Preparation and Characterization of Activated Carbons Obtained from Molasses by Phosphoric Acid Activation

Abstract

The aim of this work is to prepare and characterize activated carbons with good properties at lower cost from molasses, obtained as byproducts of the sugar industry. The samples were prepared by chemical activation with phosphoric acid (H3PO4). Their structural and textural characterization was effected by FT-IR, specific surface area, SEM, as well as functional group determination. The results showed that the H3PO4/molasses ratio, the activation temperature and the surrounding atmosphere affected the properties of the final activated carbons. The best product was obtained with a H3PO4/molasses ratio of 1.75 at 500°C in air. It presented a specific surface area of 1470 m2/g, a maximum adsorption capacity for methylene blue of 600 mg/g (Langmuir model) and an important quantity of surface functional groups. The study revealed that molasses, a by-product of food industry, could be used as raw material for the preparation of activated carbon under mild conditions and with good textural and structural properties.