Microwave-Assisted Synthesis of ZnCh-Activated Carbon from Typha australis Grass: Multi-Response Process Optimisation and Characterisation.

Authors: A. B. Makama, M. A. Sadiq, and S. A. Saidu Department of Chemical Engineering Technology. The Federal Polytechnic, Nasarawa Department of Science Laboratory Technology, The Federal Polytechnic, Nasarawa Faculty of Applied Science, Federal University, Gashua Corresponding author: abmakama@hotmail.com.

Journal: Nigerian Journal Of Technical Education | Volume: 23 | Issue: 2 | Pages: 121 - 139

Abstract

This study synthesised low-cost activated carbon from Typha australis grass via chemical activation with ZnCl2 and microwave heating. The Taguchi L16 design coupled with grey relational analysis optimised the carbon yield and iodine number by adjusting microwave power, irradiation time, ZnCl, concentration, and soaking time. The optimal conditions were 400W, 20 minutes, 50 vol% ZnCl2, and 12 hours soaking, yielding 43.77% carbon with 798.27mg/g iodine uptake. Characterisation of the Typha grass precursor used TGA, proximate, and ultimate analyses. The optimised activated carbon's surface properties were analysed by SEM, FTIR, surface area/porosity, XRD, and point of zero charge measurements. SEM revealed agglomerated spherical particles with void stacking. The carbon exhibited a BET surface area of 424.5m²/g, micropore volume of 0.164cm³/g, and presence of acidic functional groups confirmed by a pHpue of 6.6. FTIR detected various acidic surface groups beneficial for adsorption. XRD indicated an amorphous carbon structure. Overall, the ZnCl2/microwave activation successfully produced a high surface area, microporous carbon from Typha biomass with optimal pore structure and surface chemistry for adsorption applications.