(481b) Integrating Biomass Torrefaction Technology with Thermochemical Conversion Processes

Torrefaction is a process of thermal degradation of biomass (via solid state, selective decomposition of hemi-cellulose) at relatively low temperatures (180-300°C) under anoxic conditions resulting in an energy dense, stable char or coal-like material that also eliminates or minimizes coke forming precursors, such as acetic acid. Removal of these coke forming precursors could significantly improve catalytic upgrading of the bio-oil generated by pyrolysis. It is anticipated that integrating biomass torrefaction with thermo-chemical conversion processes will not only improve the energy density and quality of bio-crude oil/syngas, but also minimizes the downstream cleaning cost. Cofiring torrefied biomass with coal will also minimize GHG emissions without compromising the energy efficiency and plant production capacity. Although torrefaction pretreatment holds great promise, there is little fundamental understanding of the process especially related to biomass pyrolysis and gasification. This paper presents the recent findings on the torrefaction characteristics of biomass and the effect of torrefaction on the pyrolysis and gasification products. The benefits of biomass torrefaction on the transport and storage of biomass will also be discussed