Experimental study on the oil-water separation for marine applications

We perform a series of water-tunnel experiments to investigate the dynamic flow characteristics of oil-water mixture flows inside the channel of the oil-water separator developed for collecting and separating the marine spilled oils while varying the water hold-up and wave height. Our main focus is to understand the mechanism to determine the efficiency of oil recovery in the system. The oil-recovery rate decreases with increasing water hold-up and wave height; above 70% is achieved with a wave height (4-5 times of the channel height) but is dropped to 50% when water hold-up increases to 0.6. After analyzing the dynamics of flow patterns, two typical flow patterns are identified: wavy oil-water interface and dispersed oil phase, which are found to strongly affect the performance of oil recovery of the device. In general, as the water hold-up (or wave height) increases, the oil-recovery rate decreases while the dispersed phase of oil increases in the channel. Finally, we develop a theoretical model to predict the oil-recovery rate under the given operating conditions and to suggest a strategy to maximize the oil-recovery rate in the real marine operations.