A COMPREHENSIVE ANALYSIS OF THE USE OF CHEMICAL ACTIVATION TECHNOLOGY TO PRODUCE ACTIVATED CARBON FROM AGRICULTURAL RESIDUES

Abstract

Environmental and industrial sectors widely use activated carbon with a porous structure, a product of chemical or physical activation. In this work, we looked at both processes for making activated carbon from agricultural residue. The review focuses on the chemical agents used during chemical activation, namely phosphoric acid, potassium or sodium hydroxide, and zinc chloride. Despite phosphoric acid's extensive use in lignocellulosic materials, it produces a smaller specific surface area than zinc chloride. However, the use of the latter remains limited due to environmental problems. Potassium and sodium hydroxide generally produce activated carbons with remarkable porosity, which is beneficial for adsorbing large pollutants, such as dyes. Physical activation yields activated carbons with greater porosity, compared to chemical activation. Although chemical activation can introduce mineral impurities trapped in the pores of the coal, it remains profitable and offers the advantage of resulting in a diversified and controlled pore size distribution. This review talks about how different activating agents can change chemicals to make activated carbon from biomass. The effectiveness of activated carbons and their applications, such as wastewater pollutant absorption, are also discussed.