CO2 gasification-reforming of medical waste over mesoporous material-supported Ni catalysts

The management of medical waste presents significant challenges for public health and environmental sustainability. This study examines the CO2 gasification-reforming of medical waste using 5 %Ni/MCM-41 and 5 %Ni/SBA-15 catalysts in a two-stage fixed-bed reactor. The application of a 5 %Ni/MCM-41 catalyst led to substantial increases in total gas yields for syringes, nitrile gloves, and degreasing cotton by 354 %, 18 %, and 33 %, respectively. Similarly, with a 5 %Ni/SBA-15 catalyst, gas yields for these materials increased by 371 %, 46 %, and 42 %, respectively. Structure characterization further reveals that 5 %Ni/SBA-15 demonstrated superior Ni dispersion compared to the 5 %Ni/MCM-41, leading to enhanced catalytic performance. Additionally, the type of Ni precursor influenced Ni dispersion and catalytic efficiency, with nickel acetylacetonate outperforming nickel nitrate. Spent catalyst characterization indicates that Ni sintering and coke deposition are the primary reason for catalyst deactivation. However, the substantial formation of carbon nanotubes highlights the dual benefit of CO2 gasification-catalytic reforming of medical waste, enabling both gas production and carbon nanotube synthesis.