Micro–scale simulation of atmospheric emissions from power–plant stacks in the Po Valley

The atmospheric dispersion of the NOX plume that will be emitted from a new power–plant, at present under installation, was simulated at micro–scale with Micro–Swift–Spray (MSS) Model. The plant will be constructed in a residential urban area in the town of Modena (Po Valley, Northern Italy), where low wind speeds and thermal inversions are quite frequent. Simulation results point out a different behavior of urban canopy in influencing the 3D dispersion patterns among urban obstacles, according to atmospheric mixing conditions: in case of moderate wind events, urban canyon phenomena may occur with a consequent increasing of NOX concentration gradients among buildings, while with low winds the near–field influence of the buildings emphasizes pollutant accumulation. The MSS simulated NOX concentrations result always much lower than the regulatory limits for air quality. The comparison of simulation results with measured concentration data for NOX shows the importance of micro–scale dispersion modeling to perform an accurate and reliable assessment of meteorological condition effects on pollutant distribution, and the ability of MSS in providing reliable simulations of atmospheric dispersion

Tri-generation power plant and conventional boilers: pollutant flow rate and atmospheric impact of stack emissions

The atmospheric impact of stack emissions from a power plant (tri-generator and boilers) that will be installed in an urban area in the central Po valley (Northern Italy), characterized by calm wind events, 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 NOx emitted is simulated, both in the current and future scenario, by the software package ARIA INDUSTRY. The NOx emission rates are set equal to the regulatory emission limits for existing and future boilers, while the tri-generation system emission rates are set equal to the emission limits certified by the system manufacturer. The simulation periods focus over the 2010 winter season. The simulation estimates the impact of NOx emissions on air quality (vertical concentration profiles and concentration maps at the ground) in the urban area close to the plant. The future power plant impact on air quality results lower than the impact of the existing plant, even if the yearly total mass of pollutants emitted in atmosphere from the new power plant is higher than from the existing plant. The emissions of conventional boilers result the main responsible of the air pollution at the ground in the future scenario

Tri-generation power plant and conventional boilers: pollutant flow rate and atmospheric impact of stack emissions

The atmospheric impact of stack emissions from a power plant (tri-generator and boilers) that will be installed in an urban area in the central Po valley, characterized by calm wind events, 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 NOx emitted is simulated, both in the current and future scenario, by the software package ARIA INDUSTRY. The emission rates are set equal to the regulatory emission limits for existing and future boilers, while the tri-generation system emission rates are set equal to the emission limits certified by the system manufacturer. Local datasets have been used. The simulation periods span over the 2010 winter season. The simulation estimates the impact of emissions on air quality (vertical concentration profiles and concentration maps at the ground) in the urban area close to the plant. The future power plant impact on air quality (i.e. respect to the regulatory pollutant concentration limits) results lower than the impact of the existing plant, even if the yearly total mass of pollutants emitted in atmosphere from the new power plant is higher than from the existing plant