Method of drying biomass

A process for producing torrefied biomass, comprising:

• directing a feed stream of biomass to a fluidized bed reactor, wherein the fluidized bed reactor has an aspect ratio no greater than about 2;
• directing a gas to the fluidized bed reactor, wherein the gas comprises a reactive oxygen;
• heating the biomass in the fluidized bed reactor with a first heat source, which provides heat energy into the fluidized bed reactor, to a first temperature sufficient to evaporate water in the biomass and to convert a portion of the biomass to vaporized organic compounds, wherein a dry biomass is produced that contains less than about 10 wt. percent moisture;
• and
• heating the dry biomass with the first heat source and a second heat source associated with combustion of the vaporized organic compounds, wherein heat from the first heat source and the second heat source intermingle to provide heat energy to produce a torrefied biomass from the dry biomass.