The results of elemental and proximate analyses of raw and torrefied fibrous samples at 60 minutes holding time
are listed in Table 1. For comparison purpose, two coals of different ranks i.e. sub-bituminous and bituminous coals
were also displayed. In general, results gained indicated that oxygen and hydrogen contents decreased with the
increase of torrefaction temperature, whereas, elemental carbon content increased. Elemental oxygen and hydrogen
reductions were up to 28% and 34% for torrefied OPF and LL, respectively, while elemental carbon increased
approximately to 37% for both torrefied samples at the highest torrefaction temperature (300o
C). Decrease in
hydrogen and oxygen contents is generally attributable to destroyed hydroxyl group (-OH) in biomass samples
during torrefaction, which consequently produced solid hydrophobic fuel [15,32].