Insight into pyrolysis characteristic and mechanism of natural rubber using rapid infrared-heating fixed bed combined with pyrolysis kinetics

• Published in: Chemical engineering science 2024-12, Vol.300, p.120647, Article 120647
• Main Authors: Wen, Yuxin, Lv, Wenqing, Xu, Yilong, Ma, Liangyan, Hu, Haoquan, Jin, Lijun
• Format: Article
• Language: English
• Subjects: Dynamical method; Mechanism; Natural rubber; Pyrolysis; Tar
• ISSN: 0009-2509
• DOI: 10.1016/j.ces.2024.120647

•Thermal degradation of NR is an apparently exothermic and multistep reaction.•Tar yield reaches up to 96.59 wt%, along with a small quantity of char and gas.•Pyrolysis tar mainly consists of cycloolefin with a high proportion of D-limonene.•NR pyrolysis tar mainly consists of dimer (C10) or trimer (C15) of isoprene.•Cracking of NR molecular structure is mainly based on the β bond breakage. Pyrolysis is a potential approach to treat post-consumer waste natural rubber (NR), however, unclear pyrolysis mechanism restricts its actual utilization. In this work, thermal degradation of NR was investigated combining dynamical method with pyrolysis on the infrared-heating fixed-bed reactor. Results show that thermal degradation of NR is an apparently exothermic and multistep reaction, tar yield reaches up to 96.59 wt%. Pyrolysis tar mainly consists of cycloolefin with a small quantity of chain olefins and mono-ring aromatic hydrocarbons. High temperature reduces the cycloolefin yield but promotes the generation of mono-ring aromatic hydrocarbons. Tar is mainly composed of dimer (C10) or trimer (C15) of isoprene with different structures. H type in tar is mainly aliphatic hydrogen. Besides, a possible pyrolysis mechanism based on the β bond breakage was proposed. The work can provide a theoretical basis for direct control of high value-added products during NR pyrolysis and achieve high efficiency pyrolysis of NR.