Method of drying biomass

Abstract

A process for torrefaction of biomass is provided in which biomass are passed into a fluidized bed reactor and heated to a predetermined temperature in an oxidizing environment. The dried biomass is then fed to a cooler where the temperature of the product is reduced to approximately 100 degrees Fahrenheit.

What is claimed is: 
     
         1 . A process for drying a biomass, comprising:
 directing said biomass to a fluidized bed reactor;   heating said biomass in said fluidized bed reactor with a first heat source, which provides heat energy into said fluidized bed reactor, to a temperature sufficient to evaporate water and convert a portion of said biomass to vaporized organic compounds, such that a dry biomass is produced that contains less than about 10 wt % moisture; and   further heating said biomass with said first heat source and with a second heat source that is associated with a combustion of said vaporized organic compounds, heat from said first heat source and said second heat source each intermingling to directly provide heat energy to said biomass.   
     
     
         2 . The process of  claim 1 , further comprising adding air to said fluidized bed reactor to adjust an oxygen content of the first heat source and the second heat source within said fluidized bed reactor. 
     
     
         3 . The process of  claim 1 , wherein said biomass is combined with a coal, and wherein the coal and biomass are directed to said fluidized bed reactor. 
     
     
         4 . The process of  claim 1 , wherein said fluidized bed reactor has an aspect ratio is no greater than about 2. 
     
     
         5 . The process of  claim 1 , further comprising directing heated air to said fluidized bed reactor with a startup heater. 
     
     
         6 . The process of  claim 1 , wherein said temperature does not initiate a torrefaction reaction. 
     
     
         7 . The process of  claim 1 , wherein dried biomass is cooled in a mixer or a hollow flight screw cooler. 
     
     
         8 . The process of  claim 1 , wherein dried biomass is consolidated into pellets or briquettes before cooling.