Influence of Water Quality on the Flue Gas Desulfurization in a 350MW Coal-fired Power Plant

With the national ultra-low emission requirements, a large number of wet flue gas desulfurization has been used in the normal operation of coal-fired power plants. After long-term operation, various impurities will be enriched in the slurry of absorption tower, resulting in the reduction of desulfurization efficiency or foaming of the slurry of absorption tower, which will seriously affect the operation of the unit. It is necessary to study the influence of water quality on the desulfurization reaction of lime slurry. When the incoming water is reclaimed water, process water and filtrate respectively, the desulfurization reaction is simulated on the laboratory bench to compare its influence on the desulfurization reaction characteristics. The results show that. (1) The effect of process water on the desulfurization process is as follows. The largest amount of foaming of the desulfurization slurry and the inhibition of gypsum crystallization reaction, but the characteristics of particle size distribution in the generated gypsum slurry are most conducive to the slurry dehydration and the gypsum crystal quality is good. (2) The function of the filtrate is to minimize the foaming amount of the desulfurized slurry and the effect on the gypsum crystallization reaction. The characteristics of particle size distribution in the generated gypsum slurry are favorable for the slurry dehydration. The gypsum crystal size is the largest, but a small number of crystal particles appear at the same time, which affects the slurry dehydration to a certain extent. (3) The role of reclaimed water lies between process water and slurry.