SCR reactor for improving activity of low-temperature SCR catalyst and inhibiting byproduct N2O

Abstract

The invention provides an SCR reactor for improving the activity of a low-temperature SCR catalyst and inhibiting a byproduct N2O. The reactor comprises a smoke gas inlet, a reactor main body and a smoke gas outlet according to the smoke gas flowing direction. A catalyst bed layer used for putting the low-temperature SCR catalyst is arranged inside the reactor main body; an ammonia nitrogen mixedgas diffusion pipe group is inserted and arranged in the catalyst bed layer and comprises an ammonia nitrogen mixed gas input pipe and at least two rows of diffusion main pipes in vertical side-by-side arrangement; each row of diffusion main pipe consists of a plurality of diffusion pipes in horizontal arrangement; a plurality of diffusion branch pipes are respectively connected onto each diffusion pipe; the ammonia nitrogen mixed gas input pipe is connected between an external ammonia nitrogen mixed gas supply device and each diffusion main pipe; a plurality of diffusion holes are formed in each diffusion pipe and each diffusion branch pipe. The activity of the low-temperature catalyst can be favorably improved; the low-temperature catalytic denitration efficiency is improved; meanwhile,the effect of controlling the generation of the byproduct N2O is achieved.

Description

technical field [0001] The present invention relates to improving low temperature SCR catalyst activity and suppressing by-product N 2 O's SCR reactor belongs to the field of environmental protection flue gas purification. Background technique [0002] In the metallurgical industry, a large number of high-temperature combustion processes are often involved, resulting in a large amount of nitrogen oxides (NOx). Similarly, in chemical production, oil and gas refining, and coal-fired power generation, flue gas rich in NOx will also be produced. The flue gas discharged from the above fields needs to be denitrified to meet the requirements of environmental protection. Denitration treatment refers to reducing the generated NOx to N 2 , so as to remove NOx in flue gas, the main denitrification process in the prior art is divided into: selective catalytic reduction process (abbreviated as SCR in English) and selective non-catalytic reduction process (abbreviated as SNCR in Englis...

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Problems solved by technology

In addition, the flue gas may enter the SCR reactor after dust removal and desulfurization processes. In the SCR reactor, heating the flue gas will inevitably bring energy consumption problems

Therefore, the use of low-temperature denitrification catalysts can effectively control the cost of purification and removal. At present, the widely used low-temperature SCR catalysts are V-Mn series catalysts or catalysts with similar formulations. The introduction of Mn-based oxides can effectively improve the low-temperature SCR catalyst. activity, but laboratory studies have found that the addition of Mn-based oxides will bring N 2 The problem of selectivity decline. At present, the continuous monitoring system (English abbreviation for CEMS) of flue gas emission at the discharge end of steel plants or power plants in China is only for NO and NO. 2 The emission concentration is used as the monitoring object. In fact, Mn-based oxides will promote N 2 The generation of O, so the purified gas that seems to meet the standard actually contains a considerable amount of N 2 O, and N 2 O will not only destroy the ozone layer, but also a gas equivalent to an equivalent amount of CO 2 300 times the greenhouse gas, the damage and impact on the environment are very serious

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