Separation tower type boiler flue gas desulfurization process

Abstract

The invention discloses a process technology for removing sulfur dioxide from boiler flue gas to produce an ammonium sulfate fertilizer. High-temperature flue gas is firstly cooled by a concentrating tower and then enters a desulfurizing tower (absorption tower), and the flue gas is desulfurized together with an ammonium sulfite solution in the desulfurizing tower and is exhausted. Desulfurized ammonium sulfite solution is sent to an oxidizing tower so that ammonium sulfite is thoroughly converted into ammonium sulfate, the ammonium sulfate enters the concentrating tower to perform countercurrent heat exchange with the flue heat, so that water in the ammonium sulfite solution is evaporated. After the concentration reaches supersaturation, ammonium sulfate crystals are separated out, and a suspension containing the ammonium sulfate crystals is spirally flowed, centrifuged and dried into the finished product. The invention effectively utilizes the low-grade heat energy of the flue gas, and the ammonium sulfate evaporation system is saved; oxidation is adopted outside the desulfurizing tower, so that the oxidation is more thorough; the desulfurizing tower is a packed tower, the specific surface area is increased, the liquid-air ratio is low, the circulating volume of the absorbing liquid is reduced, and the equipment saves more energy; and the absorbing liquid controls not to crystallize at low concentration, and the phenomena of bias current and packing collapse caused by packing crystallization are avoided.

Description

Technical field: [0001] The invention relates to air pollution control desulfurization and denitrification technology in the field of environmental protection, in particular to a boiler flue gas desulfurization process with low energy consumption and high efficiency. Background technique: [0002] The shortcomings of the existing similar ammonia-fertilizer desulfurization technology are as follows: [0003] At present, most of the ammonia desulfurization process adopts the crystallization ammonia technology in the tower. The crystallization ammonia technology in the tower can be divided into two types: packed tower and empty tower. This technology belongs to the second generation ammonia desulfurization technology. [0004] The second-generation ammonia desulfurization basically adopts crystallization in the tower, which can greatly reduce the desulfurization efficiency of the circulating slurry. The packed tower is thus produced. The principle of the packed tower is to use...

AI Technical Summary

Problems solved by technology

[0010] Aiming at the problems existing in the prior art, the present invention proposes a boiler flue gas desulfurization process with low energy consumption and high efficiency to solve the problems of high energy consumption, low quality of by-products, strict requirements on the dust content of flue gas and filler crystallization in the prior art And other issues

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