Two 38-mm-diam, 5-m-high pulse columns are investigated to evaluate the droplet diameters and axial mixing in the comparison of the aqueous to organic continuous mode of operation. It is observed that the average droplet diameters are dominated by pulse intensity and are independent of throughputs. Through the evaluation of axial eddy diffusivities, it is concluded that the axial diffusivity coefficient depends mainly on pulse intensity, and the value for the disperged phase is similar to that for the continuous phase at the same pulse intensity.