(39e) Heat and Mass Transfer during Torrefaction in the Packed Bed of Biomass

In order to elucidate heat and mass mass transfer during the torrefaction of woody biomass, component in the biomass, higher heating value, time course of temperature and generated gas flow rate in the packed bed of biomass powder have been measured. The kinds of biomass were Bamboo, Douglas fir and Bark. Remarkable exothermic chemical reaction was observed during bamboo torrefaction. The char after bamboo torrefaction had a higher heating value than that of other biomass due to this exothermic chemical reaction. On the other hand, the exothermic chemical reaction during Douglas fir torrefaction was milder than that during Bamboo torrefaction. From the component analysis, mass fraction of Cellulose and Lignin in the Bamboo was as almost same as that in Douglas fir. Xylan was highest in Hemicellulose of Bamboo while Mannan was major component in Hemmicellulose of Douglas fir. Therefore, it is suggested that the difference of the component could occur the change in the exothermic chemical reaction and higher heating value.