NOVELTY - Combined tangential shear omogenizing and flashing apparatus for destructuring pretreated biomass comprises housing having inlet/outlet, where housing having an axis (20A) extending through it, where inlet being connectable to source of pressurized pretreated biomass while outlet is connectible in direct fluid communication with downstream utility; and stator (20F) and rotor (20R) mounted within housing, where stator and rotor being confrontationally disposed and spaced apart by predetermined uniformly dimensioned axial gap to define mixing zone (20Z) communicating with inlet/outlet.    USE - As combined tangential shear omogenizing and flashing apparatus for destructuring pretreated biomass (claimed).    ADVANTAGE - The gap adjustment control system enables the apparatus and a system incorporating the same to adapt automatically to adjust the gap between the rotor and the stator and to compensate for such variations in pretreated biomass composition, flow properties and particulate size. This ability to vary the gap allows the apparatus also to function as a metering device.    DETAILED DESCRIPTION - A combined tangential shear omogenizing and flashing apparatus for destructuring pretreated biomass comprises a housing having an inlet and outlet, where the housing having an axis (20A) extending through it, where the inlet being connectable to a source of pressurized pretreated biomass while the outlet is connectible in direct fluid communication with a downstream utility; and a stator (20F) and a rotor (20R) mounted within the housing, the stator and rotor being confrontationally disposed and spaced apart by a predetermined uniformly dimensioned axial gap to define a mixing zone (20Z) communicating with the inlet and the outlet; the rotor being connectable to a motor operative to rotate the rotor with respect to the stator, the gap between the rotor and the stator being sized such that, in use, with a predetermined pressure difference defined between the inlet and the outlet, rotational movement of the rotor with respect to the stator imparts a tangential shear to a predetermined volume of pretreated biomass introduced into the mixing zone at a predetermined pressure and temperature while the biomass is moving through the mixing zone in the direction of the pressure difference, the tangential shear being able to homogenize the volume of pretreated biomass and the pressure difference being able to cause a partial phase separation of the homogenized biomass into vapor and liquid phases such that the pretreated biomass undergoes at least a three-fold total volumetric increase.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of system for implementing a method for destructuring biomass.    System (10)    Feed line (16)    Pretreatment device (20A)    Entrance of mixing zone (20N)    Rotor (20R)    Stator (20S)    Mixing zone (20z)    Gap adjustment control system (34)