Plasma treatment of hospital waste

Hospital waste has been found to contain 20% plastic by weight, around 4 times than in municipal waste. Pre-packaged nonrecyclable materials lead to a large amount of chlorine containing plastics etc. In the Red or Yellow bay waste stream, the most commonly encountered plastics are polyvinylchloride, polyethylene and polypropylene. In this study, the pyrolysis of hospital waste has been studied with particular reference to PVC, which contains chlorine. The chemical analysis has indicated that H₂O or air must be added during the pyrolysis of PVC to prevent the formation of free solid carbon. By injecting steam into the first chamber, operating between 1000°C and 1500°C, carbon or soot is inhibited as the residue in the form of ash falls to the bottom. The off-gas passes to the second chamber where air may be added to provide oxidation and combustion. Operational efficiency of approximately 60% indicates a maximum input energy of 2-4 kWh/kg. Quenching of the output gases from the second chamber to around 100°C is followed by alkaline scrubbing and filtering before venting with excess air to atmosphere