Characterization of Red Pine Pyrolysis Bio-oil by Gas Chromatography鈥揗ass Spectrometry and Negative-Ion Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

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• 作者：Yang Liu ; Quan Shi ; Yahe Zhang ; Yuling He ; Keng H. Chung ; Suoqi Zhao ; Chunming Xu
• 刊名：Energy & Fuels
• 出版年：2012
• 出版时间：July 19, 2012
• 年：2012
• 卷：26
• 期：7
• 页码：4532-4539
• 全文大小：507K
• 年卷期：v.26,no.7(July 19, 2012)
• ISSN：1520-5029

文摘

A red pine fast pyrolysis bio-oil was subjected to sequential solvent fractionation into n-hexane soluble (HS), ether soluble (ES), ether insoluble (EIS), dichloromethane soluble (DS), and methanol soluble (MeS) fractions. The volatile components of bio-oil were analyzed by gas chromatography鈥搈ass spectrometry (GC鈥揗S), indicating the presence of acids, aldehydes, ketones, alcohols, phenols, and anhydromonosaccharides, which consisted of methoxy, hydroxy, and carbonyl functional groups. These results imply that the bio-oil was similar to the most reported fast pyrolysis bio-oil samples in molecular composition. The bio-oil and its five subfractions were analyzed by negative-ion electrospray ionization (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). The predominant compounds in bio-oil were O₂鈥揙₁₇ class species with 1鈥?2 double-bond equivalent (DBE) values and 4鈥?9 carbon numbers. The most abundant class species in biocrude oil, HS, ES, EIS, DS, and MeS subfractions were O₇, O₆, O₈, O₁₀, O₇, and O₈ class species, respectively. The predominant EIS subfraction presented an obvious relative low DBE value, sustaining the tentative identification as 鈥渟ugar fraction鈥? The predominant compounds in DS subfraction were likely lignin dimers, whereas those in MeS subfraction should be lignin dimers and trimers. The number of oxygen atoms of the bio-oil compounds was negatively correlated with the average DBE value, indicating that oxygen atoms were present in various functional groups of the bio-oil compounds. The N₁O_x class species were also identified, which contained 1鈥?6 DBE and 6鈥?0 carbon numbers.