Low-temperature adsorption denitration method for flue gas

Abstract

The invention discloses a low-temperature adsorption denitration method for flue gas. The method comprises the following steps: the flue gas is subjected to dust removal and desulfurization, the desulfurized flue gas is pressurized, the pressurized flue gas is pre-cooled, the pre-cooled flue gas is cooled to a room temperature or below by using a flue gas cooling system, the flue gas with a temperature lower than the room temperature enters a low-temperature denitration system, physical adsorption denitration is performed in the low-temperature denitration system, the flue gas after denitration is used to pre-cool the flue gas after dust removal and desulfurization, and clean flue gas that absorbs heat enters a chimney to be discharged. The method uses the physical adsorption denitration,simultaneously directly adsorbs and removes NO2 and NO to realize direct NOx adsorption and removal, eliminates the use of a catalyst and reducing agent NH3 in a traditional SCR denitration process, eliminates secondary pollution emission of ammonia escape, and does not need a pre-process for oxidizing NO; the method has a high NOx removal rate, and can realize NOx zero emission; a large amount ofacidic condensate water is precipitated during the cooling of the flue gas, so that the water consumption in a power plant is reduced; and the method does not need to use chemicals such as a denitration catalyst, a reducing agent and an oxidant, thereby reducing the operating costs.

Description

technical field [0001] The invention belongs to the technical field of flue gas denitrification, and in particular relates to a flue gas low temperature adsorption denitrification method. Background technique [0002] The flue gas produced by coal combustion contains a large amount of nitrogen oxides NOx, which is one of the main causes of air pollution. At present, NOx in the flue gas is mainly removed by the SCR selective catalytic reduction method. In this method, NOx is added to the NH in the flue gas under the action of the catalyst. 3 Revert to harmless N 2 , and then removed. Although the SCR denitrification technology is quite mature, there are still many problems. For example, the catalyst only has high activity in a specific temperature range. When the power plant operating load is adjusted, the change of flue gas temperature will seriously affect the SCR denitrification efficiency. In addition, SCR denitrification has secondary pollution problems such as ammon...

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