Thermogravimetric analysis and kinetics of the combustion of refining and chemicals wastewater in different oxygen concentrations

Abstract

The oxygen-enriched air combustion behaviors and kinetics of refining and chemicals wastewater (RCW) solid were investigated using thermogravimetric analysis. The results showed that the combustion process of RCW solid was a four-stage reaction. The increase in O2 concentration had negligible effects on the overall first two stages and the vast majority of the third stage, while made the fourth stage shift to a lower temperature region. The kinetic triplets of each stage were determined by Kissinger–Akahira–Sunose, Flynn–Wall–Ozawa, and the master-plots method. For the first three stages, the average E of each stage varied slightly with of O2 concentration increasing; while the fourth stage showed a rising trend. The most probable reaction models for the first and second stage were the simple order reaction model (Fn), while the random nucleation and nuclei growth model (An) for the third and fourth stage.