Even through the water extraction led to a higher carbon content than that in the
starting bio-oil, the different water:bio-oil ratios did not significantly affect the
elemental composition, and consequently the heating value, of the extracted pyrolytic
lignin. The water:bio-oil ratio of 10:1 had a high yield and low acidity and should thus
be considered. This ratio was also suggested by B. Scholze and D. Meier [10].