Standard Exemptions 81 - 89, July 26, 1985
Clicking on a highlighted number below links you to the standard exemption.81 | 82 | 83 | 84 | 85 | 86 | 87 | 88 | 89
81. Any elevated, vertical, smokeless process flare system provided that the following conditions are satisfied:
- There shall be no visible emissions from the flare for more than five (5) minutes in any two (2) hour period.
- The flare is equipped with a continuously burning pilot system or other automatic ignition system that assures flare ignition and that provides immediate notification of appropriate supervisory personnel that when the ignition system ceases to function properly.
- The flare burns waste gases containing only carbon, hydrogen, oxygen or compounds derived from these elements. (Flares burning waste gases containing sulfur shall comply with the heat release requirements of condition (4) of Standard Exemption 88.)
- The height of the flare is at least 25 feet.
82. Any pressure vessel storing carbon compounds composed only of carbon, hydrogen or oxygen provided that the pressure vessel vent is directed to an incinerator, boiler or other firebox having a stationary flue or a waste gas flare system that will operate with no visible emissions except as provided by the General Rules. However, pressure vessels not exceeding 100 barrels capacity and storing only liquified petroleum gases (LPG) or liquified natural gases (LNG) may have their vents routed directly to the atmosphere.
83. Any pressure vessel storing carbon compounds provided that the pressure vessel maintains working pressures sufficient at all times to prevent vapor or gas loss to the atmosphere.
84. Anhydrous ammonia storage tanks and distribution facilities that meet the following conditions:
- The tank is located at least 1/4 mile from any recreational area or residence or other structure not occupied or used solely by the owner of the facility or the owner of the property upon which the facility is located.
- The capacity of the storage tanks is 30,000 gallons or less.
- When transferring ammonia, all vapors shall be vented back to the host tank and never to the atmosphere.
- When relieving pressure from connectors and hoses, all vapors shall be bled into an adequate volume of water and never to the atmosphere.
- Each tank is equipped in a manner that will prevent unauthorized operation.
- Before construction/installation of the facility begins, written site approval must be received from the Executive Director of the Texas Air Control Board and the facility shall be registered with the appropriate Regional Office using Form PI-7.
85. All aqueous fertilizer storage tanks.
86. Any fixed roof or floating roof storage tank greater than 40,000 gallons capacity or change of chemical service in any such tank, used to store chemicals or mixtures of the chemicals shown in attached Table 86A provided that the following conditions are satisfied:
- The tank is located at least 500 feet from any recreational area or residence or other structure not occupied or used solely by the owner of the facility or the owner of the property upon which the facility is located.
- The total emission of non-methane, non-ethane carbon compounds is less than 25 tons per year.
- The true vapor pressure of the compound to be stored is less than eleven (11.0) psia at the maximum storage temperature.
- For those compounds that have a true vapor pressure greater than 0.5 psia and less than 11.0 psia at the maximum storage temperature, the storage vessel shall be equipped with an internal floating roof or equivalent control. (An open top tank containing an external floating roof using double seal or secondary seal technology shall be an approved control alternative to an internal floating roof tank provided the primary seal consists of either a mechanical shoe seal or a liquid-mounted seal. Double seals having a vapor-mounted primary seal are an approved control alternative for existing external floating roof tanks undergoing a change of service).
- For any tank equipped with a floating roof the integrity of the floating roof seals shall be verified annually and records maintained to describe dates, seal integrity and corrective actions taken.
- The floating roof design shall incorporate sufficient flotation to conform to the requirements of API Code 650, Appendix C or an equivalent degree of flotation.
- Compounds with a true vapor pressure of 0.5 psia or less at the maximum storage temperature may be stored in a fixed roof tank which includes a submerged fill pipe or utilizes bottom loading.
- For fixed or cone roof tanks have no internal floating cover, all uninsulated tank exterior surfaces exposed to the sun shall be painted chalk white except where a dark color is required for product heating.
- Emissions shall be calculated by methods outlined in Section 4.3 of EPA Publication AP-42.
- Before construction begins, storage tanks of 25,000 gallons capacity or greater and located in a designated non-attainment area for ozone shall be registered with the appropriate Regional Office using Form PI-7. The exemption registration shall include the following supplemental information:
(a) Table 1 of Form PI-2 listing all tanks and calculated emissions for each carbon compound in tons per year for each tank. (b) Table 7 of Form PI-2 - One table for each different tank design.
11. Prior approval of the Executive Director of the Texas Air Control Board shall be obtained before the chemical service of a storage tank is changed to store a chemical not listed in Table 86A. It will not be necessary to obtain reapproval for chemicals previously approved for service in a specific tank. 12. Mixtures of the chemicals listed in Table 86A which contain more than a total of one percent by volume of all other chemicals not listed in Table 86A are not covered by this exemption.
Acetal, Acetone, Amyl Acetate, Amyl Alcohol
Butyl Acetate, Butyl Alcohol, Butyl Ether, Butyl Formate,
Cellosolves, Cellosolve Acetates, Crude Oil, Crude Oil Condensates, Cyclohexane, Cyclohexene, Cyclopentane, Cyclopentanol, Cyclopentanone, Cyclopentene
Diethyl Ketone, Dipropyl Ketone
Ethyle Acetate, Ethyl Alcohol, Ethyl Benzene, Ethyl Butyrates, Ethyl Cyclohexane, Ethyl Cyclopentane, Ethyl Formate, Ethyl Hexane, Ethyl Pentane, Ethyl Propionate
Gasoline, Gasoline Additives (non-metallic)
Heptane, Heptene, Hexane, Hexene, Hexanone
Isobutyl Acetate, Isobutyl Isobutyrate, Isohexane, Iso Octane, Isopropyl Acetate, Isopropyl Alcohol, Isopropyl Ether
Methyl Acetate, Methyl Alcohol, Methyl Amyl Alcohol, Methyl Butyrate, Methyl Cyclohexane, Methyl Cyclopentane, Methyl Heptane, Methyl Hexane, Methyl Isoamyl Ketone, Methyl Isobutyl Ketone, Methyl Pentane, Methyl Propionate, Methyl Propyl Ketone
Naphtha, Natural Gas Condensate, Neohexane
Propyl Acetate, Propyl Alcohol, Propyl Formate, Propyl Propionate
Refinery Petroleum Products containing less than 10 percent benzene
Vinyl Acetate, Varsol
87. Any new or modified production tank battery processing sweet crude oil and condensate and consisting of one or more separators, salt water tanks, stock tanks and heater treaters provided that the following conditions are satisfied:
1. The plant is located at least 1/4 mile from any
recreational area or residence or other structure not occupied or
used solely by the owner of the facility or the owner of the
property upon which the facility is located.
2. Gas-oil separators and combustion units at a tank battery meet the requirements of Standard Exemptions No. 64 and 65 respectively.
3. The total emissions of non-methane, non-ethane volatile organic compounds are no more than 25 tons per year. Emissions shall be determined as follows:
(a) The vents shall be measured with an orifice well tester for a period of at least 24 hours. The average molecular weight and composition of the vent stream shall be determined by an analysis of the gas stream. The vent rates shall be measured when the oil or condensate production rate is at least 30 percent of the maximum production expected from the battery and the vent rates shall be corrected to the maximum expected production rate by multiplying by the appropriate factor as follows:
Vmax=Vmeas x Pmax/Pmeas
Vmax = maximum expected vent rate
Vmeas = measured vent rate
Pmax = maximum expected oil production rate
Pmeas = oil production rate during vent measurement
(b) The vents may be measured as in method (a); however, instead of analyzing the composition of the vent stream, the average molecular weight can be assumed to be 50 lb/lb mole and the composition to be 75 weight percent non-methane, non-ethane hydrocarbons.
(c) Emissions from tankage may be calculated by performing flash calculations based on an analysis of the crude oil or condensate from the separator or heater treater plus appropriate temperature and pressure data.
(d) For batteries with no more than 250 barrels per day of production and liquid volatility no more than 5 lb. Reid, the following equation can be used to estimate the vent rate from a tank.
E = Wp M [0.0005 (P / (14.7 - P)) 0.68 D1.73 + 0.00021 P Wo]
E = Emissions of non-methane, non-ethane hydrocarbons (tons/year)
M = Average molecular weight of vapors (as determined by analysis or assumed to be 50)
Wp = Weight fraction of non-methane, non-ethane hydrocarbons in the vent (as determined by analysis or assumed to be 0.75)
P = True vapor pressure at the storage temperature (psia)
D = Tank diameter (feet)
Wo = Tank throughput (thousand barrels per year)
Total emissions shall be determined by adding the calculated emissions from each tank. Emissions from gun-barrel separators must be measured as required in either (a), (b) or (c).
NOTE: Storage tanks at tank batteries meeting the requirements of this Standard Exemption are not required to meet the requirements of Standard Exemption 86.
88. Any new or modified production tank battery processing sour crude oil and condensate and consisting of one or more separators, salt water tanks, stock tanks and heater treaters provided that the following conditions are satisfied:
(1) All requirements of Standard Exemption No. 87 for batteries handling sweet crude oil and condensate are satisfied.
(2) The total emission rate of hydrogen sulfide from operation of the battery does not exceed 4 pounds per hour.
(3) The total emission rate of hydrogen sulfide from the battery determines the required height of emission for the vents. The venting of all produced gas due to loss of the gas sales line is considered to be a condition that must meet these requirements. No vent shall be less than 20 feet high. The following table determines the minimum height required for the vents. Stack heights for emission rates not covered shall be determined by linear interpolation.
|Total H2S Emissions, lb/hr||Minimum Required Height of Stack|
(4) As an alternative to the requirements of item (3) above, vents containing up to 50 pounds per hour of hydrogen sulfide may be burned in a heater or a smokeless flare which is equipped with a continuous pilot provided that the flare or heater stack is at least 25 feet tall and the flare meets the following requirements on heat release.
Q = 0.129 x 105 (BTU/hr)/(lb/hr) x ESO2
Q = minimum required heat release, BTU/hr
ESO2 = SO2 emission, lb/hr
The total emission of sulfur dioxide form normal operation must be less than 25 tons per year.
89. Any natural gas-liquids separation plant provided that the following conditions are satisfied:
- The plant is located at least 1/4 mile from any recreational area or residence or other structure not occupied or used solely by the owner of the facility or the owner of the property upon which the facility is located.
- Emissions of non-methane, non-ethane organic compounds, including fugitive losses, are less than 25 tons per year. Emissions from storage tanks and loading operations shall be calculated using methods and factors from AP-42.
- Emissions of sulfur dioxide are less than 25 tons per year and hydrogen sulfide emission are less than 4 pounds per hour. The height of the hydrogen sulfide emission point must meet condition (3) in Exemption No. 88 for tank batteries handling sour crude oil.
- Compressors associated with this facility shall meet the requirements of Exemption No. 6.
- The appropriate regional supervisor shall be notified prior to construction.
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