A coal polygeneration technical route with pyrolysis as the leading process can avoid excessive splitting of atoms in coal and maximize the utilization of the molecular structural characteristics of coal, offering advantages such as mild reaction conditions, low energy consumption, and low carbon emissions. Regulating the conversion of coal pyrolysis volatiles and elucidating their cracking reaction mechanisms are key to the high-value utilization of pyrolysis products. However, coal pyrolysis volatiles contain numerous components and have complex compositions, making it difficult to reveal their cracking mechanisms at the molecular scale. In this study, Shenfu coal tar was separated by alkali washing, extraction, and column chromatography to obtain five chemical fractions with similar compositions and relatively uniform structures. The composition and structure of each chemical fraction were thoroughly characterized, and the product distribution, composition, and interactions during the pyrolysis of each chemical fraction were investigated in depth. The results showed that solvent separation involving alkali solution, n-heptane extraction, and column chromatography could separate Shenfu coal tar into chemical fractions with similar structures/compositions. The contents of the chemical fractions followed the order aromatic phenols ≈ phenols > saturates > asphaltenes > resins. The chemical fractions had simpler compositions and more uniform structures. The pyrolysis of each chemical fraction contributed differently to the distribution and composition of gas, liquid, and solid products. The tar yield followed the order aromatics (higher than that of the whole fraction) > resins > phenols > saturates > asphaltenes; the carbon deposition yield followed the order asphaltenes > phenols > resins > aromatics (lower than that of the whole fraction) > saturates (lower than that of the whole fraction); and the gas yield was highest for saturates (significantly higher than that of the whole fraction), while the contribution order of the other chemical fractions depended on the pyrolysis temperature. Saturates mainly contributed to the formation of CH₄ and C₂H₄; phenols mainly contributed to the formation of CO; and asphaltenes mainly contributed to the formation of H₂. Notable interactions occurred during the pyrolysis of the chemical fractions. The individual pyrolysis of the chemical fractions promoted the secondary cracking of hydrocarbons and oxygen-containing structures, favoring the formation of H₂, C₂H₄, C₂H₆, and CO.
 

Solvent separation; Shenfu Coal; Tar; Pyrolysis; Interactions