Purification of Crude Glycerol Using Regenerated Spent Bleaching Earth as Palm Oil Refinery Process

Spent Bleaching Earth (SBE) is a type of solid waste generated during the palm oil refining process.Several studies have investigated the potential reuse of SBE as a valuable material, particularly as an adsorbent in glycerol purification.Crude glycerol, a by-product of biodiesel and oleochemical production from palm oil, is typically of low quality and contains numerous impurities, including free fatty acids (FFA) and pigmented compounds such as -carotene and chlorophyll.In this study, SBE was regenerated using various solvents and subsequently calcined at 500 C for 2 hours.Its surface was further modified with cetyltrimethylammonium bromide (CTAB) to enhance its adsorption capacity.The results showed that SBE regenerated with n-hexane and subjected to calcination exhibited the highest removal efficiency for -carotene and chlorophyll.Further analysis of the physical and chemical properties of crude glycerol purified using uncalcined, calcined, and CTAB-modified SBE demonstrated that the modified SBE delivered the best adsorbent performance.The purified glycerol using modified SBE had the following characteristics: moisture content (10.3%),Density (1.25 g/cm), FFA content (1.2%), salt content (4.6%), -carotene content (0.843 ppm), chlorophyll content (0.11 ppm), and pH approximately 6.