PM combustion enhancement to reduce continuous regeneration temperature of fluidized bed type PM removal device using catalyst-doped bed particle

A fluidized bed type PM removal device was developed by focusing on adhesion force as a highly efficient device for PM collection and low-temperature continuous regeneration. To further reduce the continuous regeneration temperature of this device, catalytic PM combustion was investigated. Alkaline and alkaline earth metals (potassium and calcium, respectively) are effective for PM combustion and are among the least expensive catalysts. The positive effects of these catalysts on PM combustion were compared. As their catalytic performances are almost identical, potassium was used for the continuous regeneration of this device. Potassium was doped on the bed particle via the impregnation method. Moreover, the amounts of doped potassium were compared based on the effects of PM combustion on collection efficiency, and the optimum value was determined to be 1.58 g-catalyst/kg-bed particle. Catalyst characterization was conducted via XRD and FTIR analysis of the cleaned gas. K₂CO₃ is detected on bed particle surface from the XRD patterns. The FTIR results show that potassium promotes PM combustion and selectively enhanced CO₂ generation. CO₂ is generated from the oxidation of K₂CO₃ and transformation of K₂O₂ to K₂O with the consumption of PM. K₂O is converted to K₂CO₃ with the re-absorption of CO₂. The lowest continuous regeneration temperature decreases to 350 °C with maintaining the collection efficiency 100% owing to the catalytic PM combustion. Furthermore, the effect of water vapor, which is present in exhaust gas, was investigated. It promotes PM combustion and further reduces the continuous regeneration temperature to 330 °C.