Co-pyrolysis of waste paper and tyre: Exploration of interaction of volatiles of varied origin and the influence on product evolution

Waste paper and tyre are typical solid wastes with distinct composition. Their pyrolysis could generate varied volatiles that may interact with each other or with resulting char. In this study, the co-pyrolysis of waste paper and tyre was investigated at 400 and 600 degrees C, with the focus on understanding the interaction of the volatiles on evolution of the products. The results show that the interaction of the volatiles at 400 degrees C forms more gaseous products like CO and CO2, while the interactions of the heavier organics at 600 degrees C forms more oil (49.3% vs 42.6%). The interaction of the volatiles also affects the generation of sulfur-containing organics and diminishes the paper-derived aldehydes and ketones or the heavy organics with the pi-conjugated structures in the oil. In addition, the volatile-char interactions exist and form the char of higher carbon content through promoting carbonization and deoxygenation reactions, generating char of higher thermal stability and higher hydrophilicity via tailoring functional group, pore structures and morphologies of the char.