Stack Emission Rate Calculator
Calculate pollutant mass emission rate from a combustion stack using EPA Method 19 / standard stack testing inputs: velocity, area, concentration, temperature, pressure.
Stack Parameters
Standard atmospheric = 101.325 kPa
Pollutant
mg/m³
Results
Actual Flow Rate
m³/s
Std. Flow Rate (0°C, 101.325 kPa)
m³/s
Concentration (mg/m³)
at standard conditions
Mass Emission Rate
g/s
Mass Emission Rate
kg/hr
Annual Emission (24/7)
tonnes/year
Calculation Steps
Typical Emission Limit Reference
| Pollutant | Source Type | Limit (mg/m³) | Regulation / Context |
|---|---|---|---|
| SO₂ | Large combustion plant | 200 | EU IED / EPA 40 CFR Part 60 |
| SO₂ | Industrial boiler | 500 | Typical national standard |
| NOx | Large combustion plant | 200 | EU IED (expressed as NO₂) |
| NOx | Gas turbine | 75 | EPA NSPS Subpart GG |
| CO | Industrial boiler | 100 | EU IED / typical permit |
| CO | Gas turbine | 50 | EPA NSPS Subpart KKKK |
| PM | Large combustion plant | 20 | EU IED |
| PM | Cement kiln | 30 | EU IED / EPA NSPS Subpart F |
Values are indicative. Always verify against the applicable permit and local regulation. Concentrations at dry standard conditions (0 °C, 101.325 kPa) unless noted otherwise.
Summary
Calculate pollutant mass emission rate from a combustion stack using EPA Method 19 / standard stack testing inputs: velocity, area, concentration, temperature, pressure.
How it works
- Enter stack gas velocity (m/s) and cross-sectional area (m²) to compute actual volumetric flow rate: Q_actual = v × A.
- Supply gas temperature (°C) and pressure (kPa); the tool converts to standard conditions (0 °C, 101.325 kPa): Q_std = Q_actual × (273.15 / T_K) × (P / 101.325).
- Select a pollutant gas (SO₂, NOx, CO, PM) and enter the measured concentration in mg/m³ or ppm; the tool converts ppm to mg/m³ using the selected gas molecular weight.
- Mass emission rate E = C_std × Q_std; output in g/s and kg/hr.
- Annual emission assumes continuous 24/7 operation: E_annual = E_kg_hr × 8760 / 1000 (tonnes/year).
Use cases
- Estimate SO₂, NOx, CO, or PM emission rates during source testing campaigns.
- Screen whether a combustion source meets permit emission limits before formal testing.
- Convert stack test concentration readings to mass emission rates for annual reporting.
- Compare a stack's calculated emission rate against typical regulatory benchmarks.
- Perform quick sensitivity checks on emission rate as a function of process load or fuel switch.
Frequently Asked Questions
Last updated: 2026-07-24 ·
Reviewed by Nham Vu