Production of activated carbon from oil palm shells via physical activation with H2O and its characterization for use in aqueous phase

Oil palm shells (OPS) are a solid residue of the extraction of palm oil having excellent characteristics for production of activated carbon. OPS worldwide production amounts to 17.214 ton (2018) from which Colombia participates with 364 ton. Oil palm shells were first carbonized in a horizontal oven under N2 atmosphere until 850 °C for 30 min. Carbonized samples were than submitted to physical activation with steam in the same horizontal oven. A variation of process parameters was performed. Activation temperatures of 750, 800, 850 and 900 °C were studied. Residence time varied between 60 and 400 minutes. H2O flow rates between 1 a 5 ml / min were used. 50 g of carbonized oil palm shells were used for each experiment. The influence of the process conditions on pH, soluble water content, extractable acid content, iodine number, methylene blue index, phenol adsorption, BET surface area from N2 adsorption and density were determined. Visual inspection through scanning electron microscopy and determination of surface functional groups through infrared spectroscopy were performed. The obtained activated carbons show suitable characteristics for its use in aqueous phase. Results obtained were useful to determine its optimal production conditions.