COMPARATIVE ANALYSIS OF THERMAL AND THERMOCHEMICAL ACTIVATION OF BIO-WASTE FOR CARBON ADSORBENT PRODUCTION

Abstract

This study presents a comparative analysis of thermal and thermochemical activation methods for the production of activated carbon from agricultural bio-waste, particularly fruit pit residues. Activation was carried out at temperatures of 800–850°C using conventional thermal treatment, steam activation, and thermochemical methods involving ZnCl₂ and H₂SO₄ solutions. The structural and sorption characteristics of the resulting carbon adsorbents were investigated using benzene vapor as the model adsorbate.

Key parameters such as monolayer adsorption capacity (αₘ), saturation volume (Vₛ), specific surface area (S), micropore volume (W₀), mesopore volume (Wme), and average pore radius were determined based on BET theory and micropore volume filling equations. The results showed that thermochemical activation provided significantly higher surface area and micropore development than thermal or steam activation. Adsorption isotherms indicated Type I behavior, characteristic of microporous materials.

This research demonstrates the potential of converting bio-waste into efficient and cost-effective carbon adsorbents through controlled activation techniques. The findings support the development of sustainable, environmentally friendly, and import-substituting technologies for gas purification and sorption-based applications. Such approaches contribute to waste valorization, resource efficiency, and cleaner production strategies.