Low-temperature coke oven flue waste gas desulphurization and denitration process

Abstract

The invention relates to a low-temperature coke oven flue waste gas desulphurization and denitration process. According to the process, fluidized NaHCO3 fine powder is jetted into a flue gas conveying pipeline, so as to remove most of SO2 in the flue gas through the dry process; meanwhile, a denitration catalyst structure layer and an ammonia removal catalyst structure layer are combined for use, so that NOx in the coke oven flue gas is effectively removed; a denitration catalyst adopts a filtering-bag-shaped structure, and the ammonia removal catalyst adopts a V-shaped structure. The process utilizes a system consisting of an induced draft unit, a desulphurization unit, an ammonia preparation unit, a denitration and ammonia removal unit, a compressed air unit and a particle conveying unit to realize efficient denitration and desulphurization; compared with the prior art, the process has the benefits that residual ammonia water in a coking plant is fully utilized, a process combining a dry desulphurization method with an SCR (Selective Catalytic Reduction) denitration method is adopted, and the denitration catalyst and the ammonia removal catalyst are combined together, so that the efficient low-temperature coke oven flue gas desulphurization and denitration is realized.

Description

technical field [0001] The invention relates to the technical field of harmless treatment of coke oven flue exhaust gas, in particular to a low-temperature coke oven flue exhaust gas desulfurization and denitrification process. Background technique [0002] The flue gas of the coke oven in the coking plant has the following characteristics: [0003] 1. The flue gas temperature is relatively low, generally between 180°C and 250°C. [0004] 2. For coking plants using coke oven gas as heat source, the SO in flue gas 2 The content is generally 100~150mg / Nm 3 Between, for enterprises with relatively high organic sulfur content in raw coal, the SO in coke oven flue gas 2 Content up to 350mg / Nm 3 . [0005] 3. For new coking plants, the NO X The content is effectively controlled at <500mg / Nm 3 . For existing enterprises or special regions, it is impossible to meet NO by improving the coke oven heating process X Emission standards require that post-flue gas denitrificati...

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Problems solved by technology

[0007] The treatment process of nitrogen oxides in the electric power, cement, glass and other industries is quite mature, but the temperature of the coke oven flue gas discharged from the coking plant is relatively low, and the NO X , SO 2 The content is relatively high. If the traditional denitrification process is adopted, it must be affected by the low flue gas temperature, SO 2 Restricted by factors such as high content, it cannot meet the NO requirements of the coking industry X Emission Standard Requirements

If in order to reduce SO 2 The impact on the denitrification efficiency of low-temperature flue gas, and the traditional desulfurization process in the denitrification process will further reduce the denitrification efficiency due to the decrease in flue gas temperature

Although this problem can be solved by heating the flue gas of the coke oven, it will cause energy waste and increase investment and operation costs at the same time

[0008] At present, there is no economical and reliable desulfurization and denitrification process applied in actual production in the coking industry. Therefore, it is necessary to develop a desulfurization and denitrification process and device for coke oven flue gas, and it is also a good environmental protection topic.

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