Structure and composition of mesophase pitch prepared from aromatic-rich fluid catalytic cracking slurry under different process conditions

The high aromaticity of fluidized catalytic cracking (FCC) slurry makes it a superior raw material for the production of high-performance carbon materials. In this study, direct thermal polycondensation of aromatic-rich FCC slurries is conducted to synthesize mesophase pitches with a significant anisotropic content. The effects of stirring speed and the pressurized-atmospheric two-stage reaction on the structure and composition of the products are investigated. Thermal stability analysis using thermogravimetric (TG) test, observation of mesophase content and optical structure through polarized light microscopy, characterization of material composition and molecular structure via Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance hydrogen spectrum (¹H NMR), as well as comparison of crystal structures using X-ray diffraction (XRD) are performed. The experimental results demonstrate that an increase in the stirring rate leads to a more homogeneous molecular distribution within the reaction system, thereby facilitating molecular contact polycondensation and promoting mesophase growth and development. Furthermore, the pressurized-atmospheric two-stage reaction process also contributes to mesophase development, resulting in products with more cycloalkane structure, improved thermal stability, and optimized optical structure transitioning from mosaic to flow or even domain.