Feasibility Study of New Limestone Flue Gas Desulfurization Process

AbstractA new method based on conventional limestone flue gas desulfurization (FGD) has been developed. The main difference compared to the conventional wet FGD is the utilization of granular limestone with acetic acid additives as the absorbent, which should save on the power required for pulverization of limestone and pumping the circulation slurry. This paper focuses on a feasibility study of the new limestone FGD process by comparing SO2 removal efficiency, SO2 absorption rate, limestone utilization and FGD system stability of the new FGD with those of the conventional FGD, in the same absorption equipment under the same experimental conditions. The results show that when the coarse limestone slurry (–80+100 mesh, US standard) is used directly as the absorbent, its utilization and SO2 removal efficiency, are very low at 44 and 60.7%, respectively. When the mixed slurry, which is composed of coarse limestone and 10–30 mmol/L acetic acid absorbs SO2, the degree of desulfurization is increased to 95% and the limestone utilization is enhanced to 93.5%. Finally, for the absorbent consisting of a fine limestone slurry (–300 mesh), the desulfurization efficiency and limestone utilization are 88 and 92.9%, respectively, under the same operating conditions. Therefore, the new desulfurization process is shown to be very feasible.