The optimization of the intermediate pyrolysis (IP) was made
with Eucalyptus sp. chips, taking into account that lignin structures
of Eucalyptus are more complex (syringil-guaiacyl lignin) than
Picea abies (guaiacyl lignin) and that hardwoods usually yield less
bio-oils than softwoods, due to the higher ash content (Fahmi
et al., 2008).