DISPERSION MODELING OF NITROUS OXIDE EMISSIONS FROM A NITRIC ACID PLANT IN DEVNYA REGION, BULGARIA

Maya Stefanova, Rozalina Chuturkova, Evgeni Sokolovski, Nina Ilieva

Abstract: Within the present research a mathematical modeling is done in order to study the dispersion of nitrous oxide emissions from a single organized source – a nitric acid plant with 363000 tons per year production capacity in the industrial region of Devnya, Bulgaria. Separate simulations are done for the dispersion of N2O emissions without any emission reduction measures being implemented in the plant and for N2O emission dispersion with a secondary N2O decomposing catalyst being installed under different meteorological conditions. Results indicate that a significant decrease of N2O concentration in the ground atmospheric layer is achieved after the implementation of the secondary decomposing catalyst – over 81 % reduction of the hourly average N2O concentration and up to 80 % reduction of the annual average N2O concentration is calculated. Dispersion models also indicate that the territorial dispersion of N2O emissions is reduced as well – the area with N2O concentration below 200 µg/m 3 is 15 times smaller with a secondary N2O decomposing catalyst being installed. Research results provide a tool to assess the decomposing catalyst reduction potential and to predict the impact of N2O emissions upon the ambient air quality in the source region. Research results prove that high temperature catalytic reduction of N2O emissions from nitric acid production by installing secondary decomposing catalyst is an effective method for N2O emission reduction and a tool to combat global warming effect.

Keywords: ambient air quality, air dispersion modeling, greenhouse gas, nitrous oxide, catalytic emission reduction

DOI: https://doi.org/10.15623/ijret.2014.0305083