Section 1200-03-16-.21 - PRIMARY ALUMINUM REDUCTION PLANTS(1) Applicability: (a) The affected facilities in primary aluminum reduction plants to which this rule applies are potroom groups and anode baking plants.(b) Any facility under subparagraph (a) of this paragraph that commences construction or modification after November 6, l988 is subject to the requirements of this rule.(2) Definitions: (a) "Aluminum equivalent" means an amount of aluminum which can be produced from a Mg of anodes produced by an anode bake plant as determined by subparagraph (6)(g) of this rule.(b) "Anode bake plant" means a facility which produces carbon anodes for use in a primary aluminum reduction plant.(c) "Potroom" means a building unit which houses a group of electrolytic cells in which aluminum is produced.(d) "Potroom group" means an uncontrolled potroom, a potroom which is controlled individually, or a group of potrooms or potroom segments ducted to a common control system.(e) "Primary aluminum reduction plant" means any facility manufacturing aluminum by electrolytic reduction.(f) "Primary control system" means an air pollution control system designed to remove gaseous and particulate fluorides from exhaust gases which are captured at the cell.(g) "Roof monitor" means that portion of the roof of a potroom where gases not captured at the cell exit from the potroom.(h) "Total fluorides" means elemental fluorine and all fluoride compounds as measured by reference methods specified in paragraph (6) of this rule or by equivalent or alternative methods.(3) Standards for fluorides. (a) On and after the date on which the initial performance test required to be conducted by 1200-3-16-.01(5) is completed, no owner or operator subject to the provisions of this rule shall cause to be discharged into the atmosphere from any affected facility any gases containing total fluorides as measured according to 1200-3-16-.01(5) above, in excess of:1.(i) 1.0 kg/Mg (2.0 lb/ton) of aluminum produced for potroom groups at Soderberg plants: except that emissions between 1.0 kg/Mg (2.0 lb/ton) and 1.3 kg/Mg (2.6 lb/ton) will be considered in compliance if the owner or operator demonstrates that exemplary operation and maintenance procedures were used with respect to the emission control system and that proper control equipment was operating at the affected facility during the performance tests;(ii) 0.95 kg/Mg (1.9 lb/ton) of aluminum produced for potroom groups at prebake plants; except that emissions between 0.95 kg/Mg and 1.25 kg/Mg (2.5 lb/ton) will be considered in compliance if the owner or operator demonstrates that exemplary operation and maintenance procedures were used with respect to the emission control system and that proper control equipment was operating at the affected facility during the performance test;(iii) For the purpose of compliance with the alternative standards in subparts (i) and (ii), exemplary operation and maintenance procedures include the following: (I) Hood covers should fit properly and be in good repair;(II) If the exhaust system is equipped with an adjustable air damper system, the hood exhaust rate for individual pots should be increased whenever hood covers are removed from a pot (the exhaust system should not, however, be overloaded by placing too many pots on high exhaust);(III) Hood covers should be replaced as soon as possible after each potroom operation;(IV) Dust entrainment should be minimized during materials handling operations and sweeping of the working aisles;(V) Only tapping crucibles with functional aspirator air return systems (for returning gases under the collection hooding) should be used;(VI) The primary control system should be regularly inspected and properly maintained;2. 0.05 kg/Mg (0.1 lb/ton) of aluminum equivalent for anode bake plants.(b) Within 30 days of any performance test which reveals emissions which fall between the 1.0 kg/Mg and 1.3 kg/Mg levels in part (a)1.(i) of this paragraph or between the 0.95 kg/Mg and 1.25 kg/Mg levels in part (a)1.(ii) of this paragraph, the owner or operator shall submit a report indicating whether all necessary control devices were on line and operating properly during the performance test, describing the operating and maintenance procedures followed, and setting forth any explanation for the excess emissions to the Technical Secretary.(4) Standard for visible emissions. (a) On and after the date on which the performance test required to be conducted by 1200-3-16-.01(5) is completed, no owner or operator subject to the provisions of this rule shall cause to be discharged into the atmosphere:1. From any potroom group any gases which exhibit 10 percent opacity or greater, or2. From any anode bake plant any gases which exhibit 20 percent opacity or greater.(5) Monitoring of Operations. (a) The owner or operator of any affected facility subject to the provisions of this rule shall install, calibrate, maintain and operate monitoring devices which can be used to determine daily the weight of aluminum and anode produced. The weighing devices shall have an accuracy of ± 5 percent over their operating range.(b) The owner or operator of any affected facility shall maintain a record of daily production rates of aluminum and anodes, raw material feed rates, and cell or potline voltages.(6) Test methods and procedures. (a) Following the initial performance test as required under 1200-3-16-.01(5)(a) an owner or operator shall conduct a performance test at least once each month during the life of the affected facility, except when malfunctions prevent representative sampling, as provided under 1200-3-16-.01(5)(c). The owner or operator shall give the Technical Secretary at least 15 days notice of each test. The Technical Secretary may require additional testing.(b) An owner or operator may petition the Technical Secretary to establish an alternative testing requirement that requires testing less frequently than once each month for a primary control system or an anode bake plant. If the owner or operator shows that emissions from the primary control system or the anode bake plant have low variablity during day-to-day operations, the Technical Secretary may establish such an alternative testing requirement. The alternative testing requirement shall include a testing schedule and, in the case of a primary control system, the method to be used to determine primary control system emissions for the purpose of performance tests. The Technical Secretary shall establish alternative testing requirements on the applicable operating permit as a condition.(c) Except as provided in 1200-3-16-.01(5)(b), reference methods in 1200-3-16-.01(5)(g) shall be used to determine compliance with the standards prescribed in paragraph (3) of this rule as follows: 1. For sampling emissions from stacks:(i) Method 1 as specified in 1200-3-16-.01(5)(g) 1. for sample and velocity traverses.(ii) Method 2 as specified in 1200-3-16-.01(5)(g) 2. for velocity and volumetric flow rate.(iii) Method 3 as specified in 1200-3-16-.01(5)(g) 3. for gas analysis.(iv) Method 13A and 13B as specified in 1200-3-16-.01(5)(g) 13. for the concentration of total fluorides and the associated moisture content.2. For sampling emissions from roof monitors not employing stacks or pollutant collection systems: (i) Method 1 as specified in 1200-3-16-.01(5)(g) 1. for sample and velocity traverses,(ii) Method 2 as specified in 1200-3-16-.01(5)(g) 2. and Method 14 as specified in 1200-3-16-.01(5)(g) 14. for velocity and volumetric flow rate,(iii) Method 3 as specified in 1200-3-16-.01(5)(g) 3. for gas analysis, and(iv) Method 14 as specified in 1200-3-16-.01(5)(g) 14. for the concentration of total fluorides and associated moisture content.3. For sampling emissions from roof monitors not employing stacks but equipped with pollutant collection systems, the procedures under 1200-3-16-.01(5)(b) shall be followed.(d) For Method 13A or 13B as specified in 1200-3-16-.01(5)(g) 13., the sampling time for each run shall be at least 8 hours for any potroom sample and at least 4 hours for any anode bake plant sample, and the minimum sample volume shall be 6.8 dscm (240 dscf) for any potroom sample and 3.4 dscm (120 dscf) for any anode bake plant sample except that shorter sampling times or smaller volumes, when necessiated by process variables or other factors, may be approved by the Technical Secretary.(e) The air pollution control system for each affected facility shall be constructed so that volumetric flow rates and total fluoride emissions can be accurately determined using applicable methods specified under subparagraph (c) of this paragraph.(f) The rate of aluminum production is determined by dividing 720 hours into the weight of aluminum tapped from the affected facility during a period of 30 days prior to and including the final run of a performance test.(g) For anode bake plants, the aluminum equivalent for anodes produced shall be determined as follows: 1. Determine the average weight (Mg) of anode produced in anode bake plant during a representative oven cycle using a monitoring device which meets the requirements of subparagraph (5)(a) of this rule.2. Determine the average rate of anode production by dividing the total weight of anodes produced during the representative oven cycle by the length of the cycle in hours.3. Calculate the aluminum equivalent for anodes produced by multiplying the average rate of anode production by two. (Note: An owner or operator may establish a different multiplication factor by submitting production records of the Mg of aluminum produced and the concurrent Mg of anode consumed by potrooms).(h) For each run, potroom group emissions expressed in kg/Mg of aluminum produced shall be determined using the following equation: Click to view Image
Where:
Epg = potroom group emissions of total fluorides in kg/Mg of aluminum produced.
Cs = concentration of total fluorides in mg/dscm as determined by Method 13A or 13B, as specified in 1200-3-16-.01(5)(g) 13., or by Method 14 as specified in 1200-3-16-.01(5)(g) 14., as applicable.
Qs = volumetric flow rate of the effluent gas stream in dscm/hr as determined by Method 2 as specified in 1200-3-16-.01(5)(g) 2. and/or Method 14 as specified in 1200-3-16-.01(5)(g) 14., as applicable.
10-6 = conversion factor from mg to kg.
M = rate of aluminum production in Mg/hr as determined by subparagraph (6)(f) of this rule.
(CsQs)1 = product of Cs and Qs for measurements of primary control system effluent gas streams.
(CsQs)2 = product of Cs and Qs for measurements of secondary control system of roof monitor effluent gas streams.
Where an alternative testing requirement has been established for the primary control system, the calculated value (CsQs)1 from the most recent performance test will be used.
(i) For each run, as applicable, anode bake plant emissions expressed in kg/Mg of aluminum equivalent shall be determined using the following equation: Click to view Image
Where:
Ebp = anode bake plant emissions of total fluorides in kg/Mg of aluminum equivalent.
Cs = concentration of total fluorides in mg/dscm as determined by Method 13A or 13B, as specified in 1200-3-16-.01(5)(g) 13.
Qs = volumetric flow rate of the effluent gas stream in dscm/hr as determined by Method 2, as specified in 1200-3-16-.01(5)(g) 2.
10-6 = conversion factor from mg to kg.
Me = aluminum equivalent for anodes produced by anode bake plants in Mg/hr as determined by subparagraph (6)(g) of this rule.
Tenn. Comp. R. & Regs. 1200-03-16-.21
Original rule filed January 10, 1977; effective February 9, 1977. Amendment filed September 4, 1981; effective October 19, 1981. Amendment filed March 24, 1986; effective April 23, 1986.Authority: T.C.A. §§ 68-25-105 and 4-5-202.