Reactivation of spent activated carbon for glycerine purification

Activated carbon (AC) is widely used as an adsorbent for glycerine purification. However, after prolonged usage, adsorption capacity of the resulted spent AC (SAC) reached saturation which affects its adsorption performances. In this work, the adsorption capability of SAC was restored by thermal and chemical reactivations. Chemical reactivation was carried out at room temperature with 10 M NaOH (CRAC10) which showed the best adsorption capability, concluded by its normalised iodine number which was recorded at 904.15 mg/g. Glycerine purification test showed that free fatty acid, carotenoids, chlorophyll and ash content in crude glycerine were effectively reduced by 38.64%, 40%, 64.29% and 84.65%, respectively after the adsorption by CRAC10. The same sample also contributed to the best performance with 45.46% glycerine purification while the adsorbent dosage was optimized at 20 g/l.