The effects of ammonia on SO2 emissions in a fluidized bed combustor under pseudo-staged combustion.

The reduction of SO2 by ammonia gas addition during staged combustion of bituminous coal has been studied in a 2 m high fluidized bed combustor of 30 cm static bed height and a freeboard height of 100 cm. The coal was introduced to the combustor at 42 cm above the distributor and the ammonia gas was injected at 52 cm above the distributor by an uncooled stainless steel injector. Experiments were carried out to investigate effects of ammonia gas injection on SO2 emissions of (i) air staged levels, (ii) excess air levels, (iii) primary air factor