Effect of temperature and ZSM-5 catalyst dosage on carbon char yield from catalytic pyrolysis of waste tire

Abstract. The disposal of waste tires has become a substantial environmental challenge attributed to their accumulation and potential hazards. Pyrolysis emerges as a viable approach for the valorization of waste tires, into valuable products such as pyrolytic char. This carbon-rich char can be effectively used for pollutant removal or further processed into activated carbon, which is widely utilized in purification and catalytic applications. This study explores the impact of pyrolysis temperature and zeolite catalyst dosage on the yield of carbonous materials from the catalytic degradation of pyrolytic char derived from waste tires pyrolysis. Firstly, slow pyrolysis of waste tires at 500°C for 3 hours yielded 60% solid char. Subsequently, The pyrolytic char was subjected to catalytic degradation at temperatures varying from 600°C to 800°C and catalyst dosage ranging from 0 to 1.5. The findings discovered diverse patterns in carbon char yield with increasing catalyst dosage across varying temperatures. At 800°C, a linear rise in char yield from 80% to 71% was noted with increasing catalyst dosage, attributed to coke formation on the surface of the catalyst. Conversely, at 700°C and 600°C, the carbon char yield reduced from 88% to 68% and 85% to 65%, respectively, with increasing catalyst dosage, potentially due to the promotion of liquid product formation. The present research demonstrates the significant impact of pyrolysis temperature and catalyst dosage on the carbon char yield derived from waste tires, providing valuable insight for optimizing the catalytic decomposition, for the valorization of waste tire-derived carbonaceous materials.