Enhanced CO₂ adsorption capacity using activated serpentine: A study of process variables and breakthrough curve analysis

• Activated serpentine has significant CO₂ adsorption, making it ideal for CCS use. • The effects of sorbent mesh size, activation temperature, time, and CO₂ flow rate on CO₂. • Breakthrough curve analysis shows smaller mesh sizes and lower CO₂ flow rates boost efficiency. • Serpentine is abundant and underutilized, ideal for long-term CCS use, especially in geothermal regions. • Serpentine is a sustainable, eco-friendly alternative for CCS, aiding global CO₂ reduction. This study investigates the optimization of CO₂ adsorption using activated serpentine in a fixed-bed reactor, focusing on the effects of particle size (50 to 150 mesh), activation temperature (650 to 850°C), activation duration (1.5 to 4.5 h), and CO₂ flow rate (0.1 to 1.0 SLPM). Characterization results indicate that thermal activation enhances surface area, pore structure, and adsorption efficiency. Experimental findings reveal that activation at 850°C, with a 100 mesh particle size, achieves the highest adsorption efficiency, while the 150 mesh fraction exhibits the highest adsorption rate (0.71 mL/min g). An activation duration of 1.5 hours provides an optimal balance between structural stability and reactivity, whereas a flow rate of 0.5 SLPM results in the highest adsorption efficiency (R² = 99.55%). Breakthrough curve analysis confirms that smaller particle sizes and lower flow rates extend adsorption duration and enhance overall adsorption efficiency. Kinetic modeling using the Thomas, Yoon-Nelson, and Clark models demonstrates that the Clark and Yoon-Nelson models provide the most accurate predictions, with R² values reaching up to 99.55% and lower Reduced Chi-Square values across various experimental conditions. The optimized adsorption conditions, including 850°C activation, 100 mesh particle size, 1.5 hours activation duration, and a 0.5 SLPM flow rate, achieve a balance between adsorption capacity and kinetics. These findings contribute to the advancement of serpentine-based adsorbents for carbon capture and storage (CCS) applications, supporting efforts to mitigate industrial CO₂ emissions.