Biomass separation apparatus and method

DETAILED DESCRIPTION One aspect of the invention provides a separator for use with a fluidized-bed bioreactor having a reaction chamber containing a slurry of liquid, media and biomass.
A lift is provided to urge slurry to the separator from the fluidized bed.
A biomass discharge is maintained above the height of the fluidized bed.
The biomass discharge has a position that is preferably adjustable with respect to the reaction chamber.
A media discharge is connected to the lift for return of media to the fluidized bed from the separator.
Slurry is preferably taken from an uppermost portion of the fluidized bed, and media is preferably returned to a location in the fluidized bed below the uppermost portion.
A lift fluid such as gas is preferably used to urge a portion of slurry through the lift.
The separator is preferably positioned outside the reaction chamber, but is alternatively positioned within the reaction chamber.
In operation, excess biomass is separated from a slurry of liquid, media and biomass by positioning a biomass discharge at a height above that of the fluidized bed.
A portion of slurry is urged from the fluidized bed and into a lift so that excess biomass is discharged through the biomass discharge.
Media from the slurry is discharged through a media discharge, and the media is subsequently returned to the fluidized bed.
The height of the biomass discharge is preferably adjusted with respect to the reaction chamber in order to control the effectiveness of the separator.