Gas phase oxidization-liquid phase oxidization-absorption three-section type dry-wet-process flue gas denitration process

Abstract

The invention discloses a gas phase oxidization-liquid phase oxidization-absorption three-section type dry-wet-process flue gas denitration process. According to the process, ozone is used as a gas-phase oxidant to oxidize one part of nitric oxide in flue gas into high-valence-state nitric oxide capable of being absorbed by slurry; any one or a mixture solution of more of hydrogen peroxide, sodium hypochlorite, sodium chlorite, sodium chlorate, sodium persulfate, potassium chlorate, potassium hypermanganate and potassium dichromate is sprayed to be used as a liquid-phase oxidant to oxidize the residual high-valence-state nitric oxide in the flue gas into the high-valence-state nitric oxide; and the flue gas enters an absorption tower and a magnesium hydroxide solution is sprayed to absorb the high-valence-state nitric oxide. Compared with the prior art, the process firstly adopts two times of oxidization of a gas phase and a liquid phase and a magnesium oxide wet process is used for absorbing so that a target of efficiently removing the nitric oxide is realized; and by virtue of the technical scheme, the use amount of the ozone is reduced, the equipment cost and operation cost are reduced and the denitration efficiency is improved and can reach more than or equal to 93%.

Description

technical field

[0001] The invention relates to the technical field of flue gas purification treatment, in particular to a gas-phase oxidation-liquid-phase oxidation-absorption three-stage dry-wet flue gas denitrification process. Background technique

[0002] There are two kinds of denitrification technologies that are relatively mature in China: Selective Catalytic Reduction (SCR) and Selective Non-Catalytic Reduction (SNCR).

[0003] SCR denitrification technology means that under the action of a catalyst and at a certain temperature, the nitrogen oxides in the flue gas selectively react with the reducing agent to generate nitrogen and water to achieve the purpose of removing nitrogen oxides. In the SCR denitrification technology, the catalyst is expensive, accounting for about 40-60% of the total cost of the entire denitrification system. And there are problems such as catalyst poisoning and clogging easily. How to maintain the activity of the catalyst and prolong the ...

Examples

Embodiment 1

[0026] Example 1: Ozone oxidation NO combined with magnesium hydroxide solution to absorb denitrification

[0027] When the flue gas enters the ozone purification device, the injection solubility is 150g / m 3 Ozone in the flue gas oxidizes nitric oxide into high-valence nitrogen oxides, and the oxidized NO X Enter the absorption tower, use magnesium hydroxide solution to oxidize the NO X Absorption, the denitrification efficiency of this process can reach 84%.

Embodiment 2

[0028] Example 2: Sodium chlorite solution oxidizes NO combined with magnesium hydroxide solution to absorb and denitrify

[0029] After the flue gas passes through the induced draft fan, the flue gas is sprayed with a 3% sodium chlorite solution through the atomizing nozzle to oxidize the nitric oxide in the flue gas into high-valence nitrogen oxides, and the oxidized NO X Enter the absorption tower, use magnesium hydroxide solution to oxidize the NO X Absorption, the denitrification efficiency of this process can reach 87%.

Embodiment 3

[0030] Example 3: Combining ozone and sodium chlorite solution to oxidize NO combined with magnesium hydroxide solution to absorb and denitrify

[0031] When the flue gas enters the ozone purification device, the injection solubility is 150g / m 3 After the flue gas passes through the induced draft fan, the flue gas is sprayed with a 3% sodium chlorite solution through the atomizing nozzle, and the nitric oxide in the flue gas is converted into high-valence nitrogen oxides through compound oxidation After NO X Enter the absorption tower, use magnesium hydroxide solution to oxidize the NO X Absorption, the denitrification efficiency of this process can reach 94%.

technical field

[0001] The invention relates to the technical field of flue gas purification treatment, in particular to a gas-phase oxidation-liquid-phase oxidation-absorption three-stage dry-wet flue gas denitrification process. Background technique

[0002] There are two kinds of denitrification technologies that are relatively mature in China: Selective Catalytic Reduction (SCR) and Selective Non-Catalytic Reduction (SNCR).

[0003] SCR denitrification technology means that under the action of a catalyst and at a certain temperature, the nitrogen oxides in the flue gas selectively react with the reducing agent to generate nitrogen and water to achieve the purpose of removing nitrogen oxides. In the SCR denitrification technology, the catalyst is expensive, accounting for about 40-60% of the total cost of the entire denitrification system. And there are problems such as catalyst poisoning and clogging easily. How to maintain the activity of the catalyst and prolong the ...

Examples

Embodiment 1

[0026] Example 1: Ozone oxidation NO combined with magnesium hydroxide solution to absorb denitrification

[0027] When the flue gas enters the ozone purification device, the injection solubility is 150g / m 3 Ozone in the flue gas oxidizes nitric oxide into high-valence nitrogen oxides, and the oxidized NO X Enter the absorption tower, use magnesium hydroxide solution to oxidize the NO X Absorption, the denitrification efficiency of this process can reach 84%.

Embodiment 2

[0028] Example 2: Sodium chlorite solution oxidizes NO combined with magnesium hydroxide solution to absorb and denitrify

[0029] After the flue gas passes through the induced draft fan, the flue gas is sprayed with a 3% sodium chlorite solution through the atomizing nozzle to oxidize the nitric oxide in the flue gas into high-valence nitrogen oxides, and the oxidized NO X Enter the absorption tower, use magnesium hydroxide solution to oxidize the NO X Absorption, the denitrification efficiency of this process can reach 87%.

Embodiment 3

[0030] Example 3: Combining ozone and sodium chlorite solution to oxidize NO combined with magnesium hydroxide solution to absorb and denitrify

[0031] When the flue gas enters the ozone purification device, the injection solubility is 150g / m 3 After the flue gas passes through the induced draft fan, the flue gas is sprayed with a 3% sodium chlorite solution through the atomizing nozzle, and the nitric oxide in the flue gas is converted into high-valence nitrogen oxides through compound oxidation After NO X Enter the absorption tower, use magnesium hydroxide solution to oxidize the NO X Absorption, the denitrification efficiency of this process can reach 94%.

Images