Introduction
Air pollutant emission factors are representative values that attempt to relate the quantity of a pollutant released to the ambient air with an activity associated with the release of that pollutant. These factors are usually expressed as the weight of pollutant divided by a unit weight, volume, distance, or duration of the activity emitting the pollutant (e.g., kilograms of particulate emitted per megagram of coal burned). Such factors facilitate estimation of emissions from various sources of air pollution. In most cases, these factors are simply averages of all available data of acceptable quality, and are generally assumed to be representative of long-term averages.
The equation for the estimation of emissions before emission reduction controls are applied is:
- E = A × EF
and for emissions after reduction controls are applied:
- E = A × EF × (1-ER/100)
| where: | |
| E | = emissions, in units of pollutant per unit of time |
|---|---|
| A | = activity rate, in units of weight, volume, distance, or duration per unit of time |
| EF | = emission factor, in units of pollutant per unit of weight, volume, distance, or duration |
| ER | = overall emission reduction efficiency, in % |
Emission factors are used by atmospheric dispersion modelers and others to determine the amount of air pollutants being emitted from sources within industrial facilities.
Read more about this topic: AP 42 Compilation Of Air Pollutant Emission Factors
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