Dispersion Modeling
The use of calculation models for emission’s dispersion in atmosphere allows to calculate the dry and humid deposition, the building wake effects, the dispersion from spot (point-like), area or volume sources, the gradual rise of the plume depending on the source distances, the influence of soil orography.
The dispersion modeling is an indispensable instrument, not only for studies preparatory to the authorization procedures, but also for air quality monitoring and performance evaluation of production activities.
For dispersion modeling simulations SARTEC uses the following applications:
- BREEZE AERMOD GIS PRO 5.1.7., that has been accurately studied by OAQPS (Office of Air Quality Planning and Standards) of EPA to be included in the “Guideline on Air Quality Model”, and it is officially recognized to be used for regulatory purpose.
- BREEZE CALMET CALPUFF; CALPUFF model has been indicated by US-EPA as preferred model for long distance transportation and suggested, also, for pollutant’s transportation simulation on short distances. CALMET is the meteorological model that generates a 3D field of wind and temperature and a 2D field for parameters turbulence related. CALPUFF is a non stationary Lagrangian Gaussian Puff model that can deal with variable and complex meteorological situations and conditions of complex orography, characterized by significant roughness so that physiognomy of the land influences pollutant’s dispersion.
In particular, atmospheric dispersion modeling can be inserted among the monitoring activity of an industrial site to support the analysis of specific plant functioning cases, such as:
- Plant restart after turnaround;
- Programmed/extraordinary maintenance;
- Instrument anomaly identification;
- Process anomaly identification (emissions higher than foreseen);
- Check of right functioning of monitoring instrumentation (remote control);
- Comparison of wind roses from different meteorological stations;
- Comparison of values from different air quality monitoring stations;
- Correlations between simulated and monitored data;
- Discussion with authorities about air quality and emission monitoring data.
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