Novel fluidized bed dryer for biomass drying

• A novel fluidized bed dryer was proposed for biomass drying.
• The compact dryer uses no inert particles or mechanical assistance.
• Biomass moisture content has a significant effect on fluidization behavior.
• A high drying rate was achieved owing to the fast mass and heat transfer rates.

Biomass drying is performed mainly in rotary dryers, which occupy a large footprint. To explore the efficient drying of biomass, a fluidized bed dryer was proposed. Good circulation of biomass particles could be established in the fluidized bed without the use of inert particle or mechanical aids. The initial moisture content of the input sawdust affected its fluidization performance. For the drying of sawdust of high-moisture content, the fluidization behavior could be divided into three stages: partial fluidization, full fluidization with increasing drying rate, and full fluidization with decreasing drying rate. A high drying rate could be achieved because of the fast mass and heat transfer rate in the fluidized bed. The fluidized bed dryer has a drying performance similar to the binary mixture fluidized bed dryer but more compact, and requires no separation of dried biomass particles from the inert bed particles.