Regeneration and Valorization of Spent Bleaching Earth in Edible Oil Refining Industry

The spent bleaching earth (SBE) from the edible oil refining industry was successfully regenerated through an extraction process using different organic solvents for removal of residual oil, followed by through heat treatment. The total percentage of extracted oil (PEO) for the solvents used showed the following order: PEO (Hexane) > PEO (Acetone) >PEO(Xylene) >PEO(MEK)>PEO (MIBK). The experimental results showed that regeneration by extraction process is insufficient to regenerate SBE, thus requiring also a high temperature treatment. In the current study, the effects of factors, such as liquid to solid ratio [1:1-5:1], temperature [20-40°C], and stirring time [30-60min] on the efficiency of extracted oil were investigated by maceration method. In order to determine the optimal condition, the Experience Planning Methodology (EPM) was adopted. To enhance the oil bleaching efficiency the regenerated SBE by solvent extraction was also treated at different temperatures (300°C – 500°C).