Experimental study on co-gasification of cellulose and high-density polyethylene with CO2

Co-gasification of biomass and waste plastic with CO₂ presents an effective strategy for integrating biomass conversion, waste utilization and carbon recycling. In this study, the co-gasification of cellulose and high-density polyethylene with CO₂ was investigated experimentally. The effects of mixing ratio and temperature on co-gasification characteristics, including gas yield, product gas composition, lower heating value of syngas and gasification efficiency, were comprehensively evaluated. Additionally, the interaction between cellulose and high-density polyethylene was analyzed. The results suggested that increasing the polyethylene content in feedstock resulted in decreased yields of H₂ and CO, increased CH₄ yield, increased lower heating value of syngas and reduced gasification efficiency. The interaction between cellulose and high-density polyethylene enhanced the gas yield, with the most significant effect at 40 % polyethylene content. In the range of 900 °C–1000 °C, increasing the temperature resulted in increased gas yield, reduced lower heating value of syngas and increased gasification efficiency. The positive interaction between cellulose and high-density polyethylene on gas yield was more significant at higher temperatures. This work shed light on reaction characteristics for co-gasification of biomass and high-density polyethylene with CO₂, laying the foundation for the design and application of this technology.