Zeolite-Based Sorbent for CO₂ Capture: Preparation and Performance Evaluation

In this work, zeolite-based sorbents were developed from gasified rice husk. CO₂ capture capacity of the sorbents was examined at various temperatures and pressures employing a fixed-bed flow reactor and simulated flue gas. Various physicochemical properties such as thermal stability, pore size distribution, morphology, chemical composition, etc. of the in-house-developed materials were characterized in detail and were also compared with two commercially available zeolites. Tetra-ethylenepentamine was impregnated in the in-house-developed zeolite supports to investigate its suitability to improve the CO₂ adsorption capacity. The effects of reactor pressure, temperature, Si/Al ratio, and amine loading on CO₂ uptake capacity were examined. A declining trend in CO₂ adsorption capacity was observed with the increase in adsorption temperature and amine loading. At 30 °C, zeolite-Y (designated as Z-Y-3, silica to alumina ratio of 2.25) sample exhibited maximum adsorption capacity, and the obtained values were around 114 and 190 mg CO₂/g sorbent under atmospheric and 5 bar pressure, respectively. It was also observed that the presence of alkali metal ions influenced the adsorption capacity of the zeolites. The study inferred that the adsorbent was efficient and promising for multiple adsorption-desorption cycles without much deterioration of the capture capacity.