Recovery of linseed oil dispersed within an oil-in-water emulsion using hydrophilic membrane by rotating disk filtration system

The purpose of this paper is to investigate a method to recover the linseed oil from oil-in-water (O/W) emulsion by a rotating disk filtration system. The influence of transmembrane pressure (TMP), disk rotating speed, and disk geometry on permeate flux and oil recovery has been studied. Hydrophilic polyvinylidene difluoride (PVDF) membranes with average pore size 0.15 μm and polyethersulfone (PES) membranes with 50 kDa molecular weight cut off (MWCO) were used. The results showed that the rotating disk module can produce high permeate fluxes. The highest permeate fluxes were obtained when using a rotating disk equipped with vanes, which generated the largest shear rates at the membrane. This study demonstrated that hydrophilic membranes were suitable for demulsification of linseed oil-in-water emulsion. The linseed oil droplets in the emulsions could be separated by concentration tests due to the coalescence of oil droplets in the concentration polarization layer. For an initial oil mass of 46.5 g, 35.2 g supernatant oil was obtained owing to oil droplets coalescence. This supernatant oil represented a recovery of 76%. The rotating disk with vanes consumed less specific energy than smooth disk in the concentration tests.