF units.
The initial RCRA standard for the incineration of hazardous waste (currently 40CFR Parts 264 and 265, Subpart O) came into existence on or about May 19, 1980. Regulations governing the use of hazardous waste in cement kilns were first proposed in 1987. Initial attempts at regulating hazardous waste use in cement kilns centered around regulating the cement manufacturing process very similar to hazardous waste incinerators. Complex discussions about the inherent technical differences between hazardous waste incinerators and cement kilns resulted in USEPA attempts to incorporate those differences in regulatory supplements in 1989 & 1990. Ultimately, USEPA attempts to regulate cement kilns like hazardous waste incinerators yet somehow incorporating the inherent technical differences proved difficult. Consequently, the final rule for burning hazardous waste in BIFs went into effect in 1991 with such confusing requirements as limits on hydrocarbons and CO (which turned out to be non-combustion related) and limits on cement clinker production.
The BIF rules did result in the collection of comprehensive data on the burning of hazardous waste derived fuels at 24 cement plants with over 30 cement kilns. This data was first compiled into one report with the publishing of Commercial BIF Compliance Test Results - 1992(1). This report was followed up later in 1993 with the Commercial Incinerator Trial Burn Report(2). Some of the data presented in this paper comes from these two reports. In addition, a third report entitled Commercial Thermal Treatment Facility Waste Analysis Plans(3) (1995) will also be used and referenced in this paper.
COMPLIANCE TEST RESULTS REPORTING
Much has been made by some members of the hazardous waste incinerator industry that cement kilns burning hazardous waste are not regulated as stringently as are hazardous waste incinerators. Review of the compliance test and trial burn data from both incinerators and cement kilns reveals that only particulates and HCl were treated in a similar manner for both thermal treatment processes. Dioxin emissions testing was performed on 23 of 31 cement kilns tested while only 4 of 20 hazardous waste incinerators performed dioxin emissions testing between May 1988 and March 1993. Metals emissions testing was also more comprehensive for cement kilns than for incinerators, with all 31 cement kilns reporting metals emissions results and only 13 of 20 hazardous waste incinerators reporting metals emissions results. In addition, while 18 of 31 cement kilns reported metals emissions data for all ten BIF metals (As, Be, Cd, Cr, Pb, Sb, Ba, Hg, Ag, & Tl), only 7 of 20 hazardous waste incinerators reported metals emissions for the same ten metals and 7 incinerators did not report any metals emissions data as part of their trial burns.
BOILER AND INDUSTRIAL FURNACE REQUIREMENTS
The BIF rules require that cement kilns that burn hazardous waste must comply with regulatory limits on emissions of particulate matter, metals, HCl/Cl2, total hydrocarbons, and carbon monoxide (Table 1). Automatic waste fuel cut offs are established based upon limitations such as total kiln raw feed rate, total hazardous waste fuel feed rate, ESP power or bag house pressure drops and combustion chamber (burn zone) temperatures. The primary focus of performing the associated compliance testing and setting limits is demonstrating that the kiln can be operated in accordance with the emission standards during worst case operational conditions for the testing. Contrary to some perceptions, worst case has nothing to do with normal operating conditions. Worst case means just what the name implies. It means putting your kiln into the worst possible operating scenario (which any good kiln operator desperately tries to avoid) and conducting compliance testing at maximum input rates, particularly with regards to metals, and demonstrating that your kiln can still comply with applicable regulations and make useable clinker. These required test conditions represent the worst possible operating conditions and are only artificially induced, during an approximate one week test period every three years, because the regulations require that compliance under these conditions be demonstrated. Consequently, any assumptions on the part of the USEPA or others that the BIF data collected in 1992 is representative of normal day-to-day operations at a cement plant burning hazardous waste is technically inaccurate and demonstrates a lack of technical understanding of how cement plants normally operate.
For the sake of comparison, this paper examines and compares the boiler and industrial furnace regulatory requirements with trial burn emissions test data of the Rollins hazardous waste incinerator in Bridgeport, New Jersey(4), as well as the broader universe of commercial incinerators.
INCINERATOR COMPLIANCE WITH BIF REGULATIONS
The Rollins Bridgeport, New Jersey facility was chosen because it was one hazardous waste incinerator that reported fairly comprehensive test data so that a comprehensive comparison could be made with the BIF regulations. Twenty compliance test/trial burns for commercial hazardous waste incinerators were obtained and analyzed for the Commercial Incinerator Trial Burn Report. The Rollins, New Jersey facility was only one of two facilities that reported test data for both dioxins and PICs. Again, this incinerator test data was collected between May 1988 and March 1993 and is the trial burn data that was available in 1993.
A particularly difficult operational factor for cement kilns has been the establishment of automatic waste fuel cut offs (AWFCOs). From an operational standpoint, it is difficult to think of a more potentially operationally upsetting process than having a major source of fuel cut off while trying to smoothly operate and control kiln operation. Operating a kiln is complex and difficult within the framework of usual operational factors. The introduction of AWFCOs, a process that can completely cut out a key operating parameter makes kiln control much more difficult. This has been one of the most difficult factors for the hazardous waste burning cement manufacturers to accept. Consequently, it was surprising to learn that automatic waste fuel cut offs were not even mentioned in the February 1990 Test Burn Source Emissions Compliance Test Report for the Rollins, New Jersey facility, especially since 40CFR 264.345(e) calls for "a functioning system to automatically cut off waste feed..."
As mentioned previously, the Rollins, New Jersey facility did report fairly comprehensive test data. However, four additional BIF requirements were not addressed. Neither a maximum nor a minimum combustion zone temperature were established (or at least was not reported) and neither an air pollution control device (APCD) inlet temperature nor an APCD bag house pressure drop were established in the report. It was also unclear as to whether or not worst case operational conditions were targeted for the testing. The stated objective was "to determine the emissions compliance status of the thermal processing system with New Jersey Department of Environmental Protection (DEP) permit emission limitations for hazardous waste incineration as required to complete the permitting process." Again, no mention was made as to normal vs. worst case operating conditions.
WASTE ANALYSIS PLANS
Table 2 presents a comparison of typical analytical components for a BIF waste processing facility waste analysis plan (WAP) with the July, 1995 WAP(5) for the Rollins, New Jersey commercial hazardous waste incinerator. The analytical parameters listed in Table 2 are used at many of the cement kilns that burn hazardous waste as fuel, however, only the metals and chlorine analysis are actual Federal BIF requirements. The 1995 Rollins, New Jersey WAP more than meets the basic BIF WAP requirements although it is not quite as comprehensive as some cement kiln WAPs currently in effect.
It seems very likely that incinerators are going to find very different compliance/trial burn testing scenarios in the future. Proof of worst case operational conditions while performing compliance stack testing and the establishment of automatic waste fuel cut offs seem inevitable. Simply put, an increase in the level of scrutiny experienced by commercial hazardous waste incinerators has already begun, as witnessed most recently at the WTI incinerator in East Liverpool, Ohio. It is obvious that Rollins, New Jersey has improved their 1995 WAP to withstand an increased level of scrutiny as compared to their 1990 compliance test reviewed in this paper. Thermal treatment in general is experiencing and will continue to experience a high level of regulatory scrutiny for the foreseeable future.
It is worth noting that commercial hazardous waste incineration and hazardous waste burning in the cement kiln manufacturing process are both viable thermal treatment options and actually compliment one another. Both industries should focus on those complimentary aspects and consider joining together to face an uncertain thermal treatment future.
Table 1. BIF parameter compliance comparison.
|# Commercial Incinerators Performed|
|POHCs (DRE)||YES||3 POHCs||18/20|
|APCD Inlet Temperature||YES||NO||NR*|
|Combustion Zone Temperature (Max.)||YES||NO||14/20|
|Combustion Zone Temperature (Min.)||YES||NO||14/20|
|Maximum Gas Flow Rate||YES||YES||18/20|
|APCD Power Level or Pressure Drop||YES||NO||NR*|
|Metals Fate (balance)||YES||ATTEMPTED||NR*|
(Tier III Max.)
|Chlorine Input Rate||YES||YES||14/20|
* - Not reported in trial burn reports reviewed.
Table 2. Comparison of typical
BIF related components for Waste Analysis Plans with the July, 1995
Rollins-New Jersey Waste Analysis Plan and other commercial
incinerators with hazardous waste burning cement kilns.
|# Waste Burning
As, Be, Cd, Cr, Pb, Sb, Ba, Tl, Hg, Ag
|Toxic Organic Screen(c)||1/16||10/22|
(a) - 266.102(e)(6)(iii) and 266.103(b)(3)(ii & iii), guidance frequently requires additional parameters.
(b) - Parameters tested on each blended batch of waste prior to combustion.
(c) - Parameters tested on each waste receipt or blended batch prior to combustion.
- See end note #3.
1. Commercial BIF Compliance Test Results - 1992, Gossman Consulting, Inc., Hampshire IL, 1993.
2. Commercial Incinerator Trial Burn Report, Gossman Consulting, Inc, Hampshire IL, 1994.
3. Commercial Thermal Treatment Facility Waste Analysis Plans, Gossman Consulting, Inc., Hampshire IL, 1995.
4. Test Burn Source Emissions Compliance Test Report, Rollins Environmental Services Inc., Bridgeport NJ, 1990.
5. Waste Analysis Plan, Rollins Environmental Services Inc., Bridgeport NJ, 1995.