NR 440.23(2)(a)
(a) “Nitric acid production unit" means any facility producing weak nitric acid by either the pressure or atmospheric pressure process.
NR 440.23(2)(b)
(b) “Weak nitric acid" means acid which is 30 to 70% in strength.
NR 440.23(3)(a)(a) On and after the date on which the performance test required to be conducted by
s. NR 440.08 is completed, no owner or operator subject to the provisions of this section may cause to be discharged into the atmosphere from any affected facility any gases which:
NR 440.23(3)(a)1.
1. Contain nitrogen oxides, expressed as NO
2, in excess of 1.5 kg per metric ton of acid produced (3.0 lb per ton), the production being expressed as 100% nitric acid.
NR 440.23(4)(a)(a) The source owner or operator shall install, calibrate, maintain and operate a continuous monitoring system for measuring nitrogen oxides (NO
x). The pollutant gas mixtures under Performance Specification 2 of Appendix B of
40 CFR part 60, incorporated by reference in
s. NR 440.17, and for calibration checks under
s. NR 440.13 (4) shall be nitrogen dioxide (NO
2). The span value shall be 500 ppm of NO
2. Method 7 shall be used for the performance evaluation under
s. NR 440.13 (3). Acceptable alternative methods to Method 7 are given in
sub. (5) (c).
NR 440.23(4)(b)
(b) The owner or operator shall establish a conversion factor for the purpose of converting monitoring data into units of the applicable standard (kg/metric ton, lb/ton). The conversion factor shall be established by measuring emissions with the continuous monitoring system concurrent with measuring emissions with the applicable reference method tests. Using only that portion of the continuous monitoring emission data that represents emission measurements concurrent with the reference method test periods, the conversion factor shall be determined by dividing the reference method test data averages by the monitoring data averages to obtain a ratio expressed in units of the applicable standard to units of the monitoring data, i.e., kg/metric ton per ppm (lb/ton per ppm). The conversion factor shall be reestablished during any performance test under
s. NR 440.08 or any continuous monitoring system performance evaluation under
s. NR 440.13 (3).
NR 440.23(4)(c)
(c) The owner or operator shall record the daily production rate and hours of operation.
NR 440.23(4)(e)
(e) For the purpose of reports required under
s. NR 440.07 (3), periods of excess emissions that shall be reported are defined as any 3-hour period during which the average nitrogen oxides emissions (arithmetic average of 3 contiguous one-hour periods) as measured by a continuous monitoring system exceed the standard under
sub. (3) (a).
NR 440.23(5)(a)(a) In conducting the performance tests required in
s. NR 440.08, the owner or operator shall use as reference methods and procedures the test methods in Appendix A of
40 CFR part 60, incorporated by reference in
s. NR 440.17, or other methods and procedures as specified in this subsection, except as provided in
s. NR 440.08 (2). Acceptable alternative methods and procedures are given in
par. (c).
NR 440.23(5)(b)
(b) The owner or operator shall determine compliance with the NO
x standard in
sub. (3) as follows:
NR 440.23(5)(b)1.
1. The emission rate (E) of NO
x shall be computed for each run using the following equation:
E = (Cs Qsd)/(PK)
where:
E is the emission rate of NOx as NO2, kg/metric ton (lb/ton) of 100% nitric acid
Cs is the concentration of NOx as NO2, g/dscm (lb/dscf)
Qsd is the volumetric flow rate of effluent gas, dscm/hr (dscf/hr)
P is the acid production rate, metric ton/hr (ton/hr) or 100% nitric acid
K is the conversion factor, 1000 g/kg (1.0 lb/lb)
NR 440.23(5)(b)2.
2. Method 7 shall be used to determine the NO
x concentration of each grab sample. Method 1 shall be used to select the sampling site and the sampling point shall be the centroid of the stack or duct or at a point no closer to the walls than 1 m (3.28 ft). Four grab samples shall be taken at approximately 15-minute intervals. The arithmetic mean of the 4 sample concentrations shall constitute the run value (C
s).
NR 440.23(5)(b)3.
3. Method 2 shall be used to determine the volumetric flow rate (Q
sd) of the effluent gas. The measurement site shall be the same as for the NO
x sample. A velocity traverse shall be made once per run within the hour that the NO
x samples are taken.
NR 440.23(5)(b)4.
4. The methods of
sub. (4) (c) shall be used to determine the production rate (P) of 100% nitric acid for each run. Material balance over the production system shall be used to confirm the production rate.
NR 440.23(5)(c)
(c) The owner or operator may use the following as alternatives to the methods and procedures specified in this subsection:
NR 440.23(5)(c)1.
1. For Method 7, Method 7A, 7B, 7C or 7D may be used. If Method 7C or 7D is used, the sampling time shall be at least 1 hour.
NR 440.23(5)(d)
(d) The owner or operator shall use the procedure in
sub. (4) (b) to determine the conversion factor for converting the monitoring data to the units of the standard.
NR 440.23 History
History: Cr.
Register, January, 1984, No. 337, eff. 2-1-84; am. (4) (a), (5) (a) 1., and (b),
Register, September, 1986, No. 369, eff. 10-1-86; am. (2) (intro.), (4) (e) and (5) (b),
Register, September, 1990, No. 417, eff. 10-1-90; r. and recr. (4) (a) and (5), am. (4) (b),
Register, June, 1993, No. 450, eff. 8-1-93.
NR 440.24(1)
(1)
Applicability and designation of affected facility. NR 440.24(1)(a)(a) The provisions of this section are applicable to each sulfuric acid production unit, which is the affected facility.
NR 440.24(1)(b)
(b) Any facility under
par. (a) that commences construction or modification after August 17, 1971, is subject to the requirements of this section.
NR 440.24(2)
(2) Definitions. As used in this section, terms not defined in this subsection have the meanings given in
s. NR 440.02.
NR 440.24(2)(a)
(a) “Acid mist" means sulfuric acid mist, as measured by Method 8 of
40 CFR part 60, Appendix A, incorporated by reference in
s. NR 440.17, or an equivalent or alternative method.
NR 440.24(2)(b)
(b) “Sulfuric acid production unit" means any facility producing sulfuric acid by the contact process by burning elemental sulfur, alkylation acid, hydrogen sulfide, organic sulfides and mercaptans or acid sludge, but does not include facilities where conversion to sulfuric acid is utilized primarily as a means of preventing emissions to the atmosphere of sulfur dioxide or other sulfur compounds.
NR 440.24(3)(a)(a) On and after the date on which the performance test required to be conducted by
s. NR 440.08 is completed, no owner or operator subject to the provisions of this section may cause to be discharged into the atmosphere from any affected facility any gases which contain sulfur dioxide in excess of 2.0 kg per metric ton of acid produced (4.0 lb per ton), the production being expressed as 100% H
2SO
4.
NR 440.24(4)(a)(a) On and after the date on which the performance test required to be conducted by
s. NR 440.08 is completed, no owner or operator subject to the provisions of this section may cause to be discharged into the atmosphere from any affected facility any gases which:
NR 440.24(4)(a)1.
1. Contain acid mist, expressed as H
2SO
4, in excess of 0.075 kg per metric ton of acid produced (0.15 lb per ton), the production being expressed as 100% H
2SO
4.
NR 440.24(5)(a)(a) A continuous monitoring system for the measurement of sulfur dioxide shall be installed, calibrated, maintained and operated by the owner or operator. The pollutant gas used to prepare calibration gas mixtures under Performance Specification 2 of
40 CFR part 60, Appendix B, incorporated by reference in
s. NR 440.17, and for calibration checks under
s. NR 440.13 (4) shall be sulfur dioxide (SO
2). Method 8 of
40 CFR part 60, Appendix A, incorporated by reference in
s. NR 440.17, shall be used for conducting monitoring system performance evaluations under
s. NR 440.13 (3), except that only the sulfur dioxide portion of the Method 8 results shall be used. The span value shall be set at 1000 ppm of sulfur dioxide.
NR 440.24(5)(b)
(b) The owner or operator shall establish a conversion factor for the purpose of converting monitoring data into units of the applicable standard (kg/metric ton, lb/ton). The conversion factor shall be determined, at a minimum, 3 times daily by measuring the concentration of sulfur dioxide entering the converter using suitable methods (e.g., the Reich test, National Air Pollution Control Administration Publication No. 999-AP-13) and calculating the appropriate conversion factor for each 8-hour period as follows: -
See PDF for diagram 
where:
CF is the conversion factor (kg/metric ton per ppm, lb/ton per ppm)
k is the constant derived from material balance. For determining CF in metric units, k = 0.0653. For determining CF in English units, k = 0.1306.
r is the percentage of sulfur dioxide by volume entering the gas converter. Appropriate corrections must be made for air injection plants subject to the department's approval.
s is the percentage of sulfur dioxide by volume in the emissions to the atmosphere determined by the continuous monitoring system required under par. (a).
NR 440.24(5)(c)
(c) The owner or operator shall record all conversion factors and values under
par. (b) from which they were computed (i.e., CF, r, and s).
NR 440.24(5)(d)
(d) Alternatively, a source that processes elemental sulfur or an area that contains elemental sulfur and uses air to supply oxygen may use the following continuous emission monitoring approach and calculation procedures in determining SO
2 emission rates in terms of the standard. This procedure is not required but is an alternative that would alleviate problems encountered in the measurement of gas velocities or production rate. Continuous emission monitoring systems for measuring SO
2, O
2 and CO
2, if required, shall be installed, calibrated, maintained and operated by the owner or operator and subjected to the certification procedures in Performance Specifications 2 and 3 in Appendix B,
40 CFR part 60, incorporated by reference in
s. NR 440.17 (1). The calibration procedure and span value for the SO
2 monitor shall be as specified in
par. (b). The span value for CO
2, if required, shall be 10% and for O
2 shall be 20.9% (air). A conversion factor based on process rate data is not necessary. Calculate the SO
2 emission rate as follows: -
See PDF for diagram
where:
Es is the SO2 emission rate in kg/metric ton (lb/ton) of 100% of H2SO4 produced
Cs is the concentration of SO2, kg/dscm (lb/dscf) (see the table in the note following this paragraph)
S is the acid production rate factor, 368 dscm/metric ton (11,800 dscf/ton) of 100% H2SO4 produced
%O2 is the oxygen concentration, percent dry basis
A is the auxiliary fuel factor,
= 0.00 for no fuel
= 0.0226 for methane
= 0.0217 for natural gas
= 0.0196 for propane
= 0.0172 for #2 oil
= 0.0161 for #6 oil
= 0.0148 for coal
= 0.0126 for coke
%CO2 is the carbon dioxide concentration, percent dry basis
NR 440.24 Note
Note:
It is necessary in some cases to convert measured concentration units to other units for these calculations. Use the following table for such conversions:
-
See PDF for table NR 440.24(5)(e)
(e) For the purpose of reports under
s. NR 440.07 (3), periods of excess emissions shall be all 3-hour periods (or the arithmetic average of 3 consecutive 1-hour periods) during which the integrated average sulfur dioxide emissions exceed the applicable standards under
sub. (3).
NR 440.24(6)(a)(a) In conducting the performance tests required in
s. NR 440.08, the owner or operator shall use as reference methods and procedures the test methods in Appendix A of
40 CFR part 60, incorporated by reference in
s. NR 440.17, or other methods and procedures as specified in this subsection, except as provided in
s. NR 440.08 (2). Acceptable alternative methods and procedures are given in
par. (c).
NR 440.24(6)(b)
(b) The owner or operator shall determine compliance with the SO
2 acid mist, and visible emission standards in
subs. (4) and
(5) as follows:
NR 440.24(6)(b)1.
1. The emission rate (E) of acid mist or SO
2 shall be computed for each run using the following equation:
E = (CQsd)/(PK)
where:
E is the emission rate of acid mist or SO2 kg/metric ton (lb/ton) of 100% H2SO4 produced
C is the concentration of acid mist or SO2, g/dscm (lb/dscf)
Qsd is the volumetric flow rate of the effluent gas, dscm/hr (dscf/hr)
P is the production rate of 100% H2SO4, metric ton/hr (ton/hr)
K is the conversion factor, 1000 g/kg (1.0 lb/lb)
NR 440.24(6)(b)2.
2. Method 8 shall be used to determine the acid mist and SO
2 concentrations (C's) and the volumetric flow rate (Q
sd) of the effluent gas. The moisture content may be considered to be zero. The sampling time and sample volume for each run shall be at least 60 minutes and 1.15 dscm (40.6 dscf).
NR 440.24(6)(b)3.
3. Suitable methods shall be used to determine the production rate (P) of 100% H
2SO
4 for each run. Material balance over the production system shall be used to confirm the production rate.
NR 440.24(6)(c)
(c) The owner or operator may use the following as alternatives to the reference methods and procedures specified in this subsection:
NR 440.24(6)(c)1.
1. If a source processes elemental sulfur or an ore that contains elemental sulfur and uses air to supply oxygen, the following procedure may be used instead of determining the volumetric flow rate and production rate:
NR 440.24(6)(c)1.a.
a. The integrated technique of Method 3 is used to determine the O
2 concentration and, if required, CO
2 concentration.
NR 440.24(6)(c)1.b.
b. The SO
2 or acid mist emission rate is calculated as described in
sub. (5) (d), substituting the acid mist concentration for C
s as appropriate.
NR 440.24 History
History: Cr.
Register, January, 1984, No. 337, eff. 2-1-84; cr. (5) (d) and (6) (e),
Register, September, 1986, No. 369, eff. 10-1-86; am. (2) (intro.) and (3) (a),
Register, September, 1990, No. 417, eff. 10-1-90; am. (5) (a) and (b), r. and recr. (5) (d) and (6),
Register, July, 1993, No. 451, eff. 8-1-93; cr. (5) (e),
Register, December, 1995, No. 480, eff. 1-1-96;
CR 06-109: am. (5) (d) Register May 2008 No. 629, eff. 6-1-08.
