Low-temperature denitration catalyst and application thereof

Abstract

The invention discloses a low-temperature denitration catalyst and an application. The catalyst comprises, by weight, 75%-94% alumina carrier, 3%-20% Fe2O3 and 3%-20% MnO2; the catalyst is micro-spherical, the diameter is 2-6 millimeters, the total porosity is 60-85%, the proportion of mesopores of 5-20 nano-meters in all pores is 15-55%, and the proportion of macropores of 100-1000 nano-meters is40-75%; the distribution of the macropores is uniform and the macropores are communicated in three dimensions; the crushing strength of the lateral pressing is 5-20N/mm. The catalyst is applied to alow-temperature denitration reaction, can effectively remove the nitrogen oxide and sulfur oxide in flue gas, does not cause the problem of blocking a bed layer by ammonium bisulfate, and prolongs theoperation period of the device.

Description

technical field [0001] The invention belongs to the technical field of flue gas denitration, and in particular relates to a low-temperature denitration catalyst and its application. Background technique [0002] Nitrogen oxides, collectively referred to as NOx, are one of the main sources of air pollution. The most harmful ones are: NO, NO 2 . The main hazards of NOx are as follows: (1) toxic to the human body; (2) toxic to plants; (3) can form acid rain and acid fog; (4) form photochemical smog with hydrocarbons; (5) destroy the ozone layer . [0003] Flue gas denitrification refers to the removal of NOx in flue gas. According to the treatment process, it can be divided into wet denitrification and dry denitrification. Mainly include: acid absorption method, alkali absorption method, selective catalytic reduction method, non-selective catalytic reduction method, adsorption method, plasma activation method, etc. Some researchers at home and abroad have also developed a ...

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Problems solved by technology

[0008] 2. The NOx content in the flue gas is related to the process conditions of the main device, and the fluctuation range is relatively large. However, the catalyst amount of the SCR fixed bed reactor is fixed. Once the NOx concentration range exceeds the design value, the NOx of the purified flue gas cannot Discharge

Therefore, the operating flexibility of the fixed bed is less

[0009] 3. During the operation of the fixed-bed reactor, the activity of the catalyst gradually decreases. When the NOx at the outlet of the reactor cannot meet the standard discharge, the catalyst needs to be replaced

It can be seen that the utilization rate of the catalyst in the fixed bed SCR reactor is too low

[0010] 4. After denitrification of flue gas, wet scrubbing and dust removal should be used together with desulfurization. The desulfurization waste liquid generated in the desulfurization and dust removal process also needs to be separated from liquid to solid. The process is long, the operation is complicated, and the investment and operation costs are high.

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