Separation of water droplets from water-in-diesel dispersion using superhydrophobic polypropylene fibrous membranes

Abstract

Water in diesel fuel is one of the major causes of diesel engine maintenance problems. Effective water removal from ultra low sulfur diesel (ULSD) is considered an essential requirement to improve performance of diesel engine and achieve strict emission standards for diesel engines set by the US Environmental Protection Agency. This paper discusses fabrication, characterization and use of superhydrophobic fiber mats made up of syndiotactic polypropylene for separation of dispersed water droplets from ULSD. Solutions of different weight concentrations of the polymer were electrospun to produce micron and submicron sized fibers of different fiber diameters. The electrospun fibers were layered onto glass fiber mats to form the filter media. The filter media surfaces were characterized by their water contact angles. All electrospun layers were superhydrophobic with water contact angles greater than 150°. The filter media were tested in liquid–liquid separation experiments to evaluate their performance in separation of water drops dispersed in ULSD. The experimental results showed that the superhydrophobic fiber mats removed water from fuel very effectively with water removal efficiencies reaching 99%.