The valorization of deodorizer distillates from the oil refining industry requires a stable membrane suitable to separate steryl esters (bioactive compounds with high molecular weight (MW), 650 <MW <800 g / mol) from pesticides (150 <MW <400 g / mol), whose content is restricted by the actual legislation. This work aims at identifying a suitable solvent and a solvent resistant nanofiltration (SRNF) membrane to be used in a diananofiltration process for the removal of pesticides. Hexane, ethanol and oleic acid were investigated as potential solvents. The role of solvent-membrane interactions was found to be important in the permeability of the membrane, supported by a strong relationship with the swelling/solvent viscosity ratio. Selected membranes were compared in a dead-end filtration mode, which allowed for identifying the membrane(s) that showed the best compromise between permeability and discrimination between the target compounds. The membranes with the best performance were GMT-oNF2 from Borsig/GMT, PuraMemS600 from Evonik and 030306F from Solsep. The performance of the process was enhanced while operating in a cross-flow mode, being further improved after optimization of the concentration of deodorizer distillate and of the processing solutions and the transmembrane pressure.The membranes identified in this work proved to be suitable for valorization of deodorizer distillates, presenting high rejections of steryl esters (> 96 %) and significant low rejection of pesticides (<65 %) , under optimised conditions.
- Bioactive compounds
- Organic solvent nanofiltration
- Steryl esters
- Vegetable oil