NOVELTY - Method (M1) for converting a biomass into a coal-like biofuel within an apparatus comprising a heat transfer fluid in a closed-loop heat transfer circuit, involves: (A) torrefying the biomass utilizing heat by extracting heat from the heat transfer fluid, where the torrefying produces a torrefaction gas and the biofuel; (B) exothermically reacting the torrefaction gas; and (C) heating the heat transfer fluid with the reacted torrefaction gas.    USE - For converting biomass into coal-like biofuel within apparatus comprising heat transfer fluid in closed-loop heat transfer circuit; and for converting biomass into coal-like biofuel, while providing heat from steam to heat engine (preferably Rankine cycle engine) (claimed).    ADVANTAGE - The method and apparatus convert carbonaceous materials, particularly biomass and biomass resources which are remotely located, into a high performance solid fuel. The method utilizes energy content in gasses driven off during torrefaction to operate the biomass-to-biofuel process, resulting in self contained fuel production facility, requiring only biomass for steady state operation. The torrefaction produces low energy value gas products i.e. acetic acid and methanol, which contain energy which has been lost to the solids; and the method further involves recovering the thermal energy in gas and/or converting gas to electrical energy in heat engine. The method provides continuous process which can be completely powered by energy contained in biomass, where heat, mechanical power and electrical power are provided from energy in biomass. In the method heat exchanger(s) heat and/or cool biomass using phase change of heat transfer medium. The phase change occurs on a surface of heat exchanger that is in thermal contact with biomass. The method overcomes disadvantages of prior art by remotely converting biomass to a biofuel; such as the apparatus can be placed near source of biomass, and processes biomass into a biofuel, which is then transported to market; and has several advantages, such as biomass can be converted to biofuel that is more generally usable than raw biomass; biofuels have a higher energy density than biomass, thus reduce transportation cost per energy stored within the fuel; and previously uneconomic biomass resources, particularly remote resources, can be economically brought to market. Thus method converts carbonaceous materials, such as biomass which may be remotely located, into a high performance solid fuel for use in industrial combustion processes. The biofuel produced by the method can have energy density superior to lower grade fossil coals; and physical properties, such as density, grindability, or water tolerance, that are compatible with industry needs. In this way, the apparatus is free to operate in remote locations, where no power or auxiliary fuel sources are available. With the method, it is possible to operate only from biomass and generate a biofuel having (70-90%) of the original energy of the biomass, on a dry basis. Thus method permits widespread use of biomass as a solid fuel.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) method (M1a) for converting a biomass into a coal-like biofuel, involving: drying the biomass to form steam; and providing heat from the steam to a heat engine;    (2) an apparatus (A1) for converting a biomass into a coal-like biofuel, comprising: a closed-loop heat transfer circuit having a heat transfer fluid; a heat exchanger having an input for accepting biomass, a first output for providing torrefied biomass, a second output for providing torrefaction gases, and a surface in contact with condensing heat transfer fluid of the heat transfer circuit for condensing the heat transfer fluid; and a chemical reactor for extracting chemical energy from the torrefaction gases and boiling the heat transfer fluid; and    (3) an apparatus (A2) for converting a biomass into a coal-like biofuel, comprising: a heat exchanger having an input for accepting biomass, a first output for providing at least partially dried biomass, and a second output for providing steam obtained from the biomass; and a heat engine to generate electricity from heat extracted from the steam.