Effect of final pyrolysis temperature on the composition and structure of shale oil: Synergistic use of multiple analysis and testing methods

• Published in: Energy (Oxford) Vol. 252; p. 124062
• Main Authors: Cui, Da, Yin, Helin, Liu, Yupeng, Li, Ji, Pan, Shuo, Wang, Qing
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.08.2022; Elsevier BV
• Subjects: Alkanes; aromatization; carbon; Chain branching; Chemical composition; Chromatography; Comprehensive analysis; Cycloalkanes; energy; Fourier analysis; Fourier transform infrared spectroscopy; Fourier transforms; Fuel oils; Functional groups; Gas chromatography; gas chromatography-mass spectrometry; Infrared spectroscopy; Liquid fuels; liquids; Mass spectrometry; Mass spectroscopy; Molecular chains; Molecular structure; NMR; Nuclear magnetic resonance; nuclear magnetic resonance spectroscopy; Oil shale; Pyrolysates characteristics; Pyrolysis; Regulation mechanism; Scientific imaging; Shale oil; Temperature; Comprehensive analysis; Shale oil; Pyrolysates characteristics; Regulation mechanism
• ISSN: 0360-5442; 1873-6785
• DOI: 10.1016/j.energy.2022.124062

As the focus of research on the pyrolysis mechanism of oil shale shifting towards the molecular level, identifying the effect of pyrolysis temperature on the molecular composition and structure becomes all the more important. In this study, the molecular characteristics of shale oils produced at different final pyrolysis temperatures was compared and analyzed through synergistic use of multiple analysis and testing methods. The results showed that compared with the traditional gas chromatography-mass spectrometry (GC-MS), comprehensive two-dimensional gas chromatography-time of flight mass spectrometry (GC × GC-TOF/MS) has obvious advantages in the characterization of heteroatoms and cycloalkanes. Fourier transform infrared spectrometry (FT-IR) can supplement the deficiency of nuclear magnetic resonance (NMR) in the characterization of oxygen-containing functional groups. With the increase in final temperature, the aromatization reaction of cycloalkanes intensified. Conversely, the degree of alkane branching and carbon chain length decreased. Based upon mutual verification and supplement of various analysis results, a novel method was proposed for the comprehensive molecular characterization of complex liquid fuel oil. According to the advantages and characteristics of different detection methods, synergistic use of multiple methods for different fractions is an important research direction for the molecular characterization of complex liquid fuel oil in the future. •Shale oil were classified into two fractions and characterized using multiple methods.•Pyrolysis temperature had an effect on the aromatization degree and alkane branching degree.•FT-IR and NMR spectra can supplement and verify each other.•The overlapping of chromatographic peaks could be alleviated using GC × GC-TOF/MS.