NOVELTY - The apparatus comprises a serpentine elongated housing, first and second vents present in the first and second elevated axial sections, where moisture and volatile organic compounds escape, a wire mesh enclosure for containing biomass (62) in a pellet form, a conveyor for serially moving wire mesh enclosures through an axial extent of the serpentine elongated housing, a heat recovery system for recovering heat added to an associated biomass heat-treated in the apparatus, and a device for raising the temperature of an associated heat transfer fluid within the second portion.    USE - The apparatus is useful for torrefaction of biomass such as switchgrass and other wood sources to produce a combustible fuel.    ADVANTAGE - The apparatus allows simple, safe, uniform, economical and efficient torrefaction of biomass with reduced volatile organic compounds, less smoke and good resistant to moisture and decay in an environmentally friendly manner thus producing the fuel with high quality.    DETAILED DESCRIPTION - The apparatus comprises a serpentine elongated housing, first and second vents present in the first and second elevated axial sections, where moisture and volatile organic compounds escape, a wire mesh enclosure for containing biomass (62) in a pellet form, a conveyor for serially moving wire mesh enclosures through an axial extent of the serpentine elongated housing, a heat recovery system for recovering heat added to an associated biomass heat-treated in the apparatus, and a device for raising the temperature of an associated heat transfer fluid within the second portion to a temperature of 380-550 degrees F. The housing has a first U-shaped axial portion having first and second axial extremities and an intermediate section, a second U-shaped axial portion having first and second axial extremities and an intermediate section, and a third U-shaped axial portion having first and second axial extremities and an intermediate section. The first and second axial extremities are disposed in normal use at a higher elevation than the first and second axial extremities. The intermediate section is configured for holding a liquid, where axial movement of wood of associated wood from the first axial extremity to the second axial extremity immerses the wood in a liquid in the intermediate section. The first and second axial extremities are disposed in normal use at a higher elevation than the first and second axial extremities. The second U-shaped axial portion is coupled to the first U-shaped axial portion by a first elevated axial section of the housing. The first, second and third U-shaped axial portions are disposed in fluid communication. The third U-shaped axial portion is coupled to the second U-shaped axial portion by a second elevated axial section of the housing. The first axial portion is a pre-heat portion. The second axial portion is a heat treatment section. The third axial section is a cooling section. The enclosure is dimensioned and configured for passage through the serpentine elongated housing. Each of the enclosures is dimensioned and configured or axial movement in the serpentine elongated housing. The conveyor includes elongated members such as a chain joining respective wire mesh enclosures, where a succession of alternating elongation members and wire mesh enclosures are joined together.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of an apparatus for biomass torrefaction.    Capsule (40)    Biomass (62)    Pellet mill (63)    Train (65)    Electric power plants. (67)