Ohra-Aho Taina, Ghalibaf Maryam, Alén Raimo, Lindfors Christian, Oasmaa Anja
VTT Technical Research Centre of Finland Ltd, P.O. Box 1000, FI-02044 Espoo, Finland.
Natural Resources Institute Finland (Luke), Tietotie 4, 31600 Jokioinen, Finland.
Energy Fuels. 2022 Jun 2;36(11):5797-5804. doi: 10.1021/acs.energyfuels.1c04325. Epub 2022 May 16.
Fast pyrolysis bio-oils (FPBOs) originating from forest residues contain extractive-derived substances, which may form a separate, sticky layer with char particles on the surface of these bio-oils. In this study, first, the removal of extractive-derived substances from the bio-oil top phase was studied by common solvents with different polarities. In this case, the results indicated that when aimed at the maximum yield of single-phase fuel oil and thus the maximum amount of extractives removed, the use of -heptane or -hexane seems to be of benefit for this purpose. For safety reasons, the use of -heptane was recommended. Second, an analysis practice (extraction time and the way of mixing) was optimized. In order to reduce the extraction time and enhance the extraction yield, it was important to break the oil surface in extraction. Third, based on the characterization results of the -heptane extract by gas chromatography and ultraviolet spectroscopy, the detected compounds were classified as fatty acids, resin acids, esterified fatty acids, terpenoids, and steroids, and their total content (27 wt %) was lower than that of lignin-derived compounds (70 wt %). The extraction of the FPBO top phase with -heptane followed by this analysis practice was a useful way to estimate the content and composition of lipophilic extractives.
源自森林残留物的快速热解生物油（FPBOs）含有提取物衍生的物质，这些物质可能会与这些生物油表面的炭颗粒形成一个单独的粘性层。在本研究中，首先，研究了用不同极性的常见溶剂从生物油顶层相中去除提取物衍生的物质。在这种情况下，结果表明，当以单相燃料油的最大产率以及因此去除的提取物的最大量为目标时，使用庚烷或己烷似乎有利于此目的。出于安全原因，建议使用庚烷。其次，优化了一种分析方法（提取时间和混合方式）。为了减少提取时间并提高提取产率，在提取过程中打破油面很重要。第三，基于气相色谱和紫外光谱对庚烷提取物的表征结果，检测到的化合物被分类为脂肪酸、树脂酸、酯化脂肪酸、萜类化合物和甾体，它们的总含量（27 wt%）低于木质素衍生化合物的含量（70 wt%）。用庚烷萃取FPBO顶层相并随后采用这种分析方法是估算亲脂性提取物含量和组成的一种有用方法。
