Valorization of oil palm mesocarp fiber and acid hydrolyzed residues for sustainable activated carbon production

• Activated carbon from acid hydrolysed residues highest iodine number and surface area at 1:3 ratio. • Activated carbon from oil plam mesocarp fiber had optimized fixed carbon and surface area at 1:1 ratio • Chemical activation showed minimal carbon loss, indicating high efficiency of the process. • Potential industrial-scale activated carbon production from agro-industrial waste with efficient material recovery • Both wastes are potential as precursors for activated carbon production This study aimed to evaluate the feasibility of utilizing oil palm mesocarp fiber (OPMF) and acid hydrolyzed residues (AHRs) as precursors for activated carbon production, with particular emphasis on the influence of potassium hydroxide (KOH) impregnation ratios on the physicochemical properties of the resulting materials. The precursors were subjected to a two-step process consisting of carbonization at 500°C followed by chemical activation at 85°C using KOH impregnation ratios of 1:1, 1:3, and 1:5. Mass balance calculations were performed to assess material recovery and process efficiency. The results demonstrated that AHR-derived activated carbon exhibited higher iodine numbers and surface area, particularly at the 1:3 impregnation ratio, indicating enhanced adsorption potential. In contrast, OPMF-derived activated carbon prepared at a 1:1 ratio showed the highest fixed carbon content and favourable surface characteristics, suggesting suitability for applications prioritizing carbon yield. Both feedstocks exhibited minimal carbon loss during activation, reflecting efficient material conversion. While most quality parameters of OPMF-derived activated carbon complied with SNI 06-3730-1995 standards, the iodine number remained below the required threshold. Mass balance and preliminary economic evaluation indicated promising potential for valorizing these palm oil wastes as activated carbon precursors. Overall, the findings support the sustainable conversion of OPMF and AHRs into functional carbon materials and provide practical insights for optimizing chemical activation toward improved adsorption performance and yield. Further studies are recommended to refine activation conditions and explore alternative activating agents for scalable industrial application.