Study on mercury emission characteristics of circulating fluidized bed boiler and pulverized coal boiler

A 600 MW circulating fluidized bed boiler power plant and a 1000 MW pulverized coal boiler power plant were selected to study mercury migration, transformation and emission characteristics. The mercury concentration in flue gas was sampled by EPA 30B method, and the solid and liquid samples such as furnace-incoming coal, fly ash, bottom slag, limestone, process water, desulfurization gypsum and desulfurization wastewater were collected for analysis. The synergetic effect of existing pollutant control devices on mercury removal in two power plants was studied, and the migration and transformation law of mercury was discussed. After the flue gas of the two power plants passes through APCDs, the total mercury removal rate reaches over 88%, and the final mercury concentrations of the flue gas are 1.85 and 1.10 μg/m³, which are far lower than the national requirements. Under the existing equipment conditions, the ultra-low mercury emission can be realized.