NOVELTY - Torrefaction reactor vessel comprises: inlet nozzles (32) injecting oxygen deprived gas (128) into the vessel; a rotatable shaft extending vertically down into the vessel; a stack of scrapers and trays extending into the vessel from the top plate; a torrefaction chamber in the vessel and below the stack, where the torrefaction chamber holds a pile of biomass discharged from the stack; a torrefaction gas exhaust outlet on the vessel and at an elevation below the stack and above an upper surface of the pile of biomass; and a biomass outlet at a lower region of the vessel.    USE - The torrefaction reactor vessel is useful for subjecting biomass to a torrefaction process, where the biomass is lignocellulosic biomass (all claimed), wood chips, wood pulp or other contaminated cellulosic materials.    ADVANTAGE - The torrefaction reactor vessel heats the biomass on each tray so that the biomass is uniformly heated at each elevation in the vessel.    DETAILED DESCRIPTION - Torrefaction reactor vessel comprises: inlet nozzles (32) injecting oxygen deprived gas (128) into the vessel, where the gas temperature of the oxygen deprived gas injected through the nozzles at upper elevations in the vessel is lower than the gas temperature of the oxygen deprived gas injected through the inlet nozzles at lower elevations; a rotatable shaft extending vertically down into the vessel; a stack of scrapers and trays extending into the vessel from the top plate, where each scraper is fixed to and rotates with the shaft and is immediately above an associated stationary tray, each tray is perforated to allow passage of gas and block passage of biomass and has an opening through which biomass falls, the stack includes a gas extraction chamber at an elevation below one of the trays and above one of the scrapers, the gas extraction chamber receives the gas passing through one of the trays and includes a gas extraction port to exhaust gas passing through the tray, the stack includes many lower scrapers and trays which are below the gas extraction chamber and have no gas extraction chamber between the lower scrapers and trays; a torrefaction chamber in the vessel and below the stack, where the torrefaction chamber holds a pile of biomass discharged from the stack; a torrefaction gas exhaust outlet on the vessel and at an elevation below the stack and above an upper surface of the pile of biomass; and a biomass outlet at a lower region of the vessel. INDEPENDENT CLAIMS are also included for:    (1) torrefaction (M1) of biomass using the torrefaction reactor vessel having stacked trays, comprising feeding the biomass to an upper inlet of the vessel so that the biomass material is deposited on an upper tray of a vertical stack of trays in the reactor, cascading the biomass down through the trays by passing the biomass through an opening in each of the trays to deposit the biomass on a lower tray as the biomass moves around each of the stacked trays, heating the biomass material with an oxygen deprived gas injected into the vessel, as the biomass is dried in upper trays of the stacked trays, extracting moisture containing gas having passed through the biomass on the upper trays where the extraction is immediately below each of the upper trays, and as the biomass undergoes torrefaction in the lower trays of the stacked trays, retaining the gas with the biomass until the biomass falls from the stacked trays to a pile of biomass in the reactor vessel, exhausting gases containing organic compounds volatilized by the torrefaction of the biomass through a gas outlet on the vessel at an elevation between the stacked trays and the pile of biomass, and discharging torrefied biomass from a lower outlet of the torrefaction reactor vessel; and    (2) torrefaction (M2) of lignocellulosic biomass using the torrefaction reactor having stacked tray assemblies, comprising continuously feeding the biomass to the torrefaction reactor so that the biomass material is deposited on a first tray assembly of the tray assemblies stacked vertically within the reactor as the biomass cascades down through drying trays in the tray assemblies, heating the biomass material with an oxygen deprived gas injected at a temperature below a threshold torrefaction temperature, extracting from the vessel gases flowing through each of the drying trays before the gas flows to the biomass on a next lower tray as the biomass cascades down through torrefaction trays in the tray assemblies, where the torrefaction trays are below the drying trays, heating the biomass material with an oxygen deprived gas injected at a temperature above the threshold torrefaction temperature to promote a torrefaction reaction in the biomass on the torrefaction trays containing the oxygen deprived gas passing through the torrefaction trays in the vessel as the oxygen deprived gas and biomass pass through the torrefaction trays, and exhausting the oxygen deprived gas having passed through the torrefaction tray from the vessel, and discharging torrefied biomass from a lower outlet of the torrefaction reactor.    DESCRIPTION OF DRAWING(S) - The figure shows a cross-sectional view of a torrefaction reactor showing a schematically the gas flows in and out of the reactor.    Nozzles (32)    Isolation plate (52)    Gas chamber (56)    Drying gas (126)    Oxygen deprived gas (128)