Oxidation device and process for NOx in flue gas

Abstract

The invention discloses an oxidation device for NOx in flue gas. The oxidation device comprises an oxidation tower and an ozone generator, wherein an oxidation medium inlet is formed in the oxidationtower, a fixed bed of the oxidation tower is provided with a physical adsorption layer, and the oxidation medium inlet is higher than the top end of the physical adsorption layer; an oxidation mediumoutlet of the ozone generator is communicated with the oxidation medium inlet of the oxidation tower, a flue gas inlet of the oxidation tower is communicated with a flue gas output pipeline, and a flue gas outlet of the oxidation tower is communicated with a chimney through a flue. The invention also discloses an oxidation process, in combination with advantages and disadvantages of physical adsorption enrichment oxidation and ozonation, physical adsorption enrichment oxidation is adopted in an area with higher Nox in flue gas at the inlet of the oxidation tower, and part of NO is oxidized into NO2 under the condition that an additional oxidizing agent and energy are not consumed; when the NO concentration is reduced to a certain degree, ozone is further adopted for deep oxidation, so thatNO which is difficult to remove by wet absorption in NOx is oxidized to NO2 easy to absorb. The oxidation device can realize high oxidation rate of NO under the condition that little ozone is consumed.

Description

technical field [0001] The invention belongs to the technical field of flue gas pollutant removal, and in particular relates to a flue gas nitrogen oxide oxidation device and process. 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 ammonia e...

AI Technical Summary

Problems solved by technology

In addition, about 10kg of liquid oxygen is needed to produce 1kg of ozone, so a 600MW unit needs to consume 16t / h of liquid oxygen

The consumption of electricity and liquid oxygen makes the operation cost of ozone oxidation higher, and it is not yet possible to promote and apply it on a large scale.

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