Method and system for the torrefaction of lignocellulosic material

A method for torrefaction of biomass using a torrefaction reactor vessel having stacked trays including:

• feeding the biomass to an upper inlet of the vessel such 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 wherein the extraction is immediately below each of the upper trays;
• 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 volatized 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.

A method for torrefaction of lignocellulosic biomass using a torrefaction reactor having stacked tray assemblies comprising:

• continuously feeding the biomass to the torrefaction reactor such that the biomass material is deposited on a first tray assembly of a plurality of 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, wherein the oxygen deprived gas.
• 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, wherein 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 a plurality of 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.