Burning plastic waste containing polyvinyl chloride (PVC) in fluidized bed combustor include fine shredding and addition of calcium oxide powder

摘要

Plastic waste including PVC is shredded (9) to a particle size below 30 mm and fed (7) to the lower part a fluidized bed reactor (2). Calcium oxide powder amounting to 10 to 40% of the PVC content is added (12). The inert component of the bed is sand, preferably quartz with a particle size of 0.9 to 1.5 mm, and the combustion temperature is 860 to 885 deg C. The conditions required to prevent the emission of dioxins are that the lower half of the bed is preheated to 850 deg C, the bed height is 1 to 2.5 m, the air velocity in an empty reactor is 1 to 2.5 m/sec and the temperature in the freeboard space (3) is no higher than the bed temperature to indicate complete combustion. The reactor is insulated and the bed is maintained constant by removing material through a heat exchanger (20) to preheat the incoming primary air.