NOVELTY - Torrefaction of associated biomass involves providing enclosed chamber (11) having walls capable of sustaining both a negative pressure and a positive pressure within the enclosed chamber; depositing a first quantity of biomass material in the chamber that is totally immersed in the liquid heat transfer fluid (30); and allowing the pressure within the chamber to rise to a pressure above the vapor pressure of the heat transfer fluid as a result of the expansion of liquids and gases entrained within the biomass.    USE - For torrefaction of associated biomass (claimed) or to convert the biomass, into a clean burning useful fuel.    ADVANTAGE - The method provides a practical and effective processing system that can produce large quantities of torrefied biomass pellets for use as a biofuel and reclaim more condensable gases into liquids for commercial use; minimizes environmental issues involved in torrefaction using gas-phase systems and the emissions system controls required by such approaches; more easily facilitates the exclusion of oxygen inherent in a gas-phase torrefaction process; enables the use of the heat transfer fluids having higher vapor pressures; minimizes handling of biomass pellets during the torrefaction process in order to minimize damage to the torrefied biomass pellets; minimizes production costs and minimizes the environmental impact of production as well as to produce a product that will benefit the environment and provide a method of preparing biomass into a uniform substantially homogeneous feed stock prior to gasification.    DETAILED DESCRIPTION - Torrefaction of associated biomass involves providing an enclosed chamber (11) having a body and a door having an open position allowing passage into and out of the enclosed chamber and a closed position in which the door is disposed in sealing engagement with the body; providing the enclosed chamber with walls capable of sustaining both a negative pressure and a positive pressure within the enclosed chamber; moving the door to an open position; depositing a liquid heat transfer fluid (30) within the enclosed chamber at a temperature sufficient to expel water and volatile gases from the biomass; depositing a first quantity of biomass material in the enclosed chamber that is totally immersed in the liquid heat transfer fluid whereby heat transfer occurs between the liquid heat transfer fluid and the biomass immersed in it; moving the door to a closed position in sealing engagement with the body; and allowing the pressure within the enclosed chamber to rise to a pressure above the vapor pressure of the heat transfer fluid as a result of the expansion of liquids and gases entrained within the biomass. An INDEPENDENT CLAIM is included for apparatus for torrefication of associated biomass which comprising: a enclosed chambers, each chamber having walls capable of sustaining both a negative pressure and a positive pressure in it; each chamber having a body and a door having an open position and a closed position, where the door in the close position is in sealed relationship to the body; reservoirs for heat transfer fluid at temperatures corresponding to predefined pre-heat, heat treatment and cooling temperatures; respective sets of pumps and associated fluid conduits for sequentially directing heat transfer fluid from each of the reservoirs into at least some of the enclosed chambers.    DESCRIPTION OF DRAWING(S) - The figure shows a side elevation view of apparatus for torrefication of associated biomass.    Enclosed chamber (11)    Cages or carts (12)    Wood pellets (13)    Condenser (16)    Liquid heat transfer fluid (30)