Prediction of SO2 removal efficiency for wet Flue Gas Desulfurization

The wet Flue Gas Desulfurization in the coal-fired power plants has been the most widely used because of its high SO2 removal efficiency, reliable and low utility consumption. The difficulty in the prediction of the SO2 removal from flue gas is that the performance of the system is related to a wide range of variables. In this paper, the SO2 was removed by absorbing and reacting SO2 with limestone slurry, and limestone scrubbing was accomplished in a spraying reactor. Experimental investigations for effects of different operating variables on the SO2 removal showed the reasonable process parameters such as the pH value of the liquid phase, droplet size of the spray and the flow rates of liquid and gas. The removal process was analyzed using the two-film theory of mass-transfer. Both the liquid and gas side resistances were important, and the absorption rate was controlled by a combination of both gas-film and liquid-film diffusion controls. A model of external mass-transfer with the effects of a chemical enhancement factor and sulfite concentration in the liquid phase was developed for the prediction of the SO2 removal efficiency, and the calculated values were in reasonable agreement with the experimental values. The study is considered as the one-dimensional prediction of SO2 removal and low-cost application of limestone slurry for commercial FGD technology. (C) 2009 Elsevier Ltd. All rights reserved.