Enhancing the sorption performance of surfactant-assisted CaO nanoparticles

Abstract

Microsized calcium oxide prepared via precipitation and thermal decomposition of calcium carbonates has been widely used in industrial hydrogen production and biomass gasification processes to remove CO₂ from the reactors. One of the most interesting perspectives in catalysis is the development of nano-sized, high performance, low cost catalysts. However, due to the high cost of nano-sized calcium oxide (CaO), it is critically important to develop new techniques that overcome this challenge. The main goal of this study was to prepare zwitterionic surfactant (BS-12) modified nano calcium oxide sorbents. Ctenocardia fornicata shell was used as the precursor for nano CaO, as it is cheap and easily available. The effect of BS-12 on the physico-chemical properties and the performance of the nano CaO sorbent for CO₂ capture were investigated. Thermo gravimetric analysis (TGA), X-ray diffraction (XRD), Fourier transform-infrared (FT-IR), X-ray fluorescence (XRF), N₂ adsorption–desorption (BET) measurements, transmission electron microscopy (TEM), zeta potential and temperature programmed desorption (TPD-CO₂) studies were used for the characterization of the prepared nano-sized CaO particles. The results showed that BS-12 modified nano CaO exhibited the best performance for CO₂ capture. The particle size and morphology of CaO varied from rod shape (45–33 nm) to cubic (13–23 nm) by changing the operating variables. A suggested mechanism for nanoparticle formation in the presence of BS-12 is also discussed.