LAUSR

We report two processes that enable continuous extraction of organic-free water from detergent stabilized oil-in-water emulsions. The first process is based upon a modification of the so-called “electro-coagulation”, which uses electrochemically produced metal hydroxides that remove oil droplets via heterocoagulation. In this method, metal particles are deposited over a graphite anode, whereas an aluminum tube is used as a cathode in an electrolysis cell through which the emulsion flows. With an electrical potential applied between the graphite and aluminum, the metal particles are corroded to produce metal hydroxides that sweep the oil droplets from the emulsion. The study shows that the oil extraction efficiency increases with the basicity of the metal hydroxide. A second process, based on acid–base interaction as well, uses surface functionalization of nickel particles (∼45 μm) that introduces amines onto the nickel surface. Here an additional advantage is that the metal particles bound to the oil drop...