2.2.1. Total solids and extractives quantification
Total solids (or moisture content) in biomass, were quantified
based on the NREL method [25]. The determination of extractives in
biomass was carried out according to the published NREL method
[26], using traditional soxhlet extraction apparatus. The extractives
included water soluble compounds and ethanol soluble ones.
Ash is determined gravimetrically, as the residue remaining after
combustion of the biomass material at 575 ◦C [27].