| abstract |
The invention discloses a system and method for simultaneous desulfurization and denitrification of coal-fired flue gas, which realizes efficient desulfurization and denitrification under low temperature conditions. The system includes a nitrogen oxide oxidation system, a desulfurization tower, an absorption liquid supply system and a by-product separation and recovery system; the nitrogen oxide oxidation system is set at the flue gas inlet of the desulfurization tower; it is used to transfer the flue gas entering the desulfurization tower The NO in the flue gas is partially oxidized to NO 2 ; the desulfurization tower is used to jointly remove NO 2 , NO and SO 2 in the flue gas through the absorption liquid; the absorption liquid supply system is connected to the desulfurization tower for providing The mixed solution of water-soluble sulfinyl substances and lye is used as the absorption liquid; the by-product separation and recovery system includes a slurry discharge pump, a sulfate solid-liquid separator, and a nitrate evaporation system that are sequentially connected to the bottom of the slurry tank of the desulfurization tower. A crystallizer and a nitrate solid-liquid separator, and the nitrate solid-liquid separator communicates with the slurry tank of the desulfurization tower through an additive delivery pump. |