Impact of torrefaction on properties of Miscanthus × giganteus relevant to gasification

Miscanthus × giganteus (M × G) was torrefied to improve its thermal and physical properties prior to thermal conversion. Torrefaction was undertaken at a series of temperatures from 230 to 290 C for residence times varying from 10 to 30 min and the product biomass was characterized in terms of it is suitability as a feedstock for gasification. The properties of the torrefied M × G were improved following treatment. In particular the terrified biomass showed reduced moisture and hemicellulose content a lower ratio of O/C, a more porous structure with larger specific surface area as well as higher content of alkali metals. All these features have positive effect on gasification reactivity suggesting that the torrefaction process is promising pretreatment method for biomass to combine with gasification or co-firing.