Mass transfer coefficients in a hanson mixer-settler extraction column

Abstract

-The volumetric overall mass transfer coefficients in a pilot plant Hanson mixer-settler extraction column of seven stages have been measured using toluene-acetone-water system. The effects of agitation speed and dispersed and continuous phases flow rates on volumetric overall mass transfer coefficients have been investigated. The results show that the volumetric overall mass transfer coefficient increases with increase in agitation speed and reaches a maximum. After having reached its maximum, it falls with further increase in agitation speed. It was found that the volumetric overall mass transfer coefficient increases with increase in dispersed phase flow rate, while it decreases with increase in continuous phase flow rate. By using interfacial area, the overall mass transfer coefficients for continuous and dispersed phases are determined from volumetric coefficients. An empirical correlation for prediction of the continuous phase overall mass transfer coefficient is proposed in terms of Sherwood and Reynolds numbers. Also the experimental data of the column investigated are compared with data for various extraction columns. Comparison between theoretical models and experimental results for the dispersed phase mass transfer coefficient shows that these models do not have enough accuracy for column design. Using effective diffusivity in the Gröber equation results in more accurate prediction of overall mass transfer coefficient. The prediction of overall mass transfer coefficients from the presented equations is in good agreement with experimental results.

Mass transfer investigation in a horizontal–vertical pulsed packed extraction column

“…In addition, experimental data for the overall mass transfer coefficient were compared with those obtained by the correlations that were proposed for other types of extraction column, which are presented in Table S1 †. 9,12,16,19,[29][30][31][32][33][34][35] A reliable correlation for predicting the mass transfer coefficient in a horizontalvertical pulsed packed extraction column is therefore required.…”

Influence of rotating magnetic field on gas-liquid volumetric mass transfer coefficient

“…Generally, mechanically agitated gas-liquid contractors are frequently applied in chemical processes or biochemical industries. Mechanical agitation can promote the mass transfer rate because it increases interfacial area between the liquid and gas phases (Garcia-Ochoa et al, 2009;Torab-Mostaedi et al, 2008).…”

Forced and Diffusive Mass Transfer between Pentane and Athabasca Bitumen Fractions

“…Asymptotic cases, complete miscibility of bitumen fractions in pentane, and complete immiscibility provide upper and lower extrema for mass-transfer coefficient values and their dependence upon composition. Data treatment and analysis of forced mass-transfer measurements reported here follow established approaches applied to diverse mixtures in stirred vessels, − where the focus is on the identification of the transition from diffusion-controlled mass transfer (lower bound for mass-transfer rates) to another mass-transfer rate-limiting phenomenon (upper bound for mass transfer). This transition provides a basis for selecting operating conditions for industrial processes and informs the development of in-reservoir and surface-facility process models …”