Characterization of defatted cottonseed meal-derived pyrolysis bio-oil by ultrahigh resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry

• Published in: Journal of analytical and applied pyrolysis 2018-11, Vol.136, p.96-106
• Main Authors: He, Zhongqi, Guo, Mingxin, Sleighter, Rachel L., Zhang, Hailin, Chanel, Fortier, Hatcher, Patrick G.
• Format: Article
• Language: English
• Subjects: Bio-oil; Cottonseed meal; Pyrolysis; Ultrahigh resolution mass spectrometry; van Krevelen diagram
• ISSN: 0165-2370; 1873-250X
• DOI: 10.1016/j.jaap.2018.10.018

•Defatted cottonseed meal is an agricultural biomass that deserves valorized recycling.•Slow pyrolysis was applied to produce the bio-oil from this biomass.•The bio-oil product is separated to an oily fraction and an aqueous fraction.•N species in the oily fraction are present mostly as unsaturated hydrocarbons.•N species in the aqueous fraction are present mostly as the lipid-like components. Defatted cottonseed meal is a N-rich biomass that deserves valorized recycling. In this work, slow pyrolysis was applied to produce pyrolytic bio-oil from this biomass. Both the upper oily and lower aqueous fractions were characterized by elemental analysis, Fourier transform infrared (FT-IR) spectroscopy, and ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) with both negative and positive electrospray ionization modes. The contents of C and S were much higher in the oily fraction than in the aqueous fraction. Furthermore, the composition and molecular formulas of the organic compounds in the oily fraction were much more complex and diverse. From the mass spectral analysis, 9 and 14 different oxygen heteroatom classes were detected in the aqueous and oily fractions, respectively. While CHON compounds were found in both fractions, CHONS compounds were detected only in the oily fraction. The van Krevelen diagrams from the FT-ICR-MS data showed the presence of lipid-, peptide-, and lignin-like components in both fractions. However, carbohydrate-like components were found only in the oily fraction. Furthermore, the diagrams revealed more N species in the oily fraction that mostly clustered with O/C