Abstract: The most practiced deacidification methods are alkali neutralization and steam stripping. Both methods have their own drawbacks e.g. high loss of neutral oil in the soap stock formed by the addition of alkali, and undesirable side reactions from the high temperature operation in steam stripping. Novel organic solvent nanofiltration (OSN) membranes (GreenMem) produced by Seppure is proposed for a combined deacidification and desolvation process that has a higher yield while maintaining similar product quality.
GreenMem membranes have demonstrated success in desolvation of miscella solution i.e. > 95% rejection of oil. Since no phase change in a membrane process, the energy consumption is also significantly lower than a distillation process. In recent development, the pore size of GreenMem membrane can be manipulated such that it can selectively allow or reject the passage of free fatty acid (FFA) through the membrane. By using a carefully designed OSN membrane, we combined deacidification and desolvation into a single step process, where solvent and FFA are removed from the oil as they preferentially pass through the membrane. The FFA permeated through the membrane needs to be removed from the solvent by using a tighter GreenMem membrane i.e. smaller pore size than FFA, before the solvent can be recycled for the extraction process.
