Current through Register Vol. 48, No. 38, September 20, 2024
a) Compliance Required
1) Owners or operators of closed-vent systems
and control devices used to comply with provisions of this Part must comply
with the provisions of this Section.
2) Implementation Schedule
A) The owner or operator of an existing
facility that cannot install a closed-vent system and control device to comply
with the provisions of this Subpart AA on the effective date that the facility
becomes subject to the provisions of this Subpart AA must prepare an
implementation schedule that includes dates by which the closed-vent system and
control device will be installed and in operation. The controls must be
installed as soon as possible, but the implementation schedule may allow up to
30 months after the effective date that the facility becomes subject to this
Subpart AA for installation and startup.
B) Any unit beginning operation that is
subject to the provisions of this Subpart AA when operation begins must comply
with the rules immediately (i.e., must have control devices installed and
operating on startup of the affected unit); the 30-month implementation
schedule does not apply.
C) The
owner or operator of any facility in existence on the effective date of a
statutory or regulatory amendment that renders the facility subject to this
Subpart AA must comply with all requirements of this Subpart AA as soon as
practicable, but no later than 30 months after the effective date of the
amendment. When control equipment required by this Subpart AA cannot be
installed and begin operation by the effective date of the amendment, the
facility owner or operator must prepare an implementation schedule that
includes the following information: specific calendar dates for award of
contracts or issuance of purchase orders for the control equipment, initiation
of on-site installation of the control equipment, completion of the control
equipment installation, and performance of any testing to demonstrate that the
installed equipment meets the applicable standards of this Subpart AA. The
owner or operator must enter the implementation schedule in the operating
record or in a permanent, readily available file located at the
facility.
D) An owner or operator
of a facility or unit that becomes newly subject to the requirements of this
Subpart AA due to an action other than those described in subsection (a)(2)(C)
must comply with all applicable requirements immediately (i.e., the facility or
unit must have control devices installed and operating on the date the facility
or unit becomes subject to this Subpart AA; the 30-month implementation
schedule does not apply).
b) A control device involving vapor recovery
(e.g., a condenser or adsorber) must be designed and operated to recover the
organic vapors vented to it with an efficiency of 95 weight percent or greater
unless the total organic emission limits of Section
724.932(a)(1)
for all affected process vents is attained at an efficiency less than 95 weight
percent.
c) An enclosed combustion
device (e.g., a vapor incinerator, boiler, or process heater) must be designed
and operated to reduce the organic emissions vented to it by 95 weight percent
or greater; to achieve a total organic compound concentration of 20 ppmv,
expressed as the sum of the actual compounds and not in carbon equivalents, on
a dry basis, corrected to three percent oxygen; or to provide a minimum
residence time of 0.50 seconds at a minimum temperature of 760° C. If a
boiler or process heater is used as the control device, then the vent stream
must be introduced into the flame zone of the boiler or process
heater.
d) Flares
1) A flare must be designed for and operated
with no visible emissions, as determined by the methods specified in subsection
(e)(1), except for periods not to exceed a total of five minutes during any two
consecutive hours.
2) A flare must
be operated with a flame present at all times, as determined by the methods
specified in subsection (f)(2)(C).
3) A flare must be used only if the net
heating value of the gas being combusted is 11.2 MJ/scm (300 Btu/scf) or
greater and the flare is steam-assisted or air-assisted or if the net heating
value of the gas being combusted is 7.45 MJ/scm (200 Btu/scf) or greater and
the flare is nonassisted. The net heating value of the gas being combusted must
be determined by the methods specified in subsection (e)(2).
4) Exit Velocity
A) A steam-assisted or nonassisted flare must
be designed for and operated with an exit velocity, as determined by the
methods specified in subsection (e)(3), less than 18.3 m/s (60 ft/s), except as
provided in subsections (d)(4)(B) and (d)(4)(C).
B) A steam-assisted or nonassisted flare
designed for and operated with an exit velocity, as determined by the methods
specified in subsection (e)(3), equal to or greater than 18.3 m/s (60 ft/s) but
less than 122 m/s (400 ft/s) is allowed if the net heating value of the gas
being combusted is greater than 37.3 MJ/scm (1,000 Btu/scf).
C) A steam-assisted or nonassisted flare
designed for and operated with an exit velocity, as determined by the methods
specified in subsection (e)(3), less than the velocity, V, as determined by the
method specified in subsection (e)(4), and less than 122 m/s (400 ft/s) is
allowed.
5) An
air-assisted flare must be designed and operated with an exit velocity less
than the velocity, V, as determined by the method specified in subsection
(e)(5).
6) A flare used to comply
with this Section must be steam-assisted, air-assisted, or
nonassisted.
e)
Compliance Determination and Equations
1)
Reference Method 22 (Visual Determination of Fugitive Emissions from Material
Sources and Smoke Emissions from Flares) in appendix A to 40 CFR 60 (Test
Methods), incorporated by reference in 35 Ill. Adm. Code
720.111(b),
must be used to determine the compliance of a flare with the visible emission
provisions of this Subpart AA. The observation period is two hours and must be
used according to Reference Method 22.
2) The net heating value of the gas being
combusted in a flare must be calculated using the following equation:
|
HT
|
=
|
K
|
x
|
n
[SIGMA]
i=1
|
Ci
|
x
|
Hi
|
Where:
|
HT
|
=
|
the net heating value of the sample in MJ/scm; where
the net enthalpy per mole of offgas is based on combustion at 25 °C and 760
mm Hg, but the standard temperature for determining the volume corresponding to
one mole is 20 °C
|
|
K
|
=
|
1.74 x -10-7 (1/ppm)(g
mol/scm)(MJ/kcal) where the standard temperature for (g mol/scm) is 20
°C
|
|
Ci
|
=
|
the concentration of sample component i in ppm on a
wet basis, as measured for organics by Reference Method 18 (Measurement of
Gaseous Organic Compound Emissions by Gas Chromatography) in appendix A to 40
CFR 60 (Test Methods), and for carbon monoxide, by ASTM D 1946-90 (Standard
Practice for Analysis of Reformed Gas by Gas Chromatography), each incorporated
by reference in 35 Ill. Adm. Code 720.111
|
|
Hi
|
=
|
the net heat of combustion of sample component i,
kcal/gmol at 25°C and 760 mm Hg. The heats of combustion must be determined
using ASTM D 2382-88 (Standard Test Method for Heat of Combustion of
Hydrocarbon Fuels by Bomb Calorimeter (High Precision Method)), incorporated by
reference in 35 Ill. Adm. Code
720.111(a),
if published values are not available or cannot be calculated
|
3)
The actual exit velocity of a flare must be determined by dividing the
volumetric flow rate (in units of standard temperature and pressure), as
determined by Reference Methods 2 (Determination of Stack Gas Velocity and
Volumetric Flow Rate (Type S Pitot Tube)), 2A (Direct Measurement of Gas Volume
through Pipes and Small Ducts), 2C (Determination of Gas Velocity and
Volumetric Flow Rate in Small Stacks or Ducts (Standard Pitot Tube)), or 2D
(Measurement of Gas Volume Flow Rates in Small Pipes and Ducts) in appendix A
to 40 CFR 60 (Test Methods), incorporated by reference in 35 Ill. Adm. Code
720.111(b),
as appropriate, by the unobstructed (free) cross-sectional area of the flare
tip.
4) The maximum allowed
velocity in m/s, Vmax, for a flare complying with
subsection (d)(4)(C) must be determined by the following equation:
|
log10(Vmax)
|
=
|
HT + 28.8
|
|
31.7
|
Where:
|
HT
|
=
|
the net heating value as determined in subsection
(e)(2)
|
5)
The maximum allowed velocity in m/s, Vmax, for an
air-assisted flare must be determined by the following equation:
Where:
|
HT
|
=
|
the net heating value as determined in subsection
(e)(2)
|
f) The owner or operator must monitor and
inspect each control device required to comply with this Section to ensure
proper operation and maintenance of the control device by implementing the
following requirements:
1) Install,
calibrate, maintain, and operate according to the manufacturer's specifications
a flow indicator that provides a record of stream flow from each affected
process vent to the control device at least once every hour. The flow indicator
sensor must be installed in the vent stream at the nearest feasible point to
the control device inlet but before the point at which the vent streams are
combined.
2) Install, calibrate,
maintain, and operate according to the manufacturer's specifications a device
to continuously monitor control device operation, as follows:
A) For a thermal vapor incinerator, a
temperature monitoring device equipped with a continuous recorder. The device
must have accuracy of ±1 percent of the temperature being monitored in
°C or ±0.5 °C, whichever is greater. The temperature sensor must
be installed at a location in the combustion chamber downstream of the
combustion zone.
B) For a catalytic
vapor incinerator, a temperature monitoring device equipped with a continuous
recorder. The device must be capable of monitoring temperature at two locations
and have an accuracy of ±1 percent of the temperature being monitored in
°C or ±0.5° C, whichever is greater. One temperature sensor must
be installed in the vent stream at the nearest feasible point to the catalyst
bed inlet and a second temperature sensor must be installed in the vent stream
at the nearest feasible point to the catalyst bed outlet.
C) For a flare, a heat sensing monitoring
device equipped with a continuous recorder that indicates the continuous
ignition of the pilot flame.
D) For
a boiler or process heater having a design heat input capacity less than 44 MW,
a temperature monitoring device equipped with a continuous recorder. The device
must have an accuracy of ±1 percent of the temperature being monitored
in °C or ±0.5° C, whichever is greater. The temperature sensor
must be installed at a location in the furnace downstream of the combustion
zone.
E) For a boiler or process
heater having a design heat input capacity greater than or equal to 44 MW, a
monitoring device equipped with a continuous recorder to measure parameters
that indicate good combustion operating practices are being used.
F) For a condenser, either of the following:
i) A monitoring device equipped with a
continuous recorder to measure the concentration level of the organic compounds
in the exhaust vent stream from the condenser; or
ii) A temperature monitoring device equipped
with a continuous recorder. The device must be capable of monitoring
temperature with an accuracy of ±1 percent of the temperature being
monitored in °C or ±0.5° C, whichever is greater. The
temperature sensor must be installed at a location in the exhaust vent stream
from the condenser exit (i.e., product side).
G) For a carbon adsorption system that
regenerates the carbon bed directly in the control device such as a fixed-bed
carbon adsorber, either of the following:
i)
A monitoring device equipped with a continuous recorder to measure the
concentration level of the organic compounds in the exhaust vent stream from
the carbon bed, or
ii) A monitoring
device equipped with a continuous recorder to measure a parameter that
indicates the carbon bed is regenerated on a regular, predetermined time
cycle.
3)
Inspect the readings from each monitoring device required by subsections (f)(1)
and (f)(2) at least once each operating day to check control device operation
and, if necessary, immediately implement the corrective measures necessary to
ensure the control device operates in compliance with the requirements of this
Section.
g) An owner or
operator using a carbon adsorption system such as a fixed-bed carbon adsorber
that regenerates the carbon bed directly onsite in the control device must
replace the existing carbon in the control device with fresh carbon at a
regular, predetermined time interval that is no longer than the carbon service
life established as a requirement of Section
724.935(b)(4)(C)(vi).
h) An owner or operator using a carbon
adsorption system such as a carbon canister that does not regenerate the carbon
bed directly onsite in the control device must replace the existing carbon in
the control device with fresh carbon on a regular basis by using one of the
following procedures:
1) Monitor the
concentration level of the organic compounds in the exhaust vent stream from
the carbon adsorption system on a regular schedule, and replace the existing
carbon with fresh carbon immediately when carbon breakthrough is indicated. The
monitoring frequency must be daily or at an interval no greater than 20 percent
of the time required to consume the total carbon working capacity established
as a requirement of Section
724.935(b)(4)(C)(vii),
whichever is longer.
2) Replace the
existing carbon with fresh carbon at a regular, predetermined time interval
that is less than the design carbon replacement interval established as a
requirement of Section
724.935(b)(4)(C)(vii).
i) An alternative operational or process
parameter may be monitored if the operator demonstrates that the parameter will
ensure that the control device is operated in conformance with these standards
and the control device's design specifications.
j) An owner or operator of an affected
facility seeking to comply with the provisions of this Part by using a control
device other than a thermal vapor incinerator, catalytic vapor incinerator,
flare, boiler, process heater, condenser, or carbon adsorption system is
required to develop documentation including sufficient information to describe
the control device operation and identify the process parameter or parameters
that indicate proper operation and maintenance of the control device.
k) A closed-vent system must meet either of
the following design requirements:
1) A
closed-vent system must be designed to operate with no detectable emissions, as
indicated by an instrument reading of less than 500 ppmv above background, as
determined by the methods specified at Section
724.934(b),
and by visual inspections; or
2) A
closed-vent system must be designed to operate at a pressure below atmospheric
pressure. The system must be equipped with at least one pressure gauge or other
pressure measurement device that can be read from a readily accessible location
to verify that negative pressure is being maintained in the closed-vent system
when the control device is operating.
l) The owner or operator must monitor and
inspect each closed-vent system required to comply with this Section to ensure
proper operation and maintenance of the closed-vent system by implementing the
following requirements:
1) Each closed-vent
system that is used to comply with subsection (k)(1) must be inspected and
monitored in accordance with the following requirements:
A) An initial leak detection monitoring of
the closed-vent system must be conducted by the owner or operator on or before
the date that the system becomes subject to this Section. The owner or operator
must monitor the closed-vent system components and connections using the
procedures specified in Section
724.934(b)
to demonstrate that the closed-vent system operates with no detectable
emissions, as indicated by an instrument reading of less than 500 ppmv above
background.
B) After initial leak
detection monitoring required in subsection (l)(1)(A), the owner or operator
must inspect and monitor the closed-vent system as follows:
i) Closed-vent system joints, seams, or other
connections that are permanently or semi-permanently sealed (e.g., a welded
joint between two sections of hard piping or a bolted and gasketed ducting
flange) must be visually inspected at least once per year to check for defects
that could result in air pollutant emissions. The owner or operator must
monitor a component or connection using the procedures specified in Section
724.934(b)
to demonstrate that it operates with no detectable emissions following any time
the component is repaired or replaced (e.g., a section of damaged hard piping
is replaced with new hard piping) or the connection is unsealed (e.g., a flange
is unbolted).
ii) Closed-vent
system components or connections other than those specified in subsection
(l)(1)(B)(i) must be monitored annually and at other times as requested by the
Regional Administrator, except as provided for in subsection (o), using the
procedures specified in Section
724.934(b)
to demonstrate that the components or connections operate with no detectable
emissions.
C) In the
event that a defect or leak is detected, the owner or operator must repair the
defect or leak in accordance with the requirements of subsection
(l)(3).
D) The owner or operator
must maintain a record of the inspection and monitoring in accordance with the
requirements specified in Section 724.935.
2) Each closed-vent system that is used to
comply with subsection (k)(2) must be inspected and monitored in accordance
with the following requirements:
A) The
closed-vent system must be visually inspected by the owner or operator to check
for defects that could result in air pollutant emissions. Defects include, but
are not limited to, visible cracks, holes, or gaps in ductwork or piping or
loose connections.
B) The owner or
operator must perform an initial inspection of the closed-vent system on or
before the date that the system becomes subject to this Section. Thereafter,
the owner or operator must perform the inspections at least once every
year.
C) In the event that a defect
or leak is detected, the owner or operator must repair the defect in accordance
with the requirements of subsection (l)(3).
D) The owner or operator must maintain a
record of the inspection and monitoring in accordance with the requirements
specified in Section 724.935.
3) The owner or operator must repair all
detected defects as follows:
A) Detectable
emissions, as indicated by visual inspection or by an instrument reading
greater than 500 ppmv above background, must be controlled as soon as
practicable, but not later than 15 calendar days after the emission is
detected, except as provided for in subsection (l)(3)(C).
B) A first attempt at repair must be made no
later than five calendar days after the emission is detected.
C) Delay of repair of a closed-vent system
for which leaks have been detected is allowed if the repair is technically
infeasible without a process unit shutdown, or if the owner or operator
determines that emissions resulting from immediate repair would be greater than
the fugitive emissions likely to result from delay of repair. Repair of such
equipment must be completed by the end of the next process unit
shutdown.
D) The owner or operator
must maintain a record of the defect repair in accordance with the requirements
specified in Section 724.935.
m) A closed-vent system or control device
used to comply with provisions of this Subpart AA must be operated at all times
when emissions may be vented to it.
n) The owner or operator using a carbon
adsorption system to control air pollutant emissions must document that all
carbon removed that is a hazardous waste and that is removed from the control
device is managed in one of the following manners, regardless of the volatile
organic concentration of the carbon:
1) It is
regenerated or reactivated in a thermal treatment unit that meets one of the
following:
A) The owner or operator of the
unit has been issued a final permit under 35 Ill. Adm. Code 702, 703, and 705
that implements the requirements of Subpart X; or
B) The unit is equipped with and operating
air emission controls in accordance with the applicable requirements of
Subparts AA and CC or Subparts AA and CC of 35 Ill. Adm. Code 725; or
C) The unit is equipped with and operating
air emission controls in accordance with a national emission standard for
hazardous air pollutants under 40 CFR 61 (National Emission Standards for
Hazardous Air Pollutants) or 63 (National Emission Standards for Hazardous Air
Pollutants for Source Categories), each incorporated by reference in 35 Ill.
Adm. Code
720.111(b).
2) It is incinerated in a hazardous waste
incinerator for which the owner or operator has done either of the following:
A) The owner or operator has been issued a
final permit under 35 Ill. Adm. Code 702, 703, and 705 that implements the
requirements of Subpart O; or
B)
The owner or operator has certified compliance in accordance with the interim
status requirements of Subpart O of 35 Ill. Adm. Code 725.
3) It is burned in a boiler or industrial
furnace for which the owner or operator has done either of the following:
A) The owner or operator has been issued a
final permit under 35 Ill. Adm. Code 702, 703, and 705 that implements the
requirements of Subpart H of 35 Ill. Adm. Code 726; or
B) The owner or operator has designed and
operates the boiler or industrial furnace in accordance with the interim status
requirements of Subpart H of 35 Ill. Adm. Code 726.
o) Any components of a closed-vent
system that are designated, as described in Section
724.935(c)(9),
as unsafe to monitor are exempt from the requirements of subsection
(l)(1)(B)(ii) if both of the following conditions are fulfilled:
1) The owner or operator of the closed-vent
system has determined that the components of the closed-vent system are unsafe
to monitor because monitoring personnel would be exposed to an immediate danger
as a consequence of complying with subsection (l)(1)(B)(ii); and
2) The owner or operator of the closed-vent
system adheres to a written plan that requires monitoring the closed-vent
system components using the procedure specified in subsection (l)(1)(B)(ii) as
frequently as practicable during safe-to-monitor times.
