Upcycling of medical wastes for high-value syngas over Ni-based catalysts

The amount of medical waste increases rapidly due to the continuous expansion of medical resources and the public health system. The complexity, pathogenicity and infectivity of medical waste make it difficult to be disposed properly. Pyrolysis, as a promising technology, can realize the harmless disposal and resource utilization of organic solid wastes. In this study, fundamental experiments on catalytic pyrolysis of medical waste to produce value-added syngas were conducted. Nickel-based catalysts (MK–Ni, AT–Ni, ZSM-5–Ni and CaO–Ni) were prepared to further investigate the catalysis pyrolysis behavior of medical waste containing mixed components (plastic, wood (bamboo), rubber, and synthetic fiber). The results showed that the catalyst showed the best effect on gas production at 900 ℃, adding Ni/AT has the highest gas yield (83.99%), the highest synthesis gas (H₂ + CO) yield (65.65%), with the carbon conversion ratio reached 54.31% and the best H₂/CO production ratio as 2.27 which facilitates the production of methanol. Meanwhile, Ni/HZSM-5 has the highest synthesis gas (H₂ + CO) yield (56.775%) below 900 ℃. This study aims to provide theoretical guidance for treatment and disposal of medical waste for the low cost and potential economic and environmental benefits.