Scrubber Efficiency Calculator

Work out scrubber efficiency instantly with clear inputs, formula shown and shareable results.

About Scrubber Efficiency Calculator

Scrubber removal efficiency is the fractional reduction in concentration between inlet and outlet. Wet limestone flue gas desulphurisation achieves 92-98%, dry sorbent injection 50-80%. Mass rates matter as much as concentration: the same efficiency on a larger gas flow still emits more pollutant.

Formulas

Removal efficiency

Efficiency % = (inlet - outlet) x 100 / inlet

Mass rate

Emitted (kg/h) = outlet concentration (mg/Nm3) x flow (Nm3/h) / 1,000,000

Worked example

With the default values below, Scrubber Efficiency Calculator returns Removal Efficiency of 92.800%. Change any input above and every figure here is recalculated in your browser.

Inputs used

Inlet Concentrationminimum 0 mg/Nm3: 2,500 mg/Nm3
Outlet Concentrationminimum 0 mg/Nm3: 180 mg/Nm3
Flue Gas Flowminimum 0 Nm3/hour: 1,500,000 Nm3/hour
Permit Limitminimum 0 mg/Nm3: 200 mg/Nm3

Results

Removal Efficiency: 92.800%
Pollutant Removed Per Hour: 3,480.00
Pollutant Emitted Per Hour: 270.00
Compliance Status: Compliant

Step by step

1Values used
2Removal efficiency
3Mass rate
4Removal Efficiency= 92.800
5Pollutant Removed Per Hour= 3,480.00
6Pollutant Emitted Per Hour= 270.00
7Compliance Status= Compliant

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 3 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
Emission concentrations and monitoring must comply with the applicable permit, including reference oxygen correction, averaging periods and continuous monitoring requirements.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Emission concentrations and monitoring must comply with the applicable permit, including reference oxygen correction, averaging periods and continuous monitoring requirements.

Frequently Asked Questions

Why do concentration limits need normalising?

Because diluting the flue gas with excess air lowers concentration without reducing emissions. Limits are set at a reference oxygen level, and measured values must be corrected to it.

What limits scrubber efficiency?

Liquid-to-gas ratio, reagent stoichiometry, residence time and absorber design. Pushing above about 98% requires disproportionate reagent and pumping energy.