NOxEmission Modelling and Simulation Using Point Source Dispersion Model

Process industry is a leading industrial sectorin Malaysia and a vital part ofthe national
economy. However, emissions of gases are unavoidable events during activities in
process industry whichwill cause air pollution. The objective ofthis projectis mainlyto
develop a computer simulation program of point source dispersion using Visual Basic
software. Thepurpose of this software is to estimate the NOx concentration after the gas
is released from the industrial stacks. This software is also used to estimate the
percentage of people affected as a result from the exposure to NOx at certain
concentration. The application is calledPoint Source DispersionSoftware(PSDS) and it
is specifically developed for emission ofpollutant gases released from industrial stacks.
Pasquill equation which modified by Gifford is used in this software. The model
consider the atmospheric conditions, stack parameters and distance as the inputs of the
simulation program. The simulation program is complex and this is the reason why the
computer simulation is necessary in order to derive the reliable results. The results of
PSDS show the concentration of respective pollutant gases over the distance as well as
the percentage ofpeopleaffected as a result fromthe exposure to the pollutant at certain
concentratioa The results from this software are validated with data from case studies
and SCREEN3 (US EPA air pollution modelling software) to identify any error occur
during writing the program