Practical application cases of flue gas purification technology for waste incinerators
A large waste incineration plant in Shanghai, China
Combined deacidification and dust removal system: it adopts a technology that combines semi-dry rotary spray drying deacidification with a baghouse dust collector. In the rotary spray drying tower, a lime slurry is sprayed into the flue gas and reacts with the acidic gases; after deacidification, the flue gas enters the baghouse dust collector. This system achieves a deacidification efficiency of about 85% and a dust removal efficiency of over 99.9%.
Combined SNCR-SCR denitration technology: first, selective non-catalytic reduction (SNCR) is applied at an appropriate position in the incinerator, using a urea solution as the reducing agent to preliminarily lower nitrogen oxides. Then a selective catalytic reduction (SCR) unit is installed in the downstream flue to further remove nitrogen oxides. The combined denitration technology can achieve a nitrogen oxide removal rate of over 80%.
In-depth dioxin purification: an activated carbon injection unit is installed before the baghouse dust collector, and both the injection amount and injection position of the activated carbon are optimized. At the same time, a dioxin catalytic decomposition unit is installed in the downstream flue, using a catalyst to decompose dioxins into harmless substances. Through these measures, the dioxin emission concentration can be controlled below 0.1 ng TEQ/m³.
Case background: with the rapid development of the city of Shanghai, the pressure of waste treatment has increased, and this waste incineration plant needed to treat waste efficiently while ensuring that the flue gas met emission standards, in order to comply with national and local environmental regulations.
Applied technologies:
Effect evaluation: through the application of these flue gas purification technologies, the flue gas emissions of this waste incineration plant comply with China’s stringent environmental standards. For example, the particulate matter emission concentration is below 20 mg/m³, the sulfur dioxide emission concentration is below 100 mg/m³, and the nitrogen oxide emission concentration is below 300 mg/m³, playing an important role in Shanghai’s urban environmental governance and air quality protection.
