Interactions of the Main Components in Paper‐Plastic‐Aluminum Complex Packaging Wastes during the Hydrothermal Liquefaction Process

Abstract Hydrothermal liquefaction was applied to treat paper‐plastic‐aluminum (Al‐PE‐Pa) complex packaging waste for bio‐oil production. The interactive effects between the main components of paper fiber, low‐density polyethylene (LDPE), and aluminum foil in such complex material were studied. The co‐liquefaction of paper fiber and LDPE had a significant synergistic effect. The addition of hydrogen‐rich LDPE effectively promoted the removal of oxygen‐containing groups. Aluminum foil had only a slight impact on the liquefaction of paper fiber, but it can significantly decrease the oxygen content of the bio‐oil, increase the high heating value of the bio‐oil, and significantly reduce the ester and phenol contents in the bio‐oil. The co‐liquefaction of paper fiber/LPDE/aluminum foil exhibited superimposed effects of paper‐plastic synergy and in‐situ hydrogenation of Al‐H 2 O reaction. A new pathway for the energy utilization of Al‐PE‐Pa complex packaging waste is provided.