Subpart Y Flares Unit Information


This topic provides a step-by-step description of how to enter Subpart Y Flares unit information about this facility.

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Step 1. Adding or Updating Flares Unit Information

To add or update Subpart Y Flares Unit Information for this Facility, locate the FLARES UNITS EMISSIONS SUMMARY table on the Subpart Y Overview page, click the link titled "ADD a Flare."

To edit an existing Flare Unit, click on the edit icon or the Name/ID link, which is the first column in the FLARES UNITS EMISSIONS SUMMARY table.

To delete an existing Flare Unit, click on the delete icon, which is the last column in the FLARES UNITS EMISSIONS SUMMARY table.

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Subpart Y collects the following data about your flare unit:

  • A unique name or identifier, plus optional description for this flare unit (see also About Unique Unit Names)
  • Type of flare:
    • Steam assisted
    • Air assisted
    • Unassisted
    • Other (specify)
  • Flare service type:
    • General facility flare
    • Unit flare
    • Emergency only flare
    • Back-up flare
    • Other (specify)
  • Method used to calculate the CO2 emissions:
    • 98.253(b)(1)(ii)(A) – Equation Y-1a Gas Composition Monitored (Equation Y-1a or Y-1b must be used if you have a continuous gas composition monitor on the flare or if you measure it at least weekly)
    • 98.253(b)(1)(ii)(A) – Equation Y-1b Gas Composition Monitored (Equation Y-1a or Y-1b must be used if you have a continuous gas composition monitor on the flare or if you measure it at least weekly)
    • 98.253(b)(1)(ii)(B) – Equation Y-2 Heat Content Monitored (Equation Y-2 must be used if you have a continuous higher heating value monitor or measure it at least weekly and the heating value monitor or measurement is not based on compositional analyses; if compositional analyses are used, you must use Equation Y-1a or Y-1b)
    • 98.253(b)(1)(iii) – Equation Y-3 Start-up, Shutdown, Malfunction (Equation Y-3 must be used if you do not measure gas composition or heating value at least weekly.)

When you are finished, click SAVE.

Step 2. Adding or Updating Flare Unit Emissions Information

This page provides a step-by-step description of how to enter Subpart Y Flares unit emissions information.

Step 2a: Select a flare

To add or update Subpart Y flare emissions information, locate the FLARES UNITS EMISSION SUMMARY table on the Subpart Y Overview page, and click OPEN.

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Step 2b: Equation Summary and Results

The Equation Summary is presented on this page. You can hover over an element in the equation to reveal a definition of that element.

For each flare at your facility, Subpart Y requires you to enter the following emissions information:

  • The annual CO2 emissions from flare unit operations (the output of Equation Y-1a, Y-1b, Y-2, or Y-3 depending on the calculation method used for this flare, in metric tons) [98.256(e)(4)]
  • The annual CH4 emissions from flare unit operations (the output of Equation Y-4, in metric tons) [98.256(e)(4)]
  • The basis for the fraction of carbon in the flare gas contributed by methane value:
    • Method 18 at 40 CFR part 60, appendix A-6
    • ASTM D1945-03
    • ASTM D1946-90-Reapproved 2006
    • GPA 2261-00
    • UOP539-97
    • ASTM D2503-92-Reapproved 2007
    • Chromatographic analysis: manufacturer's instructions
    • Engineering calculations
    • Other (specify)
  • The annual N2O emissions from flare unit operations (the output of Equation Y-5, in metric tons) [98.256(e)(4)]

The e-GGRT system provides links to optional worksheets that may be used to perform the calculations; use of the spreadsheet is entirely optional and is provided for your assistance. To calculate annual CO2 emissions using the optional spreadsheets, download the calculation spreadsheet by clicking the link titled "Use Y-x spreadsheet to calculate" (where 'x' represents 1a, 1b, 2, or 3 depending on the CO2 calculation method used for this flare). Fill in the spreadsheet using the instructions in the spreadsheet. After completing the spreadsheet, copy the value of CO2 calculated by the spreadsheet to this page in the red box next to "Annual CO2 emission from this flare (metric tons)."

To calculate annual CH4 and N2O emissions using the optional spreadsheets, download the calculation spreadsheets by clicking the links titled "Use Y-4 spreadsheet to calculate" and "Use Y-5 spreadsheet to calculate," respectively. Fill in the spreadsheets using the instructions in each spreadsheet. After completing the spreadsheets, copy the values of CH4 and N2O calculated by the spreadsheets to this page in the red box next to "Annual CH4 emission from this flare (metric tons)" and "Annual N2O emission from this flare (metric tons)," respectively.

If using a mass flow meter to measure flow, molecular weights may be estimated instead of measured.

Step 2c: Enter supplemental emissions information

For each flare using the Equation Y-1a calculation method, Subpart Y requires you to enter the following supplemental emissions information:

  • An indication of whether daily or weekly measurement periods are used [98.256(e)(6)]
  • The annual volume of flare gas combusted (in scf) [98.256(e)(6)]
  • The specific consensus-based standard method number or description of the procedure specified by the flow meter manufacturer [98.256(q)]
  • The number of days during the reporting year missing data procedures were used to determine the volume of flare gas combusted
  • The annual average molecular weight (in kg/kg-mole) [98.256(e)(6)]
  • The method used to measure molecular weight [98.256(q)]
    • Method 18 at 40 CFR part 60, appendix A-6
    • ASTM D1945-03
    • ASTM D1946-90 (Reapproved 2006)
    • GPA 2261-00
    • UOP539-97
    • ASTM D2503-92 (Reapproved 2007)
    • Chromatographic analysis: manufacturer's instructions
    • Other (specify)
  • The number of days during the reporting year missing data procedures were used to determine molecular weight
  • The annual average carbon content of the flare gas (kg carbon/kg flare gas) [98.256(e)(6)]
  • The method used to measure carbon content [98.256(q)]
    • Method 18 at 40 CFR part 60, appendix A-6
    • ASTM D1945-03
    • ASTM D1946-90 (Reapproved 2006)
    • GPA 2261-00
    • UOP539-97
    • ASTM D2503-92 (Reapproved 2007)
    • Chromatographic analysis: manufacturer's instructions
    • Other (specify)
  • The number of days during the reporting year missing data procedures were used to determine carbon content

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For each flare using the Equation Y-1b calculation method, Subpart Y requires you to enter the following supplemental emissions information:

  • An indication of whether daily or weekly measurement periods are used [98.256(e)(7)]
  • The annual volume of flare gas combusted (in scf) [98.256(e)(7)]
  • The specific consensus-based standard method number or description of the procedure specified by the flow meter manufacturer [98.256(q)]
  • The number of days during the reporting year missing data procedures were used to determine the volume of flare gas combusted
  • The annual average CO2 concentration (in percent by volume or mole) [98.256(e)(7)]
  • The method used to measure CO2 concentration [98.256(q)]
    • Method 18 at 40 CFR part 60, appendix A-6
    • ASTM D1945-03
    • ASTM D1946-90 (Reapproved 2006)
    • GPA 2261-00
    • UOP539-97
    • ASTM D2503-92 (Reapproved 2007)
    • Chromatographic analysis: manufacturer's instructions
    • Other (specify)
  • The number of days during the reporting year missing data procedures were used to determine CO2 concentration
  • For each carbon containing compound other than CO2 in the flare gas stream identified by the facility, and for each flare using Equation Y-1b, the system shall require the facility to identify:
  • The annual average concentration of the compound (in percent by volume or mole) [98.256(e)(7)(i)]
  • The method used to measure concentration of the compound [98.256(q)]
    • Method 18 at 40 CFR part 60, appendix A-6
    • ASTM D1945-03
    • ASTM D1946-90 (Reapproved 2006)
    • GPA 2261-00
    • UOP539-97
    • ASTM D2503-92 (Reapproved 2007)
    • Chromatographic analysis: manufacturer's instructions
    • Other (specify)
  • The number of days during the reporting year missing data procedures were used to determine the concentration of the compound

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To add a non-CO2 carbon-contain compound for the flare, click the "ADD a Compound" link in the CARBON CONTAINING COMPOUNDS (OTHER THAN CO2) IN THE FLARE GAS STREAM section on the Equation Summary and Result page and enter the required information.

When finished entering the required compound information, click SAVE.

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For each flare using the Equation Y-2 calculation method, Subpart Y requires you to enter the following supplemental emissions information:

  • An indication of whether daily or weekly measurement periods are used [98.256(e)(8)]
  • The annual volume of flare gas combusted (in MMscf) [98.256(e)(8)]
  • The specific consensus-based standard method number or description of the procedure specified by the flow meter manufacturer [98.256(q)]
  • The number of days during the reporting year missing data procedures were used to determine the volume of flare gas combusted
  • The annual average higher heating value of the flare gas (MMBtu/MMscf) [98.256(e)(8)]
  • The method used to measure higher heating value of the flare gas [98.256(q)]
    • ASTM D4809-06
    • ASTM D240-02 (Reapproved 2007)
    • ASTM D1826-94 (Reapproved 2003)
    • ASTM D3588-98 (Reapproved 2003)
    • ASTM D4891-89 (Reapproved 2006)
    • Chromatographic analysis: manufacturer's instructions
    • Other (specify)
  • The number of days during the reporting year missing data procedures were used to determine the higher heating value of the flare gas
  • An indication of whether the annual volume of flare gas combusted was determined using standard conditions of 68 ºF and 14.7 psia or 60 ºF and 14.7 psia [98.256(e)(8)]
  • An indication of whether the annual average higher heating value of the flare gas was determined using standard conditions of 68 ºF and 14.7 psia or 60 ºF and 14.7 psia [98.256(e)(8)]

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For each flare using the Equation Y-3 calculation method, Subpart Y requires you to enter the following supplemental emissions information:

  • The total number of start-up, shutdown, or malfunction (SSM) events exceeding 500,000 scf/day [98.256(e)(9)]

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Step 2d: Save Your Data

When you have finished entering emission results, click SAVE.

After you save the data on this page, the next time you open the page, the calculator on the top of the page will display the CO2, CH4, and N2O emissions, rounded to the nearest 0.1, 0.01, and 0.001 of a metric ton, respectively. The value displayed is for informational purposes only.

Step 3. Repeat Steps 1-2

Repeat Steps 1-2 until you have entered emissions information for all flares at your facility.

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See Also

Screen Errors
Using e-GGRT to Prepare Your Subpart Y Report
Subpart Y Summary Information for this Facility
Subpart Y Delayed Coking Unit Information
Subpart Y Asphalt Blowing Unit Information
Subpart Y Coke Calcining Unit Information
Subpart Y Catalytic Cracking, Fluid Coking, and Catalytic Reforming Unit Information
Subpart Y Flares Unit Information
Subpart Y Process Vents Unit Information
Subpart Y Sulfur Recovery Plant Information
Subpart Y Emissions Information for Process Units Monitored by CEMS
Subpart Validation Report

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