Patent ID: 8388813

Claim:
A reactor for treating biomass, comprising: an elongated, tubular, generally circular in cross-section, axially rotatable shell having a length and a biomass input adjacent one end thereof and an end remote from said input; a hollow, frustoconical wall section having an outer surface and an inner surface, a larger diameter end and a smaller diameter end, and a length less than the length of said shell, the larger diameter end of said frustoconical wall section operably coupled with said shell end remote from said input such that the shell and frustoconical wall section rotate together; fighting structure secured to said inner surface of said frustoconical wall section and extending inwardly from said inner surface, said fighting structure oriented spirally along the length of said inner surface; and a housing in surrounding relationship to at least a portion of the length of said shell and defining with the shell an indirect heating zone, said shell having a hot gas inlet operable to receive hot gas for indirectly thermally treating biomass within said shell, and a gas outlet, said smaller diameter end of said frustoconical wall section defining a treated biomass outlet.