Coke oven flue gas comprehensive treatment system based on sodium-based dry process and low-temperature SCR denitration

Abstract

The invention provides a coke oven flue gas comprehensive treatment system based on a sodium-based dry process and low-temperature SCR denitration. The coke oven flue gas comprehensive treatment system comprises a cooling mechanism, a desulfurizer supply mechanism, a desulfurizing tower, a bag-type dust collector, an ammonia gas supply mechanism and a denitration tower, wherein the gas inlet of the cooling mechanism is connected with a flue of coke oven flue gas; the gas outlet of the cooling mechanism is connected with the gas inlet of the desulfurizing tower through a first pipeline; the desulfurizer supply mechanism is connected with and arranged on the first pipeline; the gas outlet of the desulfurizing tower is connected with the gas inlet of the bag-type dust collector; the gas outlet of the bag-type dust collector is connected with the gas inlet of the denitration tower through a second pipeline; the ammonia gas supply mechanism is connected with and arranged on the second pipeline; and a regenerative furnace used for heating flue gas is arranged between the ammonia gas supply mechanism and the denitration tower. The system provided by the invention has simple structure, isconvenient to operate, has high removal efficiency to pollutants in the coke oven flue gas, is free of corrosivity, can stably operate for a long time, and has good emission effect and wide adaptationrange.

Description

technical field [0001] The invention belongs to the technical field of flue gas treatment, and in particular relates to a coke oven flue gas comprehensive treatment system based on sodium-based dry method and low-temperature SCR denitrification. Background technique [0002] The coking industry is a heavily polluting industry. In July 2012, the Ministry of Environmental Protection issued the "Coking Chemical Industry Pollutant Discharge Standard", which clearly stipulates the pollutant discharge of the coking industry. [0003] As one of the key pollution sources of the coking industry, coke oven chimney flue gas has attracted the attention of the Ministry of Environmental Protection. There are three main types of pollutants emitted from coke oven chimneys: SO 2 , nitrogen oxides and soot. For the treatment of these three pollutants, there have been many methods: SO 2 The treatment of nitrogen oxides mainly includes dry method (sodium-based, calcium-based, etc.), semi-dry...

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Problems solved by technology

[0004] At present, in the process of coke oven flue gas treatment, semi-dry desulfurization in the coking industry is generally placed before denitrification, the resulting temperature drop will not be conducive to the selection of denitrification catalysts, and the investment cost for flue gas treatment will increase, and semi-dry The dry system itself is corrosive, which is not conducive to the long-term stable operation of the equipment; the wet desulfurization technology is not only complicated in system and more equipment, but also has high requirements for anti-corrosion and operation personnel; in dry desulfurization, The desulfurization efficiency of the calcium method is not high, the cost of the activated coke method is relatively high, and the system resistance is relatively large

[0005] The coking industry has great resistance to adopting SNCR denitrification and low-nitrogen technology. There are two main reasons: First, SNCR denitrification has restrictions on temperature and residence time, and there is no reasonable location for the coke oven process system; while low-nitrogen combustion is solved from the source problem, but the technology is not mature in China, and there are no relatively successful cases

[0006] For flue gas in the coking industry, wet dust removal is mostly used in conjunction with wet desulfurization, which requires lower flue gas temperature, higher anti-corrosion requirements, and limited application range

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