The atmospheric impact of stack emissions from a tri-generation power plant that will be installed in a urban area in the central Po valley are studied and compared to the impact of the existing plant (conventional boilers). Both the plants are supplied by methane gas. The atmospheric dispersion of the emissions is simulated both in the current and the future scenario, i.e. before and after tri-generation plant activation respectively. The plant is assumed as a continuous emission point source. The emission rates are set equal to the regulatory emission limits for the existing plant and to the emission limits certified by the tri-generation system maker company for the future plant. The local meteorological, topographical and surface land cover datasets have been used. The simulation periods span over each one of the four seasons, using 2010 meteorological data, to test conditions both favourable and unfavourable to pollutant accumulation in the atmosphere; simulation period spanning over the whole 2010 year are also performed (long-term) . The dispersion of different air pollutants (NOx mainly) is presented; the concentration fields obtained for the same period in the two different scenarios are compared. The aim of the simulation is to estimate the impact of emissions on air quality in the urban area close to the plant, in different weather conditions, in a region characterized by calm wind events. The tri-generation power plant impact on air quality (i.e. respect to the regulatory concentration limits for pollutants in atmosphere) results lower than the impact of the existing plant, even if the yearly total mass of pollutants emitted in atmosphere from the tri-generation power plant is higher than from the existing plant. The simulation is performed by the software package ARIA INDUSTRY, that is made up of the 3D lagrangian stochastic particle dispersion model SPRAY, the diagnostic meteorological model MINERVE and the turbulence model SURFPRO.
Atmospheric impact of power plant stack emissions / Ghermandi, Grazia; Teggi, Sergio; Fabbi, Sara; Bigi, Alessandro; M. M., Zaccanti. - STAMPA. - (2011), pp. 240-244. (Intervento presentato al convegno 14th International Conference on Harmonisation within Atmospheric Dispersion Modelling for Regulatory Purposes, HARMO 2011 tenutosi a Kos, Greece nel 2-6 ottobre, 2011).