Removal of sulfur dioxide from flue gas using the sludge sodium humate

Abstract

This study shows the ability of sodium humate from alkaline treatment sludge on removing sulfur dioxide (SO in the simulated flue gas. Experiments were conducted to examine the effect of various operating parameters, like the inlet SOconcentration or temperature or O on the SOabsorption efficiency and desulfurization time in a lab-scale bubbling reactor. The sludge sodium humate in the supernatant after alkaline sludge treatment shows great performance in SOabsorption, and such efficiency can be maintained above 98% with 100 mL of this absorption solution at 298 K (flue gas rate of 0.12 m3/h). The highest SOabsorption by 1.63 g SHA-Na is 0.946 mmol in the process, which is translated to 0.037 g SOg-1 SHA-Na. The experimental results indicate that the inlet SOconcentration slightly influences the SOabsorption efficiency and significantly influences the desulfurization time. The pH of the absorption solution should be above 3.5 in this process in order to make an effective desulfurization. The products of this process were characterized by Fourier transform infrared spectroscopy and X-ray diffraction. It can be seen that the desulfurization products mainly contain sludge humic acid sediment, which can be used as fertilizer components. © 2013 Yu Zhao and Guoxin Hu.