Further increase in the degree of torrefaction treatment, the water intake of the pellets only decreased moderately to about 12–12.5 wt% at a 40–45 wt% weight loss. Fig. 3 also shows that at the same degree of weight loss, the water uptake rate decreased only slightly with increasing the torrefaction temperature, likely associated with the slight difference in the structure and composition of the torrefied biomass. In two previous studies [22,25], the decomposition of hydroxyl groups and lignin coating on particles were speculated as the two reasons for decreased water uptake rate.