Preparation of Mesophase Pitch through Supercritical Fluid Extraction of Coal Tar Pitch

This paper explores the preparation of mesophase pitch by employing supercritical fluid extraction on coal tar pitch sourced from a coal chemical company. The raw material undergoes pretreatment using various extraction solvents, and the resulting refined components are thermally polycondensed in a laboratory microreactor to create mesophase pitch. Qualitative and quantitative analyses of the mesophase pitch's structure are conducted through polarized light microscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, and other analytical methods to identify an optimal supercritical fluid extraction pretreatment solvent for coal tar pitch. The results reveal that using n-hexane solvent in the supercritical fluid extraction process yields a mesophase pitch with a remarkable mesophase content of 90.07%, displaying excellent optical texture distribution, superior directional arrangement and order, the closest lamellar accumulation, and the highest degree of anisotropy and graphitization.