Application of basic 3‐phase equilibrium distribution model to spray drying sorber for simultaneous removal of so2 and vinyl chloride

Abstract

Simultaneous removal efficiencies of hydrophilic (SO2) and hydrophobic (vinyl chloride) gaseous pollutants are experimentally determined, and the macroscopic removal mechanism of pollutants in a spray drying sorber(SDS) is analyzed using the extended model of three phase equilibrium distribution of pollutant at high temperatures which is basically based on the different morphological conditions of adsorbent and water at varying relative humidities. For the practical simplicity, the inside of spray drying sorber is divided into three regions of ; (1) absorption, (2) transition and (3) adsorption, and the removal efficiencies of each pollutants at three different regions are observed at different experimental conditions to estimate the effects of important parameters of SDS. The two types of slurry are made of the two sorbents : 10 wt% Ca(OH)2 and 10 wt% NaOH. The result of temperature effect shows the height of absorption and transition region is decreased as the operation temperature is increased. Therefore, it resulted in the lower removal efficiency for SO2, and the higher removal efficiency for vinyl chloride in the adsorption region of SDS. The removal efficiency of SO2 with NaOH slurry is higher than with Ca(OH)2 slurry due to the hygroscopic nature of NaOH, while the removal of vinyl chloride is higher in Ca(OH)2 case. From the analysis of results using three‐phase equilibrium distribution model, the effective two‐phase partition coefficients can be obtained, and the possible extension in the application of the three‐phase equilibrium model in SDS design has been demonstrated.