Desulfurization Performance and Kinetics of Potassium Hydroxide-Impregnated Char Sorbents for SO(2) Removal from Simulated Flue Gas

[Image: see text] Potassium hydroxide-impregnated char sorbents (KOH/char) prepared via an ultrasonic-assisted method were used for SO(2) removal from flue gas. The desulfurization experiment was analyzed using a fixed-bed reactor under 40–150 °C temperature range, using simulated flue gas. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy, and scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS) were used to analyze both the chemical and physical characteristics of the sorbents. The analyzed results exposed that the complete elimination of SO(2) from flue gas was achieved when using the char/KOH sorbent with a mass ratio of char to KOH of 11:1. It was noted that temperature had a substantial influence on the desulfurization performance with sulfur capacity maximized at 100 °C. Experimental results also revealed that a small amount of O(2) present in the solvent could improve the SO(2) removal efficiency of the sorbent. The analyzed XRD patterns showed that K(2)SO(4) was the main desulfurization product, which was consistent with the SEM/EDS analysis. The experimental results were well-described with the Lagergren first-order adsorption kinetics model with the activation energy (E(a)) of the SO(2) adsorption by KOH/char sorbent of 20.25 kJ/mol.