NOVELTY - An integrated process for firing of solid biomass and/or solid waste involves feeding solid biomass/waste material (1) to torrefaction reactor, heating solid biomass/waste material in torrefaction reactor at conditions effective for torrefaction of biomass; passing gaseous reaction products generated in torrefaction reactor to combustion process in boiler, where a portion of gaseous reaction products generated in torrefaction reactor are passed to gas-to-gas heat exchanger for heating of gases, and heated gases are being passed back into torrefaction reactor.    USE - As an integrated process for firing of solid biomass and/or solid waste in existing solid fuel combustion power plants for firing, or cofiring, of biomass and/or waste materials (claimed), e.g. pulverized coal (pc) boiler, or grated coal fired boiler, or fluidized bed boiler, or waste incinerator, used for heat and power production.    ADVANTAGE - The utilization of the biomass fed into the process is over 40% and up to 100%. The dust fired power plant using biomass or waste provides for high efficacy and minimum emission.    DETAILED DESCRIPTION - An integrated process for firing of solid biomass and/or solid waste in existing solid fuel combustion power plants which process also includes torrefaction of the biomass and/or waste, involves feeding a solid biomass and/or waste material (1) to a torrefaction reactor, heating the solid biomass and/or waste material in the torrefaction reactor at conditions effective for torrefaction of the biomass; passing gaseous reaction products generated in the torrefaction reactor to a combustion process in the boiler; and feeding an additional, particulate fuel to the combustion process in the boiler, which particulate fuel comprises the milled, torrefied biomass, where a portion of gaseous reaction products generated in the torrefaction reactor are passed to a gas-to-gas heat exchanger for heating of the gases, and the heated gases are being passed back into the torrefaction reactor for providing the necessary heat for the torrefaction. INDEPENDENT CLAIMS are included for the following:    (1) solid fuel fired power plant for firing, or cofiring, of biomass and/or waste materials comprising a dryer for drying biomass and/or waste materials, a torrefaction reactor for torrefaction of the dried biomass and/or waste materials, a boiler for combusting the comminuted and torrefied biomass and/or waste materials, and further comprises a gas-to-gas heat exchanger, and unit for conducting torrefaction gases obtained from torrefaction back into the torrefaction reactor after heating of the gases in the heat exchanger; and    (2) dust fired power plant further comprises a milling device for comminuting the torrefied biomass and/or waste materials.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of integrated process for firing of solid biomass and/or solid waste.    Solid biomass/waste material (1)    Torrefler (2)    Heat exchanger (3)    Boiler (4)    Dryer (10)