Emission Factors

Emission Factors Database

       The Emission Factor model is used to calculate emissions for a given operation where the speciated emissions are a function of time, production, or consumption.  For example, the emission factor model may be used to calculate the emissions from normal combustion operations (power plants and generators).  Additionally, this model could be used for calculating the emissions from fermentation operations when the emissions are a function of the feed stocks that have been charged or the length of time that the fermentation has taken place. 

From AP42, the following equation is used to calculate the emission quantity of compound i based on an activity rate and an emission factor for that compound.        

       Ei = A * EFi

Ei = is the emission quantity of compound i.

A = is the activity rate in units of weight, volume, distance, duration, or other unit of measure.

EFi = emission factor for compound i that is tied to the units of A.

       Emission Factor records can be entered into the database using the New button at the Emission Factor database window.  The user is first prompted to enter the emission unit quantity basis {lbs, kg, MMCF, hr, ...} and then to select compounds from the Chemicals database and enter specific emission quantities.  For example, AP42 provides many emission factors for the combustion of several different fuels including diesel fuel, coal, gasoline, and others.  These emission factors can be entered as individual records in the Emission Factors Database for use within the program. 

Web tutorial: www.mitchellscientific.com/tutorial/EmissionFactorDatabase.htm

Other references: http://www.epa.gov/ttn/chief/ap42/