Characterization of high-alumina coal fly ash based silicate material and its adsorption performance to CO2

摘要

Silicate material prepared from high-alumina coal fly ash (HACFA) was characterized by using XRD, SEM, FTIR spectroscopy, TGA-DSC, and elemental analysis. These spectral results show that the silicate material is mainly composed of eight elements-O, C, Si, Ca, Na, Mg, Al, and Fe, which exist as the formations of Ca2+, Na+, Mg2+, Al3+, Fe3+, SiO (3) (2-) , and COO (3) (2-) , and some adsorbed water and crystal water are determined in the silicate material. The material with surface area of 117.12m(2)/g shows a faveolate structure, and a pore size distribution of silicate material is calculated at 11.01 nm from the nitrogen desorption isotherm using the BJH model. When the material was used for CO2 adsorption at T=323.15 K and flow rate=95mL/min with 15.79% (vol) CO2, a dynamic adsorption capacity of CO2 on the surface of silicate material was found at 8.67mg/g and the adsorption values decreased weakly after seventeen recycling times. The investigation of dynamic adsorption behavior shows that the silicate material presents similar adsorption properties with commercial active carbon and stronger adsorption properties than commercial diatomite.