PERMIT MEMORANDUM 2007-206-C DRAFT 11
OKLAHOMA DEPARTMENT OF ENVIRONMENTAL QUALITY
AIR QUALITY DIVISION
MEMORANDUM November 15, 2007
TO: Phillip Fielder, P.E., Permits and Engineering Group Manager,
Air Quality Division
THROUGH: Matt Paque, Supervising Attorney, Air Quality Division
THROUGH: Kendal Stegmann, Senior Environmental Manager, Compliance and Enforcement
THROUGH: David Schutz, P.E., New Source Permit Section
THROUGH: Phil Martin, P.E., Engineering Section
THROUGH: Peer Review
FROM: Grover R. Campbell, P.E., Existing Source Permit Section
SUBJECT: Evaluation of Permit Application No. 2007-206-C
Timberline Energy, LLC
Timberline Energy at the Oklahoma City Landfill
7600 SW 15th Street, Oklahoma City
Latitude 35.450°, Longitude -97.648º
SECTION I. INTRODUCTION
Timberline Energy, LLC (Timberline) has filed an application for construction of a landfill gas (LFG) treatment system at the existing Oklahoma City Landfill (Landfill), which is owned and operated by Oklahoma City Waste Disposal, Inc. Methane and nitrogen from LFG will be recovered and sold as pipeline gas with the vent gas (mostly CO2) from the LFG treatment system combusted in a thermal oxidizer. AQD considers the two facilities a single stationary source for purposes of PSD and Title V. The Landfill is required under NSPS Subpart WWW to operate under a Part 70 permit; therefore, the Timberline facility will also be required to operate under a Part 70 permit and a major source construction permit is required to construct the Timberline facility. This application will be processed under Tier II.
Oklahoma City Waste Disposal, Inc was issued construction Permit No. 96-091-C (M-1) on January 17, 2007. The Landfill was permitted to upgrade its existing John Zink enclosed flare and to add industrial wastewater E-VAP® Units that would allow the Landfill to evaporate non-hazardous industrial wastewater; however, neither the replacement enclosed flare or the E-VAP® Units were constructed. The Timberline LFG treatment system replaces that project. An application for the Landfill’s initial Title V permit was received on March 4, 1999. That application is still under technical review by AQD.
SECTION II. TOTAL SITE EMISSIONS
Timberline and Oklahoma City Waste Disposal, Inc. are two separate entities; however, emissions from the Timberline facility and the Landfill will be aggregated for purposes of PSD applicability and NSPS and NESHAP regulations. Emissions from the total site are lower when the Timberline LFG treatment system is in operation, since most of the methane in the LFG is recovered instead of being combusted. Table II-1 shows the current potential emissions from the Landfill with the LFG combusted in the Landfill’s enclosed flare. Table II-2 shows the potential emissions from the Timberline facility when LFG from the Landfill is processed in the Timberline LFG treatment system rather than being combusted in the Landfill’s enclosed flare. Table II-3 shows the total site potential emissions when LFG from the Landfill is processed in the Timberline LFG treatment system rather than being combusted in the Landfill’s enclosed flare. Under either operating scenario, emissions from the total site are less than major source thresholds for both criteria pollutants and HAP. Landfill emissions estimates are from Permit No. 96-096-C (M-1).
Table II-1. Landfill Potential Emissions with Enclosed Flare
NOX / CO / VOC (1) / SO2 / PM / HAP (2)lb/hr / TPY / lb/hr / TPY / lb/hr / TPY / lb/hr / TPY / lb/hr / TPY / lb/hr / TPY
6.3 / 28 / 19 / 83 / 4.7 / 21 / 1.1 / 4.8 / 2.3 / 10 / 0.53 / 5.6
1. 1.8 TPY from the enclosed flare and 19 TPY from uncollected fugitive LFG.
2. 2.3 TPY of HCl from the enclosed flare and 3.3 TPY of other HAP emitted from uncollected fugitive LFG.
Table II-2. Timberline Facility Potential Emissions
NOX / CO / VOC / SO2 (1) / PM / HAP (2)lb/hr / TPY / lb/hr / TPY / lb/hr / TPY / lb/hr / TPY / lb/hr / TPY / lb/hr / TPY
2.1 / 9.4 / 2.0 / 8.8 / 0.04 / 0.18 / 0.67 / 2.9 / 0.1 / 0.4 / 0.36 / 1.6
1. Part of total sulfur in the LFG remains in the treated gas sent to pipeline.
2. All but 0.1 TPY is HCl.
Table II-3. Total Site Potential Emissions
NOX / CO / VOC (1) / SO2 / PM / HAP (2)lb/hr / TPY / lb/hr / TPY / lb/hr / TPY / lb/hr / TPY / lb/hr / TPY / lb/hr / TPY
2.1 / 9.4 / 2.0 / 8.8 / 4.4 / 19 / 0.67 / 2.9 / 2.3 / 10 / 1.1 / 4.9
1. All but 0.2 TPY is from uncollected fugitive LFG.
2. 1.6 TPY of HAP from the Timberline thermal oxidizer and 3.3 TPY of other HAP emitted from uncollected fugitive LFG.
SECTION III. FACILITY AND PROCESS DESCRIPTION
Process Description (Landfill)
At landfills, microbiological processes associated with waste decomposition result in the production of landfill gas (LFG), which is composed primarily of methane (CH4) and carbon dioxide (CO2). The CO2 composition in LFG ranges from 30% to 50% and the methane composition ranges from 40% to 60%. Initial decomposition of the wastes is rapid and continuous until the entrained oxygen (O2) within the refuse is depleted. The second stage of decomposition is anaerobic that can be divided into two separate and independent processes; non-methanogenic and methanogenic. CO2 is a byproduct of the non-methanogenic process and methane is a byproduct of the methanogenic process. LFG may also contain small amounts of non-methane organic compounds (NMOC), which include trace amounts of volatile organic compounds (VOC) and hazardous air pollutants (HAP). The production of LFG begins a few months after initial waste placement and continues until the microbial reactions are limited by substrate or moisture availability. LFG production is also affected by the solid waste disposal rate and varies over the life of the landfill. Generally, LFG production increases with time until a peak volume is reached shortly after landfill closure.
At the Landfill, an active gas collection system collects the LFG by a network of extraction wells (approximately 28 at this site) and pipes. A blower supplies the partial vacuum necessary to extract the LFG from the landfill and discharge it to an enclosed flare for combustion. The collected LFG is passed through a water knockout prior to being metered through an orifice meter. Condensate is injected into the enclosed flare also.
The existing John Zink enclosed flare is designed to combust up to 2,300 scfm of LFG at a minimum operating temperature of 1,400oF and a typical residence time of less than 1 second. This assures 98 percent destruction of VOC and HAP. All gases combusted in the enclosed flare are products of decomposition of municipal solid waste. Propane is available for startup of the flare if necessary.
Process Description (LFG Treatment System)
2.5 MMSCFD of LFG from the existing blower flows to a 1st stage of compression to increase the pressure to about 210 psig. The LFG is then processed in the LFG treatment system. Trace volatile organic compounds, sulfur compounds, carbon dioxide, oxygen, and particulate matter are removed from the LFG. The carbon dioxide, sulfur compounds, and VOC removed from the LFG are then vented to a thermal oxidizer that is operated at a temperature of approximately 1,500°F.
Approximately 1.5 MMSCFD of processed LFG is then compressed to about 300 psig and blended with an equal amount of pipeline grade natural gas. The blended gas stream is then compressed to 450-650 psig and transported by pipeline to an industrial customer.
SECTION IV. TIMBERLINE FACILITY EMISSIONS
All compressors are driven by electric motors. Fugitive VOC emissions from the LFG treatment system are negligible since LFG consists mostly of methane, carbon dioxide, and nitrogen. Emissions of VOC, SO2, and HAP (including HCl) from the thermal oxidizer are based on the manufacturer’s maximum design flowrate of 1,000 scfm, a destruction efficiency of 99%, and the vent stream’s estimated concentration (ppmv) of VOC, SO2, HCl, and other HAP, which were calculated using AP-42, Section 2.4 for Municipal Solid Waste (MSW) Landfills. Emissions of NOX are based on the manufacturer’s design heat rate of 5.35 MMBtu/hr and manufacturer’s emission factor of 0.4 lb/MMBtu. Emissions of CO are based on the emissions factor of 0.37 lb/MMBtu for industrial flares in AP-42(9/91), Section 13.5.1. Emissions of PM are based on an emission factor of 0.001 lb/hr/scfm of methane combusted from AP-42 (11/98), Table 2.4-5 (10% of the vent gas stream is methane).
Facility Potential Emissions
NOX / CO / VOC / SO2 (1) / PM / HAP (2)lb/hr / TPY / lb/hr / TPY / lb/hr / TPY / lb/hr / TPY / lb/hr / TPY / lb/hr / TPY
2.1 / 9.4 / 2.0 / 8.8 / 0.04 / 0.18 / 0.67 / 2.9 / 0.1 / 0.4 / 0.36 / 1.6
1. Part of total sulfur in the LFG remains in the treated gas sent to pipeline.
2. All but 0.1 TPY is considered HCl.
SECTION V. INSIGNIFICANT ACTIVITIES
No insignificant activities were listed in the application.
SECTION VI. OKLAHOMA AIR POLLUTION CONTROL RULES
OAC 252:100-1 (General Provisions) [Applicable]
Subchapter 1 includes definitions but there are no regulatory requirements.
OAC 252:100-2 (Incorporation by Reference) [Applicable]
This subchapter incorporates by reference applicable provisions of Title 40 of the Code of Federal Regulations. These requirements are addressed in the “Federal Regulations” section.
OAC 252:100-3 (Air Quality Standards and Increments) [Applicable]
Subchapter 3 enumerates the primary and secondary ambient air quality standards and the significant deterioration increments. At this time, all of Oklahoma is in attainment of these standards.
OAC 252:100-5 (Registration, Emissions Inventory and Annual Operating Fees) [Applicable]
Subchapter 5 requires sources of air contaminants to register with Air Quality, file emission inventories annually, and pay annual operating fees based upon total annual emissions of regulated pollutants.
OAC 252:100-8 (Major Source/Part 70 Permits) [Applicable]
Part 5 includes the general administrative requirements for Part 70 permits. Any planned changes in the operation of the facility which result in emissions not authorized in the permit and which exceed the “Insignificant Activities” or “Trivial Activities” thresholds require prior notification to AQD and may require a permit modification. Insignificant activities mean individual emission units that either are on the list in Appendix I (OAC 252:100) or whose actual calendar year emissions do not exceed the following limits:
5 TPY of any one criteria pollutant
2 TPY of any one hazardous air pollutant (HAP) or 5 TPY of multiple HAPs or 20% of any threshold less than 10 TPY for single HAP that the EPA may establish by rule
Emissions limitations have been established for each emission unit based on information from the permit application.
OAC 252:100-9 (Excess Emission Reporting Requirements) [Applicable]
In the event of any release which results in excess emissions, the owner or operator of such facility shall notify the Air Quality Division as soon as the owner or operator of the facility has knowledge of such emissions, but no later than 4:30 p.m. the next working day. Within ten (10) working days after the immediate notice is given, the owner or operator shall submit a written report describing the extent of the excess emissions and response actions taken by the facility. In addition, if the owner or operator wishes to be considered for the exemption established in OAC 252:100-9-3.3, a Demonstration of Cause must be submitted within 30 calendar days after the occurrence has ended.
OAC 252:100-13 (Open Burning) [Applicable]
Open burning of refuse and other combustible material is prohibited except as authorized in the specific examples and under the conditions listed in this subchapter.
OAC 252:100-19 (Particulate Matter) [Not Applicable]
This subchapter specifies PM emissions limitations from fuel-burning units. The thermal oxidizer does not meet the definition of “fuel-burning unit.”
OAC 252:100-25 (Visible Emissions and Particulates) [Applicable]
No discharge of greater than 20% opacity is allowed except for short-term occurrences which consist of not more than one six-minute period in any consecutive 60 minutes, not to exceed three such periods in any consecutive 24 hours. In no case shall the average of any six-minute period exceed 60% opacity. This facility has a low potential to exceed these standards when burning natural gas and a vent gas stream in the thermal oxidizer.
OAC 252:100-29 (Fugitive Dust) [Applicable]
This subchapter states that no person shall cause or permit the discharge of any visible fugitive dust emissions beyond the property line on which the emissions originate in such a manner as to damage or to interfere with the use of adjacent properties, or cause air quality standards to be exceeded, or interfere with the maintenance of air quality standards. This facility has negligible potential to violate this requirement under normal operating conditions; therefore, it is not necessary to require specific precautions to be taken.
OAC 252:100-31 (Sulfur Compounds) [Applicable]
Part 2 limits emissions of sulfur dioxide from any one existing facility or any one new petroleum and natural gas process facility with equipment subject to OAC 252:100-31-26(a)(1). Ambient air concentration of sulfur dioxide at any given point shall not be greater than 1,300 mg/m3 in a 5-minute period of any hour, 1,200 mg/m3 for a 1-hour average, 650 mg/m3 for a 3-hour average, or 130 mg/m3 for a 24-hour average. LFG does not meet the definition of natural gas. However, with potential emissions of only 0.7 lb/hr of SO2 from a thermal oxidizer, there is negligible potential to violate this requirement.