Preparation and Evaluation of CaO-Based CO₂ Sorbents Deposited on Saffil Fiber Supports

Calcium-oxide-based sorbents were coated onto Saffil ceramic fibers by means of a wet impregnation method. The effect of synthesis parameters on the crystalline structure, morphology, and texture of the CaO layer was investigated by X-ray diffraction, scanning electron microscopy, and gas adsorption techniques. The analyses revealed that the optimized synthesis method produced a uniform coating composed of a network of CaO nanoflakes. The evaluation of the materials as CO₂ sorbents was performed under repeated carbonation–decarbonation cycles using thermogravimetric analysis (TGA). A nominal 25 wt % loading of CaO gave a CO₂ uptake capacity of 0.118 mg of CO₂/mg of sorbent (carbonation at 650 °C in 90% CO₂ and decarbonation at 850 °C in N₂). A 5 wt % loading exhibited improved durability with a ∼30% decay in carrying capacity after 30 TGA cycles but at the expense of the initial uptake capacity.