Biodiesel fuel purification in a continuous centrifugal contactor separator

Wet washing is the most common method for biodiesel purification, but higher water consumption, longer purification time, and high expenses bring limitations on the use of this process. One of the suitable methods to remove such limitations is to use new techniques for purification. In this study, biodiesel purification was evaluated in a novel continuous centrifugal contactor separator (CCCS) at 0.5:1, 1:1, and 1.5:1 (V/V%)water to biodiesel ratio; 10 Hz, 20 Hz, and 30 Hz device working frequency; and 25 °C, 40 °C, and 55 °C temperatures. A mathematical model for the wet-washing process of biodiesel and energy consumption of the CCCS device using the response surface method is proposed. A 0.8:1 (V/V%) water to biodiesel ratio, 10 Hz working frequency, and 35 °C temperature were found to be the optimal conditions in the experiment. At this point, the biodiesel yield and the amount of energy consumption were reported to be 96% and 17 kJ, respectively. The results showed that compared to the traditional wet washing method, the biodiesel purification method using CCCS is cost-effective and consumes more than 75% less of water.