Co-pyrolysis kinetic characteristics of wheat straw and hydrogen rich plastics based on TG-FTIR and Py-GC/MS

The pyrolysis of various plastics generates distinct reaction intermediates, influencing co-pyrolysis with biomass feedstocks in varied manners. This work investigated the co-pyrolysis characteristics of hydrogen-rich plastics (PP, PS, PE) and wheat straw (WS) at 600 degrees C. The experimental results indicated that the co-pyrolysis of WS with hydrogen-rich plastics increased the release of alkenes and decreased the release of oxy-organics and polycyclic aromatic hydrocarbons (PAHs). The synergistic mechanism of co-pyrolysis was closely related to the type of plastics used. FTIR analysis revealed that the co-pyrolysis products of WS and plastics included hydrocarbons, aldehydes, ketones, alcohols, acids, phenols, and H2O. Co-pyrolysis effectively enhanced the proportion of combustible gas. The co-pyrolysis of WS and PP increased the yield of MAHs and alcohols. The co-pyrolysis of WS and PS decreased the formation of PAHs and acids. The co-pyrolysis of WS and PE reduced the yield of Ncompounds and acids. Compared to single pyrolysis, the product yields from co-pyrolysis of WS and hydrogen- rich plastics were significantly enhanced, especially alkenes and alcohols. The synergistic interaction between WS and PP, PS, PE contributed to enhancing the quality of co-pyrolysis bio-oil. Additionally, the research also provided a theoretical foundation for the efficient co-conversion of biomass and plastics.