SO2 Emission Behavior of a Small PFBC Test Equipment
Ichiro SAITO, Munehide KAWAMURA, Rikiya ABE, Tatsuro HARADA
This paper reports the results of investigation on sulfur dioxide reaction in a pressurized fluidized bed. In case of fluidized bed combustion, sulfur retention depends upon excess air ratio and fluidized bed height (gas residence time) respectively. Study of SO2 injection into various points conducted that sulfur dioxide was removed rapidly and completely in the fluidized bed and sprash zone. Bed material, which consisted in Ca compounds and coal ash, performed high sulfurization ability against the high CO2 partial pressure. Therefore, these results suggested that it had high sulfurization performance zone and its mechanism was not able to explain only direct sulfation of CaCO3. The coal character dependence of sulfur retention was explained the influence of coal combustion style in the fluidized bed and inorganic sulfur content in the coal. According to combustion style observation study, when coal particles burn separately and rapidly in the fluidized bed, SO2emission of these coals was high. Addition to that inorganic sulfur in the coal tend to burn over fluidized bed zone. On the other hand, when coal particle is cohesive, its primary particle burned slowly in the bed and SO2emission of this kind of coal was low.