A van Krevelen plot is also shown in Figure 1 to demonstrate the change in atomic ratio of H/C as a function of
atomic ratio O/C. Calculations of these ratios are referred to the works of Bridgeman et al [26]. Reduction of these
atomic ratios implies the measures of pyrolysis efficiency and oxidation degree of torrefied products [30]. Figure 1
shows that elementary composition of torrefied biomass moves towards coal with better results obtained from
torrefied LL. In this case, torrefied products subjected to torrefaction temperature above 275o
C even surpassed sub-
bituminous coal. This is in agreement with many literatures that have reported torrefied biomass characteristics came
close to that of lignite coal [6,7,12,33–35].