A circulating fluidized bed flue gas desulfurization, denitrification and mercury integrated device and method

Abstract

The invention discloses a flue gas desulfurization, denitration and demercuration integrated device with a circulating fluidized bed and a method. A circulating fluidized bed reaction tower in the device is sequentially provided with a smoke chamber, a venturi tube, a first-order reaction zone, a shrinking opening, a second-order reaction zone and a reaction tower outlet from bottom to top, and atomizing spray guns are respectively arranged in the first-order reaction zone and the second-order reaction zone; 4-6 bypass pipelines are uniformly arranged outside the circulating fluidized bed reaction tower, and an inlet and an outlet of each bypass pipeline are respectively connected with the smoke chamber and the bottom of the second-order reaction zone; oxidizing agent adding openings are formed in an absorbent activator and a returning material activator, and activated absorbents and returning material ash directly enter the bottom of the first-order reaction zone. Through site digestion of calcium-based absorbents, structural improvement of the circulating fluidized bed reaction tower and optimization of operating parameters, on the basis of ensuring the desulfurization efficiency, the device strengthens the catalytic oxidation ability of the absorbents in the first-order reaction zone to NOx and gaseous elemental mercury (Hg0). The device realizes integration of desulfurization, denitration and demercuration through the reasonable combination of the first-order reaction zone and the second-order reaction zone.

Description

technical field [0001] The invention relates to an integrated device and method for flue gas desulfurization, denitrification and mercury removal in a circulating fluidized bed, and belongs to the technical field of environmental protection equipment and flue gas purification. Background technique [0002] With the rapid growth of coal utilization, SO emissions from coal-fired boiler flue gas x , NO x And pollutants such as heavy metal Hg remain high, seriously affecting the ecological environment and human health. Wet flue gas desulfurization (Wet-FGD), selective catalytic reduction (SCR) denitrification and activated carbon injection (ACI) demercury are relatively mature pollutant control technologies currently used, which can obtain high pollutant removal efficiency. However, wet flue gas desulfurization has defects such as high investment, operation and maintenance costs, serious blockage, corrosion and wear, and difficult treatment of desulfurization wastewater. Due ...

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Problems solved by technology

Patent CN1498673A discloses a circulating fluidized bed flue gas desulfurization and dust removal integrated method and its device, by spraying atomized desulfurizer slurry and water into the circulating fluidized bed desulfurization tower, and combining with bag filter to realize desulfurization The dust removal is integrated, but this method has the disadvantages of difficulty in controlling the optimal reaction temperature of flue gas, easy blockage and corrosion of equipment, and can not realize SO 2 , NO x Combined removal with Hg

Patent CN1962034A discloses a method and device for simultaneous desulfurization, denitrification and demercuration of boiler flue gas. Specifically, by spraying oxygen-enriched and highly active adsorbents into the circulating fluidized bed reaction tower, SO 2 , NO x Simultaneous removal of mercury and mercury, but this method does not optimize the flue gas desulfurization tower accordingly, and also has defects such as difficult control of absorbent reaction conditions and poor load regulation performance

Patent CN102188883A discloses an integrated purification device for flue gas desulfurization, denitrification and heavy metal removal, which realizes the removal of SO in the flue gas by spraying the absorption liquid in the absorption tower. 2 , NO x It can be removed simultaneously with heavy metals. This spraying method belongs to the wet process, which has the disadvantages of complex system, easy corrosion of the device, and heavy maintenance workload.

CN203447967U discloses a kind of industrial boiler flue gas joint desulfurization denitrification demercuration device, this method uses ozone (O 3 ) and calcium-based absorbents as consumables, although SO 2 , NO x Combined removal of various pollutants such as mercury and mercury, but there are defects such as high energy consumption and low ozone utilization rate

Patent CN102019135A discloses a flue gas combined desulfurization and denitrification method and its device. This process uses the denitrification reactor and the activated coke filled in the desulfurization reactor to remove NO in the flue gas respectively. x and SO 2 , but this method not only needs to use expensive activated carbon, but also has defects such as complex system, large floor area, high initial investment and operation cost

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