Angela Hoyos Velasquez Thesis Defense

Abstract : Wet scrubbers are among the most used industrial flue gas treatment devices. Although effective at absorbing acidic gases, wet scrubbers are not designed to capture submicronic particles. However, laboratory studies have shown that it is possible to improve their fine particle collection efficiency by adjusting operating conditions. In this thesis, the performance of wet scrubbers for collecting particles was evaluated under real conditions of a waste incineration plant at two scales: (i) by operating a downscaled wet scrubber fed with real flue gases from the incineration of household waste, and (ii) by quantifying the particle collection efficiency of an industrial scrubber at a hazardous waste incineration plant. CFD numerical simulations were performed to design the downscaled system and analyze the flow patterns inside the scrubbers. A parametric study was conducted to investigate the influence of operating conditions on the performance of the downscaled scrubber. The results showed that reducing the droplet diameter and increasing the liquid/gas flow ratio improved particle collection across all sizes. No influence of gas residence time was observed. The mechanistic collection models tested overestimate the results under real operating conditions. The performance of the industrial scrubber for collecting particles was found to be nearly zero/negative due to reaction and transfer phenomena between the droplets, the gases, and the particles