Interaction during co-pyrolysis of different rubbers using rapid infrared-heating fixed bed: products distribution, tar quality and tar composition

Pyrolysis of waste tire (WT) is an efficient method to convert it into fuels and high-value chemicals. However, the main organic components of tire including natural rubber (NR), styrene butadiene rubber (SBR) and butadiene rubber (BR) usually exert interaction during pyrolysis. To investigate the interactions between different rubbers, individual pyrolysis and co-pyrolysis of three pure rubbers were conducted using an infrared-heating fixed-bed reactor, and the synergy during co-pyrolysis was revealed based on products distribution, tar quality and compositions from pyrolysis of pure rubber and waste tire. The results show that tar yields from rubber pyrolysis exceed 90 wt% and tar compositions are related to the molecular structures of rubbers. Co-pyrolysis between different rubbers promotes gases formation and inhibits char formation. The interaction between NR and SBR facilitates the formation of cycloolefin and chain olefin, but co-pyrolysis of SBR and BR contributes to the aromatic hydrocarbons formation. Similar tar components from pyrolysis of demineralized waste tire as those from pyrolysis of NR/SBR/BR sample indicate that waste tire pyrolysis contains individual pyrolysis and co-pyrolysis of different rubbers. The potential reaction process of WT was also proposed. The insight on interaction between different rubbers will provide a good guide for efficient pyrolysis of waste tire.