Experimental assessment of medical plastic waste pyrolysis and steam gasification for resource recovery

Medical plastic waste (MPW) has become a major environmental concern due to its massive production in clinics and hospitals, and the limited recycling options, especially after the COVID-19 pandemic. In this context, thermochemical technologies represent a promising approach to simultaneously reduce and valorize this waste by producing three main streams of value: a gaseous, a liquid, and a solid stream. In this study, the thermochemical conversion of four representative categories of MPW (non-woven medical textiles, FFP2 face masks, Pasteur pipettes, and natural latex gloves) was experimentally evaluated under different operating conditions. The experiments were conducted in a laboratory-scale fluidized-bed reactor at temperatures between 750 and 850°C using N₂ at 8 NL min^-1 or N₂ plus steam (6 NL min^-1N₂ + 2 NL min^-1 steam) as the process atmosphere, in order to compare predominantly pyrolytic and steam gasification conditions. These conditions correspond to nominal freeboard residence times of approximately 2.4-2.6 s. The results revealed a strong influence of both feedstock composition and operating conditions. The gas composition varied significantly with the type of MPW, leading to H₂ and CO contents reaching up to 30 vol% and 20 vol%, respectively, both for FFP2 face masks under N₂ and at 750°C. Carbon conversion to the gas phase achieved a maximum of approximately 45%. Steam addition significantly reduced carbon retention in the char fraction, while the unaccounted carbon fraction remained substantial under several steam gasification conditions. Tar analysis showed that benzene, toluene and xylene (BTX) compounds predominated for polypropylene- and polyethylene- based MPW, whereas natural latex gloves exhibited a greater tendency towards the formation of substituted aromatic compounds, naphthalene derivatives and polycyclic aromatic hydrocarbons. Overall, these findings demonstrate the potential of thermochemical conversion to recover valuable products from selected MPW fractions and provide an experimental basis for identifying suitable feedstock-specific operating conditions. Further development towards industrial implementation will require consideration of process efficiency and environmental performance.