Experimental study on CO2 co-gasification characteristics of biomass and waste plastics: Insight into interaction and targeted regulation method

Abstract

The CO2 gasification of biomass and waste plastics is one of the essential ways to utilize solid waste resources, and it is also potential negative carbon emission technology. The complex interactions in the co-gasification of biomass and waste plastics affect the quality of syngas and the efficient conversion of solid waste. In this study, sawdust, PE and PVC were selected for CO2 gasification. Firstly, the interaction and gasification characteristics were investigated by thermogravimetric experiments. Then, the impact of interaction on syngas generation and quality was studied through fluidized bed experiments. The results indicated that PE, PVC, and sawdust co-gasification exhibits both inhibitory and synergistic. PE inhibits the release of volatiles in sawdust, while PVC promotes the volatiles release. In short, PVC improves the gasification reactivity of sawdust, and PE enhances syngas quality. Adding 75 % PE, the syngas Low Heating Value by 415 % up to 30.05 MJ/kg, and Cold Gas Efficiency by 147 %. The synergistic of the sawdust/PE-PVC was manifested as the superposition and amplification of the synergistic in sawdust/PE and sawdust/PVC. Adjusting the PE and PVC proportion, syngas quality can be targeted to control. The study results exhibit new perspectives on classifying waste plastics for gasification and regulating syngas quality.