TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Method: The biomass raw material is comminuted before conveyed to impurities removal. The mechanical impurities are removed from the biomass raw material with a vibrating screen. The removal of the mechanical impurities from the biomass raw material is removed by using gravity separation. The comminuted, impurity-free biomass raw material is dried before being conveyed to carbonization reactor. The drying and carbonization of the biomass raw material are carried out in separate reactors. The drying of the biomass raw material is carried out in a fluidized bed reactor, in which the biomass raw material to be processed forms the bed of the drying reactor. The carbonization of the biomass raw material is carried out in a fluidized bed reactor, in which bio-coke forms the bed of the carbonization reactor. The drying and/or carbonization of the biomass raw material is carried out in drum kilns or a shaft furnace. In the method, a first part of the gases formed in the carbonization of the biomass raw material and dust is burned in the carbonization reactor with an air deficit: a second part of the gases formed in carbonization of the biomass raw material is conveyed to a post-combustion boiler, in which they are burned; or tar is recovered from a second part of the gases formed in carbonization of the biomass and used as a binder in briquetting. The thermal energy generated in the post-combustion boiler is utilized in a power plant to produce electricity and district heat. The cooled post-combustion boiler exhaust gases are conveyed to the drying and carbonization of the comminuted biomass raw material. The particle-like bio-coke formed in carbonization is conveyed to indirect cooling with air, from where the hot air is conveyed to the carbonization reactor. The particle-like bio-coke formed in carbonization is conveyed to indirect cooling with water or inert gas. The cooled bio-coke is screened and the finest ash- and impurity-rich fraction is separated to optimize the ash content of the coke product. The cooled, purified bio-coke is ground, mixed with a binder and water, pressed into briquettes and dried. The biomass raw material is frozen biomass raw material and it is deiced before removal of impurities by means of the hot gases generated in drying, gases generated in the de-icing is conveyed to gas scrubbing, and the water generated in the de-icing and gas scrubbing being conveyed to a wastewater purification step before their removal from the cycle. The carbonization of the biomass raw material is carried out at 650-1000?0C. The size of a briquette is 10-40 mm. The biomass raw material used for carbonization is tree stumps, peat, logging waste, reed canary grass, or straw.