In conclusion, the option of adding the maximum additive percentage
(2 wt.% d.b.) established by EN 14961-2 [5] improves the physical quality
of the pellets obtained, although the bulk density required could not be
reached with the conditions studied. New studies at different moisture
contents at the inlet should be undertaken in order to find the moisture
necessary to obtain the bulk density within the values provided by
the standards. Samuelsson et al. [31] observed that pellet bulk density
and energy consumption are mainly determined by moisture content.
According to Mani et al. [30,34] unit and bulk densities of pelletized
biomass depend upon material moisture, particle size, process temperature
and pressure.