For eucalyptus in N2 and air, the optimum operations take
place at 325 and 275 C, respectively. Since flue gases from combustion
processes have temperatures around 350 C (Kakaras
et al., 2007), it might be possible to utilize flue gases as heat
sources to pretreat biomass. The results of pretreatment with flue
gases might lie between those using N2 and air as carried gases because
the oxygen contents in the flue gases are generally larger
than zero but less than 21%.