Subpart Y consists of facilities that produce gasoline, gasoline blending stocks, naphtha, kerosene, distillate fuel oils, residual fuel oils, lubricants, or asphalt (bitumen) by the distillation of petroleum or the redistillation, cracking, or reforming of unfinished petroleum derivatives.

This page provides an overview of subtopics that are central to Subpart Y reporting:

• #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 Y Validation Report

The end of the page contains links you can use for more information on these topics.

Subpart Y Summary Information for this Facility

Subpart Y requires you to report the following data about your facility:

• The annual CO₂ emissions from sour gas sent off-site for sulfur recovery
• The annual CH₄ emissions from the following sources:
  • Uncontrolled Blowdown Systems
  • Equipment Leaks
  • Loading Operations
  • Storage Tanks
  • Delayed Coking

Subpart Y Delayed Coking Unit Information

Subpart Y requires you to report the following data for each delayed coking unit at your facility:

• A unique name or identifier, plus optional description. See also About Unique Unit Names
• Method used to calculate the CH₄ emissions

Subpart Y requires you to report the following data for each coking drum at your facility:

• A unique name or identifier, plus optional description. See also About Unique Unit Names
• Typical drum outage in feet (i.e. unfilled distance from the top of the drum)

Subpart Y Asphalt Blowing Unit Information

Subpart Y requires you to report the following data about your asphalt blowing operations:

• A unique name or identifier, plus optional description for this asphalt blowing unit. See also About Unique Unit Names.
• Specify the control device used to reduce methane (and other organic) emissions from the unit. Select from Vapor scrubber, Thermal oxidizer, Flare, Other (specify), or None.

When you are finished, click SAVE.

If you selected Thermal oxidizer, Flare, or Other, an additional question will appear requiring you to select a CO₂ AND CH₄ EMISSIONS CALCULATION METHOD. The system requires you to select the method used to calculate the CO₂ and CH₄ emissions for your asphalt blowing operations from the following list:

• Equations Y-14 and Y-15 (appears only if Other was selected)
• Equations Y-16a and Y-17
• Equations Y-16b and Y-17.

Subpart Y Coke Calcining Unit Information

Subpart Y collects the following data about your coke calcining unit:

• Maximum rated throughput of the coke calcining unit (metric tons coke calcined per stream day)
• Method used to calculate the CH₄ emissions:
  • Equation Y-9
  • Unit-specific measurement data
  • A unit-specific emission factor based on a source test of the unit
• Method used to calculate the N₂O emissions:
  • Equation Y-10
  • Unit-specific measurement data
  • A unit-specific emission factor based on a source test of the unit

Subpart Y Catalytic Cracking, Fluid Coking, and Catalytic Reforming Unit Information

Subpart Y collects the following data about your Catalytic Cracking, Fluid Coking, or Catalytic Reforming unit:

• A unique name or identifier, plus optional description for this unit (see also About Unique Unit Names)
• Specify the type of unit:
  • Fluid Catalytic Cracking Unit
  • Thermal Catalytic Cracking Unit
  • Traditional Fluid Coking Unit
  • Catalytic Reforming Unit
  • Fluid Coking Unit with Flexicoking Design (see note below)
• An indication whether each unit is monitored by a CEMS

For Catalytic Cracking or Coking units that are NOT monitored by CEMS, Subpart Y also collects the following data:

• Maximum rated throughput of the unit (bbl per stream day)
• Method used to calculate CO₂ emissions (only appears if you select No for using a CEMS):
  • 98.253(c)(2) - Equation Y-6 and continuous monitor for flow (but not meeting the CEMS monitoring requirements of 98.253(c)(1); e.g., not meeting the full CEMS quality assurance requirements)
  • 98.253(c)(2) - Equation Y-6 and Y-7a
  • 98.253(c)(2) - Equation Y-6 and Y-7b
  • 98.253(c)(3) - Equation Y-8 (option appears only for Catalytic Cracking or Coking units; available only for catalytic cracking units and fluid coking units with rated capacities of 10,000 barrels per stream day (bbls/sd) or less that do not use a continuous CO₂ CEMS for the final exhaust stack)
  • 98.253(e)(3) - Equation Y-11 (option appears only for Catalytic Reforming units)
• Method used to calculate CH₄ emissions:
  • Equation Y-9
  • Unit-specific measurement data
  • A unit-specific emission factor based on a source test of the unit
• Method used to calculate N₂O emissions:
  • Equation Y-10
  • Unit-specific measurement data
  • A unit-specific emission factor based on a source test of the unit

For Catalytic Cracking or Coking units that are monitored by CEMS, Subpart Y also collects the following data:

• Maximum rated throughput of the unit (bbl per stream day)
• Method used to calculate CH₄ emissions:
  • Equation Y-9
  • Unit-specific measurement data
  • A unit-specific emission factor based on a source test of the unit
• Method used to calculate N₂O emissions:
  • Equation Y-10
  • Unit-specific measurement data
  • A unit-specific emission factor based on a source test of the unit

Subpart Y Flares Unit Information

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
• 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 Equations 1a or 1b)
  • 98.253(b)(1)(ii) – 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.)

Subpart Y Process Vents Unit Information

Subpart Y collects the following data about your Process Vent unit:

• A unique name or identifier, plus optional description for this process vent unit (see also About Unique Unit Names):
• Operation type associated with this process vent:
• Control device used to reduce methane (and other organic) emissions from the unit:
• Annual volumetric flow discharged to the atmosphere (scf)
• Method used to measure or estimate the annual volumetric flow rate:
• Number of venting events, if vent is intermittent
• Cumulative venting time (hours)
• Greenhouse gases to report for this process vent. Select any combination of CO₂, CH₄ or N₂O. CO₂ emissions must be reported if the process vent contains greater than 2 percent by volume CO₂ or greater. CH₄ emissions must be reported if the process vent contains 0.5 percent by volume of CH₄ or greater. N₂O emissions must be reported if the process vent contains 0.01 percent by volume of N₂O or greater.

Subpart Y collects the following data if CO₂ is being reported for this Process Vent:

• Annual CO₂ emissions from this process vent (metric tons).
• Annual average mole fraction of CO₂
• Method used to measure or estimate the annual average mole fraction of CO₂:

Subpart Y collects the following data if CH₄ is being reported for this Process Vent:

• Annual CH₄ emissions from this process vent (metric tons).
• Annual average mole fraction of CH₄
• Method used to measure or estimate the annual average mole fraction of CH₄:

Subpart Y collects the following data if N₂O is being reported for this Process Vent:

• Annual N₂O emissions from this process vent (metric tons).
• Annual average mole fraction of N₂O
• Method used to measure or estimate the annual average mole fraction of N₂O:

Subpart Y Sulfur Recovery Plant Information

Subpart Y collects the following data about your sulfur recovery plant:

• Maximum rated throughput of the sulfur recovery plant (metric tons sulfur per stream day)
• Type of sulfur recovery plant:
  • Caustic scrubber
  • Claus
  • Lo-cat
  • Sulfuric acid plant
  • Other (specify)
• Method used to calculate the CO₂ emissions. Specify either Equation Y-12 or Process Vent Method. [Only appears if No is selected for using a CEMS. For Claus Plants (that do not use a CEMS according to Subpart C), Equation Y-12 must be used. For non-Claus plants (that do not use a CEMS according to Subpart C), either Equation Y-12 or the Process Vent Method may be used.]
• Indicate whether, if you recycle tail gas, the recycled flow rate and carbon content of recycled tail gas is included in the measured volumetric flow and carbon mole fraction data. If you do not recycle tail gas, please select No. [This question appears only if Equation Y-12 is selected]. Click either Yes or No.
• Indicate if a correction for CO₂ emissions in the tail gas is used. [This question appears only if Yes is selected for previous question]. Click either Yes or No. Note that per Section 98.253(f)(5), if tail gas is recycled to the front of the sulfur recovery plant and the recycled flow rate and carbon content is included in the measured data, then the annual CO₂ emissions must be corrected to avoid double counting these emissions.

Subpart Y Emissions Information for Process Units Monitored by CEMS

For each CEMS Monitoring Location, provide the following information:

• A unique unit name or identifier for the CML (see also About Unique Unit Names)
• An optional description or label for the CML
• The configuration of processes or process units that are monitored by the CML:
  • Single industrial process or process unit that exhausts to a dedicated stack
  • Multiple industrial processes or process units share a common stack
  • Industrial process or process unit shares a common stack with one or more stationary fuel combustion units
• The name of each fuel combusted in the unit(s) monitored by the CEMS
• The Tier 4/CEMS methodology start and end dates
• The cumulative total of hourly CO₂ mass emissions for each quarter of the reporting year (in metric tons) (Do not cumulate emissions data between quarters)
• The total annual CO₂ mass emissions measured by the CEMS (in metric tons)
• An indication whether emissions reported for the CEMS include emissions calculated according to 98.33(a)(4)(viii) for a slipstream that bypassed the CEMS
• The total annual biogenic CO₂ emissions from the combustion of all biomass fuels combined (in metric tons) (if applicable)
• The total annual non-biogenic CO₂ emissions (includes fossil fuel, sorbent, and process CO₂ emissions, in metric tons)
• The total annual CH₄ and N₂O emissions associated with the combustion of all Table C-2 fuels combusted in all processes/process units monitored by the CEMS derived from application of Equation C-10 (in metric tons) (if there are no combustion emissions in this CML, please enter zero)
• The total number of source operating hours in the reporting year
• The total operating hours in which a substitute data value was used in the emissions calculations for the CO₂ concentration parameter
• The total operating hours in which a substitute data value was used in the emissions calculations for the stack gas flow rate parameter
• If moisture correction is required and a continuous moisture monitor is used, the total operating hours in which a substitute data value was used in the emissions calculations for the stack gas moisture content parameter
• An indication of the process units monitored by the CML
• The CO₂ emissions from this CEMS Monitoring Location that are attributable to process CO₂ emissions from this process unit (metric tons).

Subpart Y Validation Report

You can use the Validation Report to ensure the completeness and quality of your reporting data.

You should use the Validation Report to check your work. The Validation Report performs two types of checks:

• Data Completeness: Data that are required for reporting is missing or incomplete.
• Data Quality: Data are outside of the expected range of values.

You may view the Validation Report at any time.

Note that the Validation Report is intended to assist users in entering data, but it is not an indication that the reporter has entered all necessary information, nor is it an indication that the reporter is in compliance with 40 CFR Part 98. Furthermore a negative finding on the validation report is not a guarantee that a data element was entered incorrectly.

#Back to Top

See Also

Screen Errors
Using Cal 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