Simulation of the absorption of SO into aqueous solutions

• Main Authors: Chien T''ai Hsu, 徐健泰
• Other Authors: Shin Min Shih
• Format: Others
• Language: zh-TW
• Published: 1993
• Online Access: http://ndltd.ncl.edu.tw/handle/10561052440210681932

博士 === 國立臺灣大學 === 化學工程研究所 === 81 === The absorption of sulfur dioxide into water drops is of great importance in atmospherical scavenging and flue gas desulfurization process. In the persent study，the data reported in the literature were used to study the relation between the liquid-phase mass- transfer coefficient and drop diameter and proposed a semiempirical equation which is based on the surface stretch model to correlate the experimental data available. It was found that for the prediction of liquid-phase mass-transfer coefficients for drops in the size range 0.06 to 0.6 cm dia., a semiempirical equation which is based on the surface stretch model and mutiple a correction factor 0.78 can best represents the experimemtal data. The experimental data of Walcek et al.(1981) can be well described by ignoring the effect of internal circulation and considering the diffusion of both physical dissolved sulfur dioxide and HSO3- into the drop interior and the equilibrium chemical reaction between them. Liquid-phase mass transfer was found to be rate-controlling. An analytical solution of the model was obtained by assuming an equal diffusivity for all sulfur species. The results of this study indicates that under experimental conditions of Walcek et al., the internal circulation may not be important. The absorption of SO2 by water drops was simulatd by a mathematical model. The factors considered in this model are gas phase SO2 concentration, drop size, chemical reaction and internal circulation. As the gas phase SO2 concentration increases, the mass transfer rate increases. When the drop size is small, the mass transfer rate is high and soon reach the saturated concentration. The rate of chemical absorption is greater than that of physical absoprtion. The effect of internal circualtion on absorption increases with increasing drop size, however, the neglect of the internal circulation results in a less than 10% reduction of absorption rate.