Fractionation of bio-oil is in favor of upgrading bio-oil to transport fuel or chemicals. The microalgae Dunaliella tertiolecta was hydrothermally liquefied to form a bio-oil, which was split into two layers during cooling: the lower layer contained organics with relatively high molar mass from 78 to 389 g mol⁻¹, while the super layer with relatively low molar mass from 44 to 121 g mol⁻¹. The lower layer of hydrothermally liquefaction (HTL) bio-oil was further fractionated into ethanol phase (oil 1) and dichloromethane phase (oil 2), and the super layer yielded 1 or 3-4 fractions of extracts (oil 3) via single-stage or multistage liquid-liquid extraction respectively. The compositions of each fraction were analyzed by GC-MS in detail. Dichloromethane, chloroform, cyclohexane, benzene, toluene, iso-octanol, petroleum ether, carbon tetrachloride, 1,1,1-trichloroethane, ethyl acetate were compared in terms of their extraction capabilities to organics of bio-oil. The results indicated the chloroform and dichloromethane have the highest comprehensive extraction capabilities. In multistage extraction, when dichloromethane was used as extractant, the extraction distribution ratio (calculated using COD, chemical oxygen demand) was 0.66 in first-stage, then sharply dropped with an increase in stage number, 2nd∼3rd stage extractions achieved the maximum extraction percentage (approximately 53%). That the optimum combination of chloroform, benzene and 1,1,1-trichloroethane fractionated the super layer of HTL bio-oil can obtain very low oxygen content fraction: hydrocarbons (purity of hydrocarbons: relative content 97.9%) from the 2nd stage of multistage extraction.

生物油的分馏有利于提质生物油以运输燃料或化学物质。微藻杜氏盐藻进行了水热液化，以形成生物油，其被分成两个层在冷却过程中：所述下层中所含的有机物具有相对高的摩尔质量为78〜389克摩尔^{- 1}，而具有相对低的摩尔超层质量从44至121 g mol ^{- 1}。将水热液化（HTL）生物油的下层进一步分馏为乙醇相（油1）和二氯甲烷相（油2），而上层油则通过单步分离获得1或3-4馏分的萃取物（油3）。阶段或多阶段液-液萃取。通过GC-MS详细分析每个级分的组成。比较了二氯甲烷，氯仿，环己烷，苯，甲苯，异辛醇，石油醚，四氯化碳，1,1,1-三氯乙烷，乙酸乙酯对生物油有机物的萃取能力。结果表明，氯仿和二氯甲烷具有最高的综合萃取能力。在多级萃取中，当使用二氯甲烷作为萃取剂时，萃取分布比（使用COD，化学需氧量计算）为0。第一阶段为66，然后随着阶段数的增加而急剧下降，第二至第三阶段提取达到了最大提取百分比（约53％）。分馏HTL生物油上层的氯仿，苯和1,1,1-三氯乙烷的最佳组合可以从多级反应的第二阶段获得非常低的氧含量分数：碳氢化合物（碳氢化合物的纯度：相对含量97.9％）萃取。