Bed Agglomeration during the Drying of Mallee Leaf in Fluidized Bed

Drying of mallee leaf was carried out in a laboratory fluidized-bed reactor in air at 120-250 degrees C for 15 min. Surprisingly, bed agglomeration takes place even during drying. The bed agglomeration yield (Y-AP), which is the mass of bed agglomerates expressed as the percentage of the total mass of all samples collected from the bed, increases from 5.2% at 120 degrees C to 17.3% at 250 degrees C. Similar to those that took place during biomass pyrolysis, the interaction between biomass and sand bed particles during biomass drying can also be quantified using sand loading (S-L), which is the mass of sand sticking to the biomass particles in the bed (to form bed agglomerates) normalized to the total mass of biomass fed. S-L during biomass drying also follows a similar generic equation (S-L = KR-0.5) as previously reported for biomass pyrolysis for 15 min, where K is analogous to the Arrhenius equation and R is the biomass feed to sand ratio (i.e., the ratio between the total accumulated mass of biomass fed and the total mass of sand in the fluidized bed). The activation energies for bed agglomeration during biomass drying under air and argon atmosphere are estimated to be 19.7 and 29.3 kJ/mol, respectively.