Patent ID: 8752779

Claim:
A process for the beneficiation of a comminuted woody biomass feedstock, comprising four steps: first, sort the feedstock by size on one or more sorting screens, and recover a first reject fraction of oversize material characterized by cross section dimensions larger than a pre-determined maximum dimension, a second reject fraction of undersize material characterized by cross section dimensions smaller than a pre-determined minimum dimension, and a first accept fraction of material characterized by cross section dimensions larger than the minimum dimension and smaller than the maximum dimension; second, wash and abrade the first accept fraction in a wet debarker having an undersize screen with openings corresponding to the minimum dimension, and recover a second accept fraction of material that does not pass through the undersize screen openings, and a first water fraction containing material that passes through the undersize screen openings; third, sort the second accept fraction by specific density in a water tank, and recover a third accept fraction of material that floats, a third reject fraction of material that sinks, and a second water fraction containing suspended material; and fourth, rinse and sort the third accept fraction on a rinsing screen having openings corresponding to the minimum dimension, and recover a third water fraction containing material that passes through the rinsing screen, and a fourth accept fraction comprising substantially clean white wood pieces characterized by cross section dimensions larger than the minimum dimension and smaller than the maximum dimension.