Structural characterization of pyrolysis fuel oil (PFO) was conducted via 1H NMR and 13C NMR to elucidate its molecular structure and evaluate the feasibility of using PFO as a raw material for mesophase pitch synthesis. The average structural parameters were calculated based on the data from elemental analysis and matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS), as well as 1H NMR and 13C NMR data. The resultant structural features of PFO were compared with those of fluidized catalytic cracking-decant oil (FCC-DO). Based on the calculated parameters, we proposed average molecular models of PFO and FCC-DO. The molecular model of PFO showed that it had an aromatic structure consisting of three aromatic rings and one naphthenic ring fused with one pericondensed and two catacondensed aromatic carbons, as well as a short alkyl side chain (with only a methyl group). This structural feature of PFO demonstrated that it is highly favorable for use as a raw material for mesophase pitch synthesis. The empirical findings in this study provide an in-depth understanding of the molecular structure of PFO as well as FCC-DO and can offer insights for future research on the utilization of PFO and other petroleum heavy oils.

Improved understanding of the molecular structure of pyrolysis fuel oil: towards its utilization as a raw material for mesophase pitch synthesis
    Abstract
    1 Introduction
    2 Experimental
        2.1 NNR
        2.2 MALDI-TOF-MS
        2.3 EA
    3 Results
        3.1 Elemental composition
        3.2 Molecular weight distribution
        3.3 Chemical shift classification in NMR spectra
        3.4 Average structural parameters
        3.5 Average molecular model
    4 Discussion
    5 Conclusion
    Acknowledgements 
    References

• Seunghyun Ko(Carbon Industry Frontier Research Center, Korea Research Institute of Chemical Technology (KRICT))
• Jong‑Eun Choi(Carbon Industry Frontier Research Center, Korea Research Institute of Chemical Technology (KRICT)/Advanced Materials and Chemical Engineering, Universityof Science and Technology (UST))
• Hyejin Yim(Carbon Industry Frontier Research Center, Korea Research Institute of Chemical Technology (KRICT))
• Jin Miyawaki(Interdisciplinary Graduate School of Engineering Sciences, Kyushu University/Institute for Materials Chemistry and Engineering, Kyushu University)
• Seong‑Ho Yoon(Interdisciplinary Graduate School of Engineering Sciences, Kyushu University/Institute for Materials Chemistry and Engineering, Kyushu University)
• Young‑Pyo Jeon(Carbon Industry Frontier Research Center, Korea Research Institute of Chemical Technology (KRICT)/Advanced Materials and Chemical Engineering, Universityof Science and Technology (UST))