An emission inventory tool for estimating SO2, NO2, and PM10 emissions from brick clamp kiln sites
was developed from investigations performed on three representative South African clamp kiln
sites in order to facilitate application for Atmospheric Emission Licenses (AELs) from these sources.
The tool utilizes readily available site-specific parameters to generate emission factors for
significant activities that emit the aforementioned pollutants. PM10 emission factors for significant
processes were developed using empirical expressions from the Compilation of Air Pollutant
Emission Factors (AP-42) documents.
SO2 emission factor for clamp kiln firing was obtained from “reverse-modelling”, a technique that
integrates ambient monitoring and dispersion modelling (using Atmospheric Dispersion Modelling
System software) to “standardize” actual emission rate from an assumed rate of 1 g/s. The use of
multiple point sources proved to improve the simulation of the buoyancy-induced plume rise;
therefore, a “bi-point” source configuration was adopted for the kiln. The “reverse-modelling”
technique and “bi-point” source configuration produced SO2 emission rates differing from -9 % to
+22 % from mass balance results, indicating that the “reverse-modelling” calculations provide
reliable emission estimates for SO2.
An NO2 emission factor could not be obtained from the “reverse-modelling” technique due to
experimental errors and the significant effect of NO2 emissions from other onsite air emission
sources such as internal combustion engines. The NO2 emission factor was obtained from previous
comprehensive study on a similar clamp kiln site.
The emission factors obtained from this study were utilized in developing an “emission inventory
tool” which is utilized by clay brick manufacturers in quantifying air emissions from their sites.
Emissions quantification is a requirement for brick manufacturers to obtain an AEL which is
regulated under South African environmental laws.
It is suggested that the technique used here for SO2 emission confirmation could be used to
estimate emissions from a volume or area source where combustion occurs and where knowledge
of the source parameters is limited.