Catalytic pyrolysis of waste tire using HY/MCM-41 core-shell composite

•Core-shell composite of HY and MCM-41 as a waste tire pyrolysis catalyst.•Enhancement of gasoline and valuable aromatics, especially ethylbenzene and toluene.•Enhancement of removal of sulfur content in oil.•Owing to bimodal pore size distribution and good balance of acidity in composite layers.•Role of core-shell composite of HY and MCM-41 explained.

The catalytic pyrolysis of waste tire was investigated using core-shell composite of HY and MCM-41 as a catalysts in a bench-scale reactor ramped from room temperature to 500 °C (pyrolysis zone) and 350 °C (catalyst bed), aiming to enhance the formation of petrochemicals by transformation of the bulky aromatics to valuable aromatics. The core-shell composite of HY and MCM-41 were synthesized by growing of MCM-41 over HY zeolite particles. The gaseous products were analyzed using GC-FID, whereas the GCxGC-TOF/MS and SIMDIST-GC were used for analysis of waste tire-derived oil. Moreover, the sulfur content in oils was determined by S-analyzer. It was found that The MCM-41 shell thickness was not uniform, which varied in the range of 50-100 nm. Nevertheless, the core-shell composite catalyst exhibited the great catalytic behavior in the enhancement of quality of waste tire-derived oil. The oil produced from the composite catalyst contained a higher amount of gasoline and valuable aromatics, especially ethylbenzene and toluene than the pure HY and MCM-41 catalysts, indicating the existence of bimodal pore size distribution and good balance of acidity between micropore and mesopore layers of core-shell composite exhibits a higher cracking activity and better petrochemical selectivity than pure HY and MCM-41 catalyst. Furthermore, the core-shell catalysts also provided lower sulfur content in oil than the both HY and MCM-41 catalyst. Therefore, the core-shell composite of HY and MCM-41 has a great potential in producing petrochemical-rich oil with low sulfur content from waste-tire pyrolysis.