Abstract

This study introduces an induction heating approach for producing activated carbon from biochar obtained by thermal degradation of pine pruning waste from timber-related industries, using CO2 and iron-based catalysts as activation agents. Activation experiments were performed using a 10 kW high-frequency induction system (28–40 kHz) under continuous CO₂ flow (15 mL min−1), with electric current intensities of 200, 300, 400, and 500 A (corresponding to 700–1100°C) and durations of 30, 60, and 90 min, employing 45 g of iron-based catalysts (Fe–Ni–Ti–C, 85:6:3:6 wt.%) per 3 g biochar (15:1 w/w). Mass loss increased from 13.7 % (200 A, 30 min) to 84 % (500 A, 90 min), inversely correlating with product yield, which ranged from 86.3 % to 16 %, respectively, highlighting the critical trade-off between porosity enhancement and material retention. Correspondingly, Brunauer–Emmett–Teller (BET) surface area was significantly enhanced, rising from 47.38 m2g−1in the thermally processed biochar to 607.21 m2g−1under milder activation conditions (200 A, 30 min), and further increasing to 865.07 m2g−1at optimized conditions (500 A, 60 min) though with reduced yield (20.3 %). Fourier-transform infrared (FT-IR) spectroscopy confirmed the introduction of oxygen-containing functional groups, notably carbonyl and hydroxyl functionalities, while scanning electron microscopy (SEM) demonstrated substantial porosity development. X-ray diffraction (XRD) analysis further revealed crystallographic changes attributed to catalytic activity and carbon gasification reactions. These findings demonstrate that induction-assisted CO2 activation with iron-based catalysts offers a rapid (30–90 min vs. conventional 2–4 h), energy-efficient, and scalable route for converting low-value pine pruning waste (biochar yield: 17 wt.%) into high-performance activated carbon (BET up to 865 m2g−1), suitable for water treatment, gas adsorption, and energy storage applications, while reducing reliance on chemical activators and minimizing environmental impact.

Department(s)

Chemical and Biochemical Engineering

Publication Status

Full Text Access

Keywords and Phrases

Activated carbon; Biochar; CO2activation; Induction heating; Pine pruning biomass

International Standard Serial Number (ISSN)

0165-2370

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2026 Elsevier, All rights reserved.

Publication Date

01 Mar 2026

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