CN113385008B - Method for flue gas denitration by using iron-carbon composite material as SNCR (selective non-catalytic reduction) additive - Google Patents

Method for flue gas denitration by using iron-carbon composite material as SNCR (selective non-catalytic reduction) additive Download PDF

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CN113385008B
CN113385008B CN202110718057.5A CN202110718057A CN113385008B CN 113385008 B CN113385008 B CN 113385008B CN 202110718057 A CN202110718057 A CN 202110718057A CN 113385008 B CN113385008 B CN 113385008B
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sncr
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carbon composite
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CN113385008A (en
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王亚丽
宋易徽
崔素萍
韩晓宁
马晓宇
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Beijing University of Technology
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/46—Removing components of defined structure
    • B01D53/54—Nitrogen compounds
    • B01D53/56—Nitrogen oxides
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/346—Controlling the process
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/96—Regeneration, reactivation or recycling of reactants
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2251/00—Reactants
    • B01D2251/10—Oxidants
    • B01D2251/102—Oxygen
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2251/00—Reactants
    • B01D2251/20—Reductants
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2251/00—Reactants
    • B01D2251/20—Reductants
    • B01D2251/206—Ammonium compounds
    • B01D2251/2062—Ammonia
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2258/00—Sources of waste gases
    • B01D2258/02—Other waste gases
    • B01D2258/0283—Flue gases

Abstract

A method for applying an iron-carbon-containing composite material as an SNCR additive to an SNCR technology belongs to the technical field of flue gas pollutant control. The invention firstly prepares 70% -75% of carbon and 15% -18% of Fe 3 O 4 Fully mixing with 10-12% of FeOOH, calcining for 2h at the temperature of 200-300 ℃ by using inert gas to prepare an iron-carbon composite material, cooling, drying for 24h at the temperature of 110 ℃, granulating, screening particles with the particle size of 20-60 meshes, and sealing and storing; then at 750-1000 deg.C, the oxygen concentration is 2vol.%, NH 3 Under the condition that the molar ratio of the concentration to the NO concentration is 0.5-1, the NO is carried out by using the iron-carbon composite material as the SNCR additive x And (4) removing. CO and FeOOH generated by carbon in an anoxic environment can provide active groups OH and H required by reaction for SNCR at low temperature and promote C and NH 3 Generating new reducing agent HCNO when the temperature reaches Fe 3 O 4 Oxidation temperature of (2), fe 3 O 4 The surface active sites adsorb NO, thereby promoting the reduction of NO to generate N 2 . The iron-carbon composite material is used as an additive for SNCR denitration, the existing equipment of a factory is not required to be modified, the investment cost is low, the operation is simple, and the denitration rate can be improved while the SNCR denitration temperature window is reduced.

Description

Method for denitration of flue gas by using iron-carbon composite material as SNCR (selective non-catalytic reduction) additive
Technical Field
The invention belongs to the technical field of flue gas pollutant control, and particularly relates to a method for denitration by using an iron-carbon composite material as an SNCR (selective non-catalytic reduction) additive.
Background
The emission of nitrogen oxides into the atmosphere causes the generation of photochemical smog, which stimulates human eyes and respiratory tracts or induces various respiratory tract inflammations, thus endangering human health. A large amount of nitrogen oxides in the air are also an important reason for generating acid rain, and the acid rain can cause soil acidification, so that the soil fertility is reduced, and crop yield reduction even morbid conditions occur. In the existing denitration technology, selective non-catalytic reduction (SNCR) is a commonly used NOx reduction technology in industry because of its characteristics of short construction period, low investment, and high denitration rate under a proper flue gas temperature condition. However, in the practical application of the SNCR denitration technology, the temperature of a reducing agent injection area is difficult to control in an optimal denitration temperature window, so that the NOx emission exceeds the standard. Therefore, a great deal of research is directed to widening the SNCR denitration temperature window to improve the denitration rate.
As is known from the SNCR reaction mechanism, ammonia is easily oxidized at high temperature to reduce the denitration rate, and therefore most studies are focused on widening the temperature window for SNCR denitration. The key of the SNCR reaction is that active groups OH and H do not reduce NO at low temperature because the active groups are not enough x . FeOOH can provide active groups OH and H at low temperature, and promote SNCR denitration at low temperature. Carbon, in addition to its own high ability to reduce NOx, also produces CO in an oxygen deficient environment to facilitate SNCR denitration, and likewise broadens the temperature window towards low temperatures. C can also react with NH at high temperature 3 And the reaction is carried out, under the condition that the active groups OH and O are sufficient, another reducing agent HCNO for SNCR denitration can be generated, and the NOx reducing agent is increased. The ferrous ion has strong reducibility, and can be used as a reducing agent to reduce NO at about 300 DEG C x Reduction to N 2 。Fe 3 O 4 In the presence of Fe 2+ And Fe 3+ It can be stored stably and not easy to be oxidized, and has reducing power. When the temperature reaches Fe 3 O 4 Oxidation temperature of (2), fe 3 O 4 Surface active sites adsorb NO and promote NO reduction to generate N 2 Up to Fe 3 O 4 Is oxidized to Fe 2 O 3 ，Fe 3 O 4 The reducing power is lost. Therefore, will contain Fe 3 O 4 The materials of FeOOH and carbon are used as additives for SNCR denitration, so that the temperature window of the SNCR denitration can be effectively widened to low temperature, and meanwhile, C has a reduction effect on NO, so that the denitration rate is improved, and the dosage of an SNCR reducing agent is reduced.
Disclosure of Invention
The invention aims to provide a method for applying an iron-carbon composite material as an additive to an SNCR (selective non-catalytic reduction) technology, which can effectively remove NOx, reduce the denitration temperature window of the SNCR and save the using amount of a reducing agent.
The invention adopts the following specific technical scheme:
a method for denitration of flue gas by using an iron-carbon composite material as an SNCR additive is characterized by comprising the following steps: firstly, 70 to 75 percent of carbon and 15 to 18 percent of Fe 3 O 4 Fully mixing with 10 to 12 percent of FeOOH, and calcining for 2 hours at the temperature of between 200 and 300 ℃ by using inert gas to prepare the iron-carbon composite material. Drying the cooled iron-carbon composite material at the temperature of 110 ℃ for 24h, naturally cooling to room temperature, tabletting the iron-carbon composite material under the condition of 10MP, crushing into granules for granulation, screening the granules with a sieve of 20 meshes and 60 meshes, and finally sealing and storing.
NH in the presence of 2% by volume of oxygen and 1000ppm of NO 3 The volume ratio of the concentration to the NO concentration is 0.5 and 1,N respectively 2 In the mixed gas as the balance gas, the total gas flow rate is 500mL/min, the heating speed is 10 ℃/min, and the SNCR denitration is carried out by using the iron-carbon composite material under the conditions of 750-1000 ℃, wherein the ratio of the mass of the iron-carbon composite material to the total gas flow rate is 1g:500mL/min.
The principle that the iron-carbon composite material promotes SNCR denitration is as follows:
NH 3 +OH→NH+H 2 O (1)
NH 3 +H→NH 2 +H 2 (2)
CO+OH→CO 2 +H (3)
NH 2 +NO→NNH+OH (4)
NNH→H+N 2 (5)
NH 2 +NO→N 2 +H 2 O (6)
C+NH 3 →HCN+H 2 (7)
HCN+O→HCNO (8)
HCNO+OH→NCO+H 2 O (9)
NCO+NO→N 2 +CO 2 (10)
the invention has the following effects:
(1) The ferrous ions have reducing power and reach Fe when the temperature reaches 3 O 4 Oxidation temperature of (2), fe 3 O 4 NO is adsorbed by the surface active sites, thereby promoting the reduction of NO to generate N 2 . CO and FeOOH generated by carbon anoxic combustion provide active groups H and OH for SNCR reaction at a lower temperature, and promote SNCR low-temperature denitration. And C and NH 3 Another reducing agent HCNO is generated through the reaction, reducing substances are increased, and the SNCR denitration rate is improved. The iron-carbon composite material is used as the additive for SNCR denitration, so that the SNCR denitration temperature window can be reduced, and the consumption of the reducing agent can be reduced.
(2) The iron-carbon composite material is used as the SNCR additive, the existing equipment of a factory is not required to be modified, the investment cost is low, and the operation is simple. The effect of reducing NOx in the flue gas is achieved while the dosage of the SNCR reducing agent is reduced.
Detailed Description
The present invention will be further illustrated with reference to the following examples, but the present invention is not limited to the following examples.
Firstly, drying the iron-carbon composite material at 110 ℃ for 24h, wherein the iron-carbon composite material consists of 73 percent of carbon and 16 percent of Fe 3 O 4 And 11% FeOOH at 250 ℃, N 2 Calcining for 2 hours in the atmosphere to prepare the catalyst; the first step of the following examples is to prepare an iron-carbon composite material by calcining according to the component ratio, and drying.
Example 1
Under the smoke condition of 1000ppmNO and 1000ppmNH 3 ，2vol.％O 2 ，N 2 When the total gas flow rate is 500mL/min and the temperature condition is 750 ℃, 1g of the iron-carbon composite material is added into a tubular furnace with the diameter of 3cm as balance gas, and the denitration rate reaches 83.76%.
Example 2
Under the smoke condition of 1000ppmNO and 1000ppmNH 3 ，2vol.％O 2 ，N 2 When the total gas flow rate is 500mL/min and the temperature is 800 ℃, 1g of the iron-carbon composite material is added into a tubular furnace with the diameter of 3cm, and the denitration rate reaches 88.54 percent.
Example 3
Under the smoke condition of 1000ppmNO and 1000ppmNH 3 ，2vol.％O 2 ，N 2 When the total gas flow rate is 500mL/min and the temperature is 850 ℃, 1g of the iron-carbon composite material is added into a tubular furnace with the diameter of 3cm as balance gas, and the denitration rate reaches 88.90 percent.
Example 4
Under the smoke condition of 1000ppmNO and 1000ppmNH 3 ，2vol.％O 2 ，N 2 When the total gas flow rate is 500mL/min and the temperature is 900 ℃, 1g of the iron-carbon composite material is added into a tubular furnace with the diameter of 3cm, and the denitration rate reaches 93.76%.
Example 5
Under the smoke condition of 1000ppmNO and 1000ppmNH 3 ，2vol.％O 2 ，N 2 When the total gas flow rate is 500mL/min and the temperature is 950 ℃, 1g of the iron-carbon composite material is added into a tubular furnace with the diameter of 3cm as balance gas, and the denitration rate reaches 95.23%.
Example 6
Under the smoke condition of 1000ppmNO and 1000ppmNH 3 ，2vol.％O 2 ，N 2 The balance gas is used, the total gas flow rate is 500mL/min, 1g of the iron-carbon composite material is added into a tubular furnace with the diameter of 3cm under the temperature condition of 1000 ℃, and the denitration rate reaches 92.30%.
Example 7
Under the smoke condition of 1000ppmNO and 500ppmNH 3 ，2vol.％O 2 ，N 2 For balance gas, a total gas flow rate of 500mLAnd min, when the temperature is 750 ℃, adding 1g of the iron-carbon composite material into a tubular furnace with the diameter of 3cm, wherein the denitration rate reaches 84.05%.
Example 8
Under the smoke condition of 1000ppmNO and 500ppmNH 3 ，2vol.％O 2 ，N 2 When the total gas flow rate is 500mL/min and the temperature is 800 ℃, 1g of the iron-carbon composite material is added into a tubular furnace with the diameter of 3cm, and the denitration rate reaches 86.70%.
Example 9
Under the smoke condition of 1000ppmNO and 500ppmNH 3 ，2vol.％O 2 ，N 2 When the total gas flow rate is 500mL/min and the temperature is 850 ℃, 1g of the iron-carbon composite material is added into a tubular furnace with the diameter of 3cm as balance gas, and the denitration rate reaches 89.36 percent.
Example 10
Under the smoke condition of 1000ppmNO and 500ppmNH 3 ，2vol.％O 2 ，N 2 When the total gas flow rate is 500mL/min and the temperature is 900 ℃, 1g of the iron-carbon composite material is added into a tubular furnace with the diameter of 3cm, and the denitration rate reaches 94.33 percent.
Example 11
Under the smoke condition of 1000ppmNO and 500ppmNH 3 ，2vol.％O 2 ，N 2 When the total gas flow rate is 500mL/min and the temperature is 950 ℃, 1g of the iron-carbon composite material is added into a tubular furnace with the diameter of 3cm as balance gas, and the denitration rate reaches 95.81%.
Example 12
Under the smoke condition of 1000ppmNO and 500ppmNH 3 ，2vol.％O 2 ，N 2 When the total gas flow rate is 500mL/min and the temperature is 1000 ℃, 1g of the iron-carbon composite material is added into a tubular furnace with the diameter of 3cm, and the denitration rate reaches 89.64 percent.
TABLE 1 denitration rate of each example
Figure BDA0003135765890000041

Claims (1)

1. A method for denitration of flue gas by using an iron-carbon composite material as an SNCR additive is characterized by comprising the following steps: o of the environment of use 2 The volume concentration is 2 percent, the NO concentration is 1000ppm 3 The concentration is 500ppm, N 2 In the mixed gas as the balance gas, the total gas flow rate is 500mL/min, and the denitration is carried out by using the iron-carbon composite material as the SNCR additive under the temperature of 950 ℃, wherein the mass ratio of the iron-carbon composite material to the total gas flow rate is 1g:500mL/min;
the preparation method of the iron-carbon composite material comprises the following steps: 73% carbon, 16% Fe 3 O 4 Mixing with 11% FeOOH, and heating to 250 deg.C 2 Calcining for 2h in the atmosphere, cooling, air drying at 110 deg.C for 24h, tabletting under 10MPa, crushing into granules, granulating, and sieving with 20-mesh and 60-mesh sieves.
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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3953575A (en) * 1973-11-21 1976-04-27 American Gas Association Iron oxide sorbents for regenerative sorption of Nox
US4070440A (en) * 1975-09-05 1978-01-24 Nippon Kokan Kabushiki Kaisha Method of reducing NOx present in an exhaust to harmless N2
DE19756392A1 (en) * 1997-12-18 1999-07-01 Werner Prof Dr Weisweiler Removal of nitrogen oxides from waste gas using an iron oxyhydroxide catalyst
JP2003251145A (en) * 2001-12-26 2003-09-09 Nippon Steel Corp Remove for organic chlorine compound, nitrogen oxides and sulfur oxides and method for producing the same
CN104946339A (en) * 2015-05-27 2015-09-30 上海理工大学 Method for controlling biomass combustion NO by using nano iron-base additive
CN105056950A (en) * 2015-08-26 2015-11-18 武汉科技大学 Microwave NOx removal catalyst based on coal-based carbon and preparation method thereof
CN110465179A (en) * 2019-07-16 2019-11-19 北京工业大学 A method of denitrating flue gas is carried out using pyrolysis pickling sludge

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3953575A (en) * 1973-11-21 1976-04-27 American Gas Association Iron oxide sorbents for regenerative sorption of Nox
US4070440A (en) * 1975-09-05 1978-01-24 Nippon Kokan Kabushiki Kaisha Method of reducing NOx present in an exhaust to harmless N2
DE19756392A1 (en) * 1997-12-18 1999-07-01 Werner Prof Dr Weisweiler Removal of nitrogen oxides from waste gas using an iron oxyhydroxide catalyst
JP2003251145A (en) * 2001-12-26 2003-09-09 Nippon Steel Corp Remove for organic chlorine compound, nitrogen oxides and sulfur oxides and method for producing the same
CN104946339A (en) * 2015-05-27 2015-09-30 上海理工大学 Method for controlling biomass combustion NO by using nano iron-base additive
CN105056950A (en) * 2015-08-26 2015-11-18 武汉科技大学 Microwave NOx removal catalyst based on coal-based carbon and preparation method thereof
CN110465179A (en) * 2019-07-16 2019-11-19 北京工业大学 A method of denitrating flue gas is carried out using pyrolysis pickling sludge

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
热解酸洗污泥用于氮氧化物还原的研究;王亚丽 等;《硅酸盐通报》;20200831;第39卷(第8期);第2678-2682页 *

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