One-step process of glycerol purification by adsorption using passion fruit peel-based activated carbon

The purification of glycerol from biodiesel production is essential due to its high economic value. Previous studies have applied multi-step processes which significantly increase operating costs. In this study, a one-step process of glycerol purification was performed through adsorption using passion fruit peel activated carbon (PFPAC). The objectives of this study were: (1) to synthesize and characterize PFPAC, and (2) to apply PFPAC in a one-step glycerol purification process. PFPAC was synthesized using Na 2 CO 3 as an activator, with a carbonization temperature of 600 °C for 60 minutes. The mass of PFPAC during adsorption was vary from 1 % to 11 % (wt.). PFPAC exhibited an iodine adsorption value of 2720 mg/g. SEM-EDX confirmed the presence of a relatively smooth surface with well-developed pores, with a carbon content of 89.05 %. FTIR spectra revealed the presence of hydroxyl groups and –sp3 C–H vibrations. PFPAC had a surface area of 227.301 m 2 /g, with an average particle diameter of 7.185 nm based on the BET-BJH method. The optimal PFPAC dosage was found to be 11 % (wt.), which successfully increased the glycerol purity from 64.46 % to 96.69 %, thus met the USP Grade (Degree II) purity standard. The one-step process in this study also demonstrated satisfactory performance compared to similar studies. The external mass transfer coefficient (kf) was 4.6 × 10 −5 cm/min. Although this study has not yet evaluated the reusability of PFPAC, the findings provide new insights into a more efficient and economically feasible glycerol purification method.