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

Authors: He, Zhongqi; GUO, MINGXIN - Delaware State University; SLEIGHTER, RACHEL - Old Dominion University; ZHANG, HAILIN - Oklahoma State University; Fortier, Chanel; HATCHER, PATRICK - Old Dominion University

Submitted to: Journal of Analytical & Applied Pyrolysis
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/21/2018
Publication Date: 12/1/2018
Citation: He, Z., Guo, M., Sleighter, R.L., Zhang, H., Chanel, F., Hatcher, P.G. 2018. Characterization of defatted cottonseed meal-derived pyrolysis bio-oil by ultrahigh resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry. Journal of Analytical & Applied Pyrolysis. 136:96-106. https://doi.org/10.1016/j.jaap.2018.10.018.
DOI: https://doi.org/10.1016/j.jaap.2018.10.018

Interpretive Summary: Defatted cottonseed meal is a N-rich biomass that deserves valorized recycling. Research was organized to investigate the feasibility of producing biochar and pyrolytic bio-oil from this biomass via slow pyrolysis. This study was to evaluate the quality of the cottonseed meal-derived bio-oil by characterizing the liquid pyrolysis product using elemental analysis, Fourier transform infrared spectroscopy (FT-IR) and high resolution Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICS-MS) techniques. The bio-oil was composed of the upper oily layer and the lower aqueous layer. The contents of C and S were detected much higher in the oily fraction than in the aqueous fraction. Furthermore, the composition and structures of the organic compounds in the oil fraction were much more complex and diverse. Differences in chemical characteristics between the cottonseed meal bio-oil and the literature-reported lignocellulosic bio-oils were also observed. The information is useful to both chemical fingerprinting of cottonseed meal/cake -based bio-oils. From a wider point of view, information derived from this work increased the compositional knowledge on bio-oils from N-rich biomaterials, which would be helpful to effectively utilize this type of bio-oils, not only as a bioenergy resource, but also as an industrial feedstock.

Technical Abstract: 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. Elemental analysis, Fourier transform infrared spectroscopy (FT-IR) and high resolution Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICS-MS) were used to characterize the aqueous and oily fractions of the cottonseed bio-oil. The contents of C and S were detected much higher in the oily fraction than in the aqueous fraction. Furthermore, the composition and structures of the organic compounds in the oil fraction were much more complex and diverse. Nine and 14 different oxygen heteroatom classes were detected in the aqueous and oily fractions, respectively. While N compounds were found in both fractions, CHONS compounds were detected only in the oily fraction. Van Krevelen diagrams of FT-ICR-MS identified the presence of lipid, peptide and lignin-like components in both fractions. However, carbohydrate components were found only in the oily fraction. In addition, 22% of the formulas covering 15% organic quantity (magnitude) of the aqueous fraction were unidentifiable. In contrast, there were only 4% of formulas with 2% of quantity unidentified in the oily fraction. Differences in chemical characteristics between the cottonseed meal bio-oil and the literature-reported lignocellulosic bio-oils were also observed. The information is useful to both chemical fingerprinting of cottonseed meal/cake-based bio-oils and guiding the effective uses of this N-rich type of products as a bioenergy resource and as an industrial feedstock.