The use of lime for treating flue gases is a proven technology. Flue gas is generated from the thermal treatment process in Energy from Waste plants (EfW) and contains acidic gases such as hydrogen chloride, sulphur dioxide and hydrogen fluoride. The use of lime in the three main flue gas treatment processes of dry, semi-dry and wet processes shows its flexibility and adaptability in its worldwide application.
Calcium carbonate (chalk), calcium oxide (quicklime) or calcium hydroxide (hydrated lime) can be used to neutralise acidic gases and remove sulphur dioxide from both EfW plants and power stations. This ensures that plants comply with both local and European environmental legislation for air emissions. Together with the new flue gas treatment equipment technologies, lime is the most cost effective alkali that can be used for this kind of treatment, with less dosage and less waste production compared with other reagents.