Modeling of Monthly Variations Of NO2 and SO2 Gases Dispersion from the Chimneys of Homs Fertilizer Plants

Abstract

Monthly variations of sulfur dioxide and nitrogen oxides dispersion from fertilizer plants in Homs were modeled using ALOHA software. The results of dispersion modeling of SO₂ and NO₂ in different months showed that the shape of the cloud is strongly related to the wind speed, direction, and climatic condition of each month. Concentrations were lower than the WHO guidance values in July and June, where wind speed is maximum (11.5 and 10.3 m/s). The concentrations are increased in November due to low wind speed (1.6 m/s).

The cloud carrying SO₂ with its maximum concentrations reached about 4.5 km in the months with low wind speed, while the cloud of nitrogen dioxide reached about 5.8 km, because of its low molecular weight compared to SO₂. However, the modeling results showed that the concentrations exceeded the WHO guidance levels, which necessitates the need for installation of scrapers and removals on the stacks of sulfuric acid and nitrogen acid factories (replacement of the old low efficiency scrapers) to reduce these emissions.