Fingerprinting Bio-Oils from Lignocellulose and Comparison with Fossil Fuels

Positive and negative electrospray ionization–mass spectrometry, gas chromatography–mass spectrometry and Fourier transform infrared spectroscopy were used as complementary “fingerprinting” techniques for an initial evaluation of bio-oils from lignocellulose with different origins and degrees of upgrading and also for a comparison with petroleum based fuels. The tabulated spectra and chromatograms were interpreted using principal component analysis (PCA). The samples were crude fast pyrolysis oils from different wood feedstock, bio-oils made by liquefaction of lignin (lignin-to-liquid, LtL), hydrodeoxygenated (HDO) and more extensively hydrotreated (HT) fast pyrolysis oils and some petroleum based fuels. The major trend is that the crude pyrolysis oils from different laboratories and feedstock are relatively similar in composition, and different from the LtL, HDO and HT oils and the petroleum based fuels. However, pyrolysis oils made of mixtures of spruce, bark and needles are particularly influenced by t...