Kinetics study of regeneration spent bleaching earth by microwave-assisted extraction

In this work, spent bleaching earth (SBE) from crude palm oil refineries was regenerated and converted into a valuable product by microwave-assisted extraction (MAE) method. This work aims to evaluate the effect of variables such as irradiation power and contact time on the regeneration of SBE using MAE. From this study, MAE had succeeded in regenerating SBE and extracting residual oil from SBE. The maximum yield obtained was 18.53% at 450 watts and a contact time of 40 minutes. Patricelli’s kinetic model showed the best fit with experimental data with an average value of Radj2 (0.942-0.977) and an average value of RMSD (0.130-0.217). The mass transfer coefficient calculated from the experimental data shows that the mass transfer coefficient in the washing stage is more significant than in the diffusion step. These results indicate the effectiveness of MAE during the initial process (washing stage). SEM images show similar characteristics of solid particles on the activated bleaching earth and regenerated spent bleaching earth surfaces.