Figure 5 shows the chromatograms of water-soluble fraction and pyrolytic
lignin, which was essentially the “upgraded bio-oil,” which were extracted by Method B
with a water:bio-oil ratio of 10:1, stirring duration of 2 hours, and at room temperature.
More than 50 peaks were found but only 35 peaks were identified, as list in Table 3. The
peaks can be classified as alcohol, ketone, phenol, carboxylic acid, sugar, phenolic