Removal of Elemental Mercury by Novel Chemically Modified Noncarbon Sorbents

Adsorption experiments of vapor-phase elemental mercury (Hg⁰) were carried out by using two types of chemically modified CTS/SiO₂ sorbents in a laboratory-scale fixed-bed reactor. The characterizations of the sorbents were analyzed using the methods of nitrogen (N₂) adsorption/desorption, field-scanning electron microscope (FSEM), Fourier transform infra-red spectroscopy (FTIR) and X-ray diffraction (XRD). The results revealed that the surface areas of the sorbents CTS/SiO₂ increased significantly after supporting. More active sites, such as S and Cl, can be easily obtained after silanization. And it was found that Cl and S were well distributed on surface as well as Si, especially in the smaller particles of the modified sorbents. Fixed-bed adsorber tests showed that mercury removal efficiency increased with the temperature, and it improved with the presence of O₂. The mercury efficiency of silanized CTS-SH/SiO₂ can reached more than 80% at a temperature of 120°C, which is about 3_~4 times higher than that of the same sorbent at 80°C.