Modeling of mass transfer coefficient using response surface methodology in a horizontal-vertical pulsed sieve-plate extraction column

The effects of various parameters and their interactions on the mass transfer behavior of toluene-acetone-water, n-butyl acetate-acetone-water systems in a horizontal-vertical (L-shaped) pulsed sieve-plate column were investigated using the response surface methodology (RSM). The studied parameters included pulsation intensity, interfacial tension, and dispersed and continuous phase velocities. The volumetric overall mass transfer coefficient was determined using the axial dispersion model. According to the empirical data and the results of analysis of variance (ANOVA), new correlations were presented to predict the overall mass transfer coefficient in the two sections of the column. The correlation coefficient (R2) was achieved as 0.995 and 0.986 for the horizontal and vertical sections, respectively, proving that the models fit the data well. The modeling results showed that the values of the volumetric overall mass transfer coefficient in the horizontal section were higher than those of the vertical section. This can be attributed to the direction of mass transfer (d→c) and the entry of solvent (dispersed phase) from the horizontal section of the column that creates the maximum concentration gradient and the driving force of mass transfer in the horizontal section. The optimum overall mass transfer coefficients were obtained as 0.925 × 10−3 and 0.530 × 10−3 1/s for the horizontal and vertical sections, respectively.