Oklahoma Department of Environmental Quality s13

PERMIT MEMORANDUM 2004-076-TVR DRAFT 14

OKLAHOMA DEPARTMENT OF ENVIRONMENTAL QUALITY DRAFT

AIR QUALITY DIVISION

MEMORANDUM June 14, 2005

TO: Dawson Lasseter, P.E., Chief Engineer, Air Quality Division

THROUGH: Ing Yang, P.E., New Source Permit Section

THROUGH: Grover Campbell, P.E., Existing Source Permit Section

THROUGH: Peer Review

FROM: Donna Lautzenhiser, E.I., New Source Permit Section

SUBJECT: Evaluation of Permit Application No. 2004-076-TVR

Duke Energy Field Services, Inc

Hemphill-Seiling Compressor Station

SE ¼, Section 4, T19N, R17W

Seiling, Dewey County, Oklahoma

Directions: From Seiling, 4 miles west on HWY 60 to facility gate.

SECTION I. INTRODUCTION

Duke Energy Field Services LP (DEFS) has requested renewal of their current Part 70 operating permit. The facility is currently operating under Permit No. 97-216-TV PSD. That permit was issued on August 30, 1999, and expired on August 31, 2004. The facility has a potential for issues regarding formaldehyde emissions non-compliance with the MAAC standards. No changes for MAAC compliance are being made to the facility pending the outcome of proposed regulatory changes to OAC 202:100-41. The permit may need to be reopened at a future date.

Since the facility potentially emits more than 100 TPY each of NOx, CO and VOC and 10/25 TPY of HAPs, it is subject to Title V permitting requirements. Emission units (EUs) have been arranged into Emission Unit Groups (EUGs) in the following outline.

SECTION II. FACILITY DESCRIPTION

This is a natural gas transmission and storage facility (SIC 4922). It has two grand-fathered 1,100-hp Superior 8GT825 engines (uncontrolled), three statutorily exempt 1,100-hp Superior 8GT825 engines (uncontrolled), and three permitted 896-hp Waukesha L7042GU stationary internal combustion engines (uncontrolled) in compressor service. Other equipment on-site includes two 200-bbl condensate tanks (out of service); one fuel-gas heater; two top-filled, pressurized (30 psig) 179-bbl condensate tanks (out of service); also, a 180-bbl new engine oil tank and a 100-bbl used engine oil tank, both bottom-filled. Three 130,000-gallon (3,095-bbl) condensate tanks are located at the adjacent shutdown “Old” Seiling Gas Plant (two of the three are in service, T-5 & T-6). Pipeline grade natural gas is the primary fuel with the engines operating continuously.

Facility Modifications

·  Disconnected two Glycol Dehydrator/Heater units because they are no longer needed.

·  Added two 206-bbl pressurized storage tanks to store condensate and separate water.

·  Modified fugitive emission to reflect update of equipment count.

·  Added to truck loading emissions to reflect condensate throughput.

·  Like-kind replacement of two compressor engines (C-6 and C-7).

SECTION III. EQUIPMENT

EUG 1 Grandfathered Engines

EUG 2 Permitted Engines

EUG 3 Glycol Dehydrators (removed)

EUG 4 Tanks

* Tanks 1 & 2 are rarely used and are considered to be “out of service”.

** Tanks 3 & 4 have vapor pressure <1.5 psia and are exempt under OAC 252:100-37-4.

*** Tanks 5 & 6 are pressurized bullet tanks.

EUG 5 Heater

EUG 6 Fugitives

Stack Parameters

Superior 8GT825

SECTION IV. EMISSIONS

Emissions estimates for engines C-1 through C-5 are based on continuous operation and manufacturer’s emission data (NOx: 15 g/hp-hr; CO: 15 g/hp-hr; VOC: 2.0 g/hp-hr). Emissions estimates for engines C-6 through C-8 are based on continuous operation and limits from Permit No. 97-216-TV (PSD) (NOx: 11.3 g/hp-hr; CO: 13.5 g/hp-hr; VOC: 0.2 g/hp-hr). Estimated emissions for the tanks are based on TANKS3.0. Fugitive VOC emissions are based on EPA’s 1995 Protocol for Equipment Leak Emission Estimates (EPA-453/R-95-017). VOC emissions are defined as in OAC 252:100-37.

EUGs 1 & 2 Engines

Brake-specific fuel consumption for each 896-hp Waukesha engine is listed at 8,389 BTU/hp-hr for a fuel consumption of 7,517 SCFH. Air emissions from the engine will be discharged through a stack 0.67 feet in diameter, 17 to 18.3 feet above grade, at a rate of 2,875-acfm at 840 °F. Moisture content of the stack gases has been estimated at 21% from fuel usage and the stoichiometric ratio of two SCF of water per SCF of natural gas fuel.

Toxic Emissions

The facility must demonstrate compliance with the ODEQ Ambient Air Quality Standards for nitrogen dioxide of 100 µg/m3 and the Maximum Acceptable Ambient Concentration (MAAC) standards included in OAC 252:100-41 for formaldehyde. The MAAC standard for formaldehyde is 12 µg/m3 and simply establishes the maximum allowable twenty-four hour average ambient air concentration that is acceptable for public exposure.

To assess the nitrogen dioxide and formaldehyde impacts from the Hemphill-Seiling Compressor Station, the latest version of the U.S. EPA ISCST3 model was used. The applicant supplied modeling demonstrating that the applicant is potentially unable to meet the MAAC for formaldehyde and the NAAQS for NOx. The modeling that indicated the potential exceedence of the ambient air standards is based on conservative (worst case) modeling techniques which are not representative of actual operating conditions of the Facility. Further, DEFS is unaware of any monitoring data that would indicate a violation of the standard. Since the Air Quality Division (AQD) is in the process of reviewing and proposing significant changes to Subchapter 41, the permit will be issued without the BACT review and without MAAC or NAAQS compliance. However, the permit will be re-opened to address compliance with the finalized rule.

EUG 3 Glycol Dehydrators (removed)

EUG 4 Tanks

* Out of Service

** Tanks are pressurized, emissions shown are flash emissions for all tanks estimated using Vasquez-Beggs Solution.

Wet gas enters the inlet scrubber at a pressure between 100-psig and 150-psig. Free liquids are removed from the gas and piped to the first pressurized condensate tank (T-5). The first tank is maintained at a pressure of 30-psig utilizing station discharge gas as a blanket gas filling any head space in the tank. All overheads from the T-5 are routed to the low-pressure inlet of the Orion Compressor via pipeline. T-5 is used to stabilize the liquids at the lower pressure and to remove as much water as possible. The remaining liquids (condensate) are moved to the second storage tank (T-6) that is maintained at a pressure of 10-psig. T-6 is vented to the atmosphere. There are two additional pressurized condensate storage tanks (T-1 and T-2) that are rarely used. Because the condensate storage tanks are designed to operate under pressure, breathing losses are nonexistent. The primary source of VOC emissions results from the flashing of the condensate as the pressure drops from 30-psig to 10-psig. Flash emissions were calculated at 30-psig and 10-psig using the Vasquez-Beggs Solution Gas/Oil Ratio Correlation Method. The difference of these two values gives us the resulting flash emissions.

EUG 5 Fuel Gas Heater

EUG 6 Fugitives*

* Equipment count from similar facility.

** Source: EPA Protocol for Equipment Leak Emission Estimates, Nov., 1995, EPA-453/R-95-017.

Loading Emissions

Throughput,

Gallons/year

Total Potential Emissions

C-1

SECTION V. INSIGNIFICANT ACTIVITIES

The insignificant activities identified and justified in the application are duplicated below. Records are available to confirm the insignificance of the activities. Appropriate record keeping of activities indicated below with “*” is specified in the Specific Conditions.

1. Space heaters, boilers, process heaters and emergency flares less than or equal to 5 MMbtu/hr heat input (commercial natural gas). The fuel-gas heater meet this criteria.

2. Emissions from crude oil or condensate marine and truck loading equipment operations at crude oil and natural gas production sites where the loading rate does not exceed 10,000 gallons per day averaged over a 30-day period. Unloading of tanks T-5 and T-6 into tank trucks is less than 10,000 gallons/day.

3. * Activities that have the potential to emit no more than 5 TPY (actual) of any criteria pollutant. No activities were identified at this time but may be in the future.

SECTION VI. PAST PSD REVIEW

On October 16, 1987, Don Morris of the Oklahoma State Department of Health, Air Quality Service, wrote the following memo regarding Permit No. 86-010-O (PSD).

“Panhandle Eastern was issued a construction permit on May 27, 1986, to add three identical IC engine/compressor units at this existing station where the company already operated five IC engine/compressor units, one gas turbine/compressor unit and three gas-fired heaters.

Each of the three new engines is an 896-hp naturally aspirated Waukesha L7042G with an 8 inch by 18 foot stack. The company was allowed to test one engine of the set as a representative unit for the PSD performance test. The test was conducted July 1, 1987, by Cubix Corporation, Austin, TX, with Robert E. Culien of Air Quality Service present as observer.

A series of five tests was conducted at varying air-fuel ratio settings and one fixed timing setting. The pollutants of primary concern are nitrogen oxides (NOx) and carbon monoxide (CO). The construction permit limitations for these pollutants were 10.4 and 11.2 grams per horsepower-hour (g/hp-hr), respectively.