Development of Chemical Reaction Kinetics of VOC Ozonation

Abstract

Volatile Organic Compounds (VOCs) causes many health issues related to Indoor Air Quality (IAQ). The indoor air quality improvement has been instituted by various organizations based on the concentration level of different pollutants. Though VOCs in indoor air has various adverse health effects and are primary reason for sick building syndrome, there are only few abatement technologies currently available. Ozonation of VOCs is one of the techniques to improve indoor air quality. In this paper, a compact yet comprehensive reaction kinetics of VOC ozonation have been developed for understanding the underlying chemistry behind the process. The new mechanism was developed by combining detailed reaction kinetics of Toluene, Benzene, Isobutylene and Formaldehyde oxidation reactions containing 329 species and 1888 reversible reactions and detailed Ozone decomposition reaction mechanism containing 6 species and 17 reversible reactions. Then the detailed mechanism has been reduced using DRGEPSA (Directed relation graph with error propagation and sensitivity analysis) and unimportant reaction elimination technique to 36 species and 123 reversible reactions for practical use in Computational Fluid Dynamics (CFD) simulations. The reduction was done for low temperature conditions. Then the sensitivity analysis was done to identify the most sensitive reactions. It was found that Isobutylene, Toluene and Formaldehyde readily react with nascent oxygen and undergoes oxidation reaction to give intermediate small species. Then its applicability was tested in Ansys Fluent CFD package and found it could be used to predict the VOCs ozonation and its intermediate reactions.