How Does the Facility Work?
Waste trucks are weighed when arriving at the facility. Household and commercial waste is unloaded onto the tipping floor and pushed into a storage pit and thoroughly mixed. The tipping and waste storage areas are maintained under negative air pressure so that the odours associated with waste are captured in the combustion process and destroyed.
Once fed into the combustion chamber, waste is combusted in a self-sustaining process at a temperature greater than 850 degrees Celsius. As waste is burned, the heat converts water in the steel tube-lined walls into steam. The steam turns a turbine-driven generator to produce electricity and may be used for district heating. A small portion of the electricity is used to power the facility with the remainder exported to Ireland’s national grid.
Steam from the process is cooled, condensed back into water and returned to the boiler tubes, making it an efficient “closed loop” system.
After combustion, the volume of waste is reduced by 90%, leaving an inert ash and metal. Bottom ash is sent off site where metal is recovered for recycling and the ash is put to beneficial reuse. Fly ash collected in the air pollution control equipment is put into silos and removed from the site in sealed containers by a licensed contractor.
State-of-the-art air pollution control equipment ensures that emissions are in compliance with stringent standards. Acid gases are neutralized using lime in a semi-dry scrubber reactor and activated carbon is injected for heavy metal control. A baghouse controls emissions of particulate matter and employs thousands of fabric filter bags. Flue gas receives final treatment in a wet scrubber that uses water to reduce temperature and remove hydrogen chloride. It also uses a sodium hydroxide solution to remove sulfur dioxide.
Throughout this process, the control room closely monitors emissions through a real-time continuous emission monitoring system and controls a number of other automated systems inside the facility.