These optional spreadsheets are provided to assist reporters in calculating emissions and in keeping records of these calculations.
Reporters are required to keep records of these calculations under 40 CFR 98.3(g) and additional subpartspecific provisions, but are not required to use these spreadsheets or to submit any spreadsheets to EPA.
Overview
This help page provides guidance for working with the supplemental Subpart X calculation spreadsheets. The spreadsheets calculate the CO_{2} process emissions in accordance with Equations X1 through X4 in subpart X. A facility must use these equations to calculate emissions when complying with the mass balance option in subpart X. As stated in §98.242, process emissions for the mass balance option are the total CO_{2} generated in the process itself plus the CO_{2} generated by combustion of offgas from the process. The guidance provides stepbystep instructions for the following tasks:
 Selecting the Appropriate Calculation Spreadsheet
 Downloading a Calculation Spreadsheet
 General Information on Using a Calculation Spreadsheet
 Using the Equation X1 Calculation Spreadsheet
 Using the Equation X2 Calculation Spreadsheet
 Using the Equation X3 Calculation Spreadsheet
 Using the Equation X4 Calculation Spreadsheet
Specific information on each of the calculation spreadsheets is provided below:
Calculation Spreadsheet  Calculation  Selection Criteria:  Instructions 

Net Contribution to Calculated Emissions from Carbon Materials  Gaseous  
Net Contribution to Calculated Emissions from Carbon Materials  Liquid  
Net Contribution to Calculated Emissions from Carbon Materials  Solid  
Annual CO_{2} Emissions  N/A 
Subpart X requires a facility to report annual CO_{2} process emissions from each process unit used to produce petrochemicals. To calculate emissions from a process unit, users must first calculate the annual net contribution to calculated emissions from carbon in gaseous, liquid, and solid feedstocks and products using calculation spreadsheets for equations X1, X2, and X3, respectively. Once completed, users should then copy the results from those spreadsheets into the Equation X4 Calculation Spreadsheet. This sequence must be repeated for each process unit.
For each process unit with any gaseous feedstocks or products, users should calculate the annual net contribution to calculated emissions from the gaseous carbon materials using Equation X1 and the Equation X1 Calculation Spreadsheet. Equation X1 is provided below:
(Equation X1) 

For each process unit with any liquid feedstocks or products, users should calculate the annual net contribution to calculated emissions from the liquid carbon materials using Equation X2 and the Equation X2 Calculation Spreadsheet. Equation X2 is provided below:
(Equation X2) 

For each process unit with any solid feedstocks or products, users should calculate the annual net contribution to calculated emissions from the solid carbon materials using Equation X3 and the Equation X3 Calculation Spreadsheet. Equation X3 is provided below:
(Equation X3) 

For each process unit, users should calculate the annual CO_{2} mass emissions from process operations and process offgas combustion using Equation X4 and the Equation X4 Calculation Spreadsheet. Equation X4 is provided below:
(Equation X4) 

Calculation spreadsheets for Subpart X may be downloaded by clicking one of the links in the first column of the table below. Users may also jump to instructions for each calculation spreadsheet by clicking one of the links in the third column.
Calculation Spreadsheet  Calculation  Selection Criteria:  Instructions 

Net Contribution to Calculated Emissions from Carbon Materials  Gaseous  
Net Contribution to Calculated Emissions from Carbon Materials  Liquid  
Net Contribution to Calculated Emissions from Carbon Materials  Solid  
Annual CO_{2} Emissions  N/A 
The guidance provided in this section applies to each of the calculation spreadsheets for Subpart X. Additional guidance is provided for each individual calculation spreadsheet in the sections below.
Color coding
The calculation spreadsheets contain green input cells, gray informational cells, and redbordered results cells filled with yellow or white. Users should use green input cells to enter all data specific to their facility, unit, or process. Gray informational cells contain parameter names, column and row headings, equation constants and subtotals. Calculation results are displayed in redbordered results cells filled with yellow or white. For redbordered, yellowfilled results cells, the values in these cells should be entered in the appropriate and separate calculation spreadsheet (as directed below cell) where additional calculations will be made. For redbordered, white filled results cells, the values in these cells should be entered in eGGRT for the appropriate process units. All cells that are not green input cells are locked and cannot be modified.

Green input cell (data entry) 

Gray informational cells (locked) 

Redbordered, yellowfilled results cells (enter in appropriate and separate calculation spreadsheet) 

Redbordered, white filled results cells (enter in eGGRT) 
Stop and Warning Messages
The calculation spreadsheets will display a stop message if the user enters a value that is invalid or a warning message if the user enters a value outside the EPA estimated range for a particular data element. For invalid data entries, the stop messages will not allow a user to proceed and the user must reenter valid data before moving forward. For data entries that are outside the EPA estimated range for a particular data element, the warning messages will allow a user to proceed if the user deems the entered value to be accurate.
Multiple Process Units
Users with multiple process units should use separate calculation spreadsheets for each process unit. Users should not aggregate data for multiple process units when using these calculation spreadsheets.
Calculate the annual net contribution to calculated emissions from carbon materials for each process unit with gaseous feedstocks and/or products using Equation X1 and the Equation X1 Calculation Spreadsheet. Space is provided for up to three gaseous feedstocks and three gaseous products in the spreadsheet. Use additional copies of this spreadsheet for additional materials and add the contributions prior to entering in the Equation X4 Calculation Spreadsheet. Equation X1 is provided below:
(Equation X1) 

Begin by entering the facility name, your name, the process unit name or identifier, the unit type, the reporting period, and any additional comments in the green input cells of the general information table located immediately below the equation in the calculation spreadsheet. This is for your records.
Next, enter the requested information in the green input cells in the General Input Data table.
Next, enter the requested information in the green input cells in the Input Data for Feedstocks table.
Then, enter the requested information in the green input cells in the Input Data for Products table.
The calculation spreadsheet will calculate the net contribution to calculated emissions from all carboncontaining gaseous feedstocks and products in a process unit. This calculated value will be displayed in the redbordered cell with yellow fill at the bottom of the spreadsheet. This value should be entered in the Equation X4 Calculation Spreadsheet for this process unit.
Calculate the annual net contribution to calculated emissions from carbon materials for each process unit with liquid feedstocks and/or products using Equation X2 and the Equation X2 Calculation Spreadsheet. Space is provided for up to three liquid feedstocks and three liquid products in the spreadsheet. Use additional copies of this spreadsheet for additional materials and add the contributions prior to entering in the Equation X4 Calculation Spreadsheet. Equation X2 is provided below:
(Equation X2) 

Begin by entering the facility name, your name, the process unit name or identifier, the unit type, the reporting period, and any additional comments in the green input cells of the general information table located immediately below the equation in the calculation spreadsheet. This is for your records.
Next, enter the requested information in the green input cells in the Input Data for Feedstocks table.
Then, enter the requested information in the green input cells in the Input Data for Products table.
The calculation spreadsheet will calculate the net contribution to calculated emissions from all carboncontaining liquid feedstocks and products in a process unit. This calculated value will be displayed in the redbordered cell with yellow fill at the bottom of the spreadsheet. This value should be entered in the Equation X4 Calculation Spreadsheet for this process unit.
Calculate the annual net contribution to calculated emissions from carbon materials for each process unit with solid feedstocks and/or products using Equation X3 and the Equation X3 Calculation Spreadsheet. Space is provided for up to three solid feedstocks and three solid products in the spreadsheet. Use additional copies of this spreadsheet for additional materials and add the contributions prior to entering in the Equation X4 Calculation Spreadsheet. Equation X3 is provided below:
(Equation X3) 

Begin by entering the facility name, your name, the process unit name or identifier, the unit type, the reporting period, and any additional comments in the green input cells of the general information table located immediately below the equation in the calculation spreadsheet. This is for your records.
Next, enter the requested information in the green input cells in the Input Data for Feedstocks table.
Then, enter the requested information in the green input cells in the Input Data for Products table.
The calculation spreadsheet will calculate the net contribution to calculated emissions from all carboncontaining solid feedstocks and products in a process unit. This calculated value will be displayed in the redbordered cell with yellow fill at the bottom of the spreadsheet. This value should be entered in the Equation X4 Calculation Spreadsheet for this process unit.
Calculate the annual mass of CO_{2} process emissions using the results from the X1, X2, and X3 calculation spreadsheets in Equation X4, and the Equation X4 Calculation Spreadsheet. Equation X4 is provided below:
(Equation X4) 

Begin by entering the facility name, your name, the process unit name or identifier, the unit type, the reporting period, and any additional comments in the green input cells of the general information table located immediately below the equation in the calculation spreadsheet. This is for your records.
Next, enter the requested information in the green input cells in the Input Data for Feedstocks table.
The calculation spreadsheet will calculate the annual CO_{2} process emissions in metric tons per year for a process unit. This calculated value will be displayed in the redbordered cell with white fill at the bottom of the spreadsheet. This value should be entered in eGGRT for this process unit.