Synthesis and characterization of activated carbon from olive tree by H3PO4 chemical activation

Activated carbon with a highly porous structure or surface area is mainly used as an industrial adsorbent and also wastewater treatment purposes. Phosphoric acid (H3PO4) is generally used as activator agent that increases... [ view full abstract ]

Activated carbon with a highly porous structure or surface area is mainly used as an industrial adsorbent and also wastewater treatment purposes. Phosphoric acid (H₃PO₄) is generally used as activator agent that increases the number of defects present in a hemicelluloses and act as a catalyst to promoting the bond cleavage reaction. Activating carbon process is generally carried out in two steps, carbonization and activation.Wasted tree leaf of ‘olive’ are collected.Dried leafs are crushed and passed through a sieve of 250µm.Then H₃PO₄ is used as an activated agent that changed the thermal degradation of the olive tree leafs. H₃PO₄ are increasing the number of defects which also increase the surface area.The absorption material is calcined in a box resistance furnace at 500-600 ̊C for 2 hrs. The produce char is then washed with distilled water to remove the excess H₃PO₄ until the neutral pH is obtained.Now activated carbon is prepared.

XRD result shows that, peak at angle 23̊ which revealed the presence of crystalline carbonaceous structure.In SEM, result shows that cylindrical units has deformed after the activation. This contributes towards the gas adsorption in future. Brunauer-Emmett-Teller(BET), surface area analysis has done through Micromeritics Instrument Corp machine, the total surface area are corresponding to 167.4715 m²/g. EDX analysis shows that the presence of carbon in a prepared sample is greater than 75%which reveal that the part of cellulose crystalline structure was destroyed during process and resulting activation. A little amount of Phosphoric is also present. Thermal gravimetric analysis shows that the prepared activated carbon starts their degradation from 200̊C and fully degraded at above 500 ̊C. Activated carbon made from olive tree has a significant porous structure and will start their thermally degradation at 200 ̊C and loss their major weight at 400 ̊C which is economical good for the formation of the activated carbon. Further, different activator agents like KOH, zinc chloride and potassium carbonate etc are used to studies the effect of activation on olive tree is recommended in future.