Removal Of Elemental Mercury Of Yellow Phosphorus Tail Gas By Activated Carbon Impregnated With Ferric Chloride At Low Temperature

Gaseous elemental mercury has caused wide attention of scholars both at home and abroad, because of its easy volatile, bioaccumulation, toxic and the characteristics which can spread around the world. China is considered to be the world’s largest anthropogenic mercury emissions in recent years. The mercury removal in the coal-fired flue gas and smelting gas has drawn a lot of attention and research in recent years. The mercury emissions in the yellow phosphorus tail gas, which is the important component of atmospheric mercury emissions of Guizhou, Sichuan and other provinces in our country. The mercury emission in the yellow phosphorus tail gas has aroused people’s concern increasingly. So the research of mercury removal of complex atmosphere of yellow phosphorus tail gas was badly in need of research.Activated carbon (AC) impregnated with ferric chloride (FeCl3) was tested to removal element mercury (Hg0), and the removal abilities were studied on a fixed-bed reactor. The test carried out under the condition of the N2 of 99.999%. It was found that the removal ability of Hg0 of AC was dramatically enhanced by the introduction of FeCl3. We studied the effect of the best impregnation concentration of FeCl3, the perfect calcinations and reaction temperature on the removal efficiency of Hg0. And studied the effect of H2S, H2O, O2 in the yellow phosphorus tail gas. SEM-EDX, Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and infrared spectroscopy (FTIR) analyses were used to characterize the samples.The best impregnation concentration of FeCl3 and reaction temperature was 0.15mol/L and 50℃, respectively. O2 and H2S had a prohibitive effect in the removal of Hg0 while the H2O (g) had a negative effect on Hg0 removal due to competitive adsorption with Hg0. It can be seen that Fe2O3 and C-Cl which were generated on AIFC-0.15 and resulted in improvement of the Hg0 removal from the analyses of the characterization of the samples. Results indicate that the removal of Hg was achieved through two pathways:one was that Hg0 reacted with C-Cl on the sample; another was that Hg0 bond with Fe2O3. According to XPS the analysis of Hg 4f, the element mercury on the surface of the samples was mainly in the form of mercuric chloride (HgCl2) and mercuric oxide (HgO).