N.M. Admin. Code § 20.11.46.21

Current through Register Vol. 36, No. 1, January 14, 2025

Section 20.11.46.21 - PROTOCOL WEB 1: SO[2] MONITORING OF FUEL GAS COMBUSTION DEVICES

A. Applicability.

(1) The provisions of this protocol are applicable to fuel gas combustion devices at petroleum refineries.

(2) Fuel gas combustion devices include boilers, process heaters, and flares used to burn fuel gas generated at a petroleum refinery.

(3) Fuel gas means any gas, which is generated, and combusted at a petroleum refinery. Fuel gas does not include:

(a) natural gas, unless combined with other gases generated at a petroleum refinery;

(b) gases generated by a catalytic cracking unit catalyst regenerator;

(c) gases generated by fluid coking burners;

(d) gases combusted to produce sulfur or sulfuric acid; or

(e) process upset gases generated due to startup, shutdown, or malfunctions.

B. Monitoring requirements.

(1) Except as provided in Paragraph (2) and Paragraph (3) of Subsection B of 20.11.46.21 NMAC, fuel gas combustion devices shall use a continuous fuel gas monitoring system (CFGMS) to determine the total sulfur content (reported as H₂S) of the fuel gas mixture prior to combustion, and continuous fuel flow meters to determine the amount of fuel gas burned.

(a) Fuel gas combustion devices having a common source of fuel gas may be monitored for sulfur content at one location, if monitoring at that location is representative of the sulfur content of the fuel gas being burned in any fuel gas combustion device.

(b) The CFGMS shall meet the performance requirements in Performance Specification 2 in Appendix B to 40 CFR Part 60, and the following:

(i) continuously monitor and record the concentration by volume of total sulfur compounds in the gaseous fuel reported as ppmv H₂S;

(ii) have the span value set so that the majority of readings fall between 10 and 95% of the range;

(iii) record negative values of zero drift, for initial certification and daily calibration error tests;

(iv) calibration drift shall be 5.0% of the span; and

(v) use EPA Test Method 15A or 16, or an approved alternative test method to determine total reduced sulfur emissions; these are the reference methods for the relative accuracy test; and the relative accuracy test shall include a bias test in accordance with Paragraph (3) of Subsection D of 20.11.46.21 NMAC.

(c) All continuous fuel flow meters shall comply with the provisions of Section 2.1.5 of Appendix D to 40 CFR Part 75.

(d) The hourly mass SO₂ emissions rate for all the fuel combustion devices monitored by this approach shall be calculated using the following equation:

E_t = (C_S)(Q_f)(K); where:

E_t = Total SO₂ emissions in lb/hr from applicable fuel gas combustion devices;

C_S = Sulfur content of the fuel gas as H₂S (ppmv);

Q_f = Fuel gas flow rate to the applicable fuel gas combustion devices (scf/hr); and

K = 1.660 x 10^-7 (lb/scf)/ppmv.

(2) As an alternative to using a CFGMS as required by Paragraph (1) of Subsection B of 20.11.46.21 NMAC, fuel gas combustion devices having a common source of fuel gas may be monitored with an SO₂ CEMS and flow CEMS and (if necessary) a moisture monitoring system at only one location, if the CEMS monitoring at that location is representative of the SO₂ emission rate (lb SO₂/scf fuel gas burned) of all applicable fuel gas combustion devices. Continuous fuel flow meters shall be used in accordance with Paragraph (2) of Subsection B of 20.11.46.21 NMAC, and the fuel gas combustion device monitored by a CEMS shall have separate fuel metering.

(a) Each CEMS for SO₂ and flow, and (if applicable) moisture, shall comply with the operating requirements, performance specifications, and quality-assurance requirements of 40 CFR Part 75.

(b) All continuous fuel flow meters shall comply with the provisions of Section 2.1.5 of Appendix D to 40 CFR Part 75.

(c) The SO₂ hourly mass emissions rate for all the fuel gas combustion devices monitored by this approach shall be determined by the ratio of the amount of fuel gas burned by the CEMS-monitored fuel gas combustion device to the total fuel gas burned by all applicable fuel gas combustion devices using the following equation:

E_t = (E_m)(Q_t)/(Q_m); where:

E_t = Total SO₂ emissions in lb/hr from applicable fuel gas combustion devices;

E_m = SO₂ emissions in lb/hr from the CEMS-monitored fuel gas combustion device, calculated using Equation F-1 or (if applicable) F-2 in Appendix F to 40 CFR Part 75;

Q_t = Fuel gas flow rate (scf/hr) from applicable fuel gas combustion devices; and

Q_m = Fuel gas flow rate (scf/hr) to the CEMS-monitored fuel gas combustion device.

(3) As an additional alternative to using a CFGMS as required by Paragraph (1) of Subsection B of 20.11.46.21 NMAC, fuel gas combustion devices having a common source of fuel gas may be monitored with an SO₂ - diluent CEMS at only one location, if the CEMS monitoring at that location is representative of the SO₂ emission rate (lb SO₂/mmBtu) of all applicable fuel gas combustion devices. If this option is selected, the owner or operator shall conduct fuel gas sampling and analysis for gross calorific value (GCV), and shall use continuous fuel flow metering in accordance with Paragraph (1) of Subsection B of 20.11.46.21 NMAC, with separate fuel metering for the CEMS-monitored fuel gas combustion device.

(a) Each SO_{2 -} diluent CEMS shall comply with the applicable provisions for SO₂ monitors and diluent monitors in 40 CFR Part 75, and shall use the procedures in Section 3 of Appendix F to 40 CFR Part 75 for determining SO₂ emission rate (lb/mmBtu) by substituting the term SO₂ for NO_x in that section, and using a K factor of 1.660 x 10 ^{- 7} (lb/scf) ppmv instead of the NO_x K factor.

(b) All continuous fuel flow meters and fuel gas sampling and analysis for GCV to determine the heat input ratio shall comply with the applicable provisions of Section 2.1.5 and 2.3.4 of Appendix D to 40 CFR Part 75.

(c) The SO₂ hourly mass emissions rate for all the fuel gas combustion devices monitored by this approach shall be determined by the ratio of the fuel gas heat input to the CEMS-monitored fuel gas combustion device to the total fuel gas heat input to all applicable fuel gas combustion devices using the following equation:

E_t = (E_m)(Q_t)/(GCV) / 10⁶; where:

E_t = Total SO₂ emissions in lbs/hr from applicable fuel gas combustion devices;

E_m = SO₂ emissions in lb/mmBtu from the CEMS - monitored fuel gas combustion device;

Q_t = Fuel gas flow rate (scf/hr) to the applicable fuel gas combustion devices;

GCV = Fuel Gross Calorific Value (Btu/scf); and

10⁶ = Conversion from Btu to million Btu.

(d) The owner or operator shall calculate total SO₂ mass emissions for each calendar quarter and each calendar year based on the emissions in lb/hr and Equations F-3 and F-4 in Appendix F to 40 CFR Part 75.

C. Certification and recertification requirements. All monitoring systems are subject to initial certification and recertification testing as follows:

(1) the owner or operator shall comply with the initial testing and calibration requirements in performance specification 2 in Appendix B of 40 CFR Part 60 and Subparagraph (b) of Paragraph (1) of Subsection B of 20.11.46.21 NMAC for each CFGMS;

(2) each CEMS for SO₂ and flow or each SO₂-diluent CEMS shall comply with the testing and calibration requirements specified in 40 CFR 75.20 and Appendices A and B, except that each SO₂-diluent CEMS shall meet the relative accuracy requirements for a NO_x-diluent CEMS (lb/mmBtu);

(3) a continuous fuel flow meter shall comply with certification requirements in Section 2.1.5 of Appendix D of 40 CFR Part 75.

D. Quality-assurance/quality control requirements. A quality-assurance and quality control (QA/QC) plan shall be developed and implemented for each:

(1) CEMS for SO₂ and flow or the SO₂-diluent CEMS in compliance with Sections 1, 1.1, and 1.2 of Appendix B of 40 CFR Part 75.

(2) Continuous fuel flow meter and fuel sampling and analysis in compliance with Sections 1, 1.1, and 1.3 Appendix B of 40 CFR Part 75. The owner or operator shall meet the requirements in Section 2.1.6 of Appendix D to 40 CFR Part 75, and may use the procedures set forth in Section 2.1.7 of that appendix.

(3) CFGMS in compliance with Sections 1 and 1.1 of Appendix B to 40 CFR Part 75, and the following:

(a) perform a daily calibration error test of each CFGMS at two gas concentrations, one low level and one high level; and calculate the calibration error as described in Appendix A to 40 CFR Part 75; an out of control period occurs whenever the error is greater than 5.0 percent of the span value;

(b) in addition to the daily calibration error test, an additional calibration error test shall be performed whenever a daily calibration error test is failed, whenever a monitoring system is returned to service following repairs or corrective actions that may affect the monitor measurements, and after making manual calibration adjustments;

(c) perform a linearity test once every operating quarter; calculate the linearity as described in Appendix A to 40 CFR Part 75; and an out of control period occurs whenever the linearity error is greater than 5.0 percent of a reference value, and the absolute value of the difference between average monitor response values and a reference value is greater than 5.0 ppm;

(d) perform a relative accuracy test audit once every four operating quarters; calculate the relative accuracy as described in Appendix A to 40 CFR Part 75; and an out of control period occurs whenever the relative accuracy is greater than 20.0 percent of the mean value of the reference method measurements;

(e) using the results of the relative accuracy test audit, conduct a bias test in accordance with Appendix A to 40 CFR Part 75, and calculate and apply a bias adjustment factor if required.

E. Missing data procedures. For any period in which valid data are not being recorded by a(n)

(1) SO₂ CEMS or flow CEMS specified in 20.11.46.21 NMAC, missing or invalid data shall be replaced with substitute data in accordance with the requirements in Subpart D of 40 CFR Part 75.

(2) SO₂-diluent CEMS specified in 20.11.46.21 NMAC, missing or invalid data shall be replaced with substitute data on a rate basis (lb/mmBtu) in accordance with the requirements for SO₂ monitors in Subpart D of 40 CFR Part 75.

(3) Continuous fuel flow meter or for fuel gas GCV sampling and analysis specified in 20.11.46.21 NMAC, missing or invalid data shall be replaced with substitute data in accordance with missing data requirements in Section 2.4 of Appendix D to 40 CFR Part 75.

(4) CFGMS as specified in 20.11.46.21 NMAC, hourly missing or invalid data shall be replaced with substitute data in accordance with the missing data requirements for units performing hourly gaseous fuel sulfur sampling in Section 2.4 of Appendix D to 40 CFR Part 75.

F. Monitoring plan and reporting requirements. In addition to the general monitoring plan and reporting requirements of 20.11.46.16 NMAC, the owner or operator shall meet the following additional requirements:

(1) the monitoring plan shall identify each group of units that is monitored by a single monitoring system under 20.11.46.21 NMAC, and the plan shall designate an identifier for the group of units for emissions reporting purposes; and for purpose of submitting emissions reports, no apportionment of emissions to the individual units within the group is required;

(2) if the provisions of Paragraph (2) or Paragraph (3) of Subsection B of 20.11.46.21 NMAC are used, provide documentation and an explanation to demonstrate that the SO₂ emission rate from the monitored unit is representative of the rate from non-monitored units.

N.M. Admin. Code § 20.11.46.21

20.11.46.21 NMAC - N, 12/31/03; A, 9/15/08; A, 5/16/11