Catalytic fast pyrolysis (CFP) biocrudes can comprise up to 30 wt % of oxygen content in compounds such as polyphenols, acids, carbonyls, and anhydrosugars and thus require upgrading by, e.g., hydrotreatment, to produce transport fuels. The chemical characterization of phenolic and acidic compounds in biocrudes is of great importance to optimize the CFP process. In this study, an analytical workflow is proposed for nontarget chemical fingerprinting analysis of CFP biocrudes using supercritical fluid chromatography high-resolution mass spectrometry (SFC-HRMS) with negative electrospray ionization (ESI–), followed by multivariate data analysis. The method was developed and tested on five biocrude samples from loblolly pine (Pinus taeda) with varying oxygen content (14.9–28.8 wt % wet basis) due to different CFP conditions. The pixel-based analysis displayed chemical variation between all samples. Twenty-four regions of interest were tentatively identified, including mono- and polyphenols, fatty acids, and methylated and methoxylated phenols. The identification workflow and MS/MS analysis were prioritized on the peaks with the highest relative concentration. The developed SFC-ESI–-HRMS method shows high repeatability and analyzed oxygen-containing compounds with hydroxyl and/or carboxyl moieties in combination with other moieties of up to 400 Da.
Nontarget analysis of oxygenates in catalytic fast pyrolysis biocrudes by supercritical fluid chromatography high-resolution mass spectrometry
Lubeck, J. S., Tomasi, G., Poulsen, K. G., Mante, O. D., Dayton, D. C., Verdier, S., & Christensen, J. H. (2019). Nontarget analysis of oxygenates in catalytic fast pyrolysis biocrudes by supercritical fluid chromatography high-resolution mass spectrometry. Energy & Fuels, 33(1), 296-306. https://doi.org/10.1021/acs.energyfuels.8b02983