The individual phase holdups and the mass transfer coefficients for the extraction of butyric acids from the dispersed phase to the continuous phase have been determined in two and three phase (liquid-liquid-solid) fluidized beds of 7.62cm diameter. Kerosene and water were used as the dispersed phase and the continuous phase, respectively. Glass beads of 1.0, 1.7 and 3.1mm diameter were used as the solid phase.
The effects of the continuous phase velocity (1.0-8.0cm/sec), the dispersed phase velocity (0.0-4.0cm/sec) and the particle size on the individual phase holdups and the mass transfer coefficients have been determined.
Individual phase holdups were measured using a pressure profile method and the butyric acid contents in water were determined by titration using aqueous solutions of NaOH with phenolphthalein.
In two and three phase fluidized beds, the dispersed phase holdup increased by increasing the dispersed phase velocity. However, the variation of dispersed phase holdup was insignificant with particle size. It was observed that the continuous phase holdup decreased with the presence of the solid.
In the beds of 1mm glass beads, the bed contraction was observed at low continuous phase velocities. However, in the beds of 3.1mm glass beads, significant bed expansion was observed.
The rate of extraction in the beds of 1.0, 1.7mm glass beads was found to be lower than that of two phase flow system. The mass transfer coefficients were affected by continuous and dispersed flow rates, the particle size and the height of the column.
The continuous phase holdup and the mass transfer coefficient data were correlated in terms of both fluid flow rates, the particle diameter and the height of the column.