Defining Material and Material Group Emissions Calculations

Use the Process Unit Material Emission Calculations form to specify how you want to calculate the emissions from the pollutant materials generated by a source during an emission model and scenario. Use the Process Unit Material Group Emission Calculations form to specify how you want to calculate each material group emitted at a source during an emission model and scenario.

Note:  Both forms can only be accessed through the Process Unit Emission Model form.

For instruction on defining material and material group emissions calculations, click the following links or use the scroll bar to scan the page.

Overview of Material Emission Calculations for Emission Models

The table below provides important information about how the selections made and information entered on the Process Unit Material Emission Calculations form affect calculations.

Establishing Material Emission Calculations

On the Process Unit Material Emission Calculations form, specify an emission equation for calculating material emissions.

To establish material emission calculations

1. Click Data Entry > Emission Model Information > Process Unit Emission Models in the Navigation Tree.
   
   The Process Unit Emission Models list appears.

2. Locate the emission model, click the link to display the Process Unit Emission Model form, and expand the Material Emissions section when necessary.

3. Click Material Calculations to display the Process Unit Material Emission Calculations form.
   
   For identification and tracking purposes, the Show Record Details icon is displayed next to the Material field.

4. Select a Material from the list.
   
   If the material is not listed, click the Ellipsis button and add it.

5. Select an Output Type, Equation, and Estimation Quality Rating from the list for each field.
   
   If the appropriate value is not listed, click the Ellipsis button next to the field and add it.

6. Select a Speciation Type from the list when entering a mixture, along with a different MW Physical Property and a Second MW Physical Property when applicable.
   
   Tip:  The MW physical property fields are displayed only when the Speciation Type is Standard Speciation or Selective Speciation. For additional information about speciation, refer to Speciation Method Emission Rate Determination and VLE Molecular Weight Speciation Configuration.

7. Select a Speciated Group from the list when the Selective Speciation value has been chosen.
   
   If the speciated group is not listed, click the Ellipsis button and add it.

8. Select a Vapor Pressure value.

9. Select a TRI Basis of Estimate for TRI reporting and/or an Other Basis of Estimate for non-TRI reporting (such as state emissions inventory reporting) from the list for each field.
   
   If the appropriate basis of estimate is not listed, click the Ellipsis button and add it.

10. Select a Process Unit Link from the list when the emission model source directs its emissions to another process unit.

11. Click the Save button on the form.
    
    Applicable expressions are listed in the Equation Details section. Any global constants are displayed in the Global Constants section.

12. Expand the Equation Constants section when necessary and follow these guidelines for each equation constant:

1. 1. Click the Edit button adjacent to the line item.

   2. Select a Units of measure, enter a Value, and click Save. The information specified is added to the line item in the Equation Constants section.

13. Expand the Parameters section when necessary and refer to Mapping Parameters to map a monitoring parameter or change an existing parameter mapping.

14. Expand the System Variables section when necessary and refer to Editing System Variable Data to make changes to existing data.

15. Expand the Global Emission Factors section when necessary and refer to Mapping Global Emission Factors to map one or more global emission factors to global emission-related parameters to track factor changes over time.

16. Click the Save button on the form, then click Close.
    
    The material emission information is displayed as a line item in the Material Emissions section on the Process Unit Emission Model form. Edit existing material emission information using the Edit button adjacent to the line item.

Mapping Parameters

Equation variables set up as a Parameter variable type derive their values from monitoring results data that you enter for the parameter. Because you can assign a monitoring parameter to six different parameter levels, you must specify where you are monitoring the parameter—at the entity, entity material, production unit, production unit material, process unit, or process unit material level. Additionally, you must include the parameter name in the equation. These two pieces of information—the parameter level and parameter name—constitute the parameter’s mapping.

When an equation variable is defined with a parameter name and the Enterprise Entity or Process Unit parameter level, a parameter definition record is automatically created and mapped to the equation variable at the time the equation is added to the Process Unit Material Emission Calculations or Process Unit Material Group Emission Calculations form. These parameter mappings are displayed as line items in the Parameters section and can be changed using the Edit button adjacent to the line item when necessary. Any parameter you are monitoring at your entity can be referenced.

Because of possible one-to-many relationships at the other parameter levels as described below, a parameter definition record is not automatically created.

• Entity Material - may be associated with zero or multiple materials

• Process Unit Material - may be associated with zero or multiple materials

• Production Unit - a process unit may be assigned to one or more production units (not a recommended practice)

• Production Unit Material - may be associated with zero or multiple materials

The equation variables on these levels are displayed as line items in the Parameters section with a Not Mapped value in the Parameter Type field. Use the Edit button adjacent to a line item to map the equation variable to an existing parameter; any parameter you are monitoring at your entity can be referenced.

To map equation variables to parameters

1. Click the Edit button adjacent to the equation variable line item the Parameters section on the Process Unit Material Emission Calculations or Process Unit Material Group Emission Calculations form.

2. Use the following guidelines to map to a parameter on the same level or a different level:

1. • If the parameter is being monitored on the same level, select the appropriate monitoring parameter from the Parameter field list.

   • If the parameter is being monitored on a different level, first select the parameter level from the Parameter Type field list.

   • When a production unit or process unit level has been chosen, select the Production Unit or Process Unit from the list.

   • If a material level has been chosen, select the Material from the list.

   • Only monitoring parameters that have already been associated with the chosen level will be available for selection in the Parameter field.

3. Click Save.

4. Repeat steps 2 and 3 to map other equation variables to monitoring parameters.

Editing System Variable Data

When equation variables set up as a System Variable type are added to equations, additional input may be required. The input references specific data in the database, such as physical property data, process unit property values, materials, material groups, emission model/scenarios, equation variables (including expressions), or output types. For example, a material must be associated with the "Abated Emissions - Material" system variable. In contrast, no additional input is required when the system variable "Ambient Temperature - Average" is selected.

In the System Variables section on the Process Unit Material Emission Calculations or Process Unit Material Group Emission Calculations form, each system variable associated with the equation is displayed as a line item. The required data specified when the equation was established can be changed for the model/scenario.

To edit system variable data

1. Click the Edit. button adjacent to the system variable line item in the System Variables section on the Process Unit Material Emission Calculations or Process Unit Material Group Emission Calculations form.
   
   Just the fields with entries that can be modified for the specific system variable are displayed. If there are no required inputs, just the Equation Variable field is shown.

2. Select a new value from the list for each field requiring a change and click Save.
   
   The line item in the System Variables section is updated with the new information.

3. Modify other line item system variables by clicking the Edit button adjacent to the line item and repeating step 2.

Mapping Global Emission Factors

When a material calculation for an emission model is set up with an equation that contains global emission-related parameters, one or more global emission factors can be mapped to the parameter to track factor changes over time. The unique effective date/model/material/parameter combination causes the emission calculator to recalculate emissions at the effective dates because it is assumed that the value of the parameter changes when the effective date of the factor changes.

To add a global emission factor for a parameter, specify the effective date and select the factor from the Global Emission Factor Library. The corresponding name, value, and unit of measure are automatically displayed for reference purposes. If a factor is selected that does not have an assigned name, one can be entered during the mapping process and it will also be saved to the library.

To map global emission factors

1. Open the Process Unit Emission Model form and expand the Material Emissions section when necessary.

2. Click the Edit button adjacent to a material line item to open the Process Unit Material Emission Calculations form.

3. Expand the Global Emission Factors section when necessary and click the Edit button adjacent to a line item.
   
   For identification and tracking purposes, the Show Record Details icon is displayed next to the Material field.

4. Click the Add Effective Global Emission Factor link.

5. Enter an Effective Date or click the Calendar button and select the date.

6. Select a Global Emission Factor from the list. Refer to Global Emission Factor Search for additional information.

7. The Global Emission Factor Name, Value, and Units fields are automatically populated with data in the Global Emission Factor library. If a name does not exist, one can be entered here.

8. Enter any notes in the Comments field and click OK.  
   
   The global emission factor information is displayed as a line item. Use the buttons adjacent to the line item to edit existing information.

9. Repeat steps 4 through 8 to map other factors. Otherwise, click Save and close the window.
   
   The line item in the Global Emission Factors section is updated with the newly added information.

Overview of Material Group Emission Calculations for Emission Models

Use the Process Unit Material Group Emission Calculations form to specify how you want to calculate each material group emitted at a source during an emission model and scenario.

Important:  You must be licensed for the Essential Chemical Inventory module along with the Air module to use this functionality.

In the Chemical Inventory module, the actual quantity of materials consumed at a source are tracked by entering inventory transactions. In the Air module, you reference these transactions by building an emission equation containing the system variable "Inventory Quantity - Material Group", where the materials associated with transactions belong to the material group. (Assign materials to a material group on the Material Group form.) Then, when you use this equation to model the emissions from the process unit, the exact materials and quantities used can be determined.

The table below provides important information about how the selections made and information entered on the Process Unit Material Group Emission Calculations form affect calculations. This form can only be accessed through the Process Unit Emission Model form.

To establish material group emission calculations

1. Click Data Entry > Emission Model Information > Process Unit Emission Models in the Navigation Tree.
   
   The Process Unit Emission Models list appears.

2. Locate the emission model, click the link to display the Process Unit Emission Model form, and expand the Material Group Emissions section when necessary.

3. Click Material Group Calculations to display the Process Unit Material Group Emission Calculations form.
   
   For identification and tracking purposes, the Show Record Details icon is displayed next to the Material field.

4. Select a Material Group, Output Type, Equation, and Estimation Quality Rating from the list for each field.
   
   If the appropriate value is not listed, click the Ellipsis button next to the field and add it.

5. Select a Speciation Type from the list when entering a mixture, and specify a different MW Physical Property and a Second MW Physical Property when applicable.
   
   Tip:  The MW physical property fields are displayed only when the Speciation Type is Standard Speciation or Selective Speciation. For additional information about, refer to Speciation Method Emission Rate Determination and VLE Molecular Weight Speciation Configuration.

6. Select a Speciated Group from the list when the Selective Speciation value has been chosen.
   
   If the speciated group is not listed, click the Ellipsis button and add it.

7. Select a Vapor Pressure value and Base of Estimate from the list for each field.
   
   If the appropriate base of estimate is not listed, click the Ellipsis button and add it.

8. Select a Process Unit Link from the list when the emission model source directs its emissions to another process unit.

9. Click the Save button on the form.
   
   Any global constants and system variables are displayed in the Global Constants and System Variables sections.

10. Expand the Equation Constants section when necessary and follow these guidelines for each equation constant:

    1. Click the Edit button adjacent to the line item.

    2. Select a Units of measure, enter a Value, and click Save. The information specified is added to the line item in the Equation Constants section.

11. Expand the Parameters section when necessary and refer to Mapping Parameters to map an equation variable to a monitoring parameter or change an existing parameter mapping.

12. Expand the System Variables section when necessary and refer to Editing System Variable Data to make changes to existing data.

13. Click the Save button on the Process Unit Material Group Emission Calculations form, then click Close.  
    
    The material group emission information is displayed as a line item in the Material Group Emissions section on the Process Unit Emission Model form. Edit existing material emission information using the buttons adjacent to the line item.