Method and device for reducing emission of NOx in waste flue gas of coke oven

Abstract

The invention provides a method for reducing emission of NOx in waste flue gas of a coke oven. The method comprises the following steps: (1) introducing oxygen and circulating flue gas of the coke oven into gas mixing equipment to be mixed to obtain a mixed combustion-supporting gas in which the content of O2 is 0-100 percent; (2) introducing gas of the coke oven and the mixed combustion-supporting gas into the combustion chamber of the coke oven to be burnt to produce waste flue gas of the coke oven; (3) after the waste flue gas of the coke oven, produced in the step (2), is cooled down by a heat exchanger, ensuring that part of the waste flue gas of the coke oven enters the gas mixing equipment via a flue gas recirculation blower to be mixed with pure oxygen to produce mixed combustion-supporting gas to participate in combustion and the other part of waste flue gas of the coke oven passes through a smoke removal blower and then enters a smoke discharge chimney to be directly discharged. The method controls production of nitrogen oxides by the waste flue gas of the coke oven from the source, adopts mixing of pure oxygen and circulating flue gas to avoid introduction of N2, and enables emission of nitrogen oxides in the waste flue gas of the coke oven to meet the national standards.

Description

technical field [0001] The invention belongs to the technical field of flue gas denitrification, and relates to a method for denitrification of coke oven flue gas, in particular to a method and a device for reducing the emission of nitrogen oxides in coke oven flue gas. Background technique [0002] Flue gas denitrification technology is mainly divided into source treatment and end treatment. There are three main types of terminal flue gas denitrification technologies: SCR (SelectiveCatalyticReduction, referred to as SCR, selective catalytic reduction method), SNCR (SelectiveNon-CatalyticReduction, referred to as SNCR, selective non-catalytic reduction method) and catalytic oxidation / reduction method, of which: SCR, SNCR Both belong to the dry method; the catalytic oxidation / reduction method belongs to the wet method. [0003] At present, the most widely used method is the SCR method. The SCR method is extremely expensive in terms of engineering costs, high operating costs...

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Problems solved by technology

[0004] Source control methods are now mainly low NO X (X=1, 2) combustion method, this method cannot be applied due to the small space of the coke oven combustion chamber

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