Activated carbon derived from cashew branches via chemical activation with a weak dibasic acid: production and characterization

Abstract

The aim of this study was to produce and characterize activated carbon prepared from cashew tree branches, used as a local biomass precursor. The process involved chemical activation using 20% orthophosphoric acid (H₃PO₄). The branches were impregnated for 24 hours at a ratio of 0.172 g·mL⁻¹ (50 g of precursor for 290 mL of activating agent) and then dried. Carbonization was carried out at 550 °C for 3 hours and 47 minutes, yielding an average carbonization rate of 35.36 ± 0.014%. Characterization based on the iodine index — a key test for assessing microporosity — revealed excellent performance. The highest iodine index value reached 913.68 mg/g, well above the 500 mg/g threshold considered indicative of good microporosity. These results confirm the effectiveness of chemical activation in creating and enlarging pores and demonstrate that this activated carbon derived from plant biomass can serve as a cost-effective alternative for various purification, separation, and catalytic processes.