Modeling of homogeneous tin speciation using detailed chemical kinetics

Abstract

In this work, ab initio molecular orbital methods were employed to study the reaction mechanisms of the oxidation of tin (Sn) with different oxidants, including O 2 , CO 2 , HOCl, HCl, ClO, ClO 2 and NO 3 , during coal combustion. Eleven key reaction pathways were identified. Although Cl 2 and HCl are generally low in concentration in coal and in the combustion flue gases, owing to their strong oxidizability, these oxidants should be considered for some trace element oxidation. A detailed kinetic modeling consisting of 354 reactions and 64 species especially for tin in combustion-generated flue gases was performed. The quantum chemistry and sensitivity simulations illustrated that the pathways Sn + O 2 = SnO + O and Sn + CO 2 = SnO + CO are more significant than the other nine reactions. The present study shows that O 2 and CO 2 are the two main oxidants for tin oxidation. 

Chemical and Process Engineering

“…Many researchers have investigated mercury transformation mechanisms and demonstrated its speciation in flue gas by air pollution control systems (Hall et al, 1991;Qiao et al, 2007). Mercury occurs in coal and can start to volatilize from the fuel at temperatures of around 150 • C. The volatilization rate of total Hg in the Argonne Premium Coal Samples is about 40%-75% at 550 • C (Finkelman et al, 1990;Uruski et al, 2015).…”

“…(Fig. 1) or as the particulatebound mercury Hg(p) (Gibb et al, 2000;Qiao et al, 2007; Figure 1. Transformations of mercury in solid combustion processes and flue gas (Galbreath et al, 2000).…”

On-line spectroscopic and spectrometric methods for the determination of metal species in industrial processes☆

“…A kinetic modelling study was recently performed by Qiao et al [104] using ab initio molecular orbital (MO) methods to investigate reactions of Sn with different oxidants. This work showed that the reactions with O 2 and CO 2 are the two main oxidants for Sn oxidation.…”