Oil recovery from oil in water emulsions using a flotation column

A flotation column was used to recover oil from oil in water emulsions. The feed oil concentrations investigated were relatively high, in the range of 0.25 to 8 percent by volume. Previous studies using conventional flotation cells dealt with very dilute systems where the oil concentration was less than 0.1 percent by volume. The oil recovery was found to decrease with an increase in the feed oil concentration. The addition of wash water to the froth zone of the column had little effect on the oil recovery. The oil recovery decreased with increasing feed flow rate and surfactant concentration. The effect of increasing the gas flow rate was to initially increase the oil recovery. The oil recovery data were analyzed using a kinetic model. The order of the flotation kinetics was found to be 0.6. The gas hold-up behaviour of the recovery and the froth zones of the flotation column is found to correlate well with the drift-flux model.