Emission Rate Calculator

Model dry gas flow, controls, and oxygen correction. Get hourly, daily, and yearly release estimates. Visual outputs simplify reviews, comparisons, compliance checks, and decisions.

Calculator Inputs

Used when concentration is entered in ppmv.

Example Data Table

Scenario Pollutant Basis Conc. MW Wet Flow Moisture Temp Pressure O₂ Meas. O₂ Ref. Control Hours/Year
Boiler Stack A SO2 ppmv dry 125 64.07 18,500 m³/h 8% 160°C 101.325 kPa 7% 3% 92% 7,200
Process Vent B NO2 mg/Nm³ dry 210 46.01 11,200 m³/h 4% 95°C 103.000 kPa 9% 3% 85% 6,600
Thermal Oxidizer C HCl ppmv dry 18 36.46 8,750 m³/h 11% 185°C 100.800 kPa 6% 3% 97% 8,000

Formula Used

1) Dry actual flow Qdry,actual = Qwet × (1 − Moisture/100)
2) Normalized dry flow Qdry,normal = Qdry,actual × (Pactual/Pstd) × (Tstd/Tactual)
3) ppmv to mg/Nm³ conversion Cmg/Nm³ = ppmv × Molecular Weight / 22.414
4) Oxygen correction Cref = Cmeasured × (20.9 − O₂ref) / (20.9 − O₂measured)
5) Controlled concentration Ccontrolled = Cref × (1 − Control Efficiency/100)
6) Mass emission rate kg/h = Ccontrolled × Qdry,normal / 1,000,000 g/s = Ccontrolled × Qdry,normal / 3,600,000 t/year = (kg/h × Operating Hours) / 1000

How to Use This Calculator

  1. Select a pollutant preset or enter a custom label.
  2. Choose whether the concentration is in ppmv dry or mg/Nm³ dry.
  3. Enter concentration, flow, moisture, temperature, and pressure values.
  4. Add measured oxygen, reference oxygen, and control efficiency.
  5. Enter annual operating hours for yearly release estimates.
  6. Press Calculate Emission Rate to show results above the form.
  7. Review the summary cards, detailed result table, and Plotly graph.
  8. Use the CSV or PDF buttons to export the calculated output.

Frequently Asked Questions

1) What does this calculator estimate?

It estimates pollutant mass release using concentration, dry-normalized flow, oxygen correction, and control efficiency. Outputs include g/s, kg/h, lb/h, kg/day, and t/year.

2) Why is oxygen correction included?

Oxygen correction lets engineers compare emissions at a common reference oxygen level. This is often required for permits, compliance reporting, and fair equipment benchmarking.

3) When should I use ppmv input?

Use ppmv when gas analyzers or source tests report concentration on a volumetric basis. The calculator converts that value to mg/Nm³ with molecular weight.

4) What does normalized dry flow mean?

Normalized dry flow is gas volume adjusted to dry conditions at a standard temperature and pressure. It removes moisture and operating-condition effects from the calculation.

5) Does control efficiency reduce emissions directly?

Yes. The tool applies the entered efficiency after oxygen correction. This gives an estimated outlet concentration and mass rate after pollution-control equipment performance is considered.

6) Can I use this for annual inventory work?

Yes. Enter realistic operating hours per year. The annual result helps with emissions inventories, permit planning, internal audits, and engineering comparisons across sources.

7) Why do I need pressure and temperature?

Those values convert actual wet flow into normalized dry flow. Without them, the emission estimate may not match standard reporting or source-test conventions.

8) Is this suitable for regulatory submission?

It is useful for engineering estimates and pre-checks. Final compliance submissions should still follow your permit basis, approved test method, and local regulatory guidance.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.