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.