Study on synergistic disposal of spent FCC catalysts and waste tires: Influence of pyrolysis process parameters on product distribution and quality

• The reusability of spent fluid catalytic cracking (FCC) catalysts was explored. • Spent FCC catalyst was applied as catalyst for waste tire catalytic pyrolysis. • The effects of varying pyrolysis process conditions were investigated. • Pyrolysis conditions were optimized to improve pyrolysis oil product distribution. Spent fluid catalytic cracking (FCC) catalysts and waste tires have caused severe environmental problems. The application of spent FCC catalysts in waste tire pyrolysis can not only solve the associated pollution problem but also realize the high-value reuse of the catalysts and waste tires. In this study, the influence of process parameters (including heating rate, rotate speed of pyrolysis reactor and solid circulating media) on the catalytic pyrolysis products was investigated. The experimental results showed that an increased heating rate increased the contents of the light components and valuable chemicals in the light components of the pyrolysis oil. When the heating rate was 9 K/min, the contents of light components and BTEX in the pyrolysis oil reached the highest levels, which were 37.5 % and 22.02 % respectively. Additionally, a suitable reactor rotate speed and the addition of circulating media facilitated uniform heating of the material, thus improving the yield of the pyrolysis oil. The findings collectively demonstrate the economic and social benefits of using spent FCC catalysts for waste tire pyrolysis.