Apparatus for treating a cellulosic feedstock

Abstract

An apparatus for pre-treating a cellulosic feedstock are disclosed. Embodiments of the apparatus comprise a shell defining a treatment chamber having a lower inner surface. The treatment chamber has an inlet and an outlet spaced longitudinally apart from the inlet to define an axial length. A conveyance member is housed within the shell and is configured to sweep the lower inner surface. A plurality of injection ports are provided in at least one of the shell and the conveyance member.

We claim: 
     
         1 . An apparatus for treating a cellulosic fiber feedstock, comprising:
 a) a shell defining a treatment chamber having a lower inner surface, the shell having an inlet and an outlet spaced longitudinally apart from the inlet to define an axial length;   b) a conveyance member housed within the shell and configured to sweep the lower inner surface; and,   c) a plurality of injection ports provided in at least one of the shell and the conveyance member.   
     
     
         2 . The apparatus of  claim 1 , wherein the plurality of injection ports comprises about 1 to 20 injection ports. 
     
     
         3 . The apparatus of  claim 1 , wherein the plurality of injection ports are positioned along at least a first portion of the axial length of the shell, the first portion extending from the inlet towards the outlet. 
     
     
         4 . The apparatus of  claim 1 , wherein the conveyance member comprises at least a first rotary shaft and a plurality of paddles joined to the first shaft and extending radially outwardly therefrom. 
     
     
         5 . The apparatus of  claim 4 , wherein the paddles and the lower inner surface are configured to maintain a minimum space between the paddles and the lower inner surface of less than 6.5 mm. 
     
     
         6 . The apparatus of  claim 4 , wherein the paddles comprise blades, and the blades are generally planar members, having a radially inner edge attached to stem, a radially outer edge opposite the radially inner edge, and opposing first and second side edges extending between the radially inner and outer edges and the radially outer edge is curved to match an arc swept by the outer edge when the first shaft rotates. 
     
     
         7 . The apparatus of  claim 6 , wherein each blade is canted, wherein the first side edge is axially nearer the outlet and rotationally trailing relative to a second side edge. 
     
     
         8 . The apparatus of  claim 7 , wherein axially adjacent paddles extend from the shaft at different angular positions around to the shaft axis. 
     
     
         9 . The apparatus of  claim 7 , wherein the first side edge of one paddle axially overlaps the second side edge of a next adjacent paddle. 
     
     
         10 . The apparatus of  claim 4 , wherein the conveyance member comprises a second shaft, spaced transversely apart from and extending generally parallel to the first shaft and the lower inner surface is scallop shaped in transverse section. 
     
     
         11 . The apparatus of  claim 4 , wherein the conveyance member comprises a second shaft, spaced transversely apart from and extending generally parallel to the first shaft, each shaft having a plurality of paddles attached thereto, and the lower inner surface has a first portion below the first shaft and a second portion below the second shaft wherein, when viewed in transverse cross section, each the first portion defines an arc at a constant distance to the first shaft and the second portion defines an arc at a constant distance to the second shaft. 
     
     
         12 . The apparatus of  claim 11 , wherein the second shaft rotates in an opposite direction to the first shaft. 
     
     
         13 . The apparatus of  claim 4 , further comprising a first heated fluid supply in fluid communication with the injection ports. 
     
     
         14 . The apparatus of  claim 13 , wherein the first heated fluid supply comprises water heated to from about 60 to about 70° Celsius. 
     
     
         15 . The apparatus of  claim 14 , wherein the first heated fluid supply comprises a catalyst. 
     
     
         16 . The apparatus of  claim 14 , further comprising a jacket surrounding at least a portion of the shell and defining an enclosure between the jacket and the shell. 
     
     
         17 . The apparatus of  claim 16 , further comprising a second heated fluid supply associated with the enclosure. 
     
     
         18 . The apparatus of  claim 17 , wherein the second heated fluid supply comprises steam. 
     
     
         19 . The apparatus of  claim 17 , wherein the shaft comprises a conduit extending longitudinally therethrough. 
     
     
         20 . The apparatus of  claim 19 , wherein the conveyance member includes injection ports. 
     
     
         21 . The apparatus of  claim 20 , wherein at least one of the stem and the paddles comprise injection ports. 
     
     
         22 . The apparatus of  claim 1 , further comprising a moisture sensor that measures the moisture content of the cellulosic fiber feedstock and a controller operatively controlling to an amount of moisture introduced through the injection ports whereby a predetermined moisture content of the cellulosic fiber feedstock is obtained at the outlet. 
     
     
         23 . The apparatus of  claim 22 , wherein the moisture sensor is upstream of the inlet. 
     
     
         24 . The apparatus of  claim 22 , wherein the predetermined moisture content of the cellulosic fiber feedstock is from 45 to 55 wt %.