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

Abstract

Abstract

A new composite adsorbent of sodium humate (HNa)/α-aluminium oxide (α-Al₂O₃) for flue gas desulfurization (FGD) was prepared using the impregnation method. Both the adsorbent of α-Al₂O₃ and HNa/α-Al₂O₃ 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 (NH₄OH) was investigated in a fixed-bed quartz reactor. Experimental results indicate that HNa, which coats the α-Al₂O₃ fibers impregnated with HNa solution, improved the property of α-Al₂O₃ support for FGD. On the other hand, the HNa-coating on the adsorbent of HNa/α–Al₂O₃ impregnated with NH₄OH played an important role in enhancing the desulfurization property of the α-Al₂O₃. Due to the strong adsorption capability of HNa, more NH₄OH was adsorbed in the adsorbent of HNa/α-Al₂O₃ the longer a high sulfur dioxide (SO₂) conversation rate was maintained. In addition, because the desulfurization product was a compound fertilizer consisting of ammonium sulfate [(NH₄)₂SO₄], ammonium humate (HNH₄), and HNa, the recycling use of α-Al₂O₃ was also easily achieved. Thus, this study can provide a new cost-effective way to remove SO₂ from flue gas.