Investigation of mass transfer coefficient in random and structured packed liquid extraction columns

Mass transfer coefficients of rising drops in spray and packed columns with random and structured packing in liquidliquid extraction operation were experimentally measured and the results were compared with each other. Distilled water and toluene (containing particular amount of acetic acid) were continuous and dispersed phases, respectively. Results according to random and structured packing show that random types are effective only for drop size less than 9 mm, while the structured ones are shown to have positive effect on mass transfer coefficient in a wide drop size range. Furthermore, structured packing proved to be more effective than random packing in improving the mass transfer coefficient. The effect of drop size on mass transfer coefficient has also been studied in this work and the results showed that when the drop diameter increases, mass transfer coefficient increases, too. Finally, new correlations for prediction of mass transfer coefficient in both random and structured packed column have been introduced that show better agreement with experimental data in comparison with other models such as Newman, Kronig-Brink and Handlos- Baron.

کلیدواژه ها:

Liquid-liquid extraction ، Mass transfer coefficient ، Packed column ، Random packing ، Structured packing