PROCESS OF ADSORPTION

Climate change driven by increasing atmospheric CO₂ concentrations calls for urgent implementation of atmospheric CO2 reduction. However, adsorbents are mostly expensiveand energy-intensive, especially for developing nations. Agricultural wastes, especiallycorncobs, are a sustainable alternative due to their lignocellulosic composition, natural porosity, and abundance as underutilized biomass. This study investigated the CO₂ adsorption potential of chemically activated corn cob-derived adsorbent through packed bed column experiments. Corn cobs were collected, processed, and activated using potassium hydroxide (KOH) at temperatures between 400-600°C. CO₂ gas was generated in-situ via CaCO₃-HCl reactionandpassed through glass columns (2.1 cm diameter, 5 cm bed height) at flowrates of 0.5-2.0L/min. Four particle size ranges (100, 250, 500, and above 500 µm) were evaluated over 60-minute contact periods at ambient temperature (29±2°C). Characterization via SEM-EDS revealed highly porous morphology with 90.05%carboncontent and oxygen-containing functional groups favorable for CO₂ binding. The 100µmparticle size achieved the highest equilibrium adsorption capacity of 5,459 ppm·L/g, while250 µm particles demonstrated optimal removal efficiency of 48.0%. Breakthrough analysisindicated that smaller particles delayed saturation, with 100 µm maintaining effectivenessbeyond 45 minutes compared to 25 minutes for above 500 µm particles. Flowrate influencedperformance, with reduced rates (0.5 L/min) compensating for larger particle sizes byincreasing contact time. These findings reveal that corn bobs are a viable solution for carboncapture.