CFD Prediction with Eulerian/Eulerian Approach of SO 2 Absorption from Flue Gases in Bubble-Dispersion Tower
- PDF / 1,355,205 Bytes
- 14 Pages / 595.276 x 790.866 pts Page_size
- 39 Downloads / 271 Views
RESEARCH ARTICLE-CHEMICAL ENGINEERING
CFD Prediction with Eulerian/Eulerian Approach of SO2 Absorption from Flue Gases in Bubble‑Dispersion Tower Jing Liu1,2 · Fasheng Luo1 · Xiyang Lin1 · Tuo Ye1 Received: 17 March 2019 / Accepted: 21 July 2019 © King Fahd University of Petroleum & Minerals 2020
Abstract Accurate prediction of S O2 absorption efficiency under different physical and chemical parameters is of significant importance for desulfurization of the flue gas. In order to understand the mechanism of SO2 absorption inside a bubble-dispersion tower, a three-dimensional twin Eulerian model together with two-film theory was applied to simulate the flue gas desulfurization processes in a bubble-dispersion tower. After comparing the predicted desulfurization efficiencies by using calculated gas holdup with the experimental parameters, the deviation of simulated model with the measured ones was small. Moreover, it was observed that the larger the fractional hole area, the better desulfurization performance. The bubble tower showed fine adaptability when the superficial gas velocity varies from 0.3 to 0.7 m/s. Also, there was a positive correlation between the SO2 removal ability and the hydrogen ion concentration. Considering the crystallization of calcium sulfite, the PH of slurry tank inside bubble tower is recommended to be set between 5.5 and 6, and the initial CaCO3 mass fraction is suggested to be set around 10–15% under prediction conditions. Moreover, the S O2 absorption capability could be increased by lifting the initial liquid height, while the S O2 removal efficiency would level off when tube insertion depth/column diameter H/D was over 0.128, so the H/D is suggested to be set from 0.08 to 0.128 to achieve high S O2 absorption and avoid soil erosion. It was observed that the smaller the size of bubbles generated in the slurry, the higher SO2 absorption efficiency could be. Keywords Flue gas desulfurization · Bubble-dispersion tower · Eulerian–Eulerian approach · Numerical investigation List of Symbols A specific interfacial area (m−1) Dso2 mass transfer coefficient of SO2 (m2·s−1) Td slurry temperature (T) DCa(OH)2 mass transfer coefficient of Ca(OH)2 (m2·s−1) DT diameter of the bubble tower (m) Dc diameter of the column (m) K1 reaction rate constant of sulfite NSO2 molar mass transfer rate of SO2 (kmol·m−3·s−1) ṁ SO2 , k absorption rate of SO2 in every element, kg/(m3·s)
* Jing Liu [email protected] 1
School of Electric Power, South China University of Technology, Guangzhou 510640, Guangdong, China
Department of Chemical and Biochemical Engineering, Rutgers, The State University of New Jersey, 98 Brett Rd, Piscataway, NJ 08854, USA
2
SSO2 the absorption rate of SO2 in whole device, kg/(m3·s) cp special heat capacity (J·kg−1·k−1) Mr molecular weight (kg·k−1·mol−1) db initial bubble diameter (m) dvs sauter bubble diameter (m) dp particle diameter (m) D axial dispersion coefficient (m2·s−1) Di molecular diffusivity of solute in liquid phase
Data Loading...
