Sustainable thermochemical single-step process to obtain Magnetic Activated Carbons from chestnut industrial wastes

A novel thermochemical process based on a single step was optimized to obtain magnetic activated carbons from an industrial biomass waste. Anhydrous iron chloride was used as an activating agent and mixed directly with the chestnut shell waste. The effect of the activation temperature (220–800 °C) on the chemical, morphological, textural, and magnetic properties of the materials was studied. The results demonstrated the presence of different iron compounds depending on the activation temperature set as well as their influence on morphological and textural development of the magnetic activated carbons (BET specific surface area, SBET, up to 568 m2 g–1, total pore volume, VTOT, up to 0.294 cm3 g–1 vs 1 m2 g–1 and 0.007 cm3 g–1, respectively, for the raw biomass waste). The techniques employed, especially Mossbauer spectroscopy, showed relative contributions of the different iron compounds (magnetite, maghemite, metallic iron, and so on) in the materials. The higher activation temperature (800 °C) favored th...