Illinois Administrative Code
Title 35 - ENVIRONMENTAL PROTECTION
Part 225 - CONTROL OF EMISSIONS FROM LARGE COMBUSTION SOURCES
Subpart F - COMBINED POLLUTANT STANDARDS
Appendix B - Continuous Emission Monitoring Systems for Mercury
Exhibit C - Conversion Procedures
Current through Register Vol. 48, No. 38, September 20, 2024
1. Applicability
Use the procedures in this Exhibit to convert measured data from a monitor or continuous emission monitoring system into the appropriate units of the standard.
2. Procedures for Heat Input
Use the following procedures to compute heat input rate to an affected unit (in mmBtu/hr or mmBtu/day):
Calculate and record heat input rate to an affected unit on an hourly basis. The owner or operator may choose to use the provisions specified in 40 CFR 75.16(e), incorporated by reference in Section 225.140, in conjunction with the procedures provided in Sections 2.4 through 2.4.2 to apportion heat input among each unit using the common stack or common pipe header.
For an affected unit that has a flow monitor (or approved alternate monitoring system under subpart E of 40 CFR 75, incorporated by reference in Section 225.140, for measuring volumetric flow rate) and a diluent gas (O2 or CO2) monitor, use the recorded data from these monitors and one of the following equations to calculate hourly heat input rate (in mmBtu/hr).
When measurements of CO2 concentration are on a wet basis, use the following equation:
When measurements of CO2 concentration are on a dry basis, use the following equation:
When measurements of O2 concentration are on a wet basis, use the following equation:
When measurements of O2 concentration are on a dry basis, use the following equation:
Heat Input Summation (for Heat Input Determined Using a Flow Monitor and Diluent Monitor)
Calculate total quarterly heat input for a unit or common stack using a flow monitor and diluent monitor to calculate heat input, using the following equation:
Calculate total cumulative (year-to-date) heat input for a unit or common stack using a flow monitor and diluent monitor to calculate heat input, using the following equation:
Where applicable, the owner or operator of an affected unit that determines heat input rate at the unit level by apportioning the heat input monitored at a common stack or common pipe using megawatts must apportion the heat input rate using the following equation:
Where applicable, the owner or operator of an affected unit that determines the heat input rate at the unit level by apportioning the heat input rate monitored at a common stack or common pipe using steam load must apportion the heat input rate using the following equation:
The owner or operator of an affected unit that determines the heat input rate at the unit level by summing the heat input rates monitored at multiple stacks or multiple pipes must sum the heat input rates using the following equation:
3. Procedure for Converting Volumetric Flow to STP
Use the following equation to convert volumetric flow at actual temperature and pressure to standard temperature and pressure.
4. Procedures for Mercury Mass Emissions.
Use the procedures in this Section to calculate the hourly mercury mass emissions (in ounces) at each monitored location for the affected unit or group of units that discharge through a common stack.
To determine the hourly mercury mass emissions when using a mercury concentration monitoring system that measures on a wet basis and a flow monitor, use the following equation:
To determine the hourly mercury mass emissions when using a mercury concentration monitoring system that measures on a dry basis or a sorbent trap monitoring system and a flow monitor, use the following equation:
For units that are demonstrated under Section 1.15(d) of Appendix B to emit less than 464 ounces of mercury per year, and for which the owner or operator elects not to continuously monitor the mercury concentration, calculate the hourly mercury mass emissions using Equation F-28 in Section 4.1.1 of this Exhibit, except that "Ch" will be the applicable default mercury concentration from Section 1.15(c), (d), or (e) of Appendix B, expressed in µg/scm. Correction for the stack gas moisture content is not required when this methodology is used.
Use the following equation to calculate quarterly and year-to-date mercury mass emissions in ounces:
If heat input rate monitoring is required, follow the applicable procedures for heat input apportionment and summation in Sections 2.3, 2.4 and 2.5 of this Exhibit.
5. Moisture Determination from Wet and Dry O2 Readings
If a correction for the stack gas moisture content is required in any of the emissions or heat input calculations described in this Exhibit, and if the hourly moisture content is determined from wet- and dry-basis O2 readings, use Equation F-31 to calculate the percent moisture, unless a K-factor or other mathematical algorithm is developed as described in Section 6.5.6(a) of Exhibit A to Appendix B:
