A 3D mathematical evaluation of the emission into the air of reactive BTEX compounds: A new approach for mechanism reduction

Abstract

BTEX species are abundant volatile organic compounds that are classified as main pollutants by several environmental protection agencies. In this study, a new 3D air pollution dispersion model with the capability of taking into account the BTEX's reactions was developed and evaluated. The Toxchem model is employed to estimate the amount of emitted BTEX from several area sources, followed by simulating the transport of the reactive species through a 3D model. Also, reduced mechanisms were developed, based on Master Chemical Mechanism (MCM), for the simulation of the atmospheric chemistry of BTEX. The application of the mechanism reduction method yielded a mechanism of 43 species and 45 reactions. Based on findings, the deviation of the reduced mechanism from the whole mechanism was < 4% throughout the simulation. In addition, the result showed that, during a 12 h period of simulation, the effect of the atmospheric chemical reaction on reducing the final concentration of benzene, toluene, ethylbenzene, m-xylene, o-xylene, and p-xylene was about 0.3, 1, 1.4, 5, 3.1, and 3.2%, respectively. Lastly, it was indicated that the estimated emission rates by Toxchem and simulated concentrations by the dispersion model were in good agreement with the reported experimental values.