Preparation of Sodium Humate/α-Aluminum Oxide Adsorbents for Flue Gas Desulfurization

摘要

A new composite adsorbent of sodium humate (HNa)/α-aluminium oxide (α-Al_2O_3) for flue gas desulfurization (FGD) was prepared using the impregnation method. Both the adsorbent of α-Al_2O_3 and HNa/α-Al_2O_3 were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy dispersive X-ray spectrometer (EDS), and scanning electron microscope (SEM). Desulfurization activity of the adsorbent impregnated with ammonia (NH_4OH) was investigated in a fixed-bed quartz reactor. Experimental results indicate that HNa, which coats the α-Al_2O_3 fibers impregnated with HNa solution, improved the property of α-Al_2O_3 support for FGD. On the other hand, the HNa-coating on the adsorbent of HNa/α-Al_2O_3 impregnated with NH_4OH played an important role in enhancing the desulfurization property of the α-Al_2O_3. Due to the strong adsorption capability of HNa, more NH_4OH was adsorbed in the adsorbent of HNa/α-Al_2O_3 the longer a high sulfur dioxide (SO_2) conversation rate was maintained. In addition, because the desulfurization product was a compound fertilizer consisting of ammonium sulfate [(NH_4)_2SO_4], ammonium humate (HNH_4), and HNa, the recycling use of α-Al_2O_3 was also easily achieved. Thus, this study can provide a new cost-effective way to remove SO_2 from flue gas.