[Influence and mechanism of calcium-based desulfurizer on NO conversion in fluidized bed of coal]

On the experimental table of fluidized bed which scale was phi 150 mm x 1000 mm and temperature interval was from 840 degrees C to 960 degrees C, the influence of desulfurizer variety, particle size and molar ratios Ca/S on nitrogen conversion to NO were studied. This paper elaborated on the mechanism of calcium-based desulfurizer lead to the increase of NO conversion rate. Experiment presented that given identical quantities, burnt calcium had maximum NO conversion rate, then limestone, calcite last. Nitrogen conversion to NO increased with increasing molar ratios Ca/S. When the particle size was between 1-2 mm, the NO conversion rate was the maximum, second was 2-3 mm, the last 0.2-1 mm. HCl, HF, SO2 decreased with calcium addition. At the same time H, OH, HO2 radicals increased. The CO oxidation was favored, the reaction of monoxide and NO catalyzed by char, sand, ash will weaken, therefore NO content will increase.