Biomass converter and methods

Abstract

A tubular reactor useful for converting biomass to char has walls projecting into its interior. The walls are hollow. Cavities in the walls are in fluid connection with the outside of the reactor by way of openings. The reactor may be deployed in a furnace chamber. Hot gases from the furnace chamber may enter the cavities through the openings to heat the walls from within. Biomass may be pyrolized as it passes along the reactor.

What is claimed is: 
     
         1 . A reactor for treating biomass, the reactor comprising:
 a furnace chamber;   a downwardly-sloping tubular reactor vessel extending in the furnace chamber; and,   a plurality of hollow paddles projecting inwardly into a bore of the reactor vessel, the hollow paddles each comprising an internal cavity in fluid communication with the interior of the furnace chamber by way of openings in an external surface of the reactor vessel.   
     
     
         2 . A reactor according to  claim 1  comprising a drive connected to rotate the reactor vessel about a longitudinal axis of the reactor vessel. 
     
     
         3 . A reactor according to  claim 2  wherein the drive is configured to rotate the reactor vessel at a rate of less than 2 revolutions per minute. 
     
     
         4 . A reactor according to  claim 2  wherein the paddles project inwardly into the bore past the longitudinal axis. 
     
     
         5 . A reactor according to  claim 2  wherein the paddles are substantially perpendicular to the longitudinal axis. 
     
     
         6 . A reactor according to  claim 2  wherein the paddles are tilted relative to the longitudinal axis. 
     
     
         7 . A reactor according to  claim 1  wherein the paddles have arcuate inward edges. 
     
     
         8 . A reactor according to  claim 7  wherein the paddles include first and second paddles projecting from opposing sides of the bore and the first and second paddles have a lenticular-shaped overlap when viewed from a direction end on to the reactor vessel. 
     
     
         9 . A reactor according to  claim 1  wherein the paddles project alternatingly from opposing sides of the bore. 
     
     
         10 . A reactor according to  claim 1  wherein the paddles are generally planar. 
     
     
         11 . A reactor according to  claim 1  wherein the paddles are 1½ cm to 3 cm in thickness. 
     
     
         12 . A reactor according to  claim 1  wherein the paddles are arranged to define a sinuous path along the bore of the reactor vessel. 
     
     
         13 . A reactor according to  claim 1  wherein the reactor vessel is tapered and becomes larger toward an outlet at a lower end of the reactor vessel. 
     
     
         14 . A reactor according to  claim 1  wherein the paddles are curved about axes of curvature that extend transverse to the reactor vessel. 
     
     
         15 . A reactor according to  claim 1  wherein the furnace chamber comprises
 an upper compartment of a furnace having a lower compartment and the upper compartment and the furnace comprises a burner in the lower compartment. 
 
     
     
         16 . A reactor according to  claim 15  wherein the furnace comprises one or more baffles in the upper compartment and the reactor vessel extends through the one or more baffles. 
     
     
         17 . A reactor according to  claim 1  wherein the reactor vessel is inclined at an angle in the range of 5 degrees to 25 degrees to horizontal. 
     
     
         18 . A reactor according to  claim 1  comprising an airlock at an inlet end of the reactor vessel. 
     
     
         19 . A reactor according to  claim 18  wherein a lower end of the reactor vessel is sealed to a non-rotating reactor receiver. 
     
     
         20 . A reactor according to  claim 18  comprising a drier upstream from the airlock. 
     
     
         21 . A reactor according to  claim 20  wherein the drier comprises a counterflow drier in which a flow of heated gas from the furnace chamber is directed to flow against a flow of biomass. 
     
     
         22 . A reactor vessel for use in thermal processing of biomass, the reactor vessel comprising a tubular member having a bore extending longitudinally through the tubular member and a plurality of hollow paddles projecting inwardly into the bore, each of the plurality of hollow paddles comprising an internal cavity in fluid communication with the exterior of the reactor vessel by way of openings in an external surface of the tubular member. 
     
     
         23 . The reactor vessel according to  claim 22  wherein the paddles project inwardly into the bore past a longitudinal axis of the tubular member. 
     
     
         24 . A reactor vessel according to  claim 23  wherein the paddles are substantially perpendicular to the longitudinal axis. 
     
     
         25 . A reactor vessel according to  claim 23  wherein the paddles are tilted relative to the longitudinal axis. 
     
     
         26 . A reactor vessel according to  claim 23  wherein the paddles have arcuate inward edges. 
     
     
         27 . A reactor vessel according to  claim 26  wherein the paddles include first and second paddles projecting from opposing sides of the bore and the first and second paddles have a lenticular-shaped overlap when viewed from a direction end on to the reactor vessel. 
     
     
         28 . A reactor vessel according to  claim 22  wherein the paddles project alternatingly from opposing sides of the bore. 
     
     
         29 . A reactor vessel according to  claim 22  wherein the paddles are generally planar. 
     
     
         30 . A reactor vessel according to  claim 22  wherein the paddles are 1½ cm to 3 cm in thickness. 
     
     
         31 . A reactor vessel according to  claim 22  wherein the paddles are arranged to define a sinuous path along the bore of the reactor vessel. 
     
     
         32 . A reactor vessel according to  claim 22  wherein the reactor vessel is tapered and becomes larger toward an outlet at a lower end of the reactor vessel.