Composition characteristics of the distillation waste residue from coal gasification crude phenol and pyrolysis product distribution of the corresponding residue

Crude phenol distillation residue (CPDR), a complex and hazardous by-product from coal tar processing, currently lacks sustainable treatment methods. In this paper, vacuum distillation was employed to separate it into four fractions: F-120 (≤120 °C), F120-150 (120–150 °C), F150-180 (150–180 °C), and F180-210 (180–210 °C), which were characterized by GC/MS. Results showed total distillate yields of 12.55 %, with phenolic compounds constituting over 60 % across the fractions. Mono-substituted phenols dominated the low- and high-boiling fractions, while poly-substituted phenols were concentrated in intermediate fractions. TGA and Py-GC/MS analyses revealed distinct pyrolysis behaviors: CPDR released mainly low-boiling phenols (66.19 %) and esters (16.62 %) at 160 °C, whereas the distillation residue (CPDR-R) underwent cracking at 223 °C to produce long-chain alkanes (31.52 %), arenes (16.38 %), and esters (14.22 %). This work conducts a pioneering investigation into the composition and thermochemical conversion of CPDR, demonstrating promising pathways for resource recovery: phenolic fractions as feedstocks for fine chemicals, and CPDR-R-derived products for applications in biofuels and lubricants. These findings provide fundamental insights for the sustainable management of this understudied industrial waste.