CN103252159A - Additive for denitration of smoke SNCR (selective non-catalytic reduction) and application thereof - Google Patents

Additive for denitration of smoke SNCR (selective non-catalytic reduction) and application thereof Download PDF

Info

Publication number
CN103252159A
CN103252159A CN2013101580550A CN201310158055A CN103252159A CN 103252159 A CN103252159 A CN 103252159A CN 2013101580550 A CN2013101580550 A CN 2013101580550A CN 201310158055 A CN201310158055 A CN 201310158055A CN 103252159 A CN103252159 A CN 103252159A
Authority
CN
China
Prior art keywords
additive
denitration
cellulose ether
reducing agent
sncr
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN2013101580550A
Other languages
Chinese (zh)
Other versions
CN103252159B (en
Inventor
吴忠标
寿冬金
王岳军
莫建松
李世远
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Zhejiang Tianlan Environmental Protection Technology Co Ltd
Original Assignee
Zhejiang Tianlan Environmental Protection Technology Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Zhejiang Tianlan Environmental Protection Technology Co Ltd filed Critical Zhejiang Tianlan Environmental Protection Technology Co Ltd
Priority to CN201310158055.0A priority Critical patent/CN103252159B/en
Publication of CN103252159A publication Critical patent/CN103252159A/en
Application granted granted Critical
Publication of CN103252159B publication Critical patent/CN103252159B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02C—CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG]
    • Y02C20/00—Capture or disposal of greenhouse gases
    • Y02C20/10—Capture or disposal of greenhouse gases of nitrous oxide (N2O)

Landscapes

  • Treating Waste Gases (AREA)

Abstract

The invention discloses an additive for denitration of smoke SNCR (selective non-catalytic reduction) and application thereof. The additive comprises cellulose ether and inorganic sodium salt; and the additive and the denitration reductant are mixed and then sprayed into the smoke, and the temperature interval of the smoke is between 760 DEG C and 850 DEG C. The mixture of ammonia water or urea solution containing little cellulose ether and sodium salt is sprayed into the smoke at the temperature interval of 760-850 DEG C for denitration, the additive can be adapt to different oxygen concentration changes, the generation of byproduct N2O is reduced, and the denitraiton efficiency achieves 40%-70%. Compared with the SNCR denitration method, effective denitraiton temperature area is enlarged, allowable oxygen uptake range is widened, and escaped ammonia is reduced.

Description

A kind of additive and application thereof for flue gas SNCR denitration
Technical field
The present invention relates to flue gas SNCR denitration field, be specifically related to a kind of for the denitration additive and the application thereof that improve SNCR denitrating flue gas low-temperature denitration activity and reduction the escaping of ammonia.
Background technology
Control NOx draining technology roughly is divided into two classes both at home and abroad at present: a class is low NOx combusting technology, namely control by the optimization of boiler operatiopn mode or to combustion process, the reaction that suppresses NOx in the combustion process generates, thereby reduces the final concentration of emission of NOx.Another kind of is gas denitrifying technology, namely the NOx that has generated is reduced to N 2Thereby, remove NOx in the flue gas, mainly contain SNCR technology SNCR and SCR technology SCR.
(Selective Non-Catalytic Reduction is a kind of NOx control treatment technology of maturation SNCR) to the SNCR denitration technology, and cost is lower, and it is convenient to transform, and is one of denitration technology that is fit to China's national situation.Reducing agent has ammoniacal liquor, liquefied ammonia and urea, and these reducing agents are used for gas denitrifying technology, can obtain similar denitration effect.Use urea easily to produce more N as reducing agent 2O, and reaction temperature is than the ammoniacal liquor height; Liquefied ammonia belongs to hazardous chemical, and the requirement of storage, use, management is than higher; Industrial 20% or 25% ammoniacal liquor, security requirement is than little many of liquefied ammonia, store, carry and handle all simple than liquefied ammonia, thereby at present on the engineering mainly based on ammoniacal liquor and urea.
The SNCR technology mainly is with ammonia or contains amino reducing agent and be injected in the gas fume after burning 850～1050 ℃ temperature province, and the selective reduction reaction takes place, and NO is reduced into N 2This technology has strict requirement to reaction temperature, and the temperature restriction of relative narrower is the difficult point that the SNCR technology is used.
US Patent No. 5443805 discloses the use hydrocarbon fuel and has carried the ammonia reducing agent as atomizing medium, because the reaction of hydrocarbon fuel is fast that oxygen expenditure in the flue gas is intact, the part forms reducing atmosphere, can improve the denitration effect of SNCR.Disclosed method among US Patent No. 3900554, US Patent No. 4208386 and the US US4325924, and to the SNCR method nearest improvement comprises that the also proposition described in US6030204 and the U.S. Patent Application Publication No. US2002/0025285A1 similarly acts on.
Above-mentioned SNCR patent is all in the industrial application that obtains certain limit, but existing additive, the optimum activity of denitration is all more than 850 ℃, China's boiler type is more, and operation stability is bad, and flue-gas temperature can be lower than 800 ℃ often, even to below 760 ℃, cause closing down of SNCR denitrating system, limited the SNCR The Application of Technology, the denitration additive of for this reason developing a kind of denitration activity for 760～850 ℃ of raisings, reduction the escaping of ammonia has wider application prospect.
Summary of the invention
The invention provides a kind of additive and application thereof for flue gas SNCR denitration, this additive is used for the SNCR reducing agent, improve flue gas 760～850 ℃ denitration activity, reduce the escaping of ammonia.
A kind of additive for flue gas SNCR denitration, described additive is made up of cellulose ether and inorganic sodium, and the quality mol ratio of described cellulose ether and inorganic sodium is 0.5～10g:0.01～0.1mol.
The quality mol ratio of described cellulose ether and inorganic sodium is preferably 1～5g:0.01～0.05mol.
As preferably, described cellulose ether is water-soluble cellulose ether, and the cellulose ether of hydroxyl.
Further preferred, described cellulose ether is at least a in CMC, hydroxyethylcellulose and the hydroxypropyl cellulose.
As preferably, described inorganic sodium is NaHCO 3, Na 2CO 3At least a with among the NaCl.
The present invention also provides a kind of method of utilizing described additive to carry out denitrating flue gas, with described additive with spray in the flue gas after denitrification reducing agent is mixed, the temperature range of described flue gas is 760～850 ℃.
As preferably, described denitrification reducing agent is ammoniacal liquor or urea.
As preferably, NH in cellulose ether and the denitrification reducing agent in the described additive 3The quality mol ratio be 0.5～10g/mol; NH in inorganic sodium and the denitrification reducing agent in the described additive 3Mol ratio be 0.01～0.1mol/mol.
Further preferred, NH in cellulose ether and the denitrification reducing agent in the described additive 3The quality mol ratio be 1～5g/mol; NH in inorganic sodium and the denitrification reducing agent in the described additive 3Mol ratio be 0.01～0.05mol/mol.
By spraying in the flue gas after the spray gun atomizing, reaction principle is as follows after mixing additive fully with reducing agent among the present invention:
It is denitrification reducing agent that the present invention's employing contains the ammonia reducing agent, and total chemical equation of reducing NOx mainly contains:
Figure BDA00003119352800021
Figure BDA00003119352800031
On the microcosmic elementary reaction, NH 3To NH 2Conversion reaction, have only following reaction take place:
Figure BDA00003119352800032
Figure BDA00003119352800033
Figure BDA00003119352800034
The reduction reaction of NOx below could taking place:
Figure BDA00003119352800035
Figure BDA00003119352800037
An amount of OH, O, H primitive are the necessary conditions of NOx reduction reaction, and active primitive only could produce under sufficiently high temperature, and this is that the SNCR denitrating technique is difficult to the reason of carrying out at low temperatures.The generation deficiency can cause reaction rate too slow when the active primitive in the flue gas was lower than 850 ℃ of temperature windows in temperature, can not get higher NOx clearance in the short time of staying.
An amount of cellulose ether contains high volatile matter and high ω (H)/ω (C) ratio, and in entering the flue gas of high temperature, volatile matter discharges rapidly, and combustibles such as C, H are with CH, CO, H 2Separate out etc. form, the oxygen reaction when volatile matter is separated out and in the surrounding environment consumes most of even whole oxygen, cause in the flue gas part to set up reducing atmosphere rapidly, excite the NO reduction reaction, the reaction temperature window of SNCR is expanded to low-temperature end, improved the denitration efficiency under the low temperature.
In addition, the additive selected for use of the present invention can be to improve crucial OH, NH in the denitration reaction 2The isoreactivity root, the restriction of originally low excessively reaction rate has been broken in the increase of these important active radicals concentration under the low temperature, and the NO reduction reaction is activated in advance, and denitration efficiency increases in certain time of staying.
Further preferred, NH in cellulose ether and the denitrification reducing agent in the described additive 3The quality mol ratio be 1～5g/mol.NH in cellulose ether and denitrification reducing agent 3Quality mol ratio during less than preferred proportion, the active primitive generation of flue gas deficiency can cause reaction rate too slow, in the short time of staying, can not get higher NOx clearance, OH when ratio is higher than preferred proportion, primitives such as O produce too much, below reaction can occupy main status gradually
Figure BDA00003119352800038
Figure BDA000031193528000310
A large amount of generations of above-mentioned reaction can cause the clearance of NOx to reduce, even make the NOx content in the flue gas not fall counter increasing, and denitration efficiency is reduced.
Sodium salt has good regulating action to very important active radicals concentration OH, H etc. in the SNCR reaction: at low temperatures, generate OH isoreactivity root by catalytic reaction under the low situation of active radicals concentration, cause the chain reaction of SNCR; At high temperature, under the high situation of active radicals concentration, by catalytic reaction OH, H active radicals are aggregated into H 2O reduces the ammonia root and is oxidized to NO; Na+N 2O=NaO+N 2Because NaO can regenerate Na by chain reaction, a Na atom can reduce a plurality of N 2The O molecule, so another important function can suppress the generation of denitration accessory substance, raising ammonia utilization rate.
Further preferred, NH in inorganic sodium and the denitrification reducing agent in the described additive 3Mol ratio be 0.01～0.05mol/mol.NH in inorganic sodium and denitrification reducing agent 3Mol ratio when being higher than preferred proportion, accessory substance N 2The reduction of O diminishes even is constant, thereby too much spraying into do not have increase to denitration efficiency, and the quality of flyash is reduced.
Cellulose ether, sodium salt are mixed suitable, improving the SNCR reaction temperature in the low temperature skew, improved ammonia selective to low temperature NO reduction, reduced N 2Secondary pollutions such as O have improved the utilization rate of ammonia.
Compare beneficial effect of the present invention with existing denitrating catalyst:
In 760-850 ℃ temperature range, spray into the compounding substances of sneaking into the plain ether of small amount of fibers, sodium salt in ammoniacal liquor or the urea liquid and carry out denitration, can adapt to different oxygen concentrations and change, reduce accessory substance N 2The generation of O, and denitration efficiency is reached between 40%～70%.Compare existing SNCR method of denitration, effectively the denitration humidity province enlarges, and has improved the utilization rate of ammonia agent, and the scope of the oxygen amount of permission also enlarges, and the escaping of ammonia reduces.
The specific embodiment
Following examples and Comparative Examples are all at 200Nm 3On/h SNCR denitration the experimental system for simulating.Produce flue gas by burning diesel oil in burner, the temperature that the quantity combusted of control diesel oil is regulated flue gas, this device can make flue-gas temperature adjustable controlled in 700～1200 ℃ of scopes.In device, feed the concentration level that NO modulates NOx in the flue gas, the reducing agent of pre-configured a certain proportion of cellulose ether, sodium salt is delivered to the liquid road of spray gun and controls ammonia nitrogen and compare NSR with the Lange peristaltic pump, utilize compressed air with reducing agent atomizing and spray in the flue gas, by detecting NOx concentration and the NH of tail end 3Concentration is calculated denitration activity and the escaping of ammonia rate, and the reaction time of the experimental data that adopts in this example is 0.2s, and import NOx concentration is controlled at 200mg/Nm 3
Embodiment 1
Flue-gas temperature is 760 ℃, and reducing agent is ammoniacal liquor (5% mass concentration), and NSR is 1.2, and additive level and measurement result see Table 1
The ratio of table 1 additive and denitration situation
Figure BDA00003119352800051
Wherein, cellulose ether is CMC, and inorganic sodium is NaHCO 3
Embodiment 2
Flue-gas temperature is 800 ℃, and reducing agent is ammoniacal liquor (5% mass concentration), and NSR is 1.2, and additive level and measurement result see Table 2
The ratio of table 2 additive and denitration situation
Figure BDA00003119352800052
Wherein, cellulose ether is hydroxyethylcellulose, and inorganic sodium is Na 2CO 3
Embodiment 3
Flue-gas temperature is 850 ℃, and reducing agent is ammoniacal liquor (5% mass concentration), and NSR is 1.2, and additive level and measurement result see Table 3
The ratio of table 3 additive and denitration situation
Figure BDA00003119352800053
Wherein, cellulose ether is hydroxypropyl cellulose, and inorganic sodium is NaCl.
Embodiment 4
Flue-gas temperature is 760 ℃, and reducing agent is urea liquid (10% mass concentration), and NSR is 1.2, and additive level and measurement result see Table 4
The ratio of table 4 additive and denitration situation
Figure BDA00003119352800054
Figure BDA00003119352800061
Wherein, cellulose ether is hydroxypropyl cellulose, and inorganic sodium is NaHCO 3
Embodiment 5
Flue-gas temperature is 800 ℃, and reducing agent is urea liquid (10% mass concentration), and NSR is 1.2, and additive level and measurement result see Table 5
The ratio of table 5 additive and denitration situation
Figure BDA00003119352800062
Wherein, cellulose ether is CMC, and inorganic sodium is NaCl.
Embodiment 6
Flue-gas temperature is 850 ℃, and reducing agent is urea liquid (10% mass concentration), and NSR is 1.2, and additive level and measurement result see Table 6
The ratio of table 6 additive and denitration situation
Wherein, cellulose ether is hydroxyethylcellulose, and inorganic sodium is Na 2CO 3
Comparative Examples 1
Reducing agent is ammoniacal liquor (5% mass concentration), and NSR is 1.2, and flue-gas temperature and measurement result see Table 7
The non-additive denitration situation of table 7
Figure BDA00003119352800064
Comparative Examples 2
Reducing agent is urea liquid (10% mass concentration), and NSR is 1.2, and flue-gas temperature and measurement result see Table 8
The non-additive denitration situation of table 8
Figure BDA00003119352800071
By above result contrast as can be known, in 760-850 ℃ temperature range, will be mixed with the ammoniacal liquor of additive or urea liquid among the present invention and spray into and carry out denitration in the flue gas, and can adapt to different oxygen concentration variations, minimizing accessory substance N 2The generation of O, and denitration efficiency is reached between 40%～70%, the escaping of ammonia is controlled at 6mg/Nm 3In; And under the situation of not using additive, the denitration efficiency of flue gas generally is lower than 40% in 760-850 ℃ temperature range, and the escaping of ammonia is up to more than 20%.

Claims (8)

1. an additive that is used for flue gas SNCR denitration is characterized in that described additive is made up of cellulose ether and inorganic sodium, and the quality mol ratio of described cellulose ether and inorganic sodium is 0.5～10g:0.01～0.1mol.
2. according to the described additive of claim 1, it is characterized in that described cellulose ether is water-soluble cellulose ether.
3. according to the described additive of claim 2, it is characterized in that described cellulose ether is at least a in CMC, hydroxyethylcellulose and the hydroxypropyl cellulose.
4. according to the described additive of claim 1, it is characterized in that described inorganic sodium is NaHCO 3, Na 2CO 3At least a with among the NaCl.
5. a method of utilizing the described additive of the arbitrary claim of claim 1～4 to carry out denitrating flue gas is characterized in that, with described additive with spray in the flue gas after denitrification reducing agent is mixed, the temperature range of described flue gas is 760～850 ℃.
6. method according to claim 5 is characterized in that, described denitrification reducing agent is ammoniacal liquor or urea.
7. method according to claim 6 is characterized in that, NH in cellulose ether and the denitrification reducing agent in the described additive 3The quality mol ratio be 0.5～10g/mol; NH in inorganic sodium and the denitrification reducing agent in the described additive 3Mol ratio be 0.01～0.1mol/mol.
8. method according to claim 7 is characterized in that, NH in cellulose ether and the denitrification reducing agent in the described additive 3The quality mol ratio be 1～5g/mol; NH in inorganic sodium and the denitrification reducing agent in the described additive 3Mol ratio be 0.01～0.05mol/mol.
CN201310158055.0A 2013-04-27 2013-04-27 Additive for denitration of smoke SNCR (selective non-catalytic reduction) and application thereof Active CN103252159B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201310158055.0A CN103252159B (en) 2013-04-27 2013-04-27 Additive for denitration of smoke SNCR (selective non-catalytic reduction) and application thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201310158055.0A CN103252159B (en) 2013-04-27 2013-04-27 Additive for denitration of smoke SNCR (selective non-catalytic reduction) and application thereof

Publications (2)

Publication Number Publication Date
CN103252159A true CN103252159A (en) 2013-08-21
CN103252159B CN103252159B (en) 2015-02-25

Family

ID=48956570

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201310158055.0A Active CN103252159B (en) 2013-04-27 2013-04-27 Additive for denitration of smoke SNCR (selective non-catalytic reduction) and application thereof

Country Status (1)

Country Link
CN (1) CN103252159B (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2016112716A1 (en) * 2015-01-13 2016-07-21 广州特种承压设备检测研究院 Method for optimizing sncr denitration system of garbage incinerator by adding anionic surfactant
CN106621782A (en) * 2016-12-30 2017-05-10 深圳市唯有新材料有限公司 High-polymer denitration agent and preparation method thereof
CN109316892A (en) * 2018-10-30 2019-02-12 南京清青环保科技有限公司 A kind of denitrfying agent, preparation method and Dry denitration method
CN111974186A (en) * 2020-07-22 2020-11-24 南通润启环保服务有限公司 Flue gas SNCR (selective non-catalytic reduction) denitration agent and preparation method thereof
CN113877391A (en) * 2020-07-01 2022-01-04 中冶长天国际工程有限责任公司 Composite additive for selective non-catalytic reduction denitration of flue gas and preparation method and application thereof

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5817282A (en) * 1996-03-28 1998-10-06 Dynamotive Technologies Corporation Reduction of nitrogen oxides

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5817282A (en) * 1996-03-28 1998-10-06 Dynamotive Technologies Corporation Reduction of nitrogen oxides

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
WEIJUAN YANG等: "Action of oxygen and sodium carbonate in the urea-SNCR process", 《COMBUSTION AND FLAME》 *

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2016112716A1 (en) * 2015-01-13 2016-07-21 广州特种承压设备检测研究院 Method for optimizing sncr denitration system of garbage incinerator by adding anionic surfactant
CN106621782A (en) * 2016-12-30 2017-05-10 深圳市唯有新材料有限公司 High-polymer denitration agent and preparation method thereof
CN106621782B (en) * 2016-12-30 2019-04-16 深圳华明环保科技有限公司 A kind of macromolecule denitrfying agent and preparation method thereof
CN109316892A (en) * 2018-10-30 2019-02-12 南京清青环保科技有限公司 A kind of denitrfying agent, preparation method and Dry denitration method
CN113877391A (en) * 2020-07-01 2022-01-04 中冶长天国际工程有限责任公司 Composite additive for selective non-catalytic reduction denitration of flue gas and preparation method and application thereof
CN113877391B (en) * 2020-07-01 2023-12-29 中冶长天国际工程有限责任公司 Composite additive for selective non-catalytic reduction denitration of flue gas, preparation method and application thereof
CN111974186A (en) * 2020-07-22 2020-11-24 南通润启环保服务有限公司 Flue gas SNCR (selective non-catalytic reduction) denitration agent and preparation method thereof

Also Published As

Publication number Publication date
CN103252159B (en) 2015-02-25

Similar Documents

Publication Publication Date Title
EP1570894B1 (en) Method and system for removal of mercury emissions from coal combustion
CN103480251B (en) System and method for performing desulfurization, denitration and demercuration to flue gas simultaneously
CN103252159B (en) Additive for denitration of smoke SNCR (selective non-catalytic reduction) and application thereof
CN103272470B (en) A kind of additive for improving SNCR ammonia activity and application thereof
CN203591690U (en) System for removing sulfur, nitrate and mercury in flue gas at same time
CN105457486A (en) Coke oven flue gas integrated treatment method
CN1864813A (en) Method for simultaneous purification of elementary substance mercury and nitric oxides in coal-fired flue gas
CN104437540A (en) Phosphorus-resistant low-temperature SCR denitration catalyst and preparation method thereof
CN102068888A (en) Method for simultaneously desulfurizing and denitrating flue gas by wet method
CN102989282A (en) Method and device for collaborative removal of mercury in flue gas
CN103736481B (en) CeO 2-MoO 3/ Graphene low-temperature denitration catalyst and preparation method
CN103203176B (en) Method for flue gas desulfurization, denitrification and demercuration by semidry method
CN104399360B (en) NOx and mercury combined removal process and device based on combination of SNCR-SCR
CN101708419B (en) Coal-fired flue gas denitration and desulfurization method combined with urea wet method
CN105195013A (en) Denitration and demercuration apparatus and method with CFB (circulating fluidized bed) boiler
CN102188889A (en) Device and method for combined removal of sulphur dioxide (SO2), nitrogen oxide (NOX) and mercury from fume
CN107261805B (en) Hydrazine solution special for chimney flue gas desulfurization and denitrification and preparation method thereof
CN104324610B (en) A kind of desulfurization denitration method and device
CN205550012U (en) Oxidation denitration treatment system of flue gas
CN1433834A (en) Method for urea catalyst simultaneously processing flue gas and desulfurizing denitrification
JP2014000522A (en) Denitrification method of exhaust gas
CN204275782U (en) NOx and mercury combined removal device based on combination of SNCR-SCR
CN202962241U (en) Device for synergistically removing flue gas mercury
CN204768202U (en) Flue gas desulfurization denitration dust removal integration system
CN103752161B (en) There is wet method compound additive and the application process thereof of desulfuration demercuration effect simultaneously

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant