Removal of SO2 with particles of dolomite limestone powder in a binary fluidized bed reactor with bubbling fluidization

Abstract

In this work, SO2 was treated by reaction with dolomite limestone (24 µm) in a fluidized bed reactor composed of 500-590 µm sand particles. The influence of operating temperature (500, 600, 700 and 800oC), superficial gas velocity (0.8, 1.0 and 1.2 m/s) and Ca/S molar ratio (1, 2 and 3) on SO2 removal efficiency for an inlet concentration of 1000 ppm was examined. Removal of the pollutant was found to be dependent on temperature and Ca/S molar ratio, particularly at 700 and 800oC. A maximum removal of 76% was achieved at a velocity of 0.8 m/s, a temperature of 800°C and a Ca/S of 3. The main residence time of the powder particles was determined by integrating normalized gas concentration curves as a function of time; the values found ranged from 4.1 to 14.4 min. It was concluded that the reactor operated in bubbling fluidization under every operational condition.