Structure Characteristics and Gasification Reactivity of Co-Pyrolysis Char from Lignocellulosic Biomass and Waste Plastics: Effect of Polyethylene

The rate limiting stage is char reactivity during gasification that can be influenced by its physicochemical structural characteristics. In this study, the effects of feedstock share, rice straw (RS) and polyethylene (PE), on the physicochemical properties and gasification reactivity of chars were investigated and their relationships were discussed. The char gasification reactivity was investigated via isothermal experiments using a thermal analyzer. The results indicated that the PE addition improved the specific surface area (SSA) and pore volume (Vp) of the char obtained from co-pyrolysis RS with PE. The SSA of the char increased by 1.31 times when the PE content was 60 wt%, compared with that of RS char. The order degree and gasification reactivity of the co-pyrolysis char samples increased with increasing PE content beyond 40 wt%. The char reactivity in the early stage of cogasification was primarily determined by the order degree of carbonaceous and pore structure. The char reactivity in the later stage was influenced by these two factors and the silicon dioxide content could inhibit the char co-gasification reactivity.