Experimental Study of High Levels of SO2 Removal in Atmospheric-Pressure Fluidized-Bed Combustors

摘要

The report describes tests (conducted in an atmospheric-pressure fluidized-bed combustor (FBC) with a cross-section of 1 x 1.6 m) to demonstrate high levels of SO2 removal when burning a high-sulfur coal and feeding limestone sorbent for SO2 removal. The goal was to achieve 90-plus % SO2 removals with reasonable sorbent feed rates through suitable reductions in sorbent particle size (to improve reaction kinetics) and increases in gas residence time (to increase gas/sorbent contact time), in a manner predicted by an existing mathematical model. The result supports model predictions. Reducing sorbent particle size and increasing gas residence time resulted in modest increases in SO2 removal over the range of conditions tested here. Increases in flue gas O2 content also increased removals. Only one of the three sorbents considered for the project had the attrition resistance necessary to permit use in the testing, indicating that some sorbents will not be suitable for use in dense-phase FBC. NOx emissions ranged from 130 to 236 ng/J during these tests.