A new semi-dry desulfurization process using a powder-particle spouted bed

A new semi-dry desulfurization process was tested in this study. The proces s uses the so-called powder-particle spouted bed (PPSB) as the reactor in w hich coarse medium particles, usually silica sand of several hundred microm eters in size, are fluidized with hot flue gas. A slurry of fine SOx sorben t, such as slaked lime or other alkaline powder, is continuously supplied i nto the bed of coarse particles. As a consequence, both the desulfurization reaction and slurry drying take place simultaneously in the single reactor . By using a model flue gas, SO2-air, and the sorbent Ca(OH)(2) in a labora tory-scale reactor, the removal efficiency of this process was examined wit h respect to major operating parameters in this study. It was demonstrated that SO2 removal in excess of 95% can be achieved at Ca/S = 1.2, while spen t sorbent appears in the form of dry powder. The optimal temperature of flu e gas treated with this technique was shown to be approximately 420 K. In c omparison with wet desulfurization scrubbers, this PPSB semi-dry process ap pears to have lower cost, less complicated configuration and simpler dispos al of used sorbent. (C) 2000 Elsevier Science Ltd. All rights reserved.