In the Vuosaari bioenergy heating plant, flue gas cleaning is implemented in accordance with the BAT conclusions (Best Available Techniques) for large combustion plants applied throughout the EU. The BAT conclusions determine that the best flue gas cleaning techniques available on the market must be used in reducing emissions produced in the combustion plant. In the Vuosaari bioenergy heating plant, biomass is burned in a circulating fluidized bed, i.e. CFB boiler, which is one of the most suitable boiler technologies for burning biomass of variable quality. The generation of primary emissions is minimised with a boiler technology suitable for biomass. The combustion air feed and the furnace temperature are constantly adjusted with the aid of an automation system to ensure that burning always takes place in optimal conditions. This way, the production of carbon monoxide, hydrocarbons, PAH compounds and unburned (black) carbon can be minimised. Dust emissions created in combustion are filtered from flue gases with the aid of a bag filter. In the bag filter, flue gases are directed through extremely fine filter fabric hoses, trapping the dust and allowing the clean gas to pass through. After the bag filter, flue gases cleaned of dust are directed to the flue gas scrubber where heat is recovered from the flue gas into the district heating network through condensing. In the flue gas scrubber, the remaining impurities are dissolved in the water in addition to the heat. After the scrubber, the cleaned gas is conducted into the stack that releases almost emission-free flue gas. The emissions of the Vuosaari bioenergy heating plant are monitored with continuous measurements in the stack. The condensate and waste water produced in the flue gas scrubber are utilised in full and cleaned in the bioenergy heating plant’s own water treatment plant to such a high degree that the water can be used as extra water in the district heating network and as boiler water.